US1913991A - High power clock escapement - Google Patents

Description

June 13, 1933. P, LUX

HIGH POWER CLOCK ESCAPEMENT Filed April 14, 1931 INVENTOR Paul LJu/x.

BY HIS ATTORNEY Patented June '13, 1933 um'rsn STATES PATENT OFFICE PAUL ox, or wnzrmmuny, 'CONNECTICUT, ASSIGNOR '10 LUX CLOCK MANUFACTIIIIYV; ,mc comrm, or WA'IEBBUBY, CONNECTICUT, A CORPORATION or CONNECTICUT 'HIGH POWER CLOCK ESCAIEME'NT clpplicatlon filed April 14, 1931.. Serial No. 530,035.

This invention relates to clock movements, and more particularly to a high power escapement mechanism in which means are provided for resiliently forcing the escapement lever into frictional engagement with the balance wheel shaft for damping the 0scillationsand preventing overrunning of the balance Wheel.

One object of this invention is to provide an escapement mechanism of the above nature especially adapted for use in a clock movement designed to per-form other mechanical functions in addition to that of operating a timing mechanism, such for-example as driving a special train of gears, operating an electric switch, or revolving a cam against a variable resistance.

A further object is to provide an escapement mechanism of the above nature toraccurately governing a clock movement, which is transmitting an excessively high power, withoutoverbanking or pounding.

A further object is to provide an escapement mechanism of the above nature which a will be simple in construction, inexpensive to manufacture, easy to install and manipulate, compact, and veryeflicient and durable in use.

With these and other objects in view, there has been illustrated on the accompanying drawing, one form in which the invention ma be conveniently embodied in practice.

ig. 1 represents a sectional view, looking downwardly, of a simple form ofclock movement with the top plate removed and show ing the improved high-power -ciontrolling escapement mechanism installed therein.

Fig. 2 is an enlarged ;plan View of the high power escapement "mechanism unit per se, showingone of the prongs of the escapement lever located in the notch of the balance wheel shaft.

Fig. 3 is an enlarged plan view similar to Fig. 2, showing the appearance of the escapement mechanism unit when the balance wheel prong is operating asa .brake and lies in frictional'contact with the cylindrical periphery of the balance wheel-shaft.

Fig. 4 is re fragmentary perspective view ofthe improved escapement mechanism unit.

action thereon.

Fig. 5 is a perspective view on an enlarged scale of the U-shaped banking spring for causing the escapement lever to frictionally press upon the balance wheelshaft to prevent overrunning of the balance wheel.

In practically all escapement lever clocks as now constructed the oscillation of the escapement lever is limited in both directions by a pair of so-called banking pins which hold said lever, at the end of each half oscillation thereof, until it is forced in the opposite directionby the impulse pin of the balance wheel on its return swing. With all such clocks, if the power transmitted to the escapement mechanism is greater than it can control, the balance wheel will overbank, causing the well-known pounding or rapping thereby preventing the clock from keeping correct time. The cause of this over-banking or rapping of the escapement lever is that the impulses given to the balance wheel by :the escapement lever are so strong that the balance wheel makes much larger swings than usualcausing the impulse pin thereof to rotate so far around the axis of the balance wheel shaft that it strikes against the outer banking prongs of the escapement lever. I I

The impulse pin will then rebound from the outer banking prongs of the escapement lever, causing a variable error in the swing of thebalance wheel, and of course rendering the clock inaccurate.

By means of the present invention, the above and other disadvantages have been avoided. This has been accomplished by providing means for preventing over-banking of the balance wheel and the consequent pounding-and rapping of the balance wheel pin upon the escapement lever.

vIn carrying out the invention, provision is madeofa special form of resilientbanking spring for engagement withtheescapement lever to resiliently press againstthe balance wheel shaft and exert a frictional braking The oscillation of the ,bal- .ance wheel will thus-be dampened to such an extent that the impulse pin thereof will be revented from striking against the bankmg prongs of the escapement lever.

