US2868287A - Delay timer - Google Patents

Description

Jan. 13, 1959 RTsfEsTEY DELAY TIMER F116;; July 17, 1956 INVENTORL I ROGER S. ESTEY BY MM Y YJZZM ATTORNEYS United DELAY TIMER Roger S. Estey, Palos Verdes Estates, Califi, assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Application July 17, 1956, Serial No. 598,486

2 Claims. (Cl. 1611) This invention relates to timing devices, and more specifically to mechanical timing devices capable of reliably reproducing relatively short time intervals, of being automatically resettable, and of adjustment of the time interval.

Mechanical timing devices are old and well known, and have long been used in many arts. Such timing devices have generally been spring motor types or gravity or fly-wheel operated, and have been subject to the general disadvantage that the springs thereof must be rewound or the weights reset, at'least periodically in order to be able to continue to operate. Moreover, many such devices had to be very complex in construction to achieve reliable reproducible short interval timing, and had to be manually reset after each operation. A further disadvantage of such prior timers resided in the fact that adjustment of the reproducible time interval was difficult, and in some cases impossible.

The timing device of the present invention overcomes all of these disadvantages of the prior art in a simple, economical timer design wherein the operating energy is derived from spring means which is rewound by the actuating force which starts the timer in operation so that no rewinding or resetting of actuating means Within the timer is necessary. Moreover, the mechanical timing mechanism of the present invention is automatically resettable to be prepared to institute a new timing cycle upon completion of a previous one, and simple, readily available adjustment means are provided whereby the timer may be easily adjusted for reliably reproducible variable short time interval operation.

It is, therefore, an object of the present invention to provide new and improved mechanical timing mechanism capable of the reliable reproduction of short interval time periods for effecting a control function.

A further object of this invention is to provide mechanical timing mechanism wherein all of the energy required to operate the mechanism is placed therein by the initiating impulse, whereby rewinding of springs or resetting of operating weights is unnecessary for continued operation of the device.

A still further object of the present invention is to provide new and improved mechanical timing means which is automatically self-resetting so thatat the end of each cycle it is locked and in readiness to repeat the cycle in responseto activation.

Yet another object of this invention is to provide a mechanical timing device in which the time interval measured by the device may be readily and easily varied by simple adjustment means.

Another object of my invention is to provide switch means operable by an activating impulse a given short time interval after operation of said impulse by virtue of the interposition of mechanical timing means between the impulse imparting means and the switch means, said timing means deriving all of its operating energy from said impulse, whereby automatic resetting and continued cyclic operation is achieved.

i itates Paten ice Other objects and many of the attendant advantages of this invention will be readilyappreciated as thesame becomes better understood by reference to the following detailed description when considered in connection With the accompanying drawing, wherein the single figure represents a schematic showing of a timing device according to the presentinvention, illustrating the operation and the principles thereof.

Attention is now directed to the single figure of the drawing wherein the present invention is shown as applied to the interposition of a time interval between an actuating impulse and a switch actuated thereby. The specific nature of the actuating impulse is not critical, it being necessary for the purposes of this invention only that it be capable of being transformed to rotary motion of the shaft 2. The specific illustrative example shown in the drawing is in the form of a Ledex solenoid 4 which transforms an electrical impulse into angular motion of the shaft 2, which is suitably supported for rotation, as by a bearing 6. A pinion gear 8 is fixedly mounted on the shaft 2 for rotation therewith.

A shaft 1th is rotatably supported in end bearings 12 a short distance from the shaft 2 and may be parallel thereto. A rewind block 14 is freely rotatably mounted on said shaft 10, the block being in the plane of the pinion gear 8 and being in the form of a sector gear of a size and disposition to have the gear teeth 16 thereof engaged by the teeth of pinion gear 8 for angular movement thereby. The rewind block 14, as shown in the drawing, has an elongated extension 18 on the end there-' of opposite to the gear teeth 16, and is provided with spring and stop means, not shown, tending to cause the rewind block to normally assume the position shown in the drawing. The lowermost end of the extension is provided with a shoulder 20 formed by cutting away a portion of the extension 18, as shown. A trip lever 22 is mounted for pivotal motion on the thinned portion of the rewind block, as by the shaft 24 and the trip lever is provided with an upwardly extended and directed portion 26 which is adapted to bear against the shoulder 20 to limit pivotal movement of the trip lever in that direction. Spring means, not shown, are included in the pivotal mounting of trip lever 22 on the block 14 to bias the trip lever to a position in which the portion 26 bears against said shoulder 20. The shaft 24, extended through and beyond the trip lever 22, has a pawl 28 fixedly mounted thereon, as illustrated.

