US2531273A - Escapement device - Google Patents

Description

Filed April 25, 1945 n JJ.

3 Sheets-Sheet 1 Npv. 2l, 1950 R. P. JAccARD 2,531,273

ESCAPEMENT DEVICE Filed April 23, 1945 3 Sheets-Sheet 2 Nov. 21, 1950 R. P. .JAccARD ESCAPEMENT DEVICE 3 Sheets-Sheet 3 Filed April 23, 1945 Patented Nov. 21, 1,950

UNITED STATES OFFICE ESCAPEMENT DEVCE land Application April 23, 1945, Serial No. 589,898 In Switzerland April ,27, k1534s This invention relates to escapement mechanisms ior time pieces or the like, and more par- A ticularly to a novel arrangement which is substantially shockless and noiseless in operation.

Accordingly, a primary object of the invention is to provide an escapement mechanism wherein the shock and frictional losses are reduced to a minimum, said mechanism including an escape wheel and stop and impulse controlling pawls each having pallet means, the stop pawl being pivoted, to the trame while the impulse pawl is pivotally carried by an oscillating impulse transu mitting lever, said stop and impulse pawls c0- operating with the escape wheel to easily and sub stantially noiselessly permit the same to move without the excess energy and irictional losses heretofore common to escapement mechanisms now in general use.

With the above and other objects in view, which will more readily appear as the nature of the invention is better understood, the same consists in the novel construction, combination, and arrangement or" parts hereinafter more iully described, illustrated and claimed.

Preferred and practical embodiments of the invention are shown in the accompanying draw-- ings, in which: A

Figure i is a side elevation, partly in section illustrating one form oi the mechanism.

Figure 2 is a cross section taken on the line A-A of Figure l.

Figure 3 is a iront elevation oi a modification of the invention.

Figure fl is a top plan View, partly in section, of the construction shown in Figure 3.

Figure 5 is a diagrammatic view showing a variation or the invention illustrated in Figure 2.

Figure 6 is a detail perspective view of a iurn ther variation oi the invention including a penM dulum as the regulating means.

Figure '.7 is a detail View showing a modication similar to Figure 3.

Figure 8 is a detail perspective View of another modification of the invention utilizing a balance wheel as the regulating means.

Similar reference characters designate corresponding parts throughout the several iigures of the drawings.

Referring to the drawings, it may be generally pointed out that Figures l to 8 inclusive illus trate, by way of example, and not by waf,r of limitation, two classes of embodiment of the invention. Figures l, 2, 5, and 6 illustrate the preferred form of the invention wherein the regulating element of the time mechanism is a pendu# 12 Claims. (Cl. 58-117) lum, while `Figures 3, 4, '7, `and 8 illustrate a second class wherein the regulating element is ai balance wheel subjected to the action of a spring.

Thus, the term regulating element or regulating means as used herein includes a pendulum or a spring ensioned balance wheel.

Referring to embodiments oi the rst class,

'ment mechanism ci Figures 2 and 5 has been drawn to a larger scale than in Figure i, in order 'l to more readily understand the construction and' operation involved. A distinctivefeature of the inventionresides in f the provision oi a pair of pawls each having pallet r engaging the teeth of the escape wheell'" said pauls being conveniently designated as fa stop pawl A and an impulse 'transmitting pawl BQ t? lformer pivotally mounted to a frame part'and' the latter pivotally carried by the end of an oscil- 'latable drive or impulse lever C which is con nected with the regulating means, whereby the impulse of the escape wheel may be periodically and accurately delivered to said regulating means. y In Figures l and 2, the pendulum i is flexibly'4 suspendedrby a rod :l in a conventional manner indicated as from the part 3b of a frame 3.

An escape wheel i is mounted on a shaft 4a journalled in the frame parts 3 and 3a and operatively *l connected to prime mover (not shown) in the usual manner by a system of gear wheels, only-A the nrst two of which, 5 and t, are shown.

Cooperating with escape wheel is arstop.

pawl A having the arms i and 'la and pivoted at 2i to the fi part said arms terminating in what may li.d conveniently termed the safety pallet sa and thestop pallet ub adapted alternatively to cooperate with the teeth of the escape wheel. While both pallets have a top action since pallet Sb stops the escape wheel when same is moving forward in direction f1 and pallet ,9m

stops the escape .vheei when the same is pushed a safety pallet because it avoids extensive backward movement of the escape wheel under two conditions, first, when the amplitude of the pendulum is larger than necessary as might happen.,y when starting the pendulum by hand, and, second, when manually setting the hands of the..

time piece in a counterclockwise direction.

