WO2006036044A1

WO2006036044A1 - Hinge apparatus for heavy door having automatic return function function

Info

Publication number: WO2006036044A1
Application number: PCT/KR2005/002773
Authority: WO
Inventors: Soon-Woo Choi
Original assignee: I-One Innotech Co., Ltd.
Priority date: 2004-08-24
Filing date: 2005-08-23
Publication date: 2006-04-06
Also published as: KR20060018461A; KR100586262B1; CN101018924A

Abstract

A hinge apparatus having an automatic return function for use in a heavy door, having a pair of hinges which includes a pair of camshafts having cam diagram lengths different from each other. The hinge apparatus includes a central body fixedly coupled with a first hinge and first and second guide vessels fixedly coupled with the upper/lower side ends of a second hinge, respectively. A pair of shafts are fixedly installed in the central body opposing each other, and the first and secondhinges connected with the shafts are installed in the first and second guide vessels, respectively. A cam diagram of first camshaft is partially formed so that the first hinge operates only at an initial time of opening a door and a last time of returning the door, and the second hinge is a general hinge having an automatic return function.

Description

[DESCRIPTION]

[invention Title]

HINGE APPARATUS FOR HEAVY DOOR HAVING AUTOMATIC RETURN FUNCTION [Technical Field]

The present invention relates to a hinge apparatus having an automatic return function for use in a heavy door, and more particularly, to a hinge apparatus having an automatic return function for use in a heavy door, which includes two closed hydraulic circuits, and two camshafts having cam diagram lengths different from each other in correspondence to the two closed hydraulic circuits, to thus maintain a closing power of a heavy door via a pair of the camshafts having the different cam diagram lengths without increasing the outer diameter of the hinge apparatus, and simultaneously minimize an opening power necessary for opening of the door to easily open the heavy door with a small amount of power. [Background Art] In general, a hinge apparatus makes two members spaced from each other or folded one member over another around a shaft, according to necessity. A representative example of thehingeapparatus is a left/right rotationalhinge apparatus including a horizontal actuator which is used for a door or window frame, or an up/down rotational hinge apparatus including a vertical actuator which is used in a refrigerator, a mobile phone, or a notebook computer. Korean Utility Model Registration No. 0271646 which is one of the conventional art discloses a hinge door opening and closing apparatus in which a hydraulic door closer and a spring door closer are separately configured and the former and the latter are combined with each other.

Since a door opening force is increased in proportion with an increase in a door opening angle in the case of the hinge apparatus employing both the spring door closer and the hydraulic door closer in combination, a user should apply a large force to a heavy door in order to open it.

Further, since the rotational force of inertia which is generated in a closing direction in the hinge apparatus is increased in proportion with an increase in a door opening angle thereof, a large-scale door or heavy door is closed at a high speed. Accordingly, a user may be damaged by the quickly closing heavy or large-scale door.

Also, Korean Patent Registration No. 435188 discloses a hinge apparatus using a single camshaft having a spiral cam diagram in which a final closing speed of a door is accurately established and simultaneously a multi-stage automatic return speed establishment structure is stabilized to thus prevent an excessive closing speed of a door at the time of closing it.

However, the hinge apparatus is applied to a light or small-scale door which does not require a large closing force as in a Kimchi refrigerator for use in a storage device for storing a fermentation food such as Kimchi which is one of Korean traditional foods, or a general small-sized refrigerator. Also, since a damping force of the hinge apparatus is greatly insufficient, it is very difficult to apply the hinge apparatus to a heavy or large-scale door whose difference in weight is significant in comparison with a small-sized door.

In order to make the hinge apparatus have a proper damping force corresponding a large-scale door considering weight of the large-scale door, a final closing force of the door should be increased considering weight of the large-scale door. To do this, an outer diameter of the hinge apparatus should be necessarily increased. That is, the diameter of a chamber and all components configuring a hydraulic circuit should be large-scaled in size in order to have a proper damping force corresponding to weight of the large-scale door, and thus increase a damping force of the door.

However, if the diameter of the hinge apparatus is greatly increased, an opening force which is needed for opening the large-scaled door continues to be increased in proportion with an increase in an opening angle of the door. Accordingly, it is further severely difficult to open the heavy or large-scale door.

Further, in the case that the outer diameter of a hinge apparatus applied to a door as described above is increased, the center of the hinge apparatus, that is, a rotational center of the door exceeds over a door rotational center set reference value which is generally set in order to make the door smoothly rotate. Accordingly, in a severely fatal case, the door would not be opened or closed conversely. Besides, passengers who pass near the door or carry a large volume article may be hindered during walking from the hinge apparatus which severely protrudes from the door due to the increased outer diameter. [Disclosure] [Technical Problem] To solve the above problems, it is an object of the present invention to provide a hinge apparatus for use in a large-scale and heavy door having an automatic return function which includes at least two closed hydraulic circuits including two camshafts having respectively different cam diagram lengths in an ascending and descending section and two return springs, to thus maintain a closing force of the large-scale and heavy door by the two return springs without increasing diameter of the hinge apparatus, and simultaneously minimize an opening force to be needed for opening the door via a pair of the camshafts having the respectively different cam diagram lengths, and to thereby make the large-scale and heavy door easily opened with a small force.

It is another object of the present invention to provide a hinge apparatus for use in a large-scale and heavy door havinganautomaticreturnfunctiontohavecamdiagramlength of ascending and descending guide holes and structure of hydraulic circuits which guide a pair of pistons to ascend and descend simultaneously in which a first opening force which is the largest force among the forces which are applied to the door in a range of an opening angle ranging from 0° to 15° and a second opening force which is approximately reduced by one half the first opening force since any one piston of a pair of the pistons is made to descend at an opening angle ranging from 15° to 90° are needed at the time of opening the door, whereby the large-scale and heavy door can be easily opened.

It is still another object of the present invention to provide a hinge apparatus for use in a large-scale and heavy door having an automatic return function which can increase a door closing force including a first hydraulic circuit which operates only at an initial time of opening a door and at a final time of closing the door to thereby decrease an opening force and increase a restoring force, and a second hydraulic circuit in which a hydraulic control rod is inserted into an oil path formed in a piston rod so that an amount of an oil flow, that is, an ascending speed of a piston can be variably controlled according to an ascending position of the piston.

It is yet another object of the present invention to provide a hinge apparatus for use in a large-scale and heavy door having an automatic return function, which can increase a door closing force by addition of at least one hydraulic circuit in the lengthy direction. It is still yet another object of the present invention to provide a hinge apparatus for use in a large-scale and heavy door having an automatic return function, which can control a door closing speed in a multi-step by combination of shapes of hydraulic control rods and cam diagrams with respect to first and second ascending and descending guide holes of a camshaft.

It is afurtherobjectofthepresent inventiontoprovide an automatic return hinge apparatus for use in a large-scale and heavy door which includes a hydraulic circuit having a notch portion provided in a check valve providing a uniform damping force at the time of closing a door to thereby establish a door closing speed at a constant speed.

It is a still further object of the present invention to provide an automatic return hinge apparatus for use in a large-scale and heavy door, which includes an overpressure prevention valve which can prevent damage in various 0-rings for tightly sealing a main body and a piston portion due to overpressure generated in an upper chamber in the case that a door is abruptly closed by an external force such as strong wind.

It is a yet further object of the present invention to provide an automatic return hinge apparatus for use in a large-scale andheavydoorwhich canmaintain a door opening state at a certain angular section by appropriately establishing a cam diagram with respect to first and second ascending and descending holes of a camshaft. [Technical Solution]

Toaccomplishthe aboveobjectofthepresent invention, according to a first aspect of the present invention, there is provided an automatic return hinge apparatus for use in a large-scale and heavy door which is fixed to any one of first and second hinges and is automatically returned at the time of closingthe door, the automatic returnhinge apparatus comprising: a central body whose one circumference is fixedly coupled at the center of the first hinge; first and second guide vessels whose circumferences are respectively fixedly coupled at the upper/lower sides of the second hinge in which first and second vertical guide grooves andthirdand fourthvertical guide grooves are formed up and down in positions facing each other, and first and second chambers into which oil is filled are formed therein, so as tomaintain a corresponding gap to a height of the central body; first and second camshafts which are rotated by a relative external force generated in the first and second guide vessels when the door is rotated, in which first and secondshafts are fixedlyinsertedintothe centralbodyfacing each other, first and second cylindrical bodies which are extensively formed from the first and second shafts are respectively rotatably installed in the inner circumferences of the first and second guide vessels, first and second ascending and descending guide holes and third and fourth ascending and descending guide holes having spirally shaped cam diagrams of a mutually movable symmetric structure are penetratively formed along the outer circumferences of the first and second cylindrical bodies, respectively; first and secondguidepinsbothends ofwhichare coupled with the first and second vertical guide grooves and the third and fourth vertical guide grooves via the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes, respectively; first and second piston rods on each one end of which the central portions of the first and second guide pins are penetratively coupled, and ascend and descend along the inner circumferences of the first and second cylindrical bodies of the first and second camshafts in a sliding manner along the first and second vertical guide grooves and the third and fourth vertical guide grooves according to rotation of the first and second camshafts, and on the other ends of which first and second bent throughholes perpendicularly communicating with the outer circumferences thereof are formed, respectively; first and second pistons at the center of each one side of which first and second coupling holes to which the other ends ofthe first and secondpiston rods are coupledare formed, respectively, in the other sides of which first and second central throughholes communicating with the first and second coupling holes are formed, whose outer circumferences are respectivelyslidablydisposedalongthe innercircumferences of the first and second guide vessels, and which partition the first and second chambers into upper and lower portions, respectively; first and second check valves which are formed in the first and second pistons and increase and decrease an amount of an oil flow which mutually moves in the upper and lower chambers of the first and second chambers according to ascending and descending of the first and second pistons, to thereby control an ascending/descending speed of the first and second pistons; first and second sealing caps which are coupled with the upper/lower ends of the first and second guide vessels in a sealing manner, so that respectively independent hydraulic circuits are formed in the first and second guide vessels; and first and second elastic members which are respectively installed in the upper portion of the first chamber and the lowerportionofthe secondchambersoastoelasticallysupport the first and second pistons, and which provide a restoring force which makes the first and second pistons returned into an original position at the time of returning the door, respectively, wherein the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes of the first and second camshafts are disposed in a mutually opposing direction, and cam diagram lengths of one pair of the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes are longer than those of the other pair thereof.

According to a second aspect of the present invention, there is also provided an automatic return hinge apparatus for use in a large-scale and heavy door which is fixed to any one of first and second hinges and is automatically returned at the time of closing the door, the automatic return hinge apparatus comprising: a central body whose one circumference is fixedly coupled at the center of the first hinge, whose inner side is divided into first and second chambers by a partition, and at the positions opposing each other inwards from the first and second chambers of which first and second vertical guide grooves andthird and fourthvertical grooves are formed up and down, respectively; first and second fixed bodies each whose one side is coupled with the side ends of the upper and lower portions of the second hinge, respectively, at a state of maintaining adistance therebetweenwherethe centralbodycanbe inserted; first and second camshafts which are rotated by a relative external force generated in the first and second fixed bodies when the door is rotated, in which first and second shafts are fixedly inserted into the first and second fixed bodies, respectively, first and second cylindrical bodies which are detachably coupled with the first and second shafts are respectively rotatably installed in the inner circumferences of the first and second chambers of the central body, respectively, first andsecondascendinganddescending guide holes and third and fourth ascending and descending guide holes having spirally shaped camdiagrams of amutually movable symmetric structure are penetratively formed along the outer circumferences of the first and second cylindrical bodies, respectively; first andsecondguidepinsbothends ofwhichare coupled with the first and secondvertical guide grooves and the third and fourth vertical guide grooves via the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes, respectively; first and second piston rods each upper end of which is coupledby the first and second guide pins, andwhich ascend and descend along the inner circumferences of the first and second cylindrical bodies of the first and second camshafts in a sliding manner along the first and second vertical guide grooves and the third and fourth vertical guide grooves according to rotation of the first and second camshafts, and on each one end of which first and second bent throughholes perpendicularly communicating with the outer circumferences thereof are formed, respectively; first and second pistons at the center of each one side of which first and second coupling holes to which the other ends ofthe first andsecondpiston rods are coupledare formed, respectively, in the other sides of which first and second central throughholes communicating with the first and second coupling holes are formed, whose outer circumferences are respectivelyslidablydisposedalongtheinnercircumferences of the central body, and which partition the first and second chambers into upper and lower portions, respectively; first and second check valves which are formed in the first and second pistons and increase and decrease an amount of an oil flow which mutually moves in the upper and lower chambers of the first and second chambers according to ascending and descending of the first and second pistons, to thereby control an ascending/descending speed of the first and second pistons; first and second sealing caps which are coupled with the upper/lower ends of the central body in a sealing manner, so that respectively independent hydraulic circuits are formed in the first and second chambers in the central body; and first and second elasticmembers which are respectively installed in the lower portions of the first chamber and the upperportionofthe secondchambersoastoelasticallysupport the first and second pistons, and which provide a restoring force which makes the first and second pistons returned into an original position at the time of returning the door, respectively, wherein the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes of the first and second camshafts are disposed in a mutually opposing direction, and cam diagram lengths of one pair of the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes are longer than those of the other pair thereof.