A ratchet 30 is fixedly mounted on the shaft 10 in a position to be contacted by the pawl 28 with teeth arranged in a direction to be given angular motion by the pawl as the pawl is raised by movement of the rewind block 14, which supports the pawl 28. In the orientation shown in the drawing the pinion 8 imparts a clockwise motion to the rewind block 14 which tends to move the pawl 28 in a rising arc in a clockwise direction to move the ratchet 3t) one tooth length to provide angular motion through a distance determined by the circular pitch of the ratchet. A suitable pawl 32 is arranged to prevent retrograde motion of the ratchet 3i).

Adjacent the opposite end of the shaft 10 an end disc 34 is fixedly mounted for rotation with the shaft as it is turned by motion of the pawl 30. The end disc 34 has a pin 36 on the inner face thereof to which is attached one end of a coil spring 38. The other end of the coil spring 38 is attached to a pin 42 on a face of a comparatively large geardll designated as the motor gear. Motor gear 40 is freely rotatably mounted on the shaft 14 as illustrated in the drawing and is adapted to be rotated by energy stored in the spring 38 which serves as a motor spring, and which is rewound by the motion imparted to end disc 34 by motion of the ratchet 30 in response to activating impulses imparted to the mechanism by the Ledex solenoid 4 as described hereinabove.

A shaft 44 is freely rotatably mounted in bearings 46 in a position parallel to the shaft but spaced therefrom a suitable distance such that the teeth of a small driven gear 48 afiixed to one end of the shaft 44 makes contact with the teeth of the motor gear 40 to be driven thereby. The other end of the shaft 44 has a serrated escapement wheel 50 fixedly mounted thereon so that said escapement wheel is turned with the shaft 44 when gear 43 is driven by the motor gear 40. Escapement wheel 59 has a stop pin 52 on a face thereof and a scar lever 54 having a locking notch 56 is pivotally mounted, as shown, in a position to engage said stop pin 52 to inhibit movement of the escapement wheel and of rod 44 to which it is attached. Sear 54 is provided with a protruding flange or lug 58 which is adapted to be engaged by the free end 60 of the trip lever 22, the arrangement being such that when the rewinding block, which carries the trip lever 22 is moved in a clockwise arc, as previously described, the trip lever 22 lifts the sear lever 54 so that the pin 52 is released from the locking notch 56 to release the escapement wheel 50 for motion in a counterclockwise direction.

The speed of rotation of the escapement wheel 56 is controlled by a pallet 62 suitably mounted for free angular movement as by a bearing supported rod 64. In the usual manner, the pallet 62 is provided with spaced pins 66 which alternately engage and disengage the serrations on the escapement wheel 50 to govern the speed of rotation thereof, as the pallet oscillates.

A cam member 66 is mounted on the end face of driven gear 43 and is provided with an actuating portion 68 for moving the actuating arm 72 of a switch member 70, as shown. It should be noted that the position of actuating portion 63 relative to the arm 72 of the switch at the beginning of the cycle denotes the degree of angular rotation of the cam required to actuate the switch, and that this is representative of a known time delay by virtue of the operation of the pallet member 62 to control the rate of rotation of the escapement wheel 50 and thus of the gear 48. The position of the actuating portion 63 of the cam relative to the position of actuating arm 72 of the switch is adjustable and this may be accomplished by various obvious expedients. Thus, for example, the switch 7% and its arm 72 may be mounted on a support which is arranged for pivotal motion about an axis coincident of the cam 66 whereby movement of the support causes variation of the relative positions of the switch and the cam actuating surface. Conversely, the cam position may be made adjustable relative to the gear 48 by providing arcuate slots in the cam and attaching the cam to the end of gear 48 by screws passing through said slots and engaging the gear.

