US2694287A - Escapement - Google Patents

Description

Nov. 16, 1954 a. MOGAY srn. 2,694,287

ESCAPEMEN T Filed Aug. 27, 1951 fi' l GILBERT B. CLIFT CHARLES R. RIDLEY :37- 5 BY /ZM%9Q@" m, ATT RNEYS United States Patent ESCAPEMENT John B. McGay, Gilbert B. Clift, and Charles R. Ridley, Tulsa, Okla, assignors to Precision Products, Inc., a corporation of Oklahoma Application August 27, 1951, Serial No. 243,866 17 Claims. (Cl. 5848) This invention relates to timing mechanism and has for its general object and purpose to provide a simple and compact assembly of mechanical elements for accurately controlling the transmission of power from a power source to a power take-ofi shaft, to drive said shaft at a constant angular speed throughout a predetermined time period.

Another object of the invention is to provide means for supplyin constant driving torque to an escapement mechanism without substantial diminution of the available power for driving the power take-off shaft.

It is a further object of the invention to provide a novel escapement mechanism for controlling rotation of a power driven shaft wherein constant power is periodically applied to operation of the escapement through means independent of the shaft. Further pursuant to this object, this means for applying constant drive torque is prerifodically energized from the power for driving said s a t.

in many industrial operations the timed rotation of a cam or cams or other controls is required for the sequential actuation of machine elements. When the rotation of the cam shaft is timed by an escapement mechanism the power consumed in the operation of the machine elements causes a variation of timing due to the variable power which remains available for the operation of the escapement. This is especially true in the use of escapement timed rotation powered by a spring motor, D. C. electric power, air or other motive power than a synchronous electric motor, which operates satisfactorily where timed A. C. power is available.

The best time keeping quality of an escapement mechanism is attained when an absolutely constant driving torque is applied thereto throughout a predetermined running time. A slight increase in torque tends to speed up the escapement while a decrease slows it down. This is not of great importance in a spring motor which is wound daily but in the use of an 8 or 30 day spring motor serious difticulties result, without expensive refinements. In the latter case the escapement tends to run fast for the first few days of the running period and relatively slow during the last few days of the period. The present invention eliminates this difficulty and insures a constantly maintained maximum supply of power available for the accurate timed operation of record charts, cams or other machine control elements.

it is a further object of the invention, in one of its embodiments, to provide dual escapement mechanisms contained in a casing of minimum dimensions and geared to a common power driven shaft with one of said mechanisms mounted for bodily oscillating motion relative to the other and carrying means controlling the eifective operation of the latter escapement, together with means biasing the oscillatory escapement in one direction and providing secondary, essentially constant, power or torque for drivingsaid escapement.

With the above and other objects in view the invention comprises the improved timing mechanism and the construction and relative arrangement of its several parts as will hereinafter be more fully described, illustrated in the accompanying drawing and subsequently incorporated in the subjoined claims.

in the drawing wherein we have disclosed one simple and ractical embodiment of our invention and in which similar reference characters designate corresponding parts:

Figure l is aside elevation showing our timing mechanismas applied to one type of record chart driving mechanism,

Figure 2 is an enlarged side elevation, the casing cover for the timing mechanism being removed,

Figure 3 is a detail horizontal section taken substantially on the line 3-3 of Figure 2, and

Figure 4 is a similar sectional view taken substantially on the line 44 of Figure 2.

Referring in further detail to the drawing for convenient illustration and by way of example, we have shown one embodiment of our invention as applied to a record chart driving mechanism of the type disclosed in the pending application of George E. Nicholson and John B. McGay, Serial No. 89,037, filed April 22, 1949, now Patent 2,661,815, issued December 8, 1953. For the purpose of this explanation, in the general assembly of Figure l we have shown the housing H for a spring motor M or other source of power supply drivingly con nected with the chart driving shaft S. Within the housing H, shaft S is interconnected by a gear train T with a shaft s journalled at one end in the rear wall of the housing H. Our improved timing unit, generally indicated at It), is removably mounted between spaced pins or studs P projecting from the rear side of housing H.