According to a third aspect of the present invention, there is also provided an automatic return hinge apparatus for use in a large-scale and heavy door which is fixed to any one of first and second hinges and is automatically returned at the time of closing the door, the automatic return hinge apparatus comprising: a central body whose one circumference is fixedly coupled at the center of the first hinge, in the inner circumferences of the upper/lower sides of which first and second vertical guide grooves and third and fourth vertical grooves are formedup anddown, atpositions facing eachother, respectively, andwhichhas achamberinthe innersidethereof; first and second fixed bodies each whose one side is coupled with the side ends of the upper and lower portions of the second hinge, respectively, at a state of maintaining adistancetherebetweenwherethe centralbodycanbe inserted; first and second camshafts which are rotated by a relative external force generated in the first and second fixed bodies when the door is rotated, in which first and second shafts are fixedly inserted into the first and second fixed bodies, respectively, first and second cylindrical bodies which are detachably coupled with the first and second shafts are respectively rotatably installed in the inner circumference ofthe chamberofthe centralbody, respectively, first and second ascending and descending guide holes and third and fourth ascending and descending guide holes having spirally shaped camdiagrams of a mutuallymovable symmetric structure are penetratively formed along the outer circumferences of the first and second cylindrical bodies, respectively; first andsecondguidepinsbothends ofwhichare coupled with the first and second vertical guide grooves and the third and fourth vertical guide grooves via the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes, respectively; a first piston rod one end of which is coupled by the central portion of the first guide pin, and which ascends anddescends alongthe innercircumferences ofthe cylindrical body of the first camshaft in a sliding manner along the first and second vertical guide grooves according to rotation of the first camshaft; a first piston which is extensively formed at the other end of the first piston rod and whose outer circumference is slidably disposed with the inner circumference of the central body; a second piston rod one end of which is coupled by the central portion of the second guide pin, which ascends and descends along the inner circumferences of the cylindrical body of the second camshaft in a sliding manner along the third and fourth vertical guide grooves according to rotation of the second camshaft, and on the other end of which a bent throughhole perpendicularly communicating with the outer circumference thereof is formed; a second piston at the center of one side of which a coupling hole coupled with the other end of the second piston rod is formed, in the other side ofwhich a central throughhole communicating with the coupling hole is formed, whose outer circumference is slidably disposed with the inner circumference of the chamber in the central body, and which partitions the chamber into upper and lower chambers; a check valve which is formed in the second piston and increases anddecreases an amount of an oil flowwhichmutually moves in the upper and lower chambers according to ascending and descending of the second piston, to thereby control an ascending/descending speed of the second piston; first and second sealing caps which are coupled with the upper/lower ends of the central body in a sealing manner; and anelasticmemberwhichis installedintheupper chamber so as to elastically support the first and second pistons, and which provide a restoring force which makes the first and second pistons returned into an original position at the time of returning the door, respectively, wherein the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes of the first and second camshafts are disposed in a mutually opposing direction, and cam diagram lengths of one pair of the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes are longer than those of the other pair thereof.

Inthepresent invention, the first andsecondascending and descending guide holes include only a first ascending and descending section of a door opening angle of 0° to 15°, and the third and fourth ascending and descending guide holes include a first ascending and descending section of a door opening angle of 0° to 15°, and a second ascending and descending section of a door opening angle of 15° to 90°, wherein the first ascending and descending section of the first and second ascending and descending guide holes has the same cam diagram length and angle as those of the first ascending and descending section of the third and fourth ascending and descending guide holes.

Inthis case, the camdiagramangle ofthe first ascending and descending section is preferably set larger than that of the second ascending and descending section.

Also, an ascending and descending guide hole whose cam diagram length is short among the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes in the first and second camshafts is preferably set so as to operate in the range of a door opening angle of 0° to 15°.

Also, it is preferable that the first and second check valves employ circular or spherical valve actuators. According to a fourth aspect of the present invention, there is also provided an automatic return hinge apparatus for use in a large-scale and heavy door which is fixed to any one of first and second hinges and is automatically returned at the time of closing the door, the automatic return hinge apparatus comprising: first and second shafts; a central body whose one circumference is fixedly coupled at the center of the first hinge, in which the first and second shafts are fixed at a state of being inserted facing each other; first and second guide vessels whose circumferences are respectively fixedly coupled at the upper/lower sides of the second hinge in which first and second chambers into which oil is filled are formed therein, so as to maintain a corresponding gap to a height of the central body; first and second ascending and descending units which are respectively installed in the inner circumferences of the first and second guide vessels, and make the first and second guide pins move up and down by rotational moments generated in the shafts or the first and second guide vessels when the door is rotated; first and second hydraulic circuits including first and second piston rods whose upper and lower portions are connected with the first and second guide pins in the first and second ascending and descending units and ascend and descend according to ascending and descending of the first and second guide pins, and first and second pistons which are coupled with the first and second piston rods and which partition the first and second chambers into upper and lower chambers, respectively, at a state of being inserted into the first and second guide vessels, in which oil flows as much as a first amount of an oil flow, when eachpiston ascends and descends according to opening of the door, and oil flows as much as a second amount of an oil flow less than the first amount of an oil flow, according to closing of the door; first and second sealing caps which are coupled with the upper/lower ends of the first and second guide vessels in a sealingmanner, so that respectively independent closed hydraulic circuits are formed in the first and second guide vessels; and first and second elastic members which are installed in the upperportion of the first chamber and the lowerportion of the second chamber so as to elastically support the first and second pistons, and which provide a restoring force which makes the first and second pistons returned into an original position at the time of returning the door, respectively, wherein any one of the first and second ascending and descendingunits operates onlyinthe range ofapredetermined set door opening angle.

According to a fifth aspect of the present invention, there is also provided an automatic return hinge apparatus for use in a large-scale and heavy door which is fixed to any one of first and second hinges and is automatically returned at the time of closing the door, the automatic return hinge apparatus comprising: first and second shafts; a central body whose one circumference is fixedly coupled at the center of the first hinge, in which the first and second shafts are fixed at a state of being inserted facing each other; first and second guide vessels whose circumferences are respectively fixedly coupled at the upper/lower sides of the second hinge in which first and second chambers into which oil is filled are formed therein, so as to maintain a corresponding gap at a height of the central body; first and second ascending and descending units which are respectively installed in the inner circumferences of the first and second guide vessels, and make the first and second guide pins move up and down by rotational moments generated in the shafts or the first and second guide vessels when the door is rotated; a first hydraulic circuit including a first piston rod whose lower portion is connected with the first guide pin in the first ascending and descending unit and ascends and descends according to ascending and descending of the first guide pin, and a first piston which is coupled with the first piston rod and which partitions the first chamber into upper and lower chambers, respectively, at a state of being inserted into the first guide vessel, in which oil flows as much as a first amount of an oil flow from the upper chamber of the first chamber to the lower chamber thereof, when the first piston ascends according to opening of the door, and oil flows as much as a second amount of an oil flow less than the first amount of an oil flow, from the lower chamber of the first chamber to the upper chamber thereof, when the first piston descends according to closing of the door; a second hydraulic circuit including a second piston rod whose upper portion is connected with the second guide pin in the second ascending and descending unit and ascends and descends according to ascending and descending of the second guide pin, at least one piston which is coupled with the second piston rod and which partitions the second chamber into upper and lower chambers, respectively, and at least one isolator which partitions the inner portion of the second guide vessel between the pistons according to the number of pistons increasing in multiplicity, at a state of being inserted into the second guide vessel, in which oil flows as much as a first amount of an oil flow, from the lower chamber of the second chamber when the at least one piston descends according to opening of the door, and oil flows as much as a second amount of an oil flow less than the first amount of an oil flow, and varied according to a door opening angle, from the upper chamber of the second chamber to the lower chamber thereof when the at least one piston ascends according to closing of the door; first and second sealing caps which are coupled with the upper/lower ends of the first and second guide vessels in a sealing manner, so that respectively independent closed hydraulic circuits are formed in the first and second guide vessels; and first and second elastic members which are installed in the upper portion of the first chamber and the lower portion of the second chamber so as to elastically support the first and second pistons, and which provide a restoring force which makes the first and second pistons returned into an original position at the time of returning the door, respectively, wherein any one of the first and second ascending and descendingunits operates onlyinthe rangeofapredetermined set door opening angle. Inthe hinge apparatus according to the fourth and fifth aspects of the present invention, each of the first and second ascending and descending units comprises: first and second vertical guide grooves and third and fourth vertical guide grooves which are formed up and down at positions facing each other at inner sides of the first and second guide vessels; first and second camshafts which are rotated by a relative external force generated in the first and second guide vessels when the door is rotated, in which first and secondshafts are fixedlyinsertedintothe centralbodyfacing each other, first and second cylindrical bodies which are extensively formed from the first and second shafts are respectively rotatably installed in the inner circumferences of the first and second guide vessels, first and second ascending and descending guide holes and third and fourth ascending and descending guide holes having spirally shaped cam diagrams of a mutually movable symmetric structure are penetratively formed along the outer circumferences of the first and second cylindrical bodies, respectively; first andsecondguidepinsbothends ofwhichare coupled with the first and second vertical guide grooves and the third and fourth vertical guide grooves via the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes, respectively, wherein the first and second ascending and descending guide holes and the third and fourth ascending anddescending guide holes of the first and second camshafts are disposed in a mutually opposing direction, and cam diagram lengths of one pair of the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes are longer than those of the other pair thereof. Also, the second hydraulic circuit comprises: an actuator including a second piston rod whose upper portion is connected with the second guide pin in the second ascending and descending unit and ascends and descends according to ascending and descending of the second guide pin, and at least one piston which is coupled with the second piston rod and which partitions the second chamber into upper and lower chambers, respectively, wherein the first oil path and the at least second oil path which ascend and descend according to rotation of the door and move between the upper and lower chambers are included in the second piston rod and the at least one piston; at least one isolatorwhichpartitions the innerportion of the second guide vessel between the pistons according to the number of pistons increasing in multiplicity; at least one check valve which is installed in at least one second oil path of the piston, and which opens the oil path of oil flowing fromthe lower chamber to the upper chamber only at the time of opening the door; and a hydraulic control rod whose one end is supported by the second sealing cap, and whose leading end is inserted into the first oil path in the second piston rod, for controlling an amount of an oil flow which moves to the lower chamber via the first oil path according to level of the actuator so that an ascending and descending speed of the actuator which ascends an descends by the restoring force of the second elastic member at the time of closing the door is controlled at a multi-step.

Inthis case, if the secondhydraulic circuit is a double hydraulic circuit, the first oil path in the second piston rod of the actuator comprises a first sub-oil path which is formed at a certain length fromthe lower end of the central portion of the first oil path so that oil can move to the upper and lower portions of each chamber, a second sub-oil path which makes the first sub-oil path and the upper portion of the second chamber communicate each other, a third sub-oil path which makes the first sub-oil path and the lower portion of the second chamber communicate each other, and a fourth sub-oil path which makes the first sub-oil path and the upper portion of the third chamber communicate each other, the hydraulic control rod comprises a pair of high-speed section setters which are set in an identical diameter each high-speed section setter having a large amount of an oil flow, andapairoflow-speedsectionsetterswhicharedisposed in the lower side of the pair of high-speed section setters, and are tapered so that an amount of an oil flow is varied due to an increase in diameter from the upper portion to the lower portion thereof, each low-speed section setter having a small amount of an oil flow, in comparison with that of the high-speed section setter, and the pair of low-speed section setters compensates for a decrease in a restoring force of the second elastic member since an amount of an oil flow which moves from the upper portions ofthe secondandthird chambers to the lowerportions ofthe secondandthirdchambers increases graduallyaccording to an ascending position of the piston.

Also, the pair of high-speed section setters and the pair of low-speed section setters are variably set in a length of each section according to a main body to which an automatic return hinge apparatus is applied, and an amount of taper in the low-speed section setters is determined.

Meanwhile, the second hydraulic circuit comprises: an actuator including a second piston rod whose upper portion is connected with the second guide pin in the second ascending and descending unit and ascends and descends according to ascending and descending of the second guide pin, and at least one piston which is coupled with the second piston rod and which partitions the second chamber into upper and lower chambers, respectively, wherein the first oil path and the at least second oil path which ascend and descend according to rotation of the door and move between the upper and lower chambers are included in the second piston rod and the at least one piston; at least one isolatorwhichpartitions the innerportion of the second guide vessel between the pistons according to the number of pistons increasing in multiplicity; at least one check valve which is disposed in the lower portion of each piston, and is installed in a valve supporter having at least one third oil path communicating with the at least one second oil path, and which opens the third oil path of oil flowing fromthe lower chamber to the upper chamber only at the time of opening the door; at least one overpressure prevention valve which elastically supports thevalve supporter disposed inthe lower portion of each piston and thus does not operate in the case that the door is closed at a normal speed but forms a fourth oilpathbetweenthe outercircumference ofthevalve supporter and the second guide vessel in the case that the door is closed speedily by a large external force; and a hydraulic control rod whose one end is supported by the second sealing cap, and whose leading end is inserted into the first oil path in the second piston rod, for controlling an amount of an oil flow which moves to the lower chamber via the first oil path according to level of the actuator so that an ascending and descending speed of the actuator which ascends an descends by the restoring force of the second elastic member at the time of closing the door is controlled at a multi-step. In the automatic return hinge apparatus according to the first through fifth aspects of the present invention, the first ascending and descending unit operates only in the range of a door opening angle of for example 0° to 15°.

Also, the first hinge is fixed to the door and the second hinge is fixed to the door frame in the hinge apparatus.

Reversely, the first hinge is fixed to the door frame and the second hinge is fixed to the door in the hinge apparatus.