Between said escape wheel 4 and said stop pawl A, there is provided an impulse transmitting pawl B having the arms I and |03. This pawl is pivotally supported at II on the end of the shank I2 of the oscillatory lever C whose upper end is carried by shaft I3 which turns in bearings on the frame parts 3FL and 3b. A spring blade I5 fastened by a clamp I4 to the shaft I3 moves back and forward in synchronism with the lever C and during the forward movement of each complete oscillation, a yoke I6 carried by the blade gives an energy impulse to the pendulum I through the rod 2. Owing to the flexibility of the blade I5, the oscillatory movements of the lever C and the pendulum I, although of the same frequency, may be quite different in their amplitude. It will be noted that both pawls A and B have a somewhat symmetrical shape resembling that of a ships anchor and for that reason are stated to be of the anchor type.

Referring to Figure 2, the complete cycle of operation may be described as follows:

The escape wheel 4 urged to move forward in the direction of the arrow f1, by the prime mover (not shown), is held back momentarily by the pallet 9b of the stop pawl A. Lever C, oscillatable with shaft I3, is shown in the middle position of its back swing in the direction of the arrow f2, during which it is driven by the pendulum I, to which it is operatively connected by clamp I4, spring blade I5 and yoke I6. The lever C carrying the impulse pawl B moves toward the left in Figure 2 and causes cam surface I'Ib on the underside of the arm IEI of the pawl B to come in contact with the top surface of cam I 8b on the arms l of the stop pawl A which is momentarily at rest.

When the pallet II)b of the impulse pawl B advances toward the left and rocks about pivot in the direction of arrow f7 in Figure 2 and reaches the tooth Dl of the escape wheel it pushes the same slightly backwards owing to the momentum of the pendulum. At that instant, the pressure exerted by tooth D2 of the escape wheel on the stop pallet 9b of the stop pawl A is relieved, and said stop pawl rocks or falls by gravity in a counter-clockwise direction according to arrow f3. The left arm 'I of the stop pawl A is heavier than the right arm la. This same action may be obtained by other means, such for example as light springs, shown in Figures 3 and 5. As the stop pawl A rocks in the direction of the arrow f3, the safety pallet Se locates itself between the teeth D3 and D5 and rather close to D3 with large oscillation of the pendulum. Before the lever C reaches its extreme position on the left, tooth D3 of the escape wheel abuts against the safety pallet 9n on the right arm 'Ia of the pawl A, thus preventing excessive backward movement of the escape wheel under either of the conditions heretofore mentioned.

Lever C terminates its back swing and begins a new oscillation forward, that is in the direction of the arrow f4, driven as it is by the impulse pawl B which is also itself pushed by the tooth D1 of the escape wheel. During a fraction of this part of the cycle, the lever C transmits an impulse of mechanical energy to the pendulum I and drives it. The oscillation of the lever C in the forward direction continues, and contact is established between cam surface Il at the underside of the arm I IJa of the impulse pawl B and the surface of the cam I8a on the arm Ia of the stop pawl A. 'I'his causes the stop pawl to rock in the direction of arrow f5 and stop pallet 9b of the arm 'I locates itself in the space between teeth D2 and D4 of the escape wheel and at the same time the safety pallet 9a clears the escape wheel. Said escape wheel 4 keeps moving in the direction of the arrow f1 until it is arrested by stop pallet 9b acting on tooth D4. Thus, stop pallet 9b has permitted escape of one tooth of the wheel in its direction of continuous movement. The momentum of the pendulum carries the lever C farther to the right and the pallet IUb of the impulse pawl B abandons tooth D1 while the cam surf-ace I8a of the stop pawl A acting on the surface of cam I la causes the impulse pawl B to rock in the direction of arrow f6. After the pendulum and lever C come to the end of their forward oscillation, the said pendulum then drives the lever C back to the position from which the present cycle began. The impulse cycle from the escape wheel to the pendulum is again completed, and the impulse cycle as well as the return cycle re- Ipeat themselves so long as the prime mover (not shown) is exerting suflicent force on the escape wheel.

From the foregoing it will be apparent that there is a complete absence of shocks during the entire cycle, as well as the absence of sliding motion between the power transmitting elements during the time they actually do transmit power thereby resulting in silent operation, great saving of power required from the prime mover, elimination of lubrication diiculties and making other improvements possible in the clocks, counters and the like.

In particular, each of the principal elements of the escapement device, namely, the wheel, the pawls, and their pallets having a simple duty to perform, their shape, and therefore their manufacture is simplified or facilitated owing to enlarged tolerances. For instance, instead of the rather complicated tooth shape common to most escape wheels, mechanisms according to the present invention may use straight flanked teeth. Further, each pawl and its pallets may be freely adjusted independently of one another. An adjustment performed on one pawl has little or no influence on the adjustment of the other. Further, the stiffness and shape of springs IBC I8d, and 22a may vary within reasonably large tolerances without impairing the performance of the escapement mechanisms as a whole.