In the above description, and in the drawing, it will be noted that the means for maintaining the rewind block 14 and the motor gear in proper position on the shaft 10 have not been shown or described. In the schematic showing of these elements greater clarity of illustration was achieved by removal of these parts, it being understood, of course, that appropriate fastening and bearing means would be used in actual practice.

A description of a complete cycle of operation of the previously described apparatus will now be given. When an activating electrical impulse is impressed upon the Ledex solenoid 4 an angular impulse of about degrees is imparted to the shaft 2 to rotate the pinion gear 8. This rotation is imparted to the rewind block 14 to swing said block and the trip lever attached thereto in a clockwise direction. This motion is effective to control two different but simultaneously operative mechanical movements. Thus, lifting of the trip lever 22 causes the surface 63 thereof to lift the sear lever 54 until the pin 52 is clear of the locking notch 56 of the sear lever to free the escapement wheel for rotation. With the escapement wheel free for motion the motor gear 40 is impelled by the spring 38 to drive the gear 48, and thus the cam 68, through a complete revolution until the pin 52 of the escapement wheel is again caught by the notch in the sear lever, the speed of revolution being controlled by the pallet 62, and the time during this revolution when the switch '70 will be operated being controlled by the adjusted position of the cam surface 68 at the beginning of the cycle. Simultaneously, with this driving operation a rewinding operation is performed, since the pawl 28, attached to the rewind block 14 is moved in a clockwise arc to rotate the pawl 30 one tooth length to rotate the shaft 10 and the disc 34 to rewind the spring 38, the pawl 32 preventing retrograde motion of the pawl. It should be noted that the motor gear 40 must be of such size and gear tooth arrangement relative to the gear 48 and the pawl 30 that angular rotation of gear 40 through an angle equal to that moved during each cycle by the pawl 30 and the disc 34 will result in a complete revolution of the driven gear 48. Thus, the impulse imparted by the activating impulse (Ledex solenoid 4) is elfective to return to the motor spring 38 all the energy lost therefrom in driving the driven gear 48 and the attached cam 68 through one revolution. The device is automatically cooked or reset by virtue of the fact that the rewind block 14, which is freely rotatably mounted on the shaft 10 is moved back to its normal position (as shown in the drawing) by spring biasing means, not shown, as soon as the solenoid 4 stops applying a force thereto, this movement also shifting gear 3, shaft 2, and the solenoid 4 to their original positions. Such counterclockwise motion of the rewind block causes the pawl 28 to engage the next tooth of the ratchet 30 and the trip lever to again assume its original position with the surface 60 bearing against the shoulder or lug 58 of the sear lever 54, the trip lever 22 having pivotal movement against its biasing spring, in a direction counterclockwise of its pivot point on the block 14 to assist the parts to reassume these positions, to condition the timing mechanism to the beginning of another cycle when the solenoid 4 receives an activating impulse.

From the above it may be seen that the present invention provides a simple, economical timing mechanism which is capable of providing reliably reproducible time intervals, which is self-resettable, and which does not require the addition of energy other than the activating impulse, to condition it for continuous cyclic operation. It should be particularly noticed that the spring means utilized to drive the motor gear and to cause rotation of the cam serves as a reservoir for energy and that it is auto matically rewonnd during each cycle to an extent to completely replace the energy used during the cycle.

The specific illustrative embodiment described and illustrated in the drawing is by way of example only since many modifications of the elements and variations of their arrangement are possible in the light of the above teachings. it is therefore to be understood that the present invention is not intended to be limited to the specific modification herein illustrated and discussed, its scope being rather defined by the scope and language of the appended claims.

