US3846974A

US3846974A - Motor-barrel watch movement

Info

Publication number: US3846974A
Application number: US00416430A
Authority: US
Inventors: U Giger
Original assignee: Ebauchesfabrik ETA AG
Current assignee: ETA AG; Ebauchesfabrik ETA AG
Priority date: 1972-12-18
Filing date: 1973-11-16
Publication date: 1974-11-12
Anticipated expiration: 1991-11-12
Also published as: CH566044A; DE2351169A1; GB1446356A; CH1838572A4; DE2351169B2; FR2210784B1; FR2210784A1

Abstract

A motor-barrel watch movement in which the barrel arbor is cylindrical with longitudinal grooves one of which acts as the spring anchor. There are four bearing regions for supporting the pivoting of the arbor in the frame and the pivoting of the barrel on the arbor.

Description

[ 1 Nov. 12, 1974 United States Patent [1 1 Giger MOTOR-BARREL WATCH MOVEMENT Inventor: Urs Giger, Solothurn, Switzerland [73] ASSigneeI Eta A.G. EbalICheS-Fabri Primary Examiner-Ge0rge H. Miller. Jr.

Grenchcn, Switzerland Attorney, Agent, or Firm-Stevens, Davis, Miller & 22 Filed: Nov. 16, 1973 Moshe [21] I Appl. No.: 416,430

Foreign Application Priority Data Dec. 18, 1972 Switzerland.......................

ABSTRACT A motor-barrel watch movement in which the barrel [52] US. 58/87 arbor is Cylindrical with longitudinal grooves one 0f 51 Int. Cl. G04b 1/18 w i h acts as the spring anchor There are four bear- [58] Field of Search...................;....... 58/86, 87, 139 g regions for supporting the pivoting Of the arbor in a the frame and the pivoting of the barrel on the arbor.

References Cited UNITED STATES PATENTS 9 Claims, 2 Drawing Figures 1,110,061 9/1914 Kienzie 58/86 Z: fgwk SUMMARY OF THE INVENTION Essentially the object of the present invention is to achieve a reduction in manufacturing costs of motorbarrel watch-movements by simplifying the barrel arbor and the motor assembly.

In most watch movements, the barrel arbor willbe a profile-turned'part with six to eight shoulders of different diameters along its length. Furthermore, the central part, which is of maximum diameter, is provided-with several millings forming a hookto which is fastened the inside end of a spring-motor also equipped with a hook formed by bending the spring ata right angle. Of those shoulders of different diameters, four are used for pivoting and cons-equentlymust be machine finished. It will be clear that under such conditions, the manufacture of these barrel arbors consists of a sequence of costly operations; 1

Cylindrically shaped barrel arbors already. are known, which are detachably mounted in the movement frame. However, as regards theseknown devices, an additionalpiece-acting as core, that is, as thecentral component of the arbor, and ensuring that the springmotor is hooked, will be placed inside the drum. This additional piece is provided with a cylindrical passage in the direction of its axis, and'the cylindrical arbor will be placed inside said passage. Also, the core must be machined together with its hook. Further, the detachable arbor is provided with a pivoting shoulder which must be machined on the lathe. While such a known device facilitates barrel disassembly, it-does-nothing to simplify the manufacture of the arbor and will .not

lower its manufacturing cost.

Cover-less barrels provided with an elongated hub known. However, as regards these known devices, the core again is a separate piece which must be mounted on the arbor where it will form a separate collar surrounding the hub of the drum, whereby arbor machining is considerably hampered.

Lastly, barrel arbors are known, wherein the core hook is replaced by a groove running parallel to the barrel arbor and fashioned into its central shoulder. In these devices again, many manufacturing operations are required to achieve the arbor.

In order to reduce the number of operations involved in the manufacture of a barrel arbor and to facilitate assembly of the motor-sets for watches, the object of the present invention is a motor-barrel watchmovement characterized in that the barrel arbor is made of one piece provided with anchoring means for the spring-motor and with a circular surface the pivoting of the arbor in the movement frame and pivoting of the barrel about the arbor is oriented by four annular components bearing-on said cylindrical surface of said arbor. These annular components extend to the level of the apertures made on one hand in two components of the frame and on the other hand in the drum and in the barrel cover.

The attached drawing illustrates two embodiments of the watch-movement of the invention.