It is also pointed out that the amplitude of oscillation of the lever C is determined by the combined action of the pawls A and B with the escape wheel, and that for each complete oscillation of the pendulum, the shaft I3 receives an energy impulse from the escape wheel as the lever moves in the direction of arrow f4.

Figtue 5 shows a different arrangement of the stop pallet A' and the impulse pallet B'. The operation of cams I8a and I8b in connection with the corresponding surfaces of the arms IE and ||lof pawl B in Figure 2 is replaced by the action of the lights springs I8c and iSd on the extension or head II!a of the shank I21 of the impulse transmitting lever Cl in Figure 5, said action being not necessarily continuous.

Figure 6 illustrates a different form of connection between the oscillating lever and pendulum which may be adapted to either form of embodiment of the elements A and B shown in Figure 2, or A1 and B1 shown in Figure 5. Lever I4a pivoted on clamp I4b terminates in an offset finger I6a contacting pendulum Ib at the location of the clamp Ia. Coil spring I 5a allows lever |42L to perform a, relative angular movement with respect Under certain ciroums vices, however, the noulum may be driven so r to the right o; ure

that the osciilatinN lever could not follow without straining the pawls LB or Jil-. ln spring ida gives the desired freedom 'activen the pendulum and the oscillating transmitting lever.

As to the second class or devices, wherein the regulatingl element is a balance wheel, it he observed that while the balance wheel spring, in its major portion, most usually e shape oi a true spiral, as in the grea' of Watches Where is citen ieierred "hair spring, it also t ire shape of a cylindrical coil as is u case in marine chroncmeters, or it may oe a tefsion wire, rod, blade, or even a different The term hair spring as herein is intended to spring of any whatsoever having the canas ity to produce the so-ealled restoring 'orce, which, in con iertia of the bal'- ance wheel, determines the 'frequency of oscillation of balance Wheel.

at ,'2 on the arm of a Lohaned C2 which is p oted to the framework or the mechanism as indicated at r'he arm the oscillating impulse transmitting lever C2 car ries two rollersvvhich embrace the hair spring 2'! of the balance wheel at a point rel near the fastening which anchors the i to the frame. The operatifn of the va ous eler ments in 5 ures 2' and l is in principle the same as previously descri ed. The E nsnagged lever C2 performs the iunctions 'the lever C in Figure 2 l the of he spring 27 between e.. s I replaces the leaf spring i5 ci Figure l.

For each complete oscillation oi the balance Wheel 28, an energy impulse is in the forward direction. by the rollers liti, throfgh said hair spring t balance Figure 7 shows a different form. oi hair spring anchor. The end of the hair spring mote from the balance Wheel, instead of 1oeing anchored 'to the framework at 2li as in igures 3 and 4 is fastened at 3l to the arm a of the oseillating lever C3 which in turn is subjected to the action of at least one spring t2 anchored to the frame Figure 8 is a partial perspecti e viev.,7 oi a device combi le a nai a spring, otherwise known as a torsion pendulum. In this form oi embodiment an oscillating lever C4 pivotalli7 carrying an impulse pawl B4 is itself pivoted at 24a on the frame and includes a arm 23a adapted to engage with the iree end of an auxiliary spring means lilla whose othe end is anchored at 2lb to the pendulum shaft ric. his arrangement gives a desirable freedom of motion between the balance wheel 28a and the oscillating lever C4.

From the foregoing, it will ce apparent that i respectively on all embodiments of the invention include an im j pulse-tranemiting lever or drive member C, C', C3, or C4, carrying therewith a pivotally mounted impulse pavvl. This is true even in connection with the modification shown in Fig. 5, Where the paWl is omitted ior the sake of clarity in illustrating the modiiied lorin connection between the oscillating lever and the pendulum.

From the foregoing it will he clear that the object of the'invention is not limited to the arrangements shoafn in to 8 inclusive. In particular, the lever C or' Figure 2 could have a quite different orm ant, have vpivots. located elsewhere, or instance, on the axis ci the balance member and hair spring 2l or its prolongation as is the ease lever C3 in Figure 7.

