WO1997025905A1

WO1997025905A1 - Reclining office chair

Info

Publication number: WO1997025905A1
Application number: PCT/KR1996/000025
Authority: WO
Inventors: Chul Hwang
Original assignee: Chul Hwang
Priority date: 1995-02-20
Filing date: 1996-02-21
Publication date: 1997-07-24
Also published as: KR960028190U; KR200153954Y1

Abstract

A reclining office chair is disclosed. The chair has a motor-driven caterpillar assembly instead of conventional casters. The chair thus reduces the frictional force while the chair is pushed or pulled on the floor. A retractable support frame selectively protrudes out of the back of the seat portion to support the chair when the back support portion is fully reclined back. With the above support frame, the chair can be prevented from being suddenly turned over even though the chair's center of gravity is in the reclined back support portion. The chair thus allows the user to almost horizontally lean back in the chair. The chair also has an adjustable cushion in the back support portion. The above chair thus supports comfortably the user's back regardless of user's postures.

Description

RECLINING OFFICE CHAIR

Technical Field

The present invention relates in general to a reclining office chair and, more particularly, to a structural improvement in such a chair for pushing or pulling the chair on the floor more smoothly without causing any damage to the flooring material due to frictional force generated between the moving portion of the chair and the surface of flooring material and for freely reclining the back support portion of the chair sufficiently to provide comfortable seating and resting posture for a user, and furthermore allowing the user to almost horizontally lean back in the chair.

Background Art The moving portion of a conventional reclining office chair includes a plurality of, for example, four or five, legs. The legs extend from a swivel shaft and have their casters. The casters are mounted to the ends of the legs respectively such that each caster is free to swivel about an axis at angles of 360° to the axis of the caster. When a user sitting in the chair pushes or pulls the chair in a desired direction on the floor for moving up to or away from a desk, each caster swivels abruptly about an axis at angles of 180" to the axis of the caster and rolls on the floor. A seat portion is mounted to the top of the swivel shaft such that the height of the seat portion from the floor can be adjusted. The reclining back support portion of the chair is connected to the rear side of the seat.

However, the above chair has been noted to cause the following problems.

1. As the casters abruptly swivel and roll on the floor and cause large frictional force between them and the floor when the user moves up to or away from a desk, the casters not only cause damage to the flooring material, such as floorboard or floorcloth, they also make it difficult to exactly locate the chair on a desired position.

That is, when the user repeatedly moves up to or away from the desk, the gross weight of the chair (user's weight + chair's weight) is directly applied to the floor surface. In addition, each caster abruptly swivels about an axis at angles of 180° to the axis of the caster, thereby causing the large frictional force between the casters and the floor surface. Therefore, the casters of the chair will cause damage to various expensive flooring materials, such as a floorboard, a textile carpet, a wood flooring and a floorcloth, which cover the floor for the various purposes of sound absorption, walking shock absorption, thermal insulation and interior decoration.

2. As the back support portion of the above chair has a limited reclining angle, the chair can not let the user rest comfortably with good posture.

That is, conventional office chairs are neither fixed to the floor nor mounted to chair guide rails. Different from the seats in airplanes or automobiles, office chairs need to be repeatedly pulled or pushed in the desired direction. As conventional office chairs are not fixed to the floor as described above, the back support portions of the chairs can not help being limited in their reclining angles relative to the seat portions to an extent that the chairs will not turn over when the user reclines all the way back. This limited reclined position of the back support portion is not suff cient for the user to rest comfortably, to say nothing of sleeping comfortably. Furthermore, the conventional reclining office chair with a limited reclining angle may turn over when the user fully reclines the back support portion. Therefore, the conventional reclining office chair may wound the user, so the reclining office chair has a safety problem.

In order to let the users rest comfortably with good postures, some offices may be provided with a separate resting area equipped with comfortable chairs whose back support portions can be reclined back almost fully. However, the above resting area equipped with the comfortable chairs can not help causing a waste of office space and increasing the cost of office management.

3. As the back support portion of the above chair has a fixed configuration, the back support portion does not meet with various sitting postures of the user but causes various diseases due to bad sitting postures for a long period by the user.

That is, the users of the office chairs have different physiques and do office work with various sitting postures. Otherwise stated, a user sitting in the chair may stoop over a desk to write a document or stretch oneself to see a computer monitor. The back of the user in either of the above postures is separated from the back support portion of the chair, thus to be supported by no part of the back support portion. Therefore, the back support portion having the fixed configuration can not support the back of the user in the above postures, thus to not only prevent the user from doing office work efficiently but also to cause various physical diseases, such as spinal curvature and internal maladies. Furthermore, the user using the above chair may be mentally stressed due to the mental and physical problems caused by the chair and suffer from mental trouble.