In the hinge apparatus according to the present invention having the above-described configuration, a cam diagram length of any one of a pair of camshafts is formed larger than that of the other one thereof, and thus a pair of pistons simultaneously ascend and descend by the pair of the camshafts in the range of a door opening angle of for example 0° to 15°, and only a piston moving together with a camshaft whose cam diagram length is long between the pair of the camshafts ascends and descends in the range of a door opening angle of for example 15° to 90°. Thus, the present invention preserves a door closing force without increasing the outer diameter of a hinge apparatus according to the present invention, and can open a door with an opening force smaller than an opening force necessary at a door opening angle of 0° to 15°at the time of opening a door in the range of a door opening angle of for example 15° to 90°. [Advantageous Effects]

As described above, in the case of a hinge apparatus for use in a large-scale and heavy door having an automatic return function according to the present invention, a range of ascending and descending movements of a pair of pistons is set differently from each other by a pair of camshafts having respectively different cam diagram lengths, and thus a pair of return springs providing a restoring force to the pair of the pistons function simultaneously at the initial time of opening a door and at the last time of returning the door, but only a return spring functions at the other times of opening and closing the door. As a result, a door closing force is maintained since a pair of return springs function simultaneously at the initial time of opening a door and at the last time of returning the door, and a door opening force is reduced since only a return spring functions at the other times of opening and closing the door, to accordingly easily open a heavy and large-scale door with a small power and enhance reliability of products and convenience of use.

Also, a door closing speed can be controlled in a multi-step by combination of shapes of hydraulic control rods and cam diagrams with respect to first and second ascending and descending guide holes of a camshaft.

Further, the hinge apparatus according to the present invention can provide a sufficient damping force in order to control ascending speeds of pistons in a heavy and large-scaledoorbyadditionofone ormorehydrauliccircuits and supplement an insufficient damping force taking an increasing weight of the door into consideration instead of increasing a diameter of a bodyplaying a role of a housing.

[Description of Drawings]

The above andother objects andadvantages of the present invention will become more apparent by describing the preferred embodiments thereof in detail with reference to the accompanying drawings in which:

FIG. 1 is a cross-sectional view of a large-scale and heavy automatic return hinge apparatus according to a first embodiment of the present invention viewed in the lengthy direction; FIG. 2A is a perspective view of a pair of camshafts which guide a piston rod to move up and down according to opening and closing of a door in the large-scale and heavy automatic return hinge apparatus shown in FIG. 1;

FIG. 2B is a diagram illustrating positions of a guide pin and compression states of a return spring according to operation of the hinge apparatus in ascending and descending guide holes of the pair of the camshafts shown in FIG. 2A;

FIGs.3Aand 3B are enlargedviews showinganoperational state of a circular plate-shaped valve actuator at portions "A" and "B" shown in FIG. 1, respectively;

FIGs. 4A and 4B are enlarged views showing another example of a check valve shown in FIGs. 3A and 3B, that is, a ball-type valve actuator, respectively;

FIG. 5A is a cross-sectional view illustrating a piston and a return speed adjuster at an initial position where first and second pistons are located at a top dead center and a bottom dead center, respectively;

FIG. 5B is a view illustrating an oil flow when pistons at first and second piston units ascend and descend, respectively, in a process that a door opening angle reaches from 0° to 15° according to opening of a door; FIG. 5C is a view illustrating an oil flow when a second piston descends at a state where a first piston stops, in a process that a door opening angle reaches from 15° to 90° according to opening of a door;

FIG. 5D is a view illustrating an oil flow when a second piston ascends at a state where a first piston stops, in a process that a door opening angle reaches from 90° to 15° according to closing of a door;

FIG. 5E is a view illustrating an oil flow when first and second pistons ascend and descend simultaneously, in a process that a door opening angle reaches from 15° to 0° according to closing of a door;

FIG. 5F is a cross-sectional view illustrating a piston and a return speed adjuster which are returned to an initial position where first and second pistons are located at a top dead center and a bottom dead center, respectively, when a door opening angle reaches 0° according to closing of a door; FIG. 6 is a cross-sectional view partly showing an elastic force setterwhich adjusts an elastic force of a return spring in a sealing cap shown in FIG. 1;

FIG. 7 is a cross-sectional view of a large-scale and heavy automatic return hinge apparatus according to a second embodiment of the present invention viewed in the lengthy direction;

FIG. 8 is a cross-sectional view of a large-scale and heavy automatic return hinge apparatus according to a third embodiment of the present invention viewed in the lengthy direction;

FIG. 9 is a cross-sectional view of a slim automatic return hinge apparatus having a triple hydraulic circuits according to a fourth embodiment of the present invention viewed in the lengthy direction;

FIGs. 1OA through 1OC are respectively partially cross-sectional views sequentially illustrating an oil flow when an actuator descends at a time of opening a door in the fourth embodiment of the present invention; and FIGs. 1OD through 1OE are respectively partially cross-sectional views sequentially illustrating an oil flow when an actuator ascends at a time of closing a door in the fourth embodiment of the present invention.

[Best Mode] Hereinbelow, a large-scale and heavy hinge apparatus according to preferred embodiments of the present invention willbe describedwith referenceto the accompanyingdrawings. Like reference numerals denote like elements through the following embodiments.

Referring to FIGs. 1 to 3B, the whole configuration of a large-scale and heavy automatic return hinge apparatus according to the present invention will be described below.

First, an automatic return hinge apparatus 100 for use in a large-scale and heavy door according to a first embodiment of the present invention is fixed to any one of first and secondhinges 10 and20 and is automaticallyreturned at the time of closing the door. The automatic return hinge apparatus includes a central body 11 whose one circumference is fixedly coupled at the center of the first hinge 10, and first and second guide vessels 21 and 23 whose circumferences are respectively fixedly coupled at the upper/lower sides of the second hinge 20 in which first and second vertical guide grooves 22a and 22b and third and fourth vertical guide grooves 24a and 24b are formed up and down in positions facing each other in the inner side of the second hinge 20 (see FIGs. 5A through 5F) . In this case, it is preferable that a gap between the first and second guide vessels 21 and 23 is formed as a corresponding gap to a height of the central body 11 so that the central body 11 is inserted between the first and second guide vessels 21 and 23 without having any gap. For convenience of explanation, it has been described that the first and second hinges are fixed to a door frame (or a fixed body) and a door (a moving body) , respectively. However, it is not limited thereto in use but it is possible that when any one of the first and second hinges is fixed to a door frame (a fixed body) , the other one is fixed to a door (a moving body) . Also, first and second sealing caps 93 and 97 are coupled with the one end of the first and second guide vessels 21 and 23 facing the central body, and first and second end caps 91 and 95 coupled with air discharge bolts 91a and 95a are coupled with the other ends of the first and second guide vessels 21 and 23, respectively, in order to prevent oil filled in the inner sides of the first and secondguide vessels 21 and 23 from leaking therefrom.

Meanwhile, first and second camshafts 30 and 60 are rotated by a relative external force generated in the first and second guide vessels 21 and 23 when the door is rotated, in which first and second shafts 31 and 61 are fixed by spring pins 31a and 61a at a state where the first and second shafts 31 and 61 are inserted into the central body 11 so as to face each other, respectively, and first and second cylindrical bodies 33 and 63 which are respectively extensively formed from the first and second shafts 31 and 61 are respectively rotatably installed in the inner circumferences of the first and second guide vessels 21 and 23.

Here, first and second ascending and descending guide holes 34a and 34b and third and fourth ascending and descending guide holes 64a and 64b having spirally shapes of a mutually movable symmetric structure are penetratively formed along the outer circumferences of the first and second cylindrical bodies 33 and 63, respectively.

As shown in FIG. 2A, the first and second ascending and descending guide holes 34a and 34b in the first camshaft 30 are formed shorter than the third and fourth ascending and descending guide holes 64a and 64b in the second camshaft 60. One end of each of the first and second ascending and descending guide holes 34a and 34b is formed so as to be open up to the end of the cylindrical body 33. Moreover, both ends of each of the third and fourth ascending and descending guide holes 64a and 64b in the second camshaft

60 are formed in the cylindrical body 63 so as to be closed.

InFIG.2A, the firstandsecondascendinganddescending guide holes 34a and 34b in the first camshaft 30 and the third and fourth ascending and descending guide holes 64a and 64b in the second camshaft 60 have been illustrated as spiral shapes of a mutually identical direction in order to easily explain functions of the ascending and descending guideholes inFIG.2B. However, the first andsecondascending and descending guide holes 34a and 34b in the first camshaft 30 are actually disposed in the direction opposing those of the third and fourth ascending and descending guide holes 64a and 64b in the second camshaft 60.

FIG. 2B is a diagram illustrating positions of a guide pin and compression states of a return spring according to operation of the hinge apparatus in ascending and descending guide holes of a pair of the camshafts shown in FIG. 2A. Functions of the first and second ascending and descending guide holes 34a and 34b and the third and fourth ascending and descending guide holes 64a and 64b which are involved with ascending and descending of pistons 53 and 83 will be described later in detail.

In the present invention, a pair of pistons 53 and 83 to be described later ascend and descend simultaneously at the last time of an automatic return operation of a door and thus greatly enhance a damping force to thereby increase a door closing force, due to a particular structure of the first and second ascending and descending guide holes 34a and 34b which guide the first piston 53.

Repulsive forces of return springs 111 and 113 which elastically support a pair of pistons 53 and 83 to be described later are applied between the inner circumference of the central body 11 and the shafts 31 and 61. Accordingly, when the camshaft s 30 and 60 are rotated, first and second thrust bearings 71a and 71b are inserted in the camshafts 30 and

60, respectively, in order to reduce rotational friction and noise.

Also, first and second radial bearings 75a and 75b are coupled respectivelybetween the upper end of the cylindrical body 33 and the first sealing cap 93 in the first camshaft 30 and between the upper end of the cylindrical body 63 and the second sealing cap 97 in the second camshaft 60. Thus, like the thrust bearings 71a and 71b, the first and second radial bearings 75a and 75b are inserted in the camshafts 30 and 60, respectively, inordertoreducerotational friction and noise when the camshaft s 30 and 60 are rotated.

In this case, first and second spring washers 73a and 73b are disposedrespectivelybetweenthe first thrustbearing 71a and the first sealing cap 93 and between the second thrust bearing 71b andthe second sealing cap 97. The first and second spring washers 73a and 73b remove frictional resistance when central body 11 contacts the first and second guide vessels 21 and 23, to thereby prevent the rotational forces of the first and second guide vessels from falling down in advance.

Meanwhile, both ends of first and second guide pins 41 and 43 are coupledwith first and secondvertical guide grooves

22a and 22b and third and fourth vertical guide grooves 24a and 24b via the first and second ascending and descending guide holes 34a and 34b and the third and fourth ascending and descending guide holes 64a and 64b, respectively.

Also, the central portions of the first and second guide pins 41 and 43 are penetratively coupled on each one end of first and second piston rods 51 and 81, and the first and second piston rods 51 and 81 ascend and descend along the inner circumferences of the first and second cylindrical bodies 33 and 63 of the first and second camshafts 30 and 60 in a sliding manner along the first and second vertical guide grooves 22a and 22b and the third and fourth vertical guide grooves 24a and 24b according to rotation of the first and second camshafts 30 and 60, and first and second bent throughholes 51a and 81a perpendicularly communicating with the outer circumferences thereof are formed on the other ends of the first and second piston rods 51 and 81, respectively.

Further, each one end of the first and second piston rods 51 and 81 where the throughholes 51a and 81a are formed, is detachably coupledwith coupling grooves 53b and 83b formed at the centers of first and second pistons 53 and 83.

Thus, the outer circumferences of the first and second pistons 53 and 83 are respectively slidably disposed along the inner circumferences of the first and secondguide vessels 21 and 23, together with movement of the first and second piston rods 51 and 81 and further the first and second pistons 53 and 83 partition the inner space of the first and second guide vessels 21 and 23 into first upper/lower chambers 21a and 21b and second upper/lower chambers 23a and 23b, respectively.

Also, as shown in FIGs. 3A and 3B, the first and second pistons 53 and 83 are formed smaller in diameter than those of the coupling holes 53b and 83b, and simultaneously first and second central throughholes 53a and 83a respectively communicating with the coupling holes 53b and 83b are formed in the first and second pistons 53 and 83. Central two-point chain lines illustrate flowing paths of oil in FIGs. 3A and 3B.

Accordingly, the hinge apparatus includes a first oil path communicating with the first upper/lower chambers 21a and 21b, that is, the throughhole 51a and the first central throughhole 53a in the first piston rod 51, and a second oil path communicating with the second upper/lower chambers 24a and 24b, that is, the throughhole 81a and the second central throughhole 83a in the second piston rod 81.

Meanwhile, first and second check valves A and B having first and second actuators 54 and 84 are formed in the first and second pistons 53 and 83 and open and close the first and second oil paths and increase and decrease an amount of an oil flow which mutually moves in the first and second upper/lowerchambers 21a and21b; and23aand23b, respectively according to ascending and descending of the first and second pistons 53 and 83, to thereby control an ascending/descending speed of the first and second pistons 53 and 83.

The first and secondvalve actuators 54 and 84 are formed larger in diameter than those of the first and second throughholes 53b and 83b, and slightly smaller than those of the first and second central throughholes 53a and 83a, and includes small central throughholes 54a and 84a through which oil can pass.

Also, a number of oil grooves 52 are formed along the inner circumference of the throughhole 51a of the first piston rod 51 so that oil can flow from the upper chamber 21a to the lower chamber 21b as much as an amount of a first oil flow when the throughhole 51a in the first piston rod 51 is closed by the first valve actuator 54 as shown in FIG. 3A. Likewise, a number of oil grooves 82 are formed along the inner circumference of the throughhole 81a of the second piston rod 81 so that oil can flow from the lower chamber 23b to the upper chamber 23a as much as an amount of a first oil flow when the throughhole 81a in the second piston rod 81 is closed by the first valve actuator 54 as shown in FIG. 3B. Meanwhile, the checkvalvesAandBhavingthe circularly shaped valve actuators operating according to opening and closing of a door in the hinge apparatus according to the present invention function as follows.