FIG. 1 is a fragmentary view in cross-section of one of those embodiments taken in a plane containing the barrelaxis; and

and mounted on ;a long cylindrical shoulder are also ing'machining and whic arbor 1.

2 FIG. 2 is a fragmentary view in cross-section of the other of those embodiments also taken ina plane containing the barrel axis.

As will be observed from the present description, the

two embodiments shown in the drawing maybe executed as different variations of the barrel arbor. The first embodiment relates to a watch-movement in which the ratchet-wheel 2 is mounted on the arbor of barrel 1 and lies between the drum of barrel 3 and the bridge of barrel 4. A cover 14 is fastened to the drum of barrel 3, these two components being bored by central apertures 5 and 6 of the same diameter. Further, aperture 7, which'is fashioned in bridge 4 in order to ensure rotation of the upper end of arbor'l, and aperture 8, which is fashioned in the bottom plate 9 to ensure the rotation of the lowerend of arbor l, are of the same diameter as apertures 5 and '6, however, aperture 8 being partly closed towards the outer side of the bottom plate by an annular flange 10 which was made durprovides an axial stop for Arbor l is made of a simple piece and is'mainly characterized'by cylindrical lateral surface of constant dithe frame in

apertures

7 and 8 and rotation of the barrel about the arbor, by means of apertures 5 and 6. The spring-motor 17, therefore, will be provided with a hook at its lower end for entering one of grooves 16.

Arbor 1 may be manufactured in such manner that the cost will be particularly low. Starting with calibrated cylindrical bars drawn with four grooves 16,. it will suffice to section these bars on an automatic lathe and to machinethe bevel 11 in order to obtain the arbor blanks. The latter may be tumble-polished, which provides a particularly simple and effective method for that purpose. Grooves 16 also may be milled, but it is more efficient to draw them. It will beto advantage to foresee several grooves for easier assembly. Once the arbor has been made, the ratchet-wheel 2 will be forcefitt'ed on its outer wall, the central aperture of said ratchet-wheel being provided with two or as many as four catches 18 adapted to the dimensions of grooves 16. This assembly will rigidly connect wheel 2 with arbor 1.

It is apparent that ratchet-wheel 2 will engage the movements crown-wheel which is located inside bridge 4. 5

As regards assembly, spring 17 will be so wound that its last coil will be of a lesser diameter than that of arbor 1. This spring being housed in

barrel

3, 14, the

the .tumble-polishing stage, so that the presenceof must precisely observe the tolerances of dimension a v between the lower end of arbor 1 and the location of the upper side of ratchet-wheel 2. When in operation, the positioning of the arbor with respect to height is determined on one hand by the flange supporting the lower end of arbor 1, and on the other bythe boss 19 in bridge 4 near aperture 7, said boss stopping the upper side of wheel 2. Dimension'd corresponds to the axial play of the arbor, which may be adjusted by forcefitting wheel 2 to the desired height a. Dimension 0 between barrel cover and the inside of the bottom plate must be l'argerthanzero. Such an arrangement provides a particularly simple manufacture of the barrel arbor I The embodiment of FIG. 2' shows an arbor the same as arbor 1, butofsomewhat different location with respect to the frame components'ln this latter embodiment, theratchet-wheel '20isfastened. as above to the upper end 'of arbor l. Thelatte'rs circular surface traverses aperture 21 inbarrel bridge 22 from top to bottom, then passes through aperture 23, of barrel 24, then aperture 25 of cover of barrel 26, and then aperture 27 of bottom plate 28. Spring motor 17 is fastened by its lower endto arbor l in the same manner as'in FIG. 1.

In orderto ensure that arbor 1 and wheel be kept in a proper axial position, the crown-wheel 29 is provided with teeth of which the edges 290 are slightly sloped with respect to the plane of the wheel. The teeth of wheel' 20 are similarly inclined. Crown-wheel 29 is maintained in the axial position by a screw, as in conventional watch movements, so that the edges 29a lock wheel 20 and arbor l in the axial sense in such manner that there will be no play between wheel 20 and geartrain' bridge 22. A support plate provided with pins 30 passing through apertures fashioned in bottom plate 28 and supporting the barrel in the proper height and resting against its cover is used for assembly. This support may comprise several pins 30.