Disclosure of the Invention

It is, therefore, an object of the present invention to provide a reclining office chair in which the above problems can be overcome and which minimizes frictional force generated between the chair and the floor when a user moves up to or away from a desk, allows the user to almost horizontally lean back in the chair and always supports the back of user regardless of sitting postures of the user, thereby letting the user either do office work or rest comfortably and safely.

In order to accomplish the above object, a reclining office chair in accordance with a preferred embodiment of the present invention comprises: a caterpillar assembly adapted for moving the chair on a floor while reducing the frictional force generated between the caterpillar assembly and the floor; a swivel shaft adapted for rotatably coupling a seat portion to the caterpillar assembly and adjusting the seat portion's height from the floor; the seat portion having a housing in its bottom; a reclining back support portion connected to the rear side of the seat portion; an adjustable cushion provided in the back support portion, the adjustable cushion selectively advancing forward from the back support portion to support the back of a user when the user sits in the chair such that the back of the user is spaced apart from the back support portion; means for driving the adjustable cushion; a retractable foot holder received in the housing of the seat portion and selectively protruding out of the front of the housing; and a retractable support frame adapted for supporting the chair and preventing the chair from being suddenly turned over when the back support portion is reclined back to make the chair's center of gravity move to the reclined back support portion, the support frame being provided in the housing and selectively protruding out of the back of the housing.

Brief Description of the Drawings

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a side view showing the construction of a reclining office chair in accordance with a preferred embodiment of the present invention;

Fig. 2 is a side view showing the operation of the chair of Fig. 1;

Fig. 3 is a sectional view of the chair taken along the section line A-A of Fig. 1; and Fig. 4 is a front view showing the construction of the back support portion of the chair of Fig. 1.

Best Mode for Carrying Out the Invention Fig. 1 is a side view of a reclining office chair according to a preferred embodiment of the invention. Fig. 2 is a side view showing the operation of the above chair for reclining back the back support portion of the chair and supporting the chair with the reclined back support portion to prevent the chair from being suddenly turned over due to the reclined back support portion. Fig. 3 is a sectional view of the above chair taken along the section line A-A of Fig. 1, and Fig. 4 is a front view showing the construction of the back support portion of the above chair. As shown in the drawings, the chair of this invention includes a motor-driven caterpillar assembly 10 instead of the conventional moving portion with casters. The caterpillar assembly 10, which is adapted for moving the chair on the floor, minimizes the frictional force generated between the chair and the floor. A shaft holder 10a vertically stands on the top of the caterpillar assembly 10 and vertically receives a seat height adjusting shaft 21. In order to fix the position of the shaft 21 in the holder 10a after adjusting the position of the shaft 21 relative to the holder 10a, a fixing bolt 10b is radially inserted in the holder 10a. A seat portion 20, which is provided with a bottom housing 22 described later herein, is connected to the top of the shaft 21 such that the seat portion 20 including the housing 22 swivels about the shaft 21. The swivelling structure of the seat portion 20 comprises a boss 21a which is provided to the outer bottom surface of the housing 22 and rotatably receives the top portion of the shaft 21. A reclining back support portion 30 is connected to the rear side of the seat portion 20. This back support portion 30 can be reclined sufficiently to provide comfortable seating and resting posture for a user as will be described later herein. The caterpillar assembly 10 includes a pair of caterpillars, each of which has a plurality of wheels 12 and an endless belt 11 wrapped about the wheels 12. One of the wheels 12 of each caterpillar is connected to a caterpillar drive motor 13. The motor 13 is a reversible motor which is operated by a drive switch or a three way switch 13a preferably mounted on a side surface of the housing 22. The drive motor 13 is applied with electric power from an outside power source which will be hereinafter explained. The drive switch 13 is always kept in the neutral position and maintains the drive motor 13 in the stop position when the chair is not loaded.

The seat portion 20 includes a seat cushion 26 which is laid on the housing 22. The housing 22, which is rotatably coupled to the top of the shaft 21 through the boss 21a as described above, is hollowed to define a space 22a for receiving both a retractable foot holder 23 and a retractable support frame 40.

The retractable foot holder 23 is received in the housing 22 and supported by rollers such that the holder 23 can selectively protrude out of the front of the housing 22. The above holder 23 is handled by a pair of holder handle knobs 23a to either protrude out of or retract into the housing 22. The holder handle knobs 23a are provided at both sides of the holder 23 and project out of both side walls of the housing 22 as best seen in Fig. 3. When the above holder 23 fully protrudes out of the housing 22, a user puts one's legs on the holder 23 and rests comfortably with good posture.