First, at the time of opening a door, the first valve actuator 54 descends in the coupling hole 53b by oil sequentially passing through the first oil paths 53a, 54a, and 51a in the first upper chamber 21a according to ascending of the first piston 53. Simultaneously, at the time of opening a door, the second valve actuator 84 ascends in the coupling hole 83b by oil sequentially passing through the second oil paths 83a, 84a, and 81a in the second lower chamber 23b according to descending of the second piston 83.

In this process, oil filled in the first upper chamber 21a passes through the first central throughhole 53a. Then, oil passes through a portion between the outer circumference of the first valve actuator 54 and the inner circumference of the coupling hole 53b and the small throughhole 54a, and comes out via the bent throughhole 51a. Then, when the first valve actuator 54 closes the bent throughhole 51a, oil flows toward the first lower chamber 21b as much as a first oil flow via a number of oil path grooves 52 and the small throughhole 54a, sequentially. Simultaneously, oil filled in the second lower chamber 23b passes through the second central throughhole 83a. Then, oil passes through a portion between the outer circumference of the second valve actuator 84 and the inner circumference of the coupling hole 83b and the small throughhole 84a, and comes out via the bent throughhole 81a. Then, when the second valve actuator 84 closes the bent throughhole 81a, oil flows toward the second upper chamber 23a as much as a first oil flow via a number of oil path grooves 82 and the small throughhole 84a, sequentially.

Thus, an amount of oil flowing at the time of opening the door becomes large and accordingly an ascending speed of the first piston 53 and a descending speed of the second piston 83 are also large. Thus, the rotational speed of the door during opening the door becomes fast.

Reversely, at the time of closing a door, the first valve actuator54 ascends inthecouplinghole 53bbyoil sequentially passing through the first oil paths 51a, 54a, and 53a in the first lower chamber 21b according to descending of the first piston 53. In this case, the upper surface of the first valve actuator 54 closes the first central throughhole 53a in the first piston 53. Then, issuing paths of oil flowing toward the firstupperchamber21aarelimitedtothesmallthroughhole 54a. Accordingly, oil flows with a second amount of an oil flow greatly smaller than the first amount of an oil flow. Thus, in comparison with the time of opening the door, an amount of an oil flow is greatly reduced, and thus an ascending speed of the first piston 53 is reduced. Finally, the first valve actuator 54 plays a role that a rotational speed of the door becomes slow.

Simultaneously, the second valve actuator 84 descends in the coupling hole 83b by oil sequentially passing through the second oil paths 83a, 84a, and 81a in the second upper chamber 23a. In this case, the bottom surface of the second valve actuator 84 closes the second central throughhole 83a in the second piston 83. Then, issuing paths of oil flowing toward the second lower chamber 23b are limited to the small throughhole 84a. Accordingly, oil flows with a second amount of an oil flow smaller than the first amount of an oil flow.

Thus, in comparison with the time of opening the door, an amount of an oil flow is greatly reduced, and thus a descending speed of the second piston 83 is reduced. Finally, the second valve actuator 84 plays a role that a rotational speed of the door becomes slow.

Meanwhile, first and second return springs 111 and 113 are installed in the upper side of the first upper chamber 21a and the lower side of the second lower chamber 23b to elastically support the first and second pistons 53 and 83, respectively.

The first and second return springs 111 and 113 are compressed at the time of opening a door, and then provide a restoring force which return the first and second pistons 53 and 83 to original positions thereof.

Reference numerals 131, 132, 133, 134, 135 and 136 in the drawings denote 0-rings which prevent oil from leaking.

FIGs. 4A and 4B are enlarged views showing another example of a check valve shown in FIGs. 3A and 3B, that is, check valves C and D having a ball-type valve actuator, respectively. InFIGs.4Aand4B, two-dot chainlines represent oil flowing paths.

As described above, the first and secondvalve actuators 54 and 84 of FIGs. 3A and 3B have been described with respect to the circularly shaped case, but it is apparent that they can be formed as ball type valve actuators. That is, as shown in FIG. 4A, the hinge apparatus includes a spherical first valve actuator 154 which is formed larger in diameter than those of the first central throughhole 53a in the first piston and the bent throughhole 51a in the piston rod. When the first central throughhole 53a in the first piston is closed by the first valve actuator 154 according to descending of the first piston 53, an oil path groove 55 formed in the inner circumference of the first central throughhole 53a in the first piston 53 is provided in order to make oil flow from the lower chamber 21b in the first chamber to the upper chamber 21a therein, to thereby increase and decrease an amount of an oil flow like the case of the circular plate shaped valve actuator.

Likewise, as shown in FIG. 4B, the hinge apparatus includes a spherical secondvalve actuator 184 which is formed largerindiameterthanthose ofthe secondcentral throughhole 83a in the second piston and the bent throughhole 81a in the second piston rod. When the second central throughhole 83a in the second piston is closed by the second valve actuator 184 according to ascending of the second piston 83, an oil path groove 85 formed in the inner circumference of the second central throughhole 83a in the second piston 83 is provided in order to make oil flow from the upper chamber 23a in the second chamber to the lower chamber 23b therein, to thereby increase and decrease an amount of an oil flow like the case of the circular plate shaped valve actuator. Hereinbelow, an ascending and descending guiding structure of a piston according to the present invention will be described in detail with reference to FIGs. 2A and 2B.

First, the first and second ascending and descending guide holes 34a and 34b in the first camshaft 30 includes a first section "a" where the first guide pin 41 is guided to guide a piston to ascend and descend according to a door opening angle as shown in FIG.2B, that is, the first section "a" having a door opening angle of 0° to 15° and a second section "b" to "d" when the first guide vessel 21 is rotated left and right only in the case of a camshaft fixing method according to rotation of the door without ascending and descending of the first piston 53, that is, the first guide pin at a door opening angle of 15° to 160°. Here, the first and second ascending and descending guide holes 34a and 34b is formed so that each one end of the first and second ascending and descending guide holes 34a and 34b is opened up to the end of the cylindrical body 33. Accordingly, a pattern corresponding to the second section "b" to "d" is omitted. Thus, the second section "b" to "d" is a stop section where a cam diagram angle is set as zero in which the first guide vessel 21 is rotated left and right without ascending and descending of the first guide pin 41 according to rotation of the door. That ism the first and second ascending and descending guide holes 34a and 34b is formed of a length corresponding to the first section "a."

Also, the first and second ascending and descending guide holes 64a and 64b in the second camshaft 60 includes four sections "a" to "d" according to a door opening angle as shown in FIG. 2B, that is, a first section "a" having a door opening angle of 0° to 15°, a second section "b" having a door opening angle of 15° to 90°, a third section "c" having a door opening angle of 90° to 130°, and a fourth section "d" having a door opening angle of 130° to 160°.

The first section "a" where the first and secondpistons 53 and 83 operate simultaneously is in the state of a hydraulic circuit to make a latch installed in a door have a closing force so that the latch installed in the door can be coupled with a locking device during performing an automatic return of the door (see FIG. 5E) . In this case, a loss of a closing force due to resistance of the hydraulic circuit and reduction in a proportional restoring force of the return springs 111 and 113 is supplemented by increasing a piston ascending efficiency inwhichacamdiagramangle α ofthe ascendinganddescending guide holes 34a and 34b; and 64a and 64b is established in a range of 45° to 65° which is relatively larger than an angle β of the second section "b."

As a result, although a compression spring is used as a return spring without using a torsion spring during performing an automatic return operation, the door can be completely returned to an original position, that is, completely closed.

The second section "b" where only the second piston 83 operates at a state where the first piston 53 stops is at a state of a hydraulic circuit of FIG. 5C to be described later when a door automatically returns. In this case, when the door is opened, only the second piston 83 which is elastically supportedbythe secondreturn spring 113 operates at a state where the first piston 53 stops.

Accordingly, anopeningforce is increasedinproportion with an opening angle as a door reaches 0° up to 160° where the door is completely opened at the time of opening the door in the conventional art. As a result, a force necessary for a user to open the door is also increased in proportion with adooropeningangle, that is, fromthe secondsection. However, in the present invention, an opening force similar to the conventional art is needed in order to maintain a closing force of a door in the first section "a" but the first return spring 111 is not further compressed from the second section "b" but only the second return spring 113 is compressed. Therefore, an opening force is greatly reduced in comparison with the first section "a" and thus a heavy or large-scale door can be easily opened. Meanwhile, inthe secondsection "b, " a camdiagramangle "β " of the third and fourth ascending and descending guide holes 64a and 64b is set in the range of 10° to 45° relatively smaller than an angle "α " of the first section "a" to thereby increase a rotational efficiency of the camshafts 30 and 60 proportionally when a door is opened and thus compensate for an opening force increasing portion which increases in proportion with opening of the door.

Also, in the third section "c" at a state where both the first and second pistons 53 and 83 stop, a cam diagram angle of the third section "c" is set zero, and becomes a stop section where an automatic return is interrupted by the return spring 113. In the third section "c, " an angle where the door has been opened is maintained, and a restoring force of the return spring 113 becomes the largest. The fourth section "d" is formed upwards from the third section "c, " and is a stopping force reinforcement section where the guide pin 43 does not move due to a hook. In this case, the fourth section "d" can be extended in a range of a door opening angle of 130° to 180° according to necessity. Meanwhile, in the case that the guide pin 43 ascends due to the repulsive force of the compressed return spring 113, an oil pressure at the upper portion of the secondpiston 83 is applied greater than the elastic force of the return spring 113 at a limit boundary where the second piston 83 can ascend. Accordingly, the piston 83 can abruptly descend in a reverse direction. Also, the guide pin 43 can generate internal noise and cause damage of internal components due to irregular movement at the initial time when the guide pin 43 proceeds from the third section "c" to the second section "b. " To prevent this, it is preferable that a boundary portion between a first cam diagram sustenance portion 644 and a second cam diagram sustenance portion 645 in the third and fourth ascending and descending guide holes 64a and 64b is formed as a curved surface.

Also, the first cam diagram sustenance portion 644 and the second cam diagram sustenance portion 645 are formed to have respectively opposing curved surfaces at a certain interval with respect to a third ascending and descending guide hole 64a.

Hereinbelow, the entire operation of the large-scale and heavy automatic return hinge apparatus according to the present invention will be described with reference to FIGs. 5A to 5E.

FIG. 5A is a cross-sectional view showing a piston and a return speed adjuster illustrating an initial position where first and secondpistons are located at a top dead center and a bottom dead center, respectively. FIG. 5B is a view illustrating an oil flow when pistons at first and second piston units ascend and descend, respectively, in a process that a door opening angle reaches from 0° to 15° according to opening of a door. FIG. 5C is a view illustrating an oil flow when a second piston descends at a state where a first piston stops, in a process that a door opening angle reaches from 15° to 90° according to opening of a door. FIG. 5D is a view illustrating an oil flow when a second piston ascends at a state where a first piston stops, in a process that a dooropeninganglereaches from90° to 15° accordingto closing of a door. FIG. 5E is a view illustrating an oil flow when first and second pistons ascend and descend simultaneously, in a process that a door opening angle reaches from 15° to 0° according to closing of a door. FIG.5F is a cross-sectional view illustrating a piston and a return speed adjuster which are returned to an initial position where first and second pistons are located at a top dead center and a bottom dead center, respectively, when a door opening angle reaches 0° according to closing of a door.

Inthe case ofthe large-scaleandheavyautomatic return hinge apparatus according to the first embodiment of the present invention, when a door is opened from the state where the door is closed as shown in FIG. 5A, a hydraulic circuit of FIG. 5B is set.

That is, in the case of the large-scale and heavy automatic return hinge apparatus 100 according to the first embodiment of the present invention, when a door is opened, an external rotational force is transferred to the shafts 31 and 61 of the first and second camshafts 30 and 60. Accordingly, the internal components operate as follows. If a user opens a door at an initial state of FIG. 5A where the door is closed, a rotational force of a left-hand screw direction is transferred to the first guide vessel 21. Accordingly, the guide pin 41 whose both ends are inserted intothe first andsecondascending anddescendingguideholes 34a and 34b and a pair of vertical guide grooves 22a and 22b formed in the first guide vessel 21 is rotated according to rotation of the first guide vessel 21 andmoves upwards along the first and second ascending and descending guide holes 34a and 34b of the first camshaft 30.

Simultaneously, a rotational force of a left-hand screw direction is transferred to the second guide vessel 23, as in the case of the first camshaft. Accordingly, the guide pin 43 whose both ends are inserted into the third and fourth ascending and descending guide holes 64a and 64b and a pair of vertical guide grooves 24a and 24b formed in the second guide vessel 23 is rotated according to rotation of the second guide vessel 23 andmoves downwards along the third and fourth ascending anddescendingguide holes 64a and 64b of the second camshaft 60 of the second camshaft 60.

In this case, as shown in FIG. 5B, a force which intends to move upwards and downwards is respectively applied to the first and second pistons 53 and 83 which move together with a pair of the guide pins 41 and 43 and a pair of the first and second piston rods 51 and 81 which move in the direction far from each other.

Accordingly, oil positioned at the upper side of the first piston 53, that is, the second lower chamber 23b moves when the first valve actuator 54 is opened. Therefore, oil passes through the second oil paths 53a, 54a, and 51a, and then passes through an intermediate portion between the outer circumference of the first valve actuator 84 and the inner circumference of the recess 53b, and easilymoves to the lower side of the first piston 53, that is, the first lower chamber 21b.

Simultaneously, oil positioned at the lower side of the second piston 83, that is, the second lower chamber 23b moves when the second valve actuator 84 is opened. Therefore, oil passes through the second oil paths 83a, 84a, and 81a, and then passes through an intermediate portion between the outer circumference of the second valve actuator 84 and the inner circumference of the recess 83b, and moves to the upper side of the second piston 83, that is, the second upper chamber 23a.

