US1981110A - Time piece movement - Google Patents

Description

s. E. KOCHENDARFER 1,981,110

TIME PIECE MOVEMENT Nov. 20, 1934.

Original Filed April l, 1929 INVENTOR ATTORNEY Patented Nov. 20, 1934 UNITED STATES. OFFICE 351,793, April 1,1929. This application July 5, 1934, Serial N0. 73:3,882

6` Claims.

` This invention relates to improvements in time pieces, and it consists of the constructions, combinations and arrangements herein described and claimed.

One of the outstanding objects of the invention is a perfection of the precision of a time pieceV and a simplification of the escapement mechanism.

A further o bject of the invention is to convert the characteristic rocking of the escapement lever into a continuous vrotary motion of the balance wheel thus enabling the omission of the hair spring and the necessary accessories to produce the present reciprocatory motion of the balance wheel, and also making it possible to eliminate the delicate balancing devices and in fact any particular expansion and contraction compensating means.

A further object of the invention is to provide a magnetic control for the balance wheel so that the Alatter may be definitely and invariably held toa given number of revolutions in a stated period of time, thus keeping the gear train within a well-,defined restraint.`

A still further object of the invention is to equip the balance wheel with a simple governor mechanism, the function of which is to immediately retard the rotation of the balance wheel in case of any undue acceleration thereof.

Other objects and advantages appear in the following specification, reference being had to the accompanying drawing, in which:-

Figure l is a plan view of a Watch illustrating several of the essential features of the improved time piece movement.

Figure 2 is a detail view illustrating one position of the escapement lever following an impulse of the jewel or so-called roller pin on the associated roller table.

Figure 3 is a detail view illustrating a reversal of some of the parts in Figure 2.

Figure 4 is a cross section taken on the line 4-4 of Figure 1.

Figure 5 is a detail perspective view of thev roller table mentioned in connection with Figure 2.

Figure 6 is a detail perspective view of the double fork oi the escapement lever.

Figure 7 is a detail perspective view of a portion of the balance wheel, particularly illustrating one of the governors.

Figure 8 is a perspective view of the magnet that controls the rotation of the balance wheel.

Figure 9 is a detail section taken substantially on the line 9-,9 of Figure 8, and

Figure 10 is a cross section taken on the line 10-10 of Figure 9.

As already briefly indicated in the foregoing statements of the objects of the invention, it is a purpose of the latter to improve the movement of time pieces to the ends of perfecting the pre-- cision of operation, simplification of the construction, as vwell as a cheapening thereof by virtue o the elimination of many parts that have been regardedas being indispensable from time irnmemorial.`

It isy characteristic of watches, clocks, chronometers, etc., that the balance wheel partakes of an oscillatory motion by virtue of the rocking of the escapement lever. This oscillatory motion an effect of the hair spring and should the latter be lengthened or shortened under the inuence of rising or falling temperatures the direct result upon the balance wheel would be either a slowing orspeeding up with a consequent variation in the time-indicating function of the time piece. One of the features of the invention is the elimination of the hair spring as well as such parts as are ordinarily necessary to its operation.

' It is also a matter of common knowledge that changes in temperature mustbe compensated for in the construction of the balance wheel. This is usually of bi-metal construction which is intended to oifset the effects of changing temperatures. The balance wheel is usually equipped with al numberof elements that are intended to give it a proper balance upon its bearings. The use of the invention obviates the necessity of compensating for temperature changes as well as the need for any balancing means.

A brief reflection upon these simplifications will make it apparentat once that the cost of time piece construction can be materially reduced and while it is possible to embody the principles of the invention in new time pieces, yet it is an outstanding purpose to use the invention asv a substitution for the escapement mechanism of time pieces now extant. With this in mind, the improved escapement mechanism has been designed so that it can readily be incorporated in any time piece with nothing more than'a replacement of the escapement lever, roller table, balancewheel and the addition of the magnetic control.

Attention is directed to the drawing. The watch 1 is selected as the illustration of a representative time piece.` The latter may comprise any other known time piece of a similar character. The gear train 2, in which is included all of the customary gears which transmit motion to the center staff 3 by which the hands (not shown) are carried, receives its power from a main spring (not shown) applied to the staff 4. An escap'ement wheel 5 and its lever 6 control the motion of the Vgear train so that the various gears will make no more or less than an allotted numbervof revolutions in a given division of Y rw i 'f tim?? Both the escapement wheel 5 and its lever 6 are largely of conventional structl'ire.v The latter has pallets 7 and 8 which alternately engage the heels 9 of the escapement wheel in the characteristic manner and as illustrated at the left of Figure 2. The escapement lever is pivoted at 1G. the provision of a double fork. The primary fork is indicated l1, the secondaryffork 12. These oppose each other and are situated at diametrically opposite sides of a staiT 13 which carries both a roller table 14 and the balance wheei 15. Obviously the forks must be connected and this will usually be done by an element herein identied as the fork ring 16. In conformity with the standard practice, the escapement vlever 8 is equipped with guard pins 1'7 Which coi-act with shallow and arcuate depressions 18 in the periphery of the roller table. But contrary to practice, both the guard pin and depression are duplicated to agree With the duplication of the escapement lever fork. The purpose of the guard pins and depressions is toprevent over-banking of the escapement lever, for the rocking of the'latter in respect to the escapement wheel 5 must be confined Within precise limits( Situated on the underside of the roller table 14 is a roller pin or jewel 19. An impulse delivered by the roller pin 19 to the primary fork 11 caused a release of the pallet 8 from the heel 92L with which it was formerly in engagement, the act of the heel 9a in passing under the pallet 8 havingl caused the escapement lever 6 to rock over to the left until the occurrence of an engagement of the pallet 7 by the indicated heel 9.