The retractable support frame 40 is a folding frame which is received in the housing 22 such that the frame 40 can selectively protrude out of the back of the housing 22. The above frame 40 is used for supporting the chair to prevent the chair from being suddenly turned over when the back support portion 30 is fully reclined back to make the chair's center of gravity move from the seat portion 20 to the reclined back support portion 30. The frame 40 includes a horizontal frame part 24 and a vertical frame part 25 which are coupled to each other. The frame 40 is also handled by a pair of frame handle knobs 24a when the frame 40 either protrudes out of or retracts into the housing 22. The frame handle knobs 24a are provided at both sides of the horizontal part 24 and project out of both side walls of the housing 22 as best seen in Fig. 3. The vertical part 25 is hinged to the rear side of the horizontal part 24 by means of a longitudinal pin 25a such that the part 25 can be either folded or unfolded relative to the horizontal part 24. In the above frame 40, the vertical part 25 has a length sufficient enough to reach the floor when the part 25 is fully opened and perpendicular to the horizontal part 24 as shown in Fig. 2.

Meanwhile, the housing 22 also has electric power charging means 15 which is charged with electric power supplied from an outside power source and supplies electric power for the drive motor 13.

The back support portion 30 includes a back support frame 31 which is pivoted to the rear side of the housing 22. The above portion 30 also includes a back support cushion 31a mounted on the front surface of the frame 31. This cushion 31a is used for supporting the back of a user and providing comfortable seating and resting posture for the user. In order to adjust the reclining angle of the back support frame 31 relative to the housing 22, a handle knob 39 is provided in the junction between the frame 31 and the housing 22. The above back support frame 31 can be reclined back such that the frame 31 is almost level with the housing 22 when the frame 31 is fully reclined. As shown in Figs. 1, 2 and 4, the middle portion of the back support cushion 31a is an adjustable cushion 37 which is separated from the other part of the back support cushion 31a. This adjustable cushion 37 is selectively operated by drive means provided in the back support frame 31 to move relative to the other part of the support cushion 31a. That is, the adjustable cushion 37 can either advance forward as shown in the phantom line of Fig. 1 or retract to its original position in the back support cushion 31a as shown in the solid line of Fig. 1. The adjustable cushion drive means comprises a pair of longitudinal guide shafts 32 which are longitudinally arranged in both sides of the back support frame 31 respectively as shown in Fig. 4. A pair of movable sleeves 33 are fitted over each shaft 32 and biased by their associated compression coil springs 34. The coil springs 34 are held by both ends of each shaft 32 and bias their associated sleeves 33 toward the center of each shaft 32. Pivoted to each sleeve 33 is a link 36 which in turn is pivoted to an associated end of a support shaft 38 of the adjustable cushion 37 as shown in Figs. 1 and 2. The support shaft 38 longitudinally extends on the back of the cushion 37,

Due the coil springs 34, the sleeves 33 are normally biased to the center of each shaft 32 and makes the adjustable cushion 37 be in its advanced position when the cushion 37 is applied with no load. In order to control the advancing distance of the adjustable cushion 37, a solenoid-operated fixing member 35 is provided in each sleeve 33. The fixing members 35 provided for the sleeves 33 selectively fix the sleeves 33 to the shafts 32 when the members 35 are turned off. A solenoid switch 35a for operating the members 35 is provided on, for example, a side wall of the housing 22 as shown in Figs. 1 and 2.

The operational effect of the above chair will be described hereinbelow.