The timing mechanism which controls the angular rotation speed of the shaft S is contained in a casing 12 of relatively small dimensions. As shown in Figure 3, a bushing 14 is centrally fixed in the side wall of this casing which is opposed to the housing H and in this bushing one end of a shaft 16 is journalled.

A primary escapement assembly 18 is mounted in fixed position upon the casing 12, the active parts of said escapement assembly being mounted between spaced parallel plates 20 which are rigidly connected by spaced pins 22 riveted or otherwise fixed at their opposite ends to the respective plates. In one of these plates the other end of the shaft 16 is journalled at 23, while the other plate is fixed to the bushing 14 so that plates 20 are anchored to casing 12. The opposing ends of the shaft s and shaft 16 are provided with square bores to receive a suitable coupling and drive pin 24 (Figure 3) so that shaft 16 is always subject to torque from the spring motor.

The escapement assembly 18 includes a ratcheted escapement wheel 26 mounted with a gear 27 on an arbor 2S journalled in plates 20. Gear 27 is constantly meshed with a gear 29 mounted on an arbor 30 journalled in plates 20, and a smaller gear 31 on arbor. 30 is in constant mesh with a relatively large diameter gear 32 fixed on the shaft 16.

A second escapement assembly 34 comprises mechanism mounted between plates 36 rigidly connected in spaced parallel relation by the pins 38, and plates 36 are journalled on the shaft 16 for free oscillatory motion about the axis of shaft 16. This escapement 34 may be of standard type and includes balance wheel 40 connected by a pallet lever 41 to a ratcheted escapement wheel 42 mounted on an arbor 43 journalled in plates 36. A gear 44 on arbor 43 is meshed with a gear 45 on arbor 46 and a gear 47 on arbor 46 is meshed with gear 48 on arbor 49. Gear 51 on arbor 49 meshes with gear 52 on arbor 53, and finally gear 54 on arbor 53 meshes with gear 32 fixed on shaft 16.- All arbors are parallel and journalled between plates 36.

A detent 55 is fixedly mounted between the plates 36 for periodic engagement with the teeth of wheel 26 of the primary escapement as will appear. A coiled spring 56 is attached and thereby anchored at one of its ends to one of the plate connecting pins 22 of the primary escapement, and is attached at its other end to one of the plate connecting pins 38 of the oscillatable escapement 34. Spring 56 thus normally biases the entire escapement assembly 34 in the counter-clockwise direction in Figure 2.

In operation rotation of the shaft 16 is controlled by the combined action of the escapements 18 and 34.

Assuming as a starting condition that the parts are in the position of Figure 2 wherein the entire assembly 34 has been rocked clockwise until detent 55 is engaged with wheel 26. This stops the travel of assembly 34 in that direction and locks wheel 26 against rotation. The meshed gear train 27, 29, 31, 32 thereby holds shaft 16 against rotation.

However, spring 56 which has been expanded in length or tensioned during the slight clockwise rocking of assemassembly 34 so that the entire assembly 34 bly 34 is now effective to rock the assembly 34 in the counterclockwise direction. This counterclockwise rocking of assembly 34, which takes place solely under the constant power of spring 56, removes detent 55 from engagement with ratchet wheel 26, so that the escapement 18 becomes ineffective to restrain rotation of shaft 16, and timing of this counterclockwise movement is effected by the escapement assembly 34 through gears 32, 54, 52, 51, 48, 47, 45 and 44 and the wheel and lever pallet elements at 41, 42.

As the assembly 34 turns counterclockwise about the axis of shaft 16 under the pull of spring 56, gear 54 rolls along the periphery of locked gear 32, and rotation of gear 54 about the axis of arbor 53 is controlled by the above gear train and pallet lever and wheel elements at 41, 42.

Thus during the counterclockwise rotation of assembly 34, rotation of shaft 16 is checked and timed movement of escapement 34 is powered solely by spring 56 which exerts a constant torque for effecting that counterclockwise rotation. In the illustrated embodiment, this controlled rocking of assembly 34 counterclockwise is such that detent 55 is disengaged from wheel 26 every few seconds.