This embodiment may be varied by providing the barrel arbor with a machined square at its upper end and with a threaded bore at the axis. In such case, the ratchet-wheel also would be provided with a square aperture, as in conventional circumstances, and would be fastened to the arbors square by a screw of which the heads diameter would be approximately the same as the squares diagonal. Such an arrangement also would allow to finish the rotational surfaces by tumble-polishing, which is more effective than rolling.

Another advantage will be obtained from this second embodiment and the variation that have just been described: the barrel arbor and the ratchet-wheel may be easily removed from the frame, as if of one piece. The far hook of spring 17 will be removed the moment the arbor has been pulled axially over a sufficient length. One may then withdraw the motor-barrel from the movement, provided the components fastened between the barrel bridge and the bottom plate are arranged to leave free passage to the barrel between the barrel and the periphery of the movement. In lieu of being projusted to the diameter of piece 1 and force-fitted to vided with catches at its central aperture, ratchet-wheel.

20 might also be provided with a circular aperture adbarrel.

same.

The embodiments and the variation thereof just described provide the following advantages:

One may manufacture arbors l I from, bars with grooves formed therein during drawing thanks to a drawing die of suitable shape.

over its entire length, arbor 1 meetsve-ry stringent requirements. It was observed that'the initial bars could be trued by means of grinders working on a rollermounted bar (CENTERLESS process), which fact considerably simplifies the manufacture and allows achieving high accuracy. 1

Machining on automatic lathes for bars is extremely simple.

The feasibility of tumble-polishing large quantities of arbors also constitutes simplification in manufacture.

Lastly, as previously. mentioned, the described arrangement facilitates assembly and'disassembly of the In the case of a self-winding watch-movement, the pinion(s) meshing with-the ratchet-wheel 6 may be pinions of the self-winding mechanism. They may also be provided with slanting toothing.

As explained above, the use of cylindrical bars extruded through a contoured die for four longitudinal grooves allows particularly efficient manufacture of barrel-arbors. However, hooking the spring-motor in a longitudinal groove of the arbor is not the sole economical solution to the problem in question. Fastening the spring to the arbor also may be achieved by fashioning an aperture or a cut-out in the end of the spring and winding latter around itself on the arbor. The spring then is connected to the arbor byclamping. In this case,

arbor manufacture is particularly advantageous with respect to cost, since one needs only a cylindrical bar which will be sectioned.

. What is claimed is:

1. A motor-barrel watch movement characterized in that the barrel arbor is made ofone piece with a circular, cylindricalsurface, and in which rotation of the arbor in the frame of the movement and the rotation of the barrel about the arbor are ensured by four annular bearings surrounding said cylindrical surface and which lie in the space between an aperture fashioned on one hand in two of the frame components and on the other, in the drum and the barrel cover, said arbor including an anchoring means for the spring motor characterized as a recess formed in the cylindrical surface of said arbor.

2. A movement as defined in claim 1, in which the barrel arbor is square at one end, and further comprising a ratchet-wheel-having a square central aperture fastened to said square end of said arbor.

3. A motor barrel watch movement having a barrel arbor and spring motor characterized in that the barrel arbor is made of one piece with a circular cylindrical surface and in which rotation of the arbor in the frame of the movement and the rotation of the barrel about the arbor are ensured by four annular bearings surrounding said cylindrical surface and which lie in the space between an aperture fashioned on one hand in two of the frame components and on the other in the drum and the barrelcover wherein said cylindrical surface of said arbor is provided with at least one longitudinal groove anchoring the inner end of the spring moin that said barrel arbor is tor, and thus constituting the anchoring means therefor.

4. A movement as defined in claim 3, characterized provided with four longitudinal grooves at 90 from one another.

5. A movement as defined in claim 3, further comprising a ratchet-wheel provided with a central profiled aperture with at least one catch capable of entering said groove, said ratchet-wheel being force-fitted on said arbor with said catch in said groove.

6. A motor barrel watch movement having a barrel arbor and spring motor characterized in that the barrel arbor is made of one piece with a circular cylindrical surface and in which rotation of the arbor in the frame of the movement and the rotation of the barrel about the arbor are ensured by four annular bearings surrounding said cylindrical surface and which lie in the space between an aperture fashioned on one hand in two of the frame components and on the other in the drum and the" barrel cover wherein the arbor mounting aperture of one of the frame components is provided with an innershoulder in the vicinity of its outer sur face, this shoulder acting as an axial step for the barrel arbor.