The retarding braking action of the escapement lever on the balance wheel shaft will be effective in both directions of the movement thereof and consequently the damping efiects thereof will be equalized so that the accuracy of the time-keeping mechanism will not be affected.

Referring now to the drawing in which like reference numerals denote correspond ing parts throughout the several views, the numeral 10 indicates a balance wheel rigidly mounted upon a shaft 11, said shaft being provided with a short fiat cut-away section 12 on one side for cooperating with a pair of central prongs 13 and 14 on the extremity of an escapement lever 15 pivoted on a shaft 16 to produce a form of intermittent Geneva motion of said shaft 16. The escapement lever shaft 16 carries a bell crank lever 17 spaced from said lever 15 and having a pair of pallet pins 18 and 19 for cooperating with teeth 20 on an escapement wheel 21 to control the oscillation of said escapement lever 15.

The escapement wheel 21 is adapted to receive power from a main spring 22 transmitted through a gear train 23 to a pinion 24 rigidly carried on a shaft 25 upon which the escapement wheel 21 is secured.

The central. prongs 13 and 1 1 of the escapement lever are inclined outwardly as shown, and have rounded extremities to permit a smooth, non-abrupt operation of the mechanism. The escapement lever 15 is alsoprovided with a pair of laterally extending outer banking prongs 26 and 27 having curved seats 28 and 29 for limiting the movement of an impulse pin 30 mounted on the balance wheel 10 parallel to the shaft 11. The pin 30 is adapted to receive impulses successively from the central prongs 13 and 14 for oscillating the balance wheel 10 against the action of a hair spring 31. The unwinding return movement of said hair spring 31 will cause the balance wheel to travel in the opposite direction until the impulse pin 30 engages one of the central prongs and imparts energy thereto for moving the escapement lever 15 in the opposite direction, rocking the pallet pins 18 and 19, and permitting the escapement wheel 21 to move another step. i

In order to limitthe movement of the escapement lever 15 in both directions, provision is made of a U-shaped rigid guard member 32 having an aperture 33 on its base fo receiving a rivet, not shown, for attaching said guard member to one of the two side frames 34 of the clock movement. Each arm of the U-shaped guard member 32 has an angular offset section 34a for facilitating the adjustment of an interior U-shaped spring member 35 having a pair of substantially straight outwardly-extending arms 36 and 37 located in the path of the escapement lever 15, and adapted to be engaged thereby during its oscillations.

It will be clear from the above construction that the escapement lever 15 will alternately come into contact with said arms 36 and 37 after first-striking said impulse pin 30. r i e As soon as the impulse pin 30 has left the central prong 13, or 1 1, and is traveling with the balance wheel 10 in the direction to wind up the hair spring 31,counter-clockwise in the example shown in Fig. 3,the resilient arm 36 or 37 of the spring 35 will force the central prong 13 or 14 back inwardly into contact with the balance wheel shaft 11 as shown in Fig. 3 producing a frictional braking action and retarding the abnormal swing of the balance wheel 10.

Operation In operation, when the main spring 22 of the clock movement is wound, power from the main spring 22 will be supplied to the escapement wheel 21 through the train of gears 23, as shown in Fig. 2. The teeth 20 on the escapement wheel 21 will cooperate with the bell-crank lever 17 for causing the escapement lever 15 to oscillate. The central impulse prongs of the escapement lever 15 will engage and impart energy to the balance wheel impulse pin 30, for oscillating the balance wheel against the counterforce of the hair-spring 31. s The balance wheel is shown in Fig. 2 while rotating in a counter clockwise direction just afterthe escapement lever 15 has imparted an impulse to the balance wheel in a counter-clockwise direction. The central impulse prong 13 will at this time be located within the cut-out section l2 of the balance wheel shaft 11.