What is claimed is:

1. A self resetting timing device comprising a normally stressed spring, mechanism connected to said spring to be driven thereby, said mechanism including a relatively large driving gear supported on a first shaft for free rotation relative to said first shaft, an end disc fixedly mounted on said first shaft, said end disc and said driving gear each having an eccentric pin on the side thereof facing the other, said spring having opposite ends attached to. said pins operable to cause rotational motion of said driving gear relative to said fixed end disc, an escapement wheel and a driven gear in position to be driven by said driving gear both fixedly mounted on a rotatably supported second shaft for coaxial rotation with each other, pallet means associated with said escapement wheel to control the speed of rotation thereof, latch means releasably operative to normally prevent motion of said mechanism comprising a pin on a surface of said escapement wheel and a notched sear lever pivotally mounted adjacent said escapement wheel in a position to engage said pin, means to apply an actuating force to said latch means to release said mechanism for motion including a member mounted in a position to be moved by said force to raise said sear lever out of latching contact with said pin to permit said mechanism to be operated by said spring and to then release said sear lever for gravity movement into position to catch said pin to relatch said mechanism after one IO tation of said escapement wheel is completed whereby a measurable time increment results from a given cycle of operation of said mechanism, and means interposed between said spring and said force imparting means to utilize said force to stress the spring an amount to replace the energy used thereby in said cycle of operation, said means interposed between said spring and said force imparting means to stress the spring comprising a ratchet fixedly mounted on said first shaft, a rewinding block element having a pawl member attached thereto in a position to drivingly engage said ratchet, a second pawl in contact with said ratchet to prevent retrograde motion thereof, said rewinding block element being acted on directly by said force imparting means to be caused to be moved, whereby said first mentioned pawl member is moved therewith to impart motion to said ratchet and to said end disc to rewind said spring, said rewinding block also having a trip lever means attached thereto for motion therewith, said trip lever means being normally engaged with said latch means whereby said motion causes said latch means to release said mechanism for motion.

2. A self resetting timing device comprising a normally stressed spring, mechanism connected to said spring to be driven thereby, said mechanism including a relatively large driving gear supported on a first shaft for free rotation relative to said first shaft, an end disc fixedly mounted on said first shaft, said end disc and said driving gear each having an eccentric pin on the side thereof facing the other, said spring having opposite ends attached to said pins operable to cause rotational motion of said driving gear relative to said fixed end disc, an escapement wheel and a driven gear in position to be driven by said driving gear both fixedly mounted on a rotatably supported second shaft for coaxial rotation with each other, pallet means associated with said escapement wheel to control the speed of rotation thereof, latch means releasably operative to normally prevent motion of said mechanism comprising a pin on a surface of said escapement wheel and a notched sear lever pivotally mounted adjacent said escapement wheel in a position to engage said pin, means to apply an actuating force to said latch means to release said mechanism for motion including a member mounted in a position to be moved by said force to raise said sear lever out of latching contact with said pin to permit said mechanism to be operated by said spring and to then release said sear lever for gravity movement into position to catch said pin to relatch said mechanism after one rotation of said escapement wheel is completed whereby a measurable time increment results from a given cycle of operation of said mechanism, and means interposed between said spring and said force imparting means to utilize said force to stress the spring an amount to replace the energy used thereby in said cycle of operation, said means interposed between said spring and said force imparting means to stress the spring comprising a ratchet fixedly mounted on said first shaft, a rewinding block element having a pawl member attached thereto in a position to drivingly engage said ratchet, a second pawl in contact with said ratchet to prevent retrograde motion thereof, said rewinding block element being acted on directly by said force imparting means to be caused to be moved, whereby said first mentioned pawl member is moved therewith to impart motion to said ratchet and to said end disc to rewind said spring, said rewinding block also having a trip lever means attached thereto for motion therewith, said trip lever means being normally engaged with said latch means whereby said motion causes said latch means to release said mechanism for motion, said rewinding block also being freely rotationally mounted on said first shaft, being adapted, after termination of the application of force by said force imparting means, to return to its original position whereby said first mentioned pawl is conditioned to drive said ratchet and said trip lever is conditioned to again release said latch means upon a further actuation of said force imparting means.

References Cited in the file of this patent UNITED STATES PATENTS 1,071,046 Hall Aug. 26, 1913 1,133,028 Hill Mar. 23, 1915 1,821,629 Gains Sept. 1, 1931 2,096,620 Robertson Oct. 19, 1937 2,258,474 Simmons Oct. 7, 1941 2,776,009 Tamburr Jan. 1, 1957

Images