7 A movement as defined in claim 6, characterized in that said cylindrical surface of said arbor is provided with at least one longitudinal groove, and further comprising a ratchet-wheel surrounding said arbor and having a catch in said groove, said ratchet-wheel being adjusted in height on the arbor in such manner that it will lie between the barrel and the frame component ensuring rotation of the arbors other end, the height adjustment of the ratchet-wheel being such that this wheel together with the inner surface of said frame component limits the axial play of the arbor.

8. A motor barrel watch movement having a barrel arbor and spring motor characterized in that the barrel arbor is made of one piece with a circular cylindrical surface and in which rotation of the arbor in the frame of the movement and the rotation of the barrel about the arbor are ensured by four annular bearings surrounding said cylindrical surface and which lie in the space between an aperture fashioned on one hand in two of the frame components and on the other in the drum and the barrel cover wherein the ratchet wheel is fastened to one end of the arbor and extends outside the frame and in that the axial positioning of the arbor is ensured on one hand by a stop rigidly connected to the frame and operating in concert with the ratchetwheel and on the other by an oblique toothing of a wheel-and-pinion mounted on the frame and meshing with the ratchet wheel.

9. A movement as defined in claim 8, characterized in that said wheel-and-pinion is the crown-wheel.

Claims

1. A motor-barrel watch movement characterized in that the barrel arbor is made of one piece with a circular, cylindrical surface, and in which rotation of the arbor in the frame of the movement and the rotation of the barrel about the arbor are ensured by four annular bearings surrounding said cylindrical surface and which lie in the space between an aperture fashioned on one hand in two of the frame components and on the other, in the drum and the barrel cover, said arbor including an anchoring means for the spring motor characterized as a recess formed in the cylindrical surface of said arbor.

2. A movement as defined in claim 1, in which the barrel arbor is square at one end, and further comprising a ratchet-wheel having a square central aperture fastened to said square end of said arbor.

3. A motor barrel watch movement having a barrel arbor and spring motor characterized in that the barrel arbor is made of one piece with a circular cylindrical surface and in which rotation of the arbor in the frame of the movement and the rotation of the barrel about the arbor are ensured by four annular bearings surrounding said cylindrical surface and which lie in the space between an aperture fashioned on one hand in two of the frame components and on the other in the drum and the barrel cover wherein said cylindrical surface of said arbor is provided with at least one longitudinal groove anchoring the inner end of the spring motor, and thus constituting the anchoring means therefor.

4. A movement as defined in claim 3, characterized in that said barrel arbor is provided with four longitudinal grooves at 90* from one another.

6. A motor barrel watch movement having a barrel arbor and spring motor characterized in that the barrel arbor is made of one piece with a circular cylindrical surface and in which rotation of the arbor in the frame of the movement and the rotation of the barrel about the arbor are ensured by four annular bearings surrounding said cylindrical surface and which lie in the space between an aperture fashioned on one hand in two of the frame components and on the other in the drum and the barrel cover wherein the arbor mounting aperture of one of the frame components is provided with an inner shoulder in the vicinity of its outer surface, this shoulder acting as an axial step for the barrel arbor.

7. A movement as defined in claim 6, characterized in that said cylindrical surface of said arbor is provided with at least one longitudinal groove, and further comprising a ratchet-wheel surrounding said arbor and having a catch in said groove, said ratchet-wheel being adjusted in height on the arbor in such manner that it will lie between the barrel and the frame component ensuring rotation of the arbor''s other end, the height adjustment of the ratchet-wheel being such that this wheel together with the inner surface of said frame component limits the axial play of the arbor.

8. A motor barrel watch movement having a barrel arbor and spring motor characterized in that the barrel arbor is made of one piece with a circular cylindrical surface and in which rotation of the arbor in the frame of the movement and the rotation of the barrel about the arbor are ensured by four annular bearings surrounding said cylindrical surface and which lie in the space between an aperture fashioned on one hand in two of the frame components and on the other in the drum and the barrel cover wherein the ratchet wheel is fastened to one end of the arbor and extends outside the frame and in that the axial positioning of the arbor is ensured on one hand by a stop rigidly connected to the frame and operating in concert with the ratchet-wheel and on the other by an oblique toothing of a wheel-and-pinion mounted on the frame and meshing with the ratchet wheel.