When the three way switch 13a is handled to select "forward", the motor 13 is applied with electric power from the power charging means 15 of the seat portion 20 and rotated in the forward direction. The forward rotating force of the motor 13 is transmitted to the roller 12 of the caterpillar assembly 10 and makes the assembly 10 move forward to the desired position. When the chair with the assembly 10 reaches the desired position, the switch 13a is handled to select "neutral", the motor 13 is supplied with no power and thereby stops. Of course, when the switch 13a is handled to select "reverse", the motor 13 will be rotated in the reverse direction and the assembly 10 will move in the reverse direction. The above switching motion for operating the caterpillar assembly 10 is similar to that used for operating an automobile power window. When the back support portion 30 needs to be reclined back, a user handles the knob 39 in the conventional manner. When the user wants to almost horizontally lean back in the chair, the back support portion 30 will be fully reclined back. However, the chair in this case may be suddenly turned over as the chair's center of gravity has moved from the seat portion 20 to the reclined back support portion 30. In order to support the chair in the above case, the user handles the knob 24a to make the retractable support frame 40 protrude out of the housing 22. When the frame 40 completely protrudes out of the housing, the vertical frame part 25 is turned down about the pin 25a to be perpendicular to the horizontal frame part 24. Due to the frame 40, the chair with the fully reclined back support portion 30 can be prevented from being suddenly turned over. When the user wants to put one's legs on the foot holder 23 and rest comfortably, the user handles the knob 23a to make the holder 23 protrude out of the front of the housing 22. When the back support portion 30 is fully reclined back and, at the same time, the foot holder 23 protrudes out of the housing, the user can rest comfortably while almost horizontally leaning back in the chair and putting one's legs on the holder 23. The users of the office chairs have different physiques and do office work with various sitting postures. Otherwise stated, the user may stoop over a desk to write a document or stretch oneself to see a computer monitor. The back of a user in either of the above postures is separated from the back support cushion 31a. In this case, the chair may not only prevent the user from doing office work efficiently but also cause various physical diseases. However, the chair of this invention can support the back of the user in either of the above postures and thereby overcoming the above problems. That is, when the solenoid switch 35a is turned on to activate the solenoid-operated fixing members 35 of the adjustable cushion drive means, the members 35 release their associated sleeves 33 from the shafts 32. Thus, the spring-biased sleeves 33 elastically move to the center of each shaft 32 and thereby close the links 36. Hence, the adjustable cushion 37 advances forward from the position shown in the solid line of Fig. 1 to the position shown in the phantom line. As the cushion 37 is freely movable forward and backward relative to the back support portion 30 while turning on the switch 35a, the user can freely adjust the position of the cushion 37 by moving one's upper body forward and backward. When the cushion 37 is located in an appropriate position comfortably supporting one's back, the switch 35a is turned off to let the fixing members 35 fix their associated sleeves 33 to the shafts 32 and thereby fixing the cushion 37 at that adjusted position.

Industrial Applicability

As described above, the reclining office chair of this invention includes a motor-driven caterpillar assembly instead of the conventional moving portion with casters. With the above caterpillar assembly, the chair reduces the frictional force generated between the chair and the flooring material while the chair is pushed or pulled on the floor. Additionally, the above chair has a retractable support frame which selectively protrudes out of the back of the seat portion to support the chair when the back support portion is fully reclined back. With the above support frame, the chair can be prevented from being suddenly turned over even though the chair's center of gravity is in the reclined back support portion. Therefore, a user almost horizontally leans back in the chair. As the above chair also includes a retractable foot holder which selectively protrudes of the front of the seat portion, the user can put one's legs on the holder and rest comfortably. The chair further includes an adjustable cushion in the back support portion. The adjustable cushion selectively advances forward from the back support portion to support the user's back when the user's back is separated from the back support portion while the user stoops over a desk to write a document or stretches oneself to see a computer monitor. Therefore, the above chair always supports comfortably the user's back regardless of user's postures. Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. A reclining office chair comprising: a caterpillar assembly adapted for moving the chair on a floor while reducing the frictional force generated between the caterpillar assembly and the floor; a swivel shaft adapted for rotatably coupling a seat portion to said caterpillar assembly and adjusting the seat portion's height from the floor; the seat portion having a housing in its bottom; a reclining back support portion connected to the rear side of said seat portion; an adjustable cushion provided in said back support portion, said adjustable cushion selectively advancing forward from the back support portion to support the back of a user when the user sits in the chair such that the back of the user is spaced apart from the back support portion; means for driving the adjustable cushion; a retractable foot holder received in said housing of the seat portion and selectively protruding out of the front of the housing; and a retractable support frame adapted for supporting the chair and preventing the chair from being suddenly turned over when the back support portion is reclined back to make the chair's center of gravity move to the reclined back support portion, said support frame being provided in said housing and selectively protruding out of the back of the housing.

2. The reclining office chair according to claim 1, wherein said cushion driving means comprises: a pair of guide shafts longitudinally arranged in both sides of the back support portion respectively; a pair of spring-biased sleeves movably fitted over each guide shaft, each sleeve being biased toward the center of each guide shaft; a plurality of links for moving said cushion relative to the back support portion in accordance with a sliding motion of said sleeves along the guide shafts, both ends of each link being pivoted to an associated sleeve and to said adjustable cushion respectively; and a solenoid-operated fixing member provided for each sleeve to selectively fix each sleeve to an associated shaft and to control the advancing distance of said adjustable cushion.

3. The reclining office chair according to claim 1, wherein said retractable support frame comprises: a horizontal frame part movably supported in said housing by roller means such that the part selectively protrudes out of the back of the housing; and a vertical frame part pivoted to the rear side of said horizontal frame part, said vertical frame part having a length sufficient enough to reach the floor when it is opened to be perpendicular to the horizontal frame part.

4. The reclining office chair according to claim 1, wherein said caterpillar assembly is driven by a motor.