Furthermore, tl Jresent invention is not limcally driven a pendulum or a balance o applied time mecha b] the present i' utilising, for instance, meenar ally or elf`f=trically driven,

or an electroml.. .tically AWn, escapement Wheel.

claim:

l. An escapement mechanism for time pieces and the like, including, a frame, an escape Wheel having teeth and mounted :for rotation on said frame, driving means ror driving said Wheel, regulatine" means for said wheel including a oscilfataiz-le dr' e einher fixed "i liet means Impulse palmeans for contro Alng the l terlittent moveT ment of the escajoe Wheel, stop pallet means being pivoted to the frame the wheel and said ise pallet i pivotally carried hy anVL sai-o. di c member of the regulating neans, and coo" erating means the stop pallet m ans and ims ins reiative peet to the successive teeth pulse naliet 'n -M J- e movements wit or the e cape 'mit lor time pieces an escape Wheel having te .on on said frame, driv means ior s lever c n'ieans for tra regulating the essafety e ng the 'teeth oi `oallets for also-.

an impulse controlling pavvl the escape wheel,

pivotally carried the impulse transmitting lever hai of the pallets of th s stop and safety se lever transl to the reguiovement oi the pallets of the engaging a tooth let means for alternatively engaging the teeth of the escape wheel, an osciliable lever for conveying impulses from the wheel to the regulating means, an impulse controlling pawl pivoted to said oscillatable lever and having pallet means, and cooperating means on said stop pawl and impulse controlling pawl for coordinating their relative movements.

4. An escapement mechanism for time pieces,

according to claim 3, wherein, the teeth on the escapement wheel have substantially straight and radial working flanks and the pallet means of the stop'pawl and impulse controlling pawl are complementary thereto.

5. An escapement mechanism for time pieces,

according to claim 3, wherein, the cooperating means on the stop pawl and impulse pawl are inwardly projecting cams on the stop pawl and corresponding cam surfaces on the impulse pawl.

6. An escapement mechanism for time pieces, according to claim 3, wherein, the cooperating means on the stop pawl and impulse pawl are an extension on the impulse pawl below its pivot and spring elements carried by the stop pawl.

7. An escapement mechanism for time pieces or the like, according to claim 3, wherein, the regulating means is a spring and balance wheel, and the oscillating lever is of substantially Z-shape formation and pivoted at one of its angles to the frame while one free end engages said spring and the other free end supports the impulse controlling pawl.

8. An escapement mechanism for time pieces and the like, including, a frame, an escape wheel having teeth, regulating means, a stop pawl rockably pivoted on the frame and having arms angularly disposed with respect to the pivot, the ends of said arms having pallet means for alternately engaging the teeth of the escape wheel,

an impulse pawl having pallet means for also engaging the teeth of the escape wheel, said impulse pawl being located between the arms of the stop pawl, an oscillatable impulse transmitting lever having said impulse pawl pivoted at one end and having its opposite end connected With said regulating means, and cooperating means on the stop pawl and impulse pawl for coordinating their relative movements with respect to the escape wheel.

9. An escapement mechanism for time pieces and the like, including, a frame, an escape wheel having teeth, regulating means, a two armed stop pawl pivoted to the frame and having pallet means at the ends of the arms for alternate engagement with the teeth of the escape Wheel, a two armed impulse pawl having pallet means for engaging the teeth of the escape wheel, said impulse pawl being located between the arms of the stop pawl, an oscillatable impulse transmitting lever having the impulse pawl pivoted to one end and having its opposite end connected with said regulating means, and cooperating means on the stop pawl and impulse pawl for coordinating their relative movements with respect to the escape Wheel.

10. A substantially shockless and noiseless escapement for time pieces, including, a frame, an escape wheel having teeth and supported by the frame, regulating means also supported by the frame, an oscillatable impulse transmitting lever having one end connected to said regulating means, impulse pallet means pivotally connected to the other end of said lever, stop pallet means pivoted for rocking movement on the frame, and cooperating means on the impulse pallet means and stop pallet means for coordinating their relative movements with respect to the teeth of the escape wheel, whereby, the turning effort of the Wheel is cushioned with respect to the stop pallet means by the impulse transmitting element connected to the regulating means.

11. In a substantially shockless and noiseless escapement for time pieces and the like, a frame, an escape wheel having teeth, regulating means for the wheel an oscillatable lever connected with said regulating means, and a pair of anchor type pallet elements for engaging the teeth of the wheel, one of said pallet elements being pivoted to the frame and the other being pivoted to said oscillatable lever, and cooperating means on the pallet elements for coordinating their relative movements with respect to the teeth of the escapement wheel.

l2. An escapement mechanism for time pieces and the like, including, a frame, an escape wheel mounted on said frame and having teeth, regulating means for the wheel, a two-armed stop pawl pivoted to the frame adjacent the wheel and having stop and safety pallets respectively at the end of each arm for alternate engagement with the teeth of the escape wheel, said stop pallet limiting the forward movement of said escape wheel and said safety pallet limiting the backward movement thereof, an oscillatable impulsetransmitting lever pivotally supported at its up- I per end in the frame and connected to the reg- REN PHILIPPE JACCARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 244,684 Stahlberg July 19, 1881 1,395,148 Saul Oct. 25, 1921 FOREIGN PATENTS Number Country Date 6,409 Great Britain Mar. 14, 1913 451,035 Germany Oct. 22, 1927

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