Thus, the first guide pin 41 moves only in the first section "a" as in the operational state in the first and second ascending and descending guide holes 34a and 34b shown in FIG. 2B, and thus the first piston 53 compresses the return spring 111 and ascends. Simultaneously, the second guide pin 43 sequentially moves in the first and second sections "a" and "b" as in the operational state in the third and fourth ascending and descending guide holes 64a and 64b, and thus the second piston 83 compresses the return spring 113 and descends.

Also, in the case that the second camshaft 60 continues to rotate, as shown in FIG. 5C, at a state where the first guide pin 41 stops, the second guide pint 43 reaches the thirdsection "c" andrestrictivelymovesbythe first stopper 642 in the third section "c" of the third and fourth ascending and descending guide holes 64a and 64b. Accordingly, as shown in FIG. 5C, the second piston 83 is maintained in a stop state at a state where the second piston 83 is located at a bottom dead center. That is, the door is temporarily maintained in the stop state (see FIG. 5D) .

Meanwhile, if a user closes a door within a door opening angle below 90°or opens and closes within a door opening angle below 90°, the hinge apparatus according to the present invention performs an automatic return operation of the door when the door is closed.

When a door opening angle is 90°, that is, the door is in a stop state, if a user rotates the door so that a small amount of an external force of a right-hand screw direction is transferred to the second guide vessel 23, the second guide pin 43 passes through the first stopper 642 and is beyond the third section "c." Then, the second piston 83 starts to move upwards due to a repulsive force of the compressed return spring 113, and the guide pin 43 connected with the second piston 83 also rises up along the second section "b" of the third and fourth ascending and descending guide holes 64a and 64b, that is, the ascending and descending guide 641 of a slow sloped angle of 10 to 45°. As a result, the second guide vessel 23 rotates in the right-hand screw direction together with the guide pin43 andintends tomakeadoorreturntoaninitialposition. Here, the oil in the second upper chamber 23a moves from the secondupper chamber 23a to the second central throughhole 83a, respectively via the second oil paths 81b, 84a, and 83a by the second piston 83 which rises up as shown in FIG. 5D. As a result, the secondvalve actuator 84 is safelyseated in the recess 83b of the piston 83 at a state where the second central throughhole 83a in the second piston 83 is closed by the oil having flown via the second oil paths 81a, 84a, and 83a, and thus closes the second central throughhole 83a. Thereafter, the secondoilpath is isolatedbythe second valve actuator 84, and thus the oil on the upper portion of the second piston 83 moves to the second lower chamber 23b only via the throughhole 84a of the second valve actuator 84. Thus, an amount of a second oil flow is greatly reduced, and thus the second piston 83 slowly rises up at a second speedslower than that of the first speedat the time of opening the door.

In this case, the guide pin 43 connected with the second piston 83 rises upalongthe secondsection "b" ofthe ascending anddescendingguideholes 34a and 34b, that is, the ascending and descending guide 641 of a slow sloped angle. The slow second speed rise-up of the second piston 83 is maintained until the door opening angle reaches 15°, and thus a user can avoid a safety accident or inconveniences due to an abrupt or sudden return of a door. Thereafter, inthe case that a door openingangle reaches beyond 15°as shown in FIG. 5E, the first piston 53 which stops together with the second piston 83 which consistently ascends toward the top dead center starts to descend. That is, the guide pins 41 and 43 respectively connected with the first and second pistons 53 and 83 start to descend and ascend along the ascending and descending guide 641 which is set at an abruptly sloped angle in the first section "a" of the ascending and descending guide holes 34a and 34b; and 64a and 64b, that is, from 45° to 65°. Here, the oil in the first lower chamber 21b moves from the first upper chamber 21a to the first central throughhole 53a, respectively via the first oil paths 51b, 54a, and 53a by the first piston 53 which falls down as shown in FIG. 5E. As a result, the first valve actuator 54 is safely seated in the recess 53b of the piston 53 at a state where the first central throughhole 53a in the first piston 53 is closed by the oil having flown via the first oil paths 51a, 54a, and 53a, and thus closes the first central throughhole 53a.

Accordingly, the oil on the lower portion of the first piston 53 moves to the first upper chamber 21a only via the throughhole 54a ofthe firstvalve actuator 54. Thus, an amount of an oil flow is greatly reduced, and thus the first piston descends slowly at a second speed slower than that of the first speed at the time of opening the door.

Meanwhile, when a door opening angle ranges from 15° to 0% a hydraulic circuit is set in the same manner as that of when the door opening angle ranges from 90° to 15°. However, a sloped angle of the ascending and descending guide 641 is set relatively larger than that of the second section "b." As a result, a restoring force of the first and second return springs 111 and 113 is reduced, but a frictional resistance of the ascending and descending guide 641 is reduced. Accordingly, a descending speed and an ascending speed of the first and secondpistons 53 and 83 are accelerated at a third speed, respectively.

Further, in the case that a restoring force of the first return spring 111 is set larger than a damping force of the first check valve "A, " the restoring force of the first return spring 111 is added to that of the second return spring 113, and contributes for a closing force at the last time of returning the door. Thus, the door returns to the initial position and becomes a locking state by means of a latch of the door. Also, the first and second pistons 53 and 83 return to the initial positions as shown in FIG. 5F.

As described above, in the hinge apparatus according to the present invention, a cam diagram angle with respect to the ascending and descending guide 641 of the ascending and descending guide holes 34a and 34b; and 64a and 64b is set properly so that a frictional resistance is small, and also a damping force of an additional hydraulic circuit and a restoring force of the first return spring 111 which are applied only at the last time of returning a door are added. Accordingly, although compression springs are used as first and second return springs, a restoring force of the return springs is reduced in the case that the door is close to the initial position during performing an automatic return operation in a large-scale and heavy door. As a result, the hinge apparatus accordingto thepresent invention can solve the problem that the door is not completely closed.

The hinge apparatus according to the present invention having the above-described configuration does not only maintain a door closing force at the time of closing a large-scale andheavydoor, but also reduces an opening force from a case that the door is opened above 15° by about half the force necessary for opening the door in comparison with the opening force in a case that the door is opened between 0° and 15° to thereby enable a user to easily open the large-scale and heavy door with a small power.

Also, the present invention can control an automatic return speed and a restoring force during performing an automatic returnoperation, byanadditional restoring force of an additional return spring, an oil path control of hydraulic circuits, and alteration of a frictional resistance due to alteration of a cam diagram angle in ascending and descending guide holes. FIG. 6 is a cross-sectional view partly showing an elastic force setterwhich adjusts an elastic force of a return spring in a sealing cap shown in FIG. 1.

Meanwhile, the hinge apparatus according to the first embodiment of the present invention can include a structure of adjust an opening force and a closing force of a door by setting an elastic force of each spring as shown in FIG.

6.

That is, a particular elastic force setter can be installed in the first or second sealing cap 91 or 95 shown inFIG.1. InFIG.6, theelasticforce setterhasbeeninstalled in the second sealing cap 95.

First, a screw coupling groove 95b and a sliding hole

95c which penetrate a second sealing cap 95 are formed at the center of the second sealing cap 95 with a step on an identical axis. Also, a head portion 951 of a push bolt 950 is screw-coupled with the screw coupling groove 95b and a body 952 which is extensively formed in one end of the head portion 951 is slidably inserted into the sliding hole 95c. Further, a wrench groove (not shown) is formed in one surface of the head portion 951 of the push bolt 950 so as to be rotated using a tool such as a wrench.

Also, a pressing plate 960 which ascends along the inner circumference of the second guide vessel 23 by the push bolt 950 forpressing a secondreturn spring 113 is disposedbetween the second sealing cap 95 and the second return spring 113.

Further, the pressing plate 960 is preferably formed to have a diameter larger than that of the second return spring 113.

Thus, in the case that an opening force and a closing force of a door are enhanced by increasing an elastic force of the second return spring 113, and the push bolt 951 is rotated, the head portion 951 moves to the inner side of the hinge apparatus along the screw coupling groove 95b. Then, the body 952 pushes one surface of the pressing plate 960 and thus compresses the return spring 113.

Accordingly, the elastic force of the return spring 113 increases as much as the compressed distance. Finally, a door opening force and a door closing force can be enhanced.

Reversely, when the push bolt 950 rotationally moves to the outer side of the hinge apparatus, the elastic force of the return spring 113 is reduced, and thus the door opening force and the door closing force can be reduced. Accordingly, intensity of the door opening and closing forces can be easily controlled through adjustment of the push bolt 950.

FIG. 7 is a cross-sectional view of a large-scale and heavy automatic return hinge apparatus according to a second embodiment of the present invention viewed in the lengthy direction.

Meanwhile, a hinge apparatus according to the second embodiment of the present invention is slightly similar to that of the first embodiment thereof, in view of the overall structure and the operation thereof. The hinge apparatus according to the first embodiment of the present invention includes hydraulic circuits formed in the first and second guide vessels 21 and 23 which are disposed oppositely to each other around the central body 11. However, in the case of the hinge apparatus 200 according to the second embodiment of the present invention, the central body 210' is formed relatively long in comparisonwith the upper and lower bodies 221 and 223 as shown in FIG. 4, differently from the first embodiment of the present invention. Also, a partition 211 is formed in the inner-center of the central body 210' and first and second sealing caps 293 and 297 are coupled with both ends of the central body 210', respectively, to thereby form two hydraulic closed circuits in the central body 210 ' , differently from the first embodiment of the present invention.

Also, in the case of the first embodiment of the present invention, the camshafts 30 and 60 are of a fixed state, respectively. However, in the case of the first embodiment of the present invention, the central body 210' is fixed to a door frame via the first hinge 210, and first and second camshafts 230 and 260 are supported to a door via a second hinge 220 whose both ends are fixed to the upper and lower bodies 221 and223. Accordingly, the first andsecondcamshafts 230 and 260 are supported by the upper and lower bodies 221 and 223 so as to be rotated according to rotation of the door, differently from the first embodiment of the present invention.

Also, shafts 231 and261 ofthe first andsecondcamshafts 230 and 260 are formed using a key fixing method that the shafts 231 and 261 are inserted and fixed via keys 299a and 299b in the inner sides of the upper and lower bodies 221 and 223, respectively. However, portions which are inserted into the upper and lower bodies 221 and 223 of the shafts 231 and 261 are formed in the form of a polygon, respectively, and the inner circumferences of the upper and lower bodies 221 and 223 can be fixed in the form corresponding to the inner circumferences thereof. Moreover, it is of course possible in the second embodiment of the present invention to adopt a fixing method using spring pins which perpendicularly penetrates the shafts as in the first embodiment of the present invention.

Like the first embodiment of the present invention, in the hinge apparatus 200 according to the second embodiment of the present invention, cam diagram lengths of the first and second camshafts 230 and 260 are set differently from each other. Accordingly, in the case of a door opening angle of 0° to 15°, first and second return springs 212 and 214 are set so as to operate simultaneously. As a result, a pair of pistons 253 and 283 ascend and descend simultaneously so as to move together with ascending and descending of first and second guide pins 241 and 243.

As a result, when a door is closed, a door closing force is not only maintained by a restoring force of the first and second return springs 212 and 214, but also an opening force from a case that the door is opened above 15° is reduced by about half the force necessary for opening the door in comparison with the opening force in a case that the door is openedbetween 0° and 15° to thereby enable a user to easily open the large-scale and heavy door with a small power.

In FIG. 7, reference numerals 233 and 263 denote a cylindrical body in the camshafts, respectively.

FIG. 8 is a cross-sectional view of a large-scale and heavy automatic return hinge apparatus according to a third embodiment of the present invention viewed in the lengthy direction. A hinge apparatus 300 according to a third embodiment of the present invention employs a pair of camshafts as in the first and second embodiments of the present invention. Also, the overall structure and operations of the third embodiment thereof are similar to those of the third embodiment thereof.

The first and second embodiments include two hydraulic closed circuits, but the third embodiment thereof includes an oil pressure closed circuit which is partitioned into the upper and lower chambers 323a and 323b by the piston 383. Further, oil paths 383a, 384a and 381a exist to move to the upper and lower chambers 323a and 323b, respectively.

That is, a first piston 353 has no oil paths and valve actuators for controlling the oil paths, and plays only a role of a piston at a state of being elastically supported by a return spring 311.

In FIG. 8, reference numerals 310 and 320 denote first and second hinges, respectively, 310', 321, and 323 denote a central body, an upper body, and a lower body, respectively,

330 and 360 denote first and second camshafts, respectively,

331 and 361 denote shafts of the first and second camshafts, respectively, 333 and 336 denote a .cylindrical body of the first and second camshafts, respectively, 341 and 343 denote first and second guide pins, respectively, and 399a and 399b denote a key for fixing the shafts 331 and 361 to the upper body 321 and the lower body 323, respectively.

Like the first and second embodiments of the present invention, in the hinge apparatus 300 according to the third embodiment of the present invention, cam diagram lengths of the first and second camshafts 330 and 360 are set differently from each other. Accordingly, in the case of a door opening angle of 0° to 15°, a pair of pistons 353 and 383 ascend and descend simultaneously so as to move together with ascending and descending of first and second guide pins 341 and 343. As a result, the return spring 311 is compressed up and down.

Also, in a door opening angle over 15°, the first guide pin 341 andthe piston 353 do not descend anymore, andmaintain the states as they are. The return spring 311 is compressed according to ascending of the second piston 383 in the hydraulic circuit located below the return spring 311.

Meanwhile, at the time of closing a door, the restoring force of the return spring 311 contributes for descending of only the second piston 383 in a door opening angle up to 15°, and the restoring force of the return spring 311 contributes the first and secondpistons 353 and 383 to ascend and descend at the time of returning the door in a door opening angle of 15° to 0°.