In Fig. 3, the position of the escapement mechanism is shown when the balance wheel 10 has rotated still farther with the central prong 13 of the escapement lever lying in frictional braking contact with the cylindrical surface of the balance wheel shaft 11. The spring action of the resilient arm 37 is at this time exerted against the escapement lever to press the prong 13 in a counterclockwise direction against the'balance wheel shaft 11. The oscillation of the balance wheel 10 will thus be dampened and the excess power transmitted to it will be absorbed so that the impulse pin 30 will be prevented from striking the banking prongs 26 and 27, pounding and rapping being thus prevented.

One advantage of the present invention is that it permits the use of "escapement mechanisms to overn the accurate running of heavy duty c l'ocks which would be otherwise impossible to manufacture.

While there has been disclosed in this specification one form in which the invention may be embodied, it is to be understood that this form is shown for the purpose of illustration only, and that the invention is not to be limited to the specific disclosure but may be modified and embodied in various other forms without departing from its spirit. In short, the invention includes all the modifications and embodiments coming within the scope of the following claims.

Having thus fully disclosed the invention, what is claimed as new and for which it is desired to secure Letters Patent, is:

1. In a clock escapement mechanism, a spring-driven escapement wheel, an escapement lever driven thereby, a balance wheel cooperating with said escapement lever to control the speed of said clock, a balance wheel shaft, and a U-shaped resilient banking device located in a plane at right-angles to the plane of movement of said lever for embracing said escapement lever at a point adjacent said balance wheel, said banking device being adapted to press said lever against said shaft in its extreme side positions, whereby the oscillation of said balance wheel will be dampened.

2. In an escapement mechanism for a timing device, a frame, a power driven toothed escapement wheel, an escapement lever actuated by said escapement wheel, a balance wheel, a balance wheel shaft, a rigid U-shaped banking guard embracing said lever, a U-shaped spring member located within said guard and being reinforced thereby, said spring member being adapted to press the end of said escapement lever against said balance wheel shaft to dampen the oscillations of said balance wheel and prevent pounding and consequent errors in timing.

3. In an escapement mechanism for a timing device, a frame, a power driven toothed escapement wheel, an escapement lever actuated by said escapement wheel, a balance wheel, a balance wheel shaft, a rigid U-shaped banking guard embracing said lever, a U-shaped spring member located within said guard and being reinforced thereby, said spring member being adapted to press the end of said escapement lever against said balance wheel shaft to dampen the oscillations of said balance wheel and prevent pounding and consequent errors in timing, the arms of said U-shaped guard having outwardly-offset V-shaped sections to facilitate the adjustment of said spring member.

4. In an escapement mechanism for a timing device, a frame, a power driven toothed escapement wheel, an escapement lever actuated by said escapement wheel, a balance wheel, a balance wheel shaft, a rigid U-shaped banking guard embracing said lever, a U-shaped spring member located within said guard and being reinforced thereby,

said spring member being adapted to press I the end of said escapement lever against said balance wheel shaft to dampen the oscillations of said balance wheel and prevent pounding and consequent errors in timing, said U-shaped guard and spring members being attached to said frame, said guard being constructed from relatively thick rigid metal and said spring member being constructed from relatively thin resilient metal.

5. In an escapement mechanism for a timing device, a frame, a power driven toothed escapement wheel, a forked escapement lever actuated by said escapement wheel, a balance wheel, a balance wheel shaft, a U-shaped spring member for cushioning the swings of said escapement lever and pressing said lever against said balance wheel shaft at the extreme positions of the oscillation of the balance wheel for dampening the vibrations thereof and preventing overbanking.

6. In a clock escapement mechanism having a spring driven toothed escapement wheel, an escapement lever, a balance wheel shaft, means for frictionally pressing the end of said escapement lever against said shaft in the extreme positions of its oscillations to dampen the oscillations of said balance wheel and prevent pounding and rapping.

7. In a clock escapement mechanism having a spring driven toothed escapement wheel, a vibratingescapement lever having a fork, a balance wheel shaft driven thereby, and means for frictionally pressing the fork of said lever against said shaft in both of its extreme positions to dampen the oscillations of said balance wheel and prevent pounding and rapping.

In testimony whereof, I have affixed my signature to this specification.

PAUL LUX.

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