VThe roller pin 19 still being under the iniluence of the 'foregoing impulse will travel in the clockwise direction until it strikes the secondary fork 12. The blow imparted to the secondary fork is sufficient to'unlock the pallet "I from the indicated heel 9 so that the latter in riding under the pallet can rock the escapement lever to its other position (see the dotted lines in Figure 3). The force imparted to the escapement lever by the action of the heel 9 against the pallet '7, then becomes the driving force which impels the roller pin 19 from the position 19a in Figure 3 tothe position shown in Figure 2.

The position 19D in Fig. 3 is that from which the roller pin is about to depart from the secondary fork 12 after the impulse described in connection with Figure 2 has been imparted to the secondary fork. The actions of the roller pin and double forks are mutual. The blow imparted to one or the other of the two forks by the roller pin is such to dislodge one or the other of the pallets '7 and 8 from the escapement wheel heels and after the dislodgment has occurred then the spring blower behind the escapement wheel 5 rocks the escapement lever 6 over and so imparts an impulse to the roller pin 19 that keeps it moving in one direction.

The ultimate result of these actions is a continuous rotation of the roller table 14, staiT 13 and balance Wheel 15. It might appear that the successive engagements of the roller pin 19 with the primary and secondary forks would result inV a step motion of the roller table but the impulses of the roller pin are so rapid that there vis no perceptible hesitation of the roller table, hence the latter and its associated parts rotate continuously. The rotation is indicated The change in its constructionV comprises as being clockwise but it is possible to so start the movement that the rotation of the staff 13 will be counter-clockwise. This does not require any reversal of the directions of the gear train 2. It is merely a matter of the direction in which one might start the sta-ii 13.

v According to the showing in the drawing, the balance wheel has a magnetic rim or annulus 20 whichmight presuppose that the inner portion or felly of the wheel is of nonmagnetic material. This is not essential for the wheel might comprise but a single rim. However, the double showing is made, and this may have some advantage in the manufacture of the balance wheel. The spokes 21 join the wheel with the staff 13. At places adjoining the extremities'of` the spokes the balance wheel carries governors 22 which are affixed to the inner periphery of the wheel by screws 23 or the like.y The governors comprise fine strips of metal or some other suitable substance which by virtue of their neness have a measure of resiliency. This is enhanced by the constrictions 24 which are subject to flexure when thewings 25 at the extremities of the governors are raised. To this end the leading edges of the wings are bent inwardly at 26, permitting the air to get under the wings, flex the constrictions 24 and exercise a retarding function on the balance wheel should the latter for any reason exhibit an undue tendency toward acceleration.

'A permanent magnet 27 exercises a perpetual restraint upon the balance wheel 15. This magnet is located substantially in the plane of revolution of the balance wheel and the rim 20 thereof. The poles are enlarged so as to partly embrace the magnetic rim thereby to increase the magnetic area. Itmust be borne in mind that in practice the magnet 2'7 is very small, especially when embodied in a watch, and thus enlargement in the poles is a somewhat necessary provision. y

'A non-magnetic plate 29 provides a base for the magnet. The plate is secured to a customarily found partition in the time piece by screws 30. Portions at each end of the plate are bent upward to form a bridge 31 and lug 32 respectively. VThe bridge is cut in at 33 to leave ears 34. The magnet is received by the recesses defined by the cut-in places and the ears bear down on the magnet to hold it in place.

For a similar purpose the closed end of the magnet has a lug 35 corresponding to the lug 32. A screw 36 applied to the pair of lugs provides for what might be called a rough adjustment of the magnet. A fine adjustment is obtained by means of a keeper 37 of magnetic material and nut 38 that receives and is capable of being worked along a screw stem 39. The ends of this stem are fixed' in the bridge 3l and in an upstanding part 40 of a cross piece 41. The latter is a part of the plate 29.

A lug 42 pendent from the keeper 37 receives the shank 43 of the nut 38. The lug 42 has a smooth hole to receive the smooth part of the shank. The right extremity of the shank is threaded toreceive a lock nut 44. The lock nut is intended to bind against the shoulder were the threaded portion meets the smooth portion of thev shank. This arrangement composes a swivel mounting for the nut 38, and when the latter isv turned by pushing it in the notches 45 (Fig. 10) the keeper will be moved back and forth along the magnet, short-circuiting that portion of the magnetic field traversing the maglll;

het and bringing more or less of the magnetic field into play.