As a result, when a door is closed, a door closing force is not only maintained by a restoring force of the return spring 311, but also an opening force from a case that the door is opened above 15° is reduced by about half the force necessary for opening the door in comparisonwith the opening force in a case that the door is opened between 0° and 15° to thereby enable a user to easily open the large-scale and heavy door with a small power.

Meanwhile, even in the case of the first and second embodiments of the present invention, any one of a pair of pistons is designed to have no separate oil paths and check valves (that is, valve actuators) for controlling the oil paths and to the state of being elastically supported by the return spring, like the third embodiment of the present invention. In this case, it is preferable that oil should be removed from a chamber having the simplified piston. Also, eveninthe caseofthe secondandthirdembodiments of the present invention, it is of course possible to make a valve actuator into a ball-type as well as a circular plate-shape.

The large-scale and heavy hinge apparatus according to the first through third embodiments of the present invention include a hydraulic circuit having a notch providing a uniform damping force at the time of closing a door in a check valve. Accordingly, a door closing speed is set at a constant speed.

However, in addition to the upper hydraulic circuit which is disposed in the upper side and operates only in a predetermined opening angle, a hydraulic control rod is inserted into an oil path formed in a piston rod in a lower hydraulic circuit, so that an amount of an oil flow (that is, a piston ascending speed) can be variably controlled according to an ascending position of the piston, and thus it is possible to control a returning speed in a multi-step while maintaining a door closing force.

Inthis case, the lowerhydraulic circuit canbe a single hydraulic circuit. Otherwise, the lower hydraulic circuit can be designed to have a number of hydraulic circuits connected in a multi-step, according to necessity of a requireddamping force. The following fourth embodiment will be described with respect to a structure that the lower hydraulic circuit is formed of a double hydraulic circuit.

FIG. 9 is a cross-sectional view of a slim automatic return hinge apparatus having a triple hydraulic circuits according to a fourth embodiment of the present invention viewed in the lengthy direction. FIGs. 1OA through 1OC are respectively partially cross-sectional views sequentially illustrating an oil flow when an actuator descends at a time of opening a door in the fourth embodiment of the present invention. FIGs. 1OD through 1OE are respectively partially cross-sectional views sequentially illustrating an oil flow when an actuator ascends at a time of closing a door in the fourth embodiment of the present invention.

In the following description of the fourth embodiment of the present invention, like reference numerals denote like elements with respect to those of the fourth embodiment which are similar to those of the first embodiment of the present invention. The detailed description thereof will be omitted.

First, referring to FIG. 9, an automatic return hinge apparatus having a triple hydraulic circuit according to the fourth embodiment of the present invention, includes a central body 11 whose one circumference is fixedly coupled at the center of a first hinge 10, in the same manner as that of the first embodiment, and first and second guide vessels 21 and 23 whose circumferences are respectively fixedly coupled at the upper/lower sides of a second hinge 20 in which first and second vertical guide grooves and third and fourth vertical guide grooves are formed up and down in positions facing each other in the inner side of the second hinge 20. In this case, it is preferable that a gap between the first and second guide vessels 21 and 23 is formed as a corresponding gap to a height of the central body 11 so that the central body 11 is inserted between the first and second guide vessels 21 and 23 without having any gap. Also, first and second sealing caps 93 and 97 are coupled with the one end of the first and second guide vessels 21 and 23 facing the central body, and first and second end caps 91 and 95 are coupled with the other ends of the first and second guide vessels 21 and 23, respectively, in order to prevent oil filled in the inner sides of the first and second guide vessels 21 and 23 from leaking therefrom. Meanwhile, first and second camshafts 30 and 60 are rotated by a relative external force generated in the first and second guide vessels 21 and 23 when the door is rotated, in which a pair of shafts 31 and 61 in the first and second camshafts 30 and 60 are fixed by spring pins 31a and 61a at a state where the pair of the shafts 31 and 61 are inserted intothe centralbody 11 so as to face eachother, respectively, and first and second cylindrical bodies 33 and 63 which are respectively extensively formed from the pair of the shafts 31 and 61 are respectively rotatably installed in the inner circumferences of the first and second guide vessels 21 and 23.

Here, first and second ascending and descending guide holes and third and fourth ascending and descending guide holes having spirally shapes of a mutuallymovable symmetric structure are penetratively formed along the outer circumferences of the first and second cylindrical bodies 33 and 63, respectively, in the same manner as those of the first embodiment of the present invention.

As shown in FIG. 2A, the first and second ascending anddescending guide holes in the first camshaft 30 are formed shorter than the third and fourth ascending and descending guide holes in the second camshaft 60. One end of each of the first and second ascending and descending guide holes is formed so as to be open up to the end of the cylindrical body 33. Moreover, both ends of each of the third and fourth ascending and descending guide holes in the second camshaft 60 are formed in the cylindrical body 63 so as to be closed.

Meanwhile, both ends of first and second guide pins 41 and 43 are coupledwith first and secondvertical guide grooves and third and fourth vertical guide grooves via the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes, respectively.

Also, the central portions of the first and second guide pins 41 and 43 are penetratively coupled on each one end of first and second piston rods 51 and 81, and the first and second piston rods 51 and 161 ascend and descend along the inner circumferences of the first and second cylindrical bodies 33 and 63 of the first and second camshafts 30 and 60 in a sliding manner along the first and second vertical guide grooves and the third and fourth vertical guide grooves according to rotation of the first and second camshafts 30 and 60 (see the first embodiment) .

As described above, the upper hydraulic circuit 400a employed in the fourth embodiment of the present invention has the same structure as that of the first embodiment thereof. However, the lower hydraulic circuit 400b employed in the fourth embodiment of the present invention has the same structure of guiding the pistons to ascend and descend as that of the first embodiment but the other structures thereof are different from those of the first embodiment thereof. Hereinbelow, a configurational structure differing from that of the first embodiment of the present invention, that is, a structure of forming two independent hydraulic circuits adjusting a piston ascending speed, and thus supplementing an insufficient damping force without increasing diameter of the hinge apparatus according to a trend of large-scale doors will be described.

First, in the hinge apparatus according to the fourth embodiment of the present invention, the upper end of the second piston rod 161 is coupled with the second guide pin 43 so as to move together with rotation of the second camshaft 60, the second and third pistons 162a and 162b are coupled with the center and lower portion of the second piston rod 161 with a predetermined distance, respectively, and an isolator 120 which axially movably supports the piston rod 161 and is fixed to the second guide vessel 23 is disposed between the second and third pistons 162a and 162b.

The second and third pistons 162a and 162b which is coupled with the second piston rod 161 and moves together with the second piston rod 161 are referred to as actuators 160.

The isolator 200 is disposed between the second lower chamber 193a andthe thirdupper chamber 191b so as topartition the second and third upper and lower chambers 191a and 193a; and 191b and 193b by the second and third pistons 162a and

162b.

Further, thepiston rod 161 of the actuator 160 includes a first oil path 168a which is formed at a certain length from the lower end of the central portion of the piston rod so that oil can move to the upper and lower portions of each chamber, a second oil path 168b which makes the first oil path 168aandthe secondupperchambercommunicate eachother, a third oil path 168c which makes the first oil path 168a and the second lower chamber communicate each other, and a fourth oil path 168d which makes the first oil path 168a and the third upper chamber communicate each other, so that oil filled in the third lower chamber 193b can move to the second upper chamber 191b according to descending of the second piston 162b.

In this case, one end of a hydraulic control rod 145 for controlling an oil pressure is inserted into the first oil path 168a and the other end thereof is fixed to a supporter 143 which is supportedto a second sealing cap 95. Anadjustment bolt 141 which is perpendicularly coupled with the center of the second sealing cap 95 is coupled with the inner side of the supporter 143. Accordingly, level of the hydraulic control rod145 is set accordingto a forward/reverse rotation of the adjustment bolt 141. Therefore, an amount of oil passing through the first oil path 168a can be freely set. As a result, an automatic return speedof a door is determined.

In the hydraulic control rod 145 according to the fourth embodiment of the present invention, a pair of high-speed section setters (1-Fast, 2-Fast) 145a and 145c whose oil flow amount is large and a pair of low-speed section setters (1-Slow, 2-Slow) 145b and 145d whose oil flow amount is small are disposed alternately as shown in FIGs. 1OD and 1OE, so as to be appropriate for controlling a double hydraulic circuit.

The pair of the high-speed section setters (1-Fast, 2-Fast) 145a and 145c are set in an identical diameter so that a comparatively much oil can flow, that is, about half the oil can flow in comparison with an amount of an oil flow when check valves E and F (see FIG. 10A) to be described later do not operate (in an off-state) , that is, when a door is opened (that is, when pistons descend) . The pair of the low-speed section setters 145b and 145d are tapered with a diameter increasing from the upper portion to the lower portion so that oil by about 1/2 to 1/80 degrees can variably flow in comparison with an amount of an oil flow when the check valves E and F are both in an off-state, that is, when the pistons 162a and 162b ascend.

In this case, when the pistons 162a and 162b ascend, anamount ofanoil flowfromthe secondandthirdupperchambers 191a and 191b to the second and third lower chambers 193a and 193b is remarkably increased in a section where the pair of the high-speed section setters 145a and 145c correspond to the third and fourth oil paths 168c and 168d in comparison with the case of the pair of the low-speed section setters 145b and 145d, to thereby accomplish a high-speed return of the door.

Also, an amount of an oil flow from the second and third upper chambers 191a and 191b to the second and third lower chambers 193a and 193b is gradually increased according to the ascending positions of the pistons 162a and 162b in a section where the pair of the low-speed section setters 145b and 145d correspond to the third and fourth oil paths 168c and 168d in comparison with the case of the pair of the low-speed section setters 145b and 145d, to thereby compensate for a reduction in a restoring force of the return spring 113.

The high-speed section setters 145a and 145c and the low-speed section setters 145b and 145d variably establish length of each section according to an object to which the automatic return hinge apparatus is applied, to thereby determine an amount of a tapered degree in the low-speed section setters 145b and 145d. For example, since architectural doors such as a fire-fighting steel door should be closed when fire takes place, the high-speed section setters 145a and 145c start from a door opening angle of 30°. In the case of small-sized doors of home appliances or indoor doors, the high-speed section setters 145a and 145c start from a door opening angle of for example 5°. In the case of up-down rotating type doors such as a Kimchi refrigerator for use in a storage device for storing a fermentation food such as Kimchi which is one of Korean traditional foods, the high-speed section setters 145a and 145c are not necessary, due to no-need of setting high-speed sections and only the low-speed section setters 145b and 145d are provided.

Meanwhile, the hinge apparatus according to the fourth embodiment of the present invention includes overpressure prevention valves 130a and 130b where first and second overpressure prevention units 163a and 163b are elastically installed below second and third pistons 162a and 162b by first and second dish-shaped springs 164a and 164b. In this case, it is necessary to formdiameters of the first and second overpressure preventionunits 163a and 163b so as tobe smaller than the inner diameter of the second guide vessel 23, so that an eighth oil path 169d is formed between each of the first and second overpressure prevention units 163a and 163b and the second guide vessel 23. Also, the first and second dish-shaped springs 164a and 164b are supported by first and second snap rings 165a and 165b, respectively. Accordingly, the first and second dish-shaped springs 164a and 164b are prevented from being pushed down along the piston rod 161 due to occurrence of overpressure to thereby make the overpressure prevention valves 130a and 130b smoothly operate.

Hereinbelow, operations of the overpressure prevention valves 130a and 130bwill be described in detail with reference to FIGs. 9 and 1OA.

The overpressure prevention valves 130a and 130b do not operatewhen a user closes a door at a normal speed, but operate only in the case that a door is abruptly closed due to a large external force such as strong wind. That is, in the case that a door is opened or closed at a normal speed, at least one pair of check valves E and F function according to opening and closing balls 170 and 171 buried in the overpressure prevention valves 130a and 130b, to thus close a sixth oil path 169b (see FIG. 10D) . The dish-shaped springs 164a and 164b elastically support the overpressure prevention units 163a and 163b with a predetermined pressure at the lower ends of the pistons 162a and 162b. In the case that overpressure generated in the upper chambers 191a and 191b becomes larger than elastic forces of the dish-shaped springs 164a and 164b, the overpressure prevention units 163a and 163b move downwards by the pressure of oil. If the overpressure prevention units 163a and 163bmove downwards, a seventh oil path 169c is formed between the lower surfaces of the pistons 162a and 162b and the upper surfaces of the overpressure prevention units 163a and 163b, and oil in the upper chambers 191a and 191b flows in from a fifth oil path 169a to the lower chambers 193a and 193b via the seventh and eighth oil paths 169c and 169d, to thus release an overpressure state. As a result, one ofvarious 0-rings disposed in order to seal the periphery of the second guide vessel 23 and the pistons 162a and 162b is damaged or the guide vessel is damaged due to overpressure of the upper chambers 191a and 191b, and therefore prevent oil from leaking in advance.

However, inthe case thatpressure generated inthe upper chambers 191a and 191b is smaller than the elastic forces of the dish-shaped springs 164a and 164b, according to normal closing of a door, the overpressure prevention units 163a and 163b do not move downwards due to the pressure of oil. If the overpressure prevention units 163a and 163b do not move downwards and maintain to elastically contact the lower surfaces of the pistons 162a and 162b, the seventh oil path 169c is not formed between the lower surfaces of the pistons 162a and 162b and the upper surfaces of the overpressure prevention units 163a and 163b.

As a result, the sixth oil path 169b is closed according to functions of the opening and closing balls 170 and 171, whena door is closed, andthus oil filledintheupperchambers 191a and 191b move to the lower chambers 193a and 193b via the first through third oil paths 168a-168c. Also, when a door is opened, oil moves from the lower chambers 193a and 193b to the upper chambers 191a and 191b via the sixth oil path 169b and the check valves E and F.