Counterclockwise rotation of assembly 34 stops after detent 55 has moved out of engagement with ratchet wheed 26, because now torque exerted by shaft 16, which is not now restrained by escapement 18, tends to rotate gear 54. However, rotation of gear 54 is restrained by the associated gear train and escapement in is rocked quickly clockwise about the axis of shaft 16. This tensions spring 56, which thereby stores energy derived from shaft 16, and continues until detent 55 is engaged with the teeth of wheel 26 to stop rotation of wheel 26 and again lock the shaft 16 against rotation. Then the spring 56 takes over as above described to exert a constant torque on the assembly 34 and thus provide constant power for the escapement control of shaft 16 during this phase of operation.

The torque or power on shaft 16 is not critical but it must exceed that required to power the escapement and in this embodiment that required to tension spring 56. In the invention we meter essentially constant torque to the escapement 34, deriving the torque from shaft 16 which may be of variable torque. If shaft 16 is to serve as a power take-off shaft, as it may in some forms of the inventionQthe power supplied to shaft 16 must of course fill such requirements also.

The rocking movement of escapement assembly 34 about shaft 16 takes place over only a few degrees of arc corresponding to the travel of the detent with respect to the teeth of wheel 26 and requires a negligible amount of power, and spring 56 is tensioned well within its working range so that it exerts a constant power pull on the assembly 34 during opertaion. During the relatively speedy clockwise travel of assembly 34, there is little or negligible rotation of gear 54 about its axis, out this period is so small as compared to the counterclockwise rocking period of the assembly 34 that it has negligible effect on the operation.

We have therefore provided an escapement arrangement wherein a primary escapement wheel is periodically locked against rotation by a detent, which detent is withdrawn under constant power and timed by a second escapement.

It will be apparent that our improved timing mechanism may be advantageously employed in a wide variety of industrial operations where accurately timed sequential operation of mechanical elements by means of cams, eccentrics or other actuating or control devices is a prime consideration. In such applications of the invention the motor spring M or other primary power source may be connected directly with the shaft 16.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrtaive and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

. constant power means.

2. In an escapement device, a shaft adapted to be driven from a source of power, a primary escapement assembly connected for controlling rotation of said shaft, and means for actuating said escapement assembly under constant power regardless of variations in power at said shaft comprising a second escapement assembly mounted for bodily rocking about the axis of said shaft so that torque exerted by said shaft may rock said second escapement assembly in one direction, and resilient means biasing said second escapement assembly in the opposite direction, said resilient means being energized by said bodily movement of said second escapement assembly in said one direction.

3. In combination, a support, a shaft rotatable on said support and adapted to be driven from a source of power, a gear on said shaft, a first escapement assembly mounted for bodily rocking about the axis of said shaft and comprising an escapement un'it connected by a gear train to said shaft gear, a second escapement assembly fixed on said support and comprising a toothed wheel connected by gearing to said shaft gear, a detent on said first escapement assembly adapted to engage said toothed wheel to lock said shaft against rotation in one limit position of rocking of said first escapement assembly, and resilient means urging said first escapement assembly to rock in the direction of disengagement of said detent from said toothed wheel.

4. In combination, a shaft adapted to be driven from a source of power, a gear on said shaft, a primary escapement connected to said gear to control rotation of said shaft, a secondary escapement mounted to rotate bodily about said shaft with said gear in one direction to engage said primary escapement and lock said shaft against rotation and to planetate about said gear in the opposite direction to release said shaft for rotation and a spring energized by said movement in said one direction for applying constant torque to said secondary escapement assembly in the other direction.

5. In an escapement device, a support, a shaft rotatable on said support and adapted to be rotated from a power source, a gear fixed on said shaft, a primary escapement assembly fixed on said support and connected to said gear to control said shaft, a secondary escapement assembly mounted on said support for bodily rocking about the axis of said shaft and having a gear train one gear of which is constantly meshed with said shaft gear and an escapement unit connected to said gear train, said secondary escapement assembly being rocked in one direction under the power of said shaft to engage said primary escapement assembly and arrest rotation of said shaft and a spring biasing said secondary escapement assembly bodily in the other direction to effect timed release of said shaft.