The principle of the control that the magnet 27 aiiords is that of magnetic attraction. Obviously, the nearer that the magnet is adjusted toward the periphery of the balance wheel 15 the greater will be the attraction and the slower the rate of rotation of the balance wheel. Conversely, the greater the distance between the pole pieces 28 and the rim of the balance wheel, the less will be the magnetic attraction and the faster the rate of rotation. To these ends a rough adjustment of the magnet 27 will be made by means of the screw 36.

A finer adjustment is then made by means of the nut 38. The consequent shifting of the keeper 37 along the magnet will introduce more or less of the magnetic flux in the circuit so that the magnet will be strengthened or weakened. It is possible to secure an extremely fine regulation with the nut 38.

The operation is briefly reviewed. The step motion of the escapement wheel 5 and the rocking motion of the escapement lever 6 are characteristic. Alternate release and locking occur between the pallets 7, 8 and the heels 9. The escapement wheel 5 has the main spring power behind it, and portions of this power are transferred to the stair 13 by way of the escapement lever 6 and its primary and secondary forks 11 and 12 to the roller pin 19.

Assume that the roller pin 19 has just arrived at the primary fork 11 in the Figure 2 and imparted a blow of sufficient force to dislodge the pallet 8 from a prior engagement with the heel 9a. The heel 9a in then passing under the pallet 8 rocks the escapement lever to the position shown in Figure 2. This also imparts an irnpulse to the roller pin 19 and the latter is shown as about ready to continue its journey in the clockwise direction to a point of engagement with the secondary fork 12 as indicated at 19a in Figure 3.

Again the blow imparted by the roller pin is sufficient to dislodge the escapement lever 6 from its momentarily locked engagement with the balance wheel. This time it is the pallet 7 that will be dislodged. As the heel 9 passes under the pallet 7 the escapement lever 6 will be forcibly rocked to the right (see the dotted lines in Figure 3) and the impulse imparted to the secondary fork 12 is sufcient to send the roller pin down to the primary fork 11. The position 19b in Figure 3 indicates the point of departure of the roller pin after the impulse of the latter has rocked the escapement lever 6 to its other position.

These actions occur very quickly and as a result the rotation of the stai 13 is continuous in v one direction. Obviously, the roller table 14 and balance wheel move as one. The magnet 27 exercises a restraint upon the rotation of the balance wheel, and this restraint will be manifested in the entire gear train 2 so that the measurement of time will be accurately indicated.

Should the balance wheel 15 become suddenly accelerated the diametrically opposed ends of the wings 25 would fly away from the internal rim of the Wheel by virtue of the air catching thereunder. The wings would thus act as brakes and retard the balance' wheel. The adjustments of the magnet 27 have been enlarged upon, and it is only necessary to say that by moving the magnet away from or toward the magnetic rim 20 of the balance wheel, a very fine control of the rate of turning of the latter will be had.

While the construction and arrangement of the improved time piece movement is that of a generally preferred form, obviously modifications and changes may be made without departing from the spirit of the invention or the scope of the claims.

I claim:-

1. A time piece having an escapement mechanism, a balance wheel and stair, means for converting the characteristic movements of the escapement mechanism to a continuous rotary motion of the balance wheel and staff, and a governor carried by the balance wheel moving to an operative position upon an undue acceleration of the balance wheel to retard the rotary motion thereof.

2. A time piece having an escapement mechanism, a, balance wheel and staff, means for converting the characteristic movements of the escapement mechanism to a continuous rotary motion of the balance wheel, a governor comprising a thin flexible strip carried by the balance wheel, and a constriction in said strip producing a free wing lying against a surface of the balance wheel, but having a bent portion for directing the air under the wing and causing fiexure of the constriction upon an undue acceleration of the balance wheel.

3. In a time piece, a balance wheel having a magnetic rim, a permanent magnet having its poles confronting the rim of the balance wheel and having a lug, a base on which the magnet is mounted having a bridge holding the magnet down and having a lug, a screw tted in the lug of the base and the lug of the magnet for bodily adjusting the magnet upon the base in reference to the balance Wheel, a screw stem xed between the bridge and a portion of the base, a keeper fitted across the magnet having a lug traversed by the screw stern, and means swivelly mounted in the lug receiving the screw stem i'or adjusting the keeper along the magnet.

4. In a time piece, a revoluble balance wheel, a magnetic rim on the periphery of the balance wheel, a permanent magnet located substantially in the plane of revolution of the balance wheel and having confronting pole pieces partly ernbracing said rim, and means to adjust the magnet toward and away from the balance wheel.

5. In a time piece, a balance wheel having a magnetic rim, means to revolve the balance wheel continuously, and a permanent magnet located substantially in the plane of revolution of the balance wheel and having confronting pole pieces partly embracing said rim.

6. In a time piece, a balance wheel having a magnetic rim, means to revolve the balance wheel continuously, a permanent magnet located substantially in the plane of revolution of the balance wheel and having confronting pole pieces partly embracing said rim, means to adjust the magnet toward and away from the balance wheel, and means to variably short-circuit the lines of force of the magnet.

SIRIUS E. KOCHENDARFER.

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