In this case, the dish-shaped springs 164a and 164b are preferably designed to have an elasticity coefficient to a degree that the overpressure prevention units 163a and 163b can be moved in the case of occurrence of overpressure.

Meanwhile, a support nut 166 is screw-coupled with the end of the piston rod 145. The support nut 166 plays a role of preventing an elastic force of the return spring 113 elastically supporting the actuator 160 from directly influencinguponthe elastic forces ofthe dish-shapedsprings 164a and 164b, to thereby smoothly perform an overpressure prevention function in the chambers.

In the fourth embodiment of the present invention shown in FIG. 9, the check valve 631 is separated from the pistons 162a and 162b in order to employ the overpressure prevention valves 130a and 130b of FIG. 1OA, and is built in the overpressure prevention units 163a and 163b. However, in the case that the overpressure prevention valves 130a and 130b are not employed, the check valve 631 is of a well-known built-in structure other than a fifth oil path 169a formed in the pistons 162a and 162b. In the fourth embodiment, two closed circuit chambers are formed to thus form two independent hydraulic circuits in lengthy direction so that a damping force which lacks ordecreases accordingto large-scalingofadoorandslimming of a hinge apparatus used for a door. Hereinbelow, operationofthehingeapparatus according to the fourth embodiment of the present invention will be described in detail with reference to FIGs. 1OA through 1OE. Atthetimeofopeningadoor, the lowerhydraulic circuit 400b operates and thus the second and third pistons 162a and 162b are positioned at a top dead center of each chamber as shown in FIG. 1OA, in the case that a door opening angle is 0°. In the case that a door opening angle ranges from 0° to 30°, the second and third pistons 162a and 162b descend and thus the first and second check valves E and F are in an off-state as shown in FIG. 1OB. Accordingly, oil filled in the lower chambers 193a and 193b moves abruptly to the second and third upper chambers 191a and 191b via the first and second check valves E and F and the first through fourth oil paths 168a-168d in the piston rod 161.

Also, in the case that a door opening angle ranges from 30° to 90°, oil filled in the second and third lower chambers 193a and 193b moves abruptly to the second and third upper chambers 191a and 191b via the first and second check valves E and F and the first through fourth oil paths 168a-168d in the piston rod 161, as shown in FIG. 1OC.

Here, in the case that a door opening angle ranges from 0° to 30°, since oil moving via the first through fourth oil paths 168a-168d corresponds to the high-speed section setters 145a and 145c, an amount of an oil flow slightly increases in comparison with the case that a door opening angle ranges from 30° to 90° corresponding to the low-speed section setters 145b and 145d, but most of oil moves via the sixth oil path 169b, the first and second check valves E and F, and the fifth oil path 169a, in sequence.

At the time of opening a door, since the upper hydraulic circuit 400a operates in the same manner as that of the first embodiment ofthepresent invention, anincrease inanelastic force of the return spring 111 stops when a door opening angle exceeds a set opening angle, for example, 5°. Thus, an opening force is greatly reduced at the time of opening a door after a set opening angle, to thus easily open a heavy and large-scale door. Meanwhile, at the time of closing a door, in the case that a door opening angle ranges from 90° to 30°, as shown in FIG. 1OD, oil filled in the second and third upper chambers 191a and 191b moves to the second and third lower chambers 193a and 193b at a first speed being a low speed, via the first through fourth oil paths 168a-168d in the piston rod 161, in which the first and second check valves E and F are an on-state.

Inthis case, oilmovingthroughthe first through fourth oil paths 168a-168d is determined in correspondence to the tapered low-speed section setters 145b and 145d, andan amount of an oil flow is gradually increased so that a reduction in a restoring force of the return spring 113 is compensated for.

Thereafter, in the case that a door openingangle ranges from 30° to 0°, as shown in FIG. 1OE, oil filled in the second and third upper chambers 191a and 191b moves to the second and third lower chambers 193a and 193b at a second speed being relatively faster than the first speed, via the first through fourth oil paths 168a-168d in the piston rod 161, in which the first and second check valves E and F are an on-state.

Inthis case, oilmovingthroughthe first through fourth oil paths 168a-168d is determined in correspondence to the high-speed section setters 145a and 145c, and a reduction in a restoring force of the return spring 113 is compensated for and a door closing force is reinforced.

Thereafter, in the case that a door opening angle is below a set opening angle, that is, below 15°, the upper hydraulic circuit 400a resumes to operate as in the first embodiment, and thus an elastic restoring force of the first return spring 111 is additionally applied to the upper hydraulic circuit 400a, to accordinglyenhance a door closing force. In this case, the restoring force of the first return spring 111 in the upper hydraulic circuit 400a is set larger than a damping force formed by the check valve "A" and thus contributes for reinforcement of the door closing force.

Also, when a door opening angle ranges from 15° to 0°, ascending and descending speeds of the pistons 162a and 162b can be accelerated at a third speed according to setting of a large sloped angle of the ascending and descending guide 641. Thus, the door is returned to an original position and is in a locked state by a latch of the door. First, inthe fourthembodiment ofthepresent invention as described above, a door closing speed can be controlled in a multi-step, by combination of shape of a hydraulic control rodandcamdiagrams of the first and secondascending and descending guide holes in the camshafts.

Also, in the hinge apparatus according to the fourth embodiment of the present invention, at least one hydraulic circuit is added in order to supplement an insufficient damping force considering an increasing weight of a door instead of increasing diameter of a body playing a role of a housing. Accordingly, a sufficient damping force can be supplied to control ascending speeds of the pistons 162a and 162b in the case of a heavy and large-scale door.

In the case of the fourth embodiment, it has been described that a double hydraulic circuit is employed as the hydraulic circuit 400b. However, it is possible to determine and then increase and decrease the number of hydraulic circuits according to a damping force to be required for a door. That is, hydraulic circuits can be easily increased anddecreasedinamannerthatpistons andisolators including check valves are added or omitted.

Further, even in the case of the fourth embodiment of the present invention, a cam diagram of the first camshaft 30 is formed so that the upperhydraulic circuit 400a operates only at a door opening initial time and a door return last time to thus contrive a reduction in an opening force and an increase in a restoring force. Accordingly, at the time of opening a door, compression of the first return spring 111 stops in a section other than a set angle, and thus a door opening force is decreased. As a result, a heavy and large-scale door can be easily opened. At the time of returning a door, the first and second return springs 111 and 113 operate simultaneously when a door opening angle corresponds to the set opening angle. Accordingly, a door closing force is reinforced to thus accomplish perfect return of the door. [Mode for Invention]

As described above, the present invention has been describedwithrespecttoparticularIypreferredembodiments. However, the present invention is not limited to the above embodiments, and it is possible for one who has an ordinary skill in the art tomake various modifications andvariations, without departing off the spirit of the present invention.

Thus, the protective scope of the present invention is not definedwithinthe detaileddescriptionthereofbut is defined by the claims to be described later and the technical spirit of the present invention.

[industrial Applicability]

As described above, an automatic return hinge apparatus according to the present invention can be used for a large-scale and heavy door which is supported by a door frame of a hinge type. At a door opening initial time and a door return last time, a pair of return springs operate simultaneously, to maintain a door closing force. In the other opening and closing sections, only one return spring operates, and thus an opening force necessary for opening the door is reduced, to thereby easily open the heavy and large-scale door with small power.

Claims

[CLAIMS]

[Claim 1]

An automatic return hinge apparatus for use in a large-scale and heavy door which is fixed to any one of first and second hinges and is automatically returned at the time of closing the door, the automatic return hinge apparatus comprising: a central body whose one circumference is fixedly coupled at the center of the first hinge; first and second guide vessels whose circumferences are respectively fixedly-coupled at the upper/lower sides of the second hinge in which first and second vertical guide grooves andthird and fourthvertical guide grooves are formed up and down in positions facing each other, and first and second chambers into which oil is filled are formed therein, so as tomaintain a corresponding gap to a height of the central body; first and second camshafts which are rotated by a relative external force generated in the first and second guide vessels when the door is rotated, in which first and secondshafts are fixedlyinsertedintothecentralbodyfacing each other, first and second cylindrical bodies which are extensively formed from the first and second shafts are respectively rotatably installed in the inner circumferences of the first and second guide vessels, first and second ascending and descending guide holes and third and fourth ascending and descending guide holes having spirally shaped cam diagrams of a mutually movable symmetric structure are penetratively formed along the outer circumferences of the first and second cylindrical bodies, respectively; first andsecondguidepinsbothends ofwhichare coupled with the first and second vertical guide grooves and the third and fourth vertical guide grooves via the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes, respectively; first and second piston rods on each one end of which the central portions of the first and second guide pins are penetratively coupled, and ascend and descend along the inner circumferences of the first and second cylindrical bodies of the first and second camshafts in a sliding manner along the first and second vertical guide grooves and the third and fourth vertical guide grooves according to rotation of the first and second camshafts, and on the other ends of which first and second bent throughholes perpendicularly communicating with the outer circumferences thereof are formed, respectively; first and second pistons at the center of each one side of which first and second coupling holes to which the other ends ofthe first andsecondpistonrods are coupledare formed, respectively, in the other sides of which first and second central throughholes communicating with the first and second coupling holes are formed, whose outer circumferences are respectivelyslidablydisposedalongthe innercircumferences of the first and second guide vessels, and which partition the first and second chambers into upper and lower portions, respectively; first and second check valves which are formed in the first and second pistons and increase and decrease an amount of an oil flow which mutually moves in the upper and lower chambers of the first and second chambers according to ascending and descending of the first and second pistons, to thereby control an ascending/descending speed of the first and second pistons; first and second sealing caps which are coupled with the upper/lower ends of the first and second guide vessels in a sealing manner, so that respectively independent hydraulic circuits are formed in the first and second guide vessels; and first and second elasticmembers which are respectively installed in the upper portion of the first chamber and the lowerportionofthe secondchambersoastoelasticallysupport the first and second pistons, and which provide a restoring force which makes the first and second pistons returned into an original position at the time of returning the door, respectively, wherein the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes of the first and second camshafts are disposed in a mutually opposing direction, and cam diagram lengths of one pair of the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes are longer than those of the other pair thereof.

[Claim 2]

The automatic return hinge apparatus for use in a large-scale and heavy door according to claim 1, wherein the first and second ascending and descending guide holes include only a first ascending and descending section of a door opening angle of 0° to 15°, and the third and fourth ascending and descending guide holes include a first ascending and descending section of a door opening angle of 0° to 15°, and a second ascending and descending section of a door opening angle of 15° to 90°, wherein the first ascending and descending section of the first and second ascending and descending guide holes has the same cam diagram length and angle as those of the first ascendinganddescending sectionofthethirdandfourth ascending and descending guide holes.

[Claim 3]

The automatic return hinge apparatus for use in a large-scale and heavy door according to claim 1, wherein the first and second checkvalves employ circular or spherical valve actuators.

[Claim 4]

An automatic return hinge apparatus for use in a large-scale and heavy door which is fixed to any one of first and second hinges and is automatically returned at the time of closing the door, the automatic return hinge apparatus comprising: a central body whose one circumference is fixedly- coupled at the center of the first hinge, whose inner side is divided into first and second chambers by a partition, and at the positions opposing each other inwards from the first and second chambers of which first and second vertical guide grooves andthirdandfourthvertical grooves are formed up and down, respectively; first and second fixed bodies each whose one side is coupled with the side ends of the upper and lower portions of the second hinge, respectively, at a state of maintaining adistancetherebetweenwherethecentralbodycanbeinserted; first and second camshafts which are rotated by a relative external force generated in the first and second fixed bodies when the door is rotated, in which first and second shafts are fixedly inserted into the first and second fixed bodies, respectively, first and second cylindrical bodies which are detachably coupled with the first and second shafts are respectively rotatably installed in the inner circumferences ofthe first andsecondchambers ofthe central body, respectively, firstandsecondascendinganddescending guide holes and third and fourth ascending and descending guide holes having spirally shaped camdiagrams of amutually movable symmetric structure are penetratively formed along the outer circumferences of the first and second cylindrical bodies, respectively; firstandsecondguidepinsbothendsofwhicharecoupled with the first and second vertical guide grooves and the third and fourth vertical guide grooves via the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes, respectively; first and second piston rods each upper end of which is coupledbythe first and second guide pins, andwhich ascend and descend along the inner circumferences of the first and second cylindrical bodies of the first and second camshafts in a sliding manner along the first and second vertical guide grooves and the third and fourth vertical guide grooves according to rotation of the first and second camshafts, and on each one end of which first and second bent throughholes perpendicularly communicating with the outer circumferences thereof are formed, respectively; first and second pistons at the center of each one side of which first and second coupling holes to which the other ends ofthe first andsecondpistonrods are coupledare formed, respectively, in the other sides of which first and second central throughholes communicating with the first and second coupling holes are formed, whose outer circumferences are respectivelyslidablydisposedalongthe innercircumferences of the central body, and which partition the first and second chambers into upper and lower portions, respectively; first and second check valves which are formed in the first and second pistons and increase and decrease an amount of an oil flow which mutually moves in the upper and lower chambers of the first and second chambers according to ascending and descending of the first and second pistons, to thereby control an ascending/descending speed of the first and second pistons; first and second sealing caps which are coupled with the upper/lower ends of the central body in a sealing manner, so that respectively independent hydraulic circuits are formed in the first and second chambers in the central body; and first and second elastic members which are respectively installed in the lower portions of the first chamber and the upperportionofthesecondchamberso astoelasticallysupport the first and second pistons, and which provide a restoring force which makes the first and second pistons returned into an original position at the time of returning the door, respectively, wherein the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes of the first and second camshafts are disposed in a mutually opposing direction, and cam diagram lengths of one pair of the first and second ascending and descending guide holes and the third and fourth ascending anddescending guide holes are longer than those of the other pair thereof.