6. In a compact escapement device, a casing, a shaft adapted to be driven from a source of power and journaled in said casing, a primary escapement assembly fixed to said casing and ooerativelv connected to said shaft, a secondary escapement assembly operatively com nected to said shaft and including mounting means journaled on said shaft for free rocking with respect to said shaft, coacting means on said escapement assemblies operable when said secondary escapement assembly has rocked in one direction for checking rotation of said shaft, and a spring biasing said secondary escapement assembly in the o posite direction to release s id shaft.

7. In the combination defined in claim 6, said spring being a coil spring interconnecting said escapement assemblies and being tensioned when said secondary escapement assembly is rocked in said one direction.

8. In the combination defined in claim 6, said checking means comprising a toothed wheel on said primary escapement assembly and a detent on said secondary escapement assembly adapted to engage said toothed wheel.

9. In combination, a shaft adapted to be rotated from a source of power, an escapement assembly connected to said shaft and comprising a toothed wheel geared to said shaft, a detent mounted for rocking movement and adapted to engage and release said toothed wheel, means for rocking said detent into engagement with said toothed wheel under torque exerted by said shaft, and means for effecting timed release of said detent from said toothed wheel operated under constant power independently of said shaft.

10. In combination with a power driven shaft, mechanism for timing the rotation of said shaft comprising a gear fixed to said shaft, a primary escapement unit including an escapement wheel, a second escapement unit including means mounting said unit for oscillatory motion about the axis of said shaft, each of said escapement units including a gear train in constant mesh with the gear on said shaft, means carried by said second escapement unit coacting with a part of said primary escapement unit upon rocking movement of said second escapement unit in one direction by rotation of said power driven shaft and gear to control operation of said primary escapement unit, and secondary power means connected with said second escapement unit and energized by rocking motion of said second escapement unit in said one direction adapted to periodically rock said second escapement unit in the opposite direction to release said primary escapement unit.

11. The combination defined in claim 10 wherein said secondary power means comprises spring means tensioned by rocking motion of said second escapement unit in said one direction.

12. The combination defined in claim 10 wherein said second escapement unit includes a support frame journalled on said power driven shaft.

13. The combination defined in claim 12 wherein said control means for the primary escapement unit comprises a fixed detent on said frame coacting with the escapement wheel of said primary escapement unit.

14. The combination defined in claim 10, together with a fixed bushing in which said power driven shaft is journalled, and wherein said primary escapement unit includes a support frame fixed to said bushing.

15. In combination with a power driven shaft, a support on which said shaft is rotatably mounted, mechanism for timing the rotation of said shaft comprising a gear fixed to said shaft, a primary escapement unit fixed to said support, a second escapement unit including spaced plates oscill-atably mounted on said shaft and betweenwhich the active parts of said second unit are journalled, each of said units including a gear train in constant mesh with the gear on said shaft, a detent fixed between the spaced plates of said second escapement unit coacting with the escapement wheel of said primary escapement unit upon rocking motion of said second escapement unit in one direction by rotation of said power driven shaft and gear to control intermittent operation of said primary escapement unit, and a coiled spring connected with said second escapement unit tensioned by rocking motion of said unit in said one direction and constituting secondary power means to rock said second unit in the opposite direction relative to said gear and operate said second escapement unit and release said primary escapement unit for operation by said gear.

16. In combination, means for rotating a shaft comprising, torque generating means drivingly connected to said shaft, a pivotally mounted escapement for controlling rotation of said shaft, means for actuating said escapement under substantially constant power at said shaft, and means responsive to the position of said pivotally mounted escapement for periodically energizing said constant power means from said shaft.

17. In combination, means to rotate a shaft comprising a first power means drivingly connected to said shaft, a swingably mounted escapement governing the rotation of said shaft, second power means constant in value for actuating said escapement and means for periodically transferring energy from said first power means to said second power means in response to the position of said escapement.

ame

Number N Sylvan Date 88 8,271

May 19, 1908

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