DEVICE FOR PINNING UP TO THE STUD AND ADJUSTING THE ACTIVE LENGTH OF A BALANCE-SPRING FOR A HOROLOGICAL MOVEMENT AND PROCESS FOR SETTING THE ACTIVE LENGTH

Abstract

The invention relates to a device (1) for pinning up to the stud and setting an active length of a balance-spring (2) for a horological movement, this balance-spring (2) being arranged in coils along a determined length, this device (1) comprising a push-button (6) arranged to hold the balance-spring (2) mechanically at a location of the length of this balance-spring (2).

The invention also relates to a process for setting the active length of the balance-spring by means of the device (1) for setting and adjusting the active length of the balance-spring.

Claims

1. A device (1) for pinning up to the stud and setting an active length of a balance-spring (2) for a horological movement, this balance-spring (2) being arranged in coils along a determined length, this device (1) comprising a push-button (6) arranged to hold the balance-spring (2) mechanically at a location of the length of this balance-spring (2).

2. The device (1) according to claim 1, wherein the push-button (6) is composed of a button (8) and a tube (10) wherein the button (8) is capable of sliding, the button (8) being returned elastically to a locking position by an elastic organ (12), the button (8) being, in an operating position, kept separate from the locking position thereof by the insertion of a portion of the balance-spring (2) between the button (8) and the tube (10), which ensures the mechanical hold of the balance-spring (2).

3. The device (1) according to claim 2, wherein the button (8) extends between a head (14) and a foot (16) wherein a groove (18) is arranged which goes at least partially around the foot (16) and wherein is engaged a portion of the balance-spring (2) at the location where it is sought to stop the balance-spring (2) by gripping between the foot (16) of the button (8) and an end facing the tube (10) along two distinct points, so as to enable the push-button (6) to transmit a holding torque to the balance-spring (2) so that this balance-spring (2) does not slide or does not turn about its fastening point over the lifetime of the timepiece.

4. The device (1) according to claim 3, wherein the groove (18) extends along an entire outer perimeter of the button (8).

5. The device (1) according to claim 2, wherein the elastic organ (12) is a spring.

6. The device (1) according to claim 5, wherein the spring is an elastic strip.

7. The device (1) according to claim 1, wherein the button (8) is provided with a groove (18) wherein is engaged the portion of the balance-spring (2) the presence of which holds the button (8) in the operating position.

8. The device (1) according to claim 1, wherein the push-button (6) is fastened to a balance bridge (20) of the horological movement.

9. The device (1) according to claim 1, wherein the device (1) for pinning up to the stud and setting the active length of the balance-spring (2) comprises a push-piece support (22) which bears the push-button (6), this push-piece support (22) being arranged to be capable of pivoting about a pivoting axis (D) of a spring balance assembly (26) of the horological movement.

10. The device (1) according to claim 8, wherein the push-piece support (22) is mounted pivoting on a support.

11. The device (1) according to claim 10, wherein the support is a balance bridge (20) or a bearing borne by this bridge.

12. The device (1) according to claim 11, wherein the bearing is a shock-absorbing bearing (30).

13. The device (1) according to claim 1, wherein a scale (40) comprising a plurality of graduations, each of which corresponds to a gain or loss time fraction of the horological movement is mounted on a bridge (20) of a plate of the horological movement or on the plate.

14. A balance-spring (2) formed from a spiral strip of a determined length for a horological movement, at least a portion of the strip being provided with a scale (40) comprising a plurality of graduations, each of which corresponds to a gain or loss time fraction of the horological movement.

15. The balance-spring (2) according to claim 14, wherein the scale (40) comprises graduations which each represent 0.1 s.

16. A process for setting the active length of a balance-spring (2) of a horological movement by means of the device (1) according to claim 1, wherein, to adjust the active length of the balance-spring (2), the balance-spring (2) is momentarily released by pressing on the push-button (6), then a balance (24) the beats of which are provided by the balance-spring (2) is pivoted by a desired angle, then the pressure is released on the push-button (6) to once again stop the balance-spring (2), the pivoting of the balance (24) triggering the movement of a guide-mark which is subsequently realigned by turning the device (1).

Description

BRIEF DESCRIPTION OF THE FIGURES

[0034] Other special embodiments and advantages of the present invention will be better understood upon reading the following detailed description of one embodiment of a device for pinning up to the stud and adjusting the active length of a balance-spring according to the invention, said example being provided for the purposes of illustration only and not intended to limit the scope of the invention, given with reference to the accompanying drawing, in which:

[0035] FIG. 1 is a top view of the device for pinning up to the stud and setting the active length of a balance-spring for a horological movement according to the invention;

[0036] FIG. 2 is a sectional view along the sectional line II-II of FIG. 1;

[0037] FIG. 3 is a perspective view of a particular embodiment of the terminal curve of a balance-spring particularly adapted for cooperating with the device according to the invention;

[0038] FIG. 4 is a bottom perspective view showing the arrangement between the push-button of the device according to the invention and the balance-spring of FIG. 3;

[0039] FIG. 5 is a schematic representation of the device according to the invention fastened to a bridge of the horological movement by means of a screw.