[Claim 5]

An automatic return hinge apparatus for use in a large-scale and heavy door which is fixed to any one of first and second hinges and is automatically returned at the time of closing the door, the automatic return hinge apparatus comprising: a central body whose one circumference is fixedly coupled at the center of the first hinge, in the inner circumferences of the upper/lower sides of which first and second vertical guide grooves and third and fourth vertical grooves are formedupanddown, atpositions facingeachother, respectively, andwhichhasachamberintheinnersidethereof; first and second fixed bodies each whose one side is coupled with the side ends of the upper and lower portions of the second hinge, respectively, at a state of maintaining adistancetherebetweenwherethecentralbodycanbeinserted; first and second camshafts which are rotated by a relative external force generated in the first and second fixed bodies when the door is rotated, in which first and second shafts are fixedly inserted into the first and second fixed bodies, respectively, first and second cylindrical bodies which are detachably coupled with the first and second shafts are respectively rotatably installed in the inner circumferenceofthechamberofthecentralbody, respectively, first and second ascending and descending guide holes and third and fourth ascending anddescending guide holes having spirally shaped camdiagrams of amutuallymovable symmetric structure are penetratively formed along the outer circumferences of the first and second cylindrical bodies, respectively; firstandsecondguidepinsbothendsofwhicharecoupled with the first and secondvertical guide grooves and the third and fourth vertical guide grooves via the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes, respectively; a first piston rod one end of which is coupled by the central portion of the first guide pin, and which ascends anddescends alongthe innercircumferences ofthe cylindrical body of the first camshaft in a sliding manner along the first and second vertical guide grooves according to rotation of the first camshaft; a first piston which is extensively formed at the other end of the first piston rod and whose outer circumference is slidably disposed with the inner circumference of the central body; a second piston rod one end of which is coupled by the central portion of the second guide pin, which ascends and descends along the inner circumferences of the cylindrical body of the second camshaft in a sliding manner along the third and fourth vertical guide grooves according to rotation of the second camshaft, and on the other end of which a bent throughhole perpendicularly communicating with the outer circumference thereof is formed; a second piston at the center of one side of which a coupling hole coupled with the other end of the second piston rod is formed, in the other side of which a central throughhole communicating with the coupling hole is formed, whose outer circumference is slidably disposed with the inner circumference of the chamber in the central body, and which partitions the chamber into upper and lower chambers; a check valve which is formed in the second piston and increases anddecreases an amount of an oil flowwhichmutually moves in the upper and lower chambers according to ascending and descending of the second piston, to thereby control an ascending/descending speed of the second piston; first and second sealing caps which are coupled with the upper/lower ends of the central body in a sealing manner; and anelasticmemberwhich is installed intheupper chamber so as to elastically support the first and second pistons, and which provide a restoring force which makes the first and second pistons returned into an original position at the time of returning the door, respectively, wherein the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes of the first and second camshafts are disposed in a mutually opposing direction, and cam diagram lengths of one pair of the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes are longer than those of the other pair thereof.

[Claim 6]

An automatic return hinge apparatus for use in a large-scale and heavy door which is fixed to any one of first and second hinges and is automatically returned at the time of closing the door, the automatic return hinge apparatus comprising: first and second shafts; a central body whose one circumference is fixedly coupled at the center of the first hinge, in which the first and second shafts are fixed at a state of being inserted facing each other; first and second guide vessels whose circumferences are respectively fixedly coupled at the upper/lower sides of the second hinge in which first and second chambers into which oil is filled are formed therein, so as to maintain a corresponding gap to a height of the central body; first and second ascending and descending units which are respectively installed in the inner circumferences of the first and second guide vessels, and make the first and second guide pins move up and down by rotational moments generated in the shafts or the first and second guide vessels when the door is rotated; first and second hydraulic circuits including first and second piston rods whose upper and lower portions are connected with the first and second guide pins in the first and second ascending and descending units and ascend and descend according to ascending and descending of the first and second guide pins, and first and second pistons which are coupled with the first and second piston rods and which partition the first and second chambers into upper and lower chambers, respectively, at a state of being inserted into the first and second guide vessels, in which oil flows as much as a first amount of an oil flow, when eachpiston ascends and descends according to opening of the door, and oil flows as much as a second amount of an oil flow less than the first amount of an oil flow, according to closing of the door; first and second sealing caps which are coupled with the upper/lower ends of the first and second guide vessels in a sealing manner, so that respectively independent closed hydraulic circuits are formed in the first and second guide vessels; and first and second elastic members which are installed in the upperportion of the first chamber and the lowerportion of the second chamber so as to elastically support the first and second pistons, and which provide a restoring force which makes the first and second pistons returned into an original position at the time of returning the door, respectively, wherein any one of the first and second ascending and descendingunits operates onlyinthe rangeofapredetermined set door opening angle.

[Claim 7]

The automatic return hinge apparatus for use in a large-scale and heavy door according to claim 6, wherein each of the first and second ascending and descending units comprises: first and second vertical guide grooves and third and fourth vertical guide grooves which are formed up and down at positions facing each other at inner sides of the first and second guide vessels; first and second camshafts which are rotated by a relative external force generated in the first and second guide vessels when the door is rotated, in which first and secondshafts are fixedlyinsertedintothe centralbodyfacing each other, first and second cylindrical bodies which are extensively formed from the first and second shafts are respectively rotatably installed in the inner circumferences of the first and second guide vessels, first and second ascending and descending guide holes and third and fourth ascending and descending guide holes having spirally shaped cam diagrams of a mutually movable symmetric structure are penetratively formed along the outer circumferences of the first and second cylindrical bodies, respectively; first andsecondguidepinsbothends ofwhichare coupled with the first and second vertical guide grooves and the third and fourth vertical guide grooves via the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes, respectively, wherein the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes of the first and second camshafts are disposed in a mutually opposing direction, and cam diagram lengths of one pair of the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes are longer than those of the other pair thereof. [Claim 8]

An automatic return hinge apparatus for use in a large-scale and heavy door which is fixed to any one of first and second hinges and is automatically returned at the time of closing the door, the automatic return hinge apparatus comprising: first and second shafts; a central body whose one circumference is fixedly coupled at the center of the first hinge, in which the first and second shafts are fixed at a state of being inserted facing each other; first and second guide vessels whose circumferences are respectively fixedly coupled at the upper/lower sides of the second hinge in which first and second chambers into which oil is filled are formed therein, so as to maintain a corresponding gap to a height of the central body; first and second ascending and descending units which are respectively installed in the inner circumferences of the first and second guide vessels, and make the first and second guide pins move up and down by rotational moments generated in the shafts or the first and second guide vessels when the door is rotated; a first hydraulic circuit including a first piston rod whose lower portion is connected with the first guide pin in the first ascending and descending unit and ascends and descends according to ascending and descending of the first guide pin, and a first piston which is coupled with the first piston rod and which partitions the first chamber into upper and lower chambers, respectively, at a state of being inserted into the first guide vessel, in which oil flows as much as a first amount of an oil flow from the upper chamber of the first chamber to the lower chamber thereof, when the first piston ascends according to opening of the door, and oil flows as much as a second amount of an oil flow less than the first amount of an oil flow, from the lower chamber of the first chamber to the upper chamber thereof, when the first piston descends according to closing of the door; a second hydraulic circuit including a second piston rod whose upper portion is connected with the second guide pin in the second ascending and descending unit and ascends and descends according to ascending and descending of the second guide pin, at least one piston which is coupled with the second piston rod and which partitions the second chamber into upper and lower chambers, respectively, and at least one isolator which partitions the inner portion of the second guide vessel between the pistons according to the number of pistons increasing in multiplicity, at a state of being inserted into the second guide vessel, in which oil flows as much as a first amount of an oil flow, from the lower chamber of the second chamber when the at least one piston descends according to opening of the door, and oil flows as much as an amount of an oil flow less than the first amount of an oil flow, and varied according to a door opening angle, from the upper chamber of the second chamber to the lower chamberthereofwhenthe at least onepistonascends according to closing of the door; first and second sealing caps which are coupled with the upper/lower ends of the first and second guide vessels in a sealingmanner, so that respectively independent closed hydraulic circuits are formed in the first and second guide vessels; and first and second elastic members which are installed in the upper portion of the first chamber and the lowerportion of the second chamber so as to elastically support the first and second pistons, and which provide a restoring force which makes the first and second pistons returned into an original position at the time of returning the door, respectively, wherein any one of the first and second ascending and descendingunits operates onlyintherangeofapredetermined set door opening angle. [Claim 9] The automatic return hinge apparatus for use in a large-scale and heavy door according to claim 8, wherein the second hydraulic circuit comprises: an actuator including a second piston rod whose upper portion is connected with the second guide pin in the second ascending and descending unit and ascends and descends according to ascending and descending of the second guide pin, and at least one piston which is coupled with the second piston rod and which partitions the second chamber into upper and lower chambers, respectively, wherein the first oil path and the at least second oil path which ascend and descend according to rotation of the door and move between the upper and lower chambers are included in the second piston rod and the at least one piston; at least one isolator whichpartitions the inner portion of the second guide vessel between the pistons according to the number of pistons increasing in multiplicity; at least one check valve which is installed in at least one second oil path of the piston, and which opens the oil path of oil flowing fromthe lower chamber to the upper chamber only at the time of opening the door; and a hydraulic control rod whose one end is supported by the second sealing cap, and whose leading end is inserted into the first oil path in the second piston rod, for controlling an amount of an oil flow which moves to the lower chamber via the first oil path according to level of the actuator so that an ascending and descending speed of the actuator which ascends an descends by the restoring force of the second elastic member at the time of closing the door is controlled at a multi-step. [Claim lθ]

The automatic return hinge apparatus for use in a large-scale and heavy door according to claim 9, wherein ifthe secondhydraulic circuit is adoublehydrauliccircuit, the first oil path in the second piston rod of the actuator comprises a first sub-oil path which is formed at a certain length from the lower end of the central portion of the first oil path so that oil can move to the upper and lower portions of each chamber, a second sub-oil path which makes the first sub-oil path and the upper portion of the second chamber communicate each other, a third sub-oil path which makes the first sub-oil path and the lower portion of the second chamber communicate each other, and a fourth sub-oil path which makes the first sub-oil path and the upper portion of the third chamber communicate each other, the hydraulic control rod comprises a pair of high-speed section setters which are set in an identical diameter each high-speed section setter having a large amount of an oil flow, andapairoflow-speedsectionsetterswhicharedisposed in the lower side of the pair of high-speed section setters, and are tapered so that an amount of an oil flow is varied due to an increase in diameter from the upper portion to the lower portion thereof, each low-speed section setter having a small amount of an oil flow, in comparison with that of the high-speed section setter, and the pair of low-speed section setters compensates for a decrease in a restoring force of the second elastic member since an amount of an oil flow which moves from the upper portions of the secondandthirdchambers to the lowerportions ofthe first andsecondchambers increases graduallyaccording to an ascending position of the piston. [Claim 11]

The automatic return hinge apparatus for use in a large-scale and heavy door according to claim 8, wherein each of the first and second ascending and descending units comprises : first and second vertical guide grooves and third and fourth vertical guide grooves which are formed up and down at positions facing each other at inner sides of the first and second guide vessels; first and second camshafts which are rotated by a relative external force generated in the first and second guide vessels when the door is rotated, in which first and secondshafts are fixedlyinsertedintothe centralbodyfacing each other, first and second cylindrical bodies which are extensively formed from the first and second shafts are respectively rotatably installed in the inner circumferences of the first and second guide vessels, first and second ascending and descending guide holes and third and fourth ascending and descending guide holes having spirally shaped cam diagrams of a mutually movable symmetric structure are penetratively formed along the outer circumferences of the first and second cylindrical bodies, respectively; first andsecondguidepinsbothends ofwhichare coupled with the first and second vertical guide grooves and the third and fourth vertical guide grooves via the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes, respectively, wherein the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes of the first and second camshafts are disposed in a mutually opposing direction, and cam diagram lengths of one pair of the first and second ascending and descending guide holes and the third and fourth ascending and descending guide holes are longer than those of the other pair thereof. [Claim 12]

The automatic return hinge apparatus for use in a large-scale and heavy door according to claim 8, wherein the second hydraulic circuit comprises: an actuator including a second piston rod whose upper portion is connected with the second guide pin in the second ascending and descending unit and ascends and descends according to ascending and descending of the second guide pin, and at least one piston which is coupled with the second piston rod and which partitions the second chamber into upper and lower chambers, respectively, wherein the first oil path and the at least second oil path which ascend and descend according to rotation of the door and move between the upper and lower chambers are included in the second piston rod and the at least one piston; at least one isolatorwhichpartitions the innerportion of the second guide vessel between the pistons according to the number of pistons increasing in multiplicity; at least one check valve which is disposed in the lower portion of each piston, and is installed in a valve supporter having at least one third oil path communicating with the at least one second oil path, and which opens the third oil path of oil flowing from the lower chamber to the upper chamber only at the time of opening the door; at least one overpressure prevention valve which elasticallysupports thevalve supporterdisposedinthe lower portion of each piston and thus does not operate in the case that the door is closed at a normal speed but forms a fourth oilpathbetweentheoutercircumferenceofthevalve supporter and the second guide vessel in the case that the door is closed speedily by a large external force; and a hydraulic control rod whose one end is supported by the second sealing cap, and whose leading end is inserted into the first oil path in the second piston rod, for controlling an amount of an oil flow which moves to the lower chamber via the first oil path according to level of the actuator so that an ascending and descending speed of the actuator which ascends an descends by the restoring force of the second elastic member at the time of closing the door is controlled at a multi-step.