DETAILED DESCRIPTION OF THE INVENTION

[0040] The present invention stems from the general inventive idea which consists of bringing together in a single part at least some of the functions relating to a balance-spring intended to provide the isochronous beats of a balance of a spring balance assembly of a horological movement. For this purpose, the present invention provides a device comprising firstly a push-button arranged so as to stop a balance-spring of a horological movement at a location of the length thereof without needing to use glue. Hence, the horologist designer benefits from complete freedom in terms of the choice of material of which the balance-spring is made and, furthermore, given that the balance-spring is not glued, the device according to the invention can be dismantled at any time, for example when the timepiece is returned to the factory. Consequently, the device according to the invention already allows, firstly, repositionable pinning of the balance-spring up to the stud. On the other hand, thanks to the use of a push-button, the balance-spring can be stopped at any location of the length thereof, which allows the setting of the active length of this balance-spring, i.e. the distance separating the point where the balance-spring is stopped by the push-button from the free end of the first coil inside this balance-spring. The device according to the invention therefore makes it possible to set ad libitum the pivoting frequency of the spring balance assembly equipped with the device according to the invention. Finally, in the preferred embodiment thereof, the device according to the invention is equipped with a push-piece support which allows the fixed mounting thereof for example on a bridge of the horological movement, or the pivoting mounting thereof on a support such as balance bridge or a bearing borne by this bridge. In this embodiment, the device according to the invention thus fulfils four separate functions: repositionable pinning up to the stud of the balance-spring, mounting of the stud support on its support, setting the active length of said balance-spring, and setting the guide-mark of the balance. The device according to the invention, consisting of a single part formed, in a simplified alternative embodiment, from a tube, a button and an elastic organ, therefore advantageously replaces the assembly of the components of the prior art such as balance-spring stud, stud support, index, index key, index tail and eccentric, which makes it possible to reduce the number of components required to fasten the balance-spring and for setting the pivoting frequency of the spring balance assembly, and facilitates the mounting of the device according to the invention in the horological movement on account of the reduced size thereof. Another key advantage of the invention lies in the fact that it makes it possible to avoid any use of glue.

[0041] Designated as a whole by general reference number 1, the device according to the invention is represented as a top view in FIG. 1, and as a sectional view along the line II-II of FIG. 1 in FIG. 2.

[0042] In a simplified embodiment thereof, the device 1 according to the invention enables the pinning up to the stud of a balance-spring 2 for a horological movement, and the setting of an active length of this balance-spring 2.

[0043] The balance-spring 2, arranged in coils, has a determined length between a free end of an inner first coil and a free end of an outer last coil 3. For example only, the balance-spring 2 can be shaped into a flat strip delimited by first and second faces which extend parallel with and at a distance from one another.

[0044] More specifically, the device 1 according to the invention makes it possible to stop, advantageously removably as described hereinafter, the balance-spring 2 at any location of the length thereof, and to set the length separating a point 4 wherein this balance-spring 2 is stopped from the free end of the first coil inside said balance-spring 2.

[0045] To this end, the device 1 according to the invention comprises firstly a push-button 6 arranged to hold in a releasable manner the balance-spring 2 at a location of the length of the strip of this balance-spring 2.

[0046] As seen in FIG. 2, the push-button 6 comprises essentially a button 8 and a tube 10 wherein the button 8 is capable of sliding. Advantageously, the button 8 is returned elastically to a locking position by an elastic organ 12 such as a spring or an elastic strip (see, in particular, FIG. 1).

[0047] The button 8 is, in an operating position, kept separate from its locking position by inserting a portion of the balance-spring 2 between the button 8 and the tube 10, which ensures the mechanical stopping of the balance-spring 2.

[0048] According to one of the essential advantages of the invention, it is easily understood that the balance-spring 2 can be released at any time from its engagement with the push-button 6. For this, it is simply necessary to apply a pressure on the button 8 going against the return force of the elastic organ 12 so as to make it come out of the tube 10 more. Moreover, it is understood that via a suitable choice of the coefficient of rigidity of the elastic organ 12, it is possible to control precisely the gripping force exerted on the balance-spring 2 when it is kept immobile between the button 8 and the tube 10 of the push-button 6. Consequently, the risks of breaking the balance-spring 2, in particular when it is made of silicon, are limited.

[0049] It is seen in FIG. 2 that the button 8 extends between a head 14 and a foot 16 wherein a groove 18 which goes at least partially around the foot 16 is arranged. Subsequently, the balance-spring 2 is passed around the foot 16 of the button 8 in its portion where it is sought to be stopped by the push-button 6 by gripping between the foot 16 of the button 8 and the end facing the tube 10. The balance-spring 2 is thus gripped between the foot 16 of the button 8 and the end facing the tube 10 along two points, which enables the push-button 6 to transmit a holding torque to the balance-spring 2 so that this balance-spring 2 does not slide or does not turn about its fastening point over the lifetime of the timepiece.

[0050] According to a simplified embodiment of the invention illustrated in FIG. 5, the device 1 according to the invention and its push-button 6 are simply fastened to a bridge 20 of a plate of the horological movement, typically by means of a screw 21.

[0051] According to an enhanced embodiment of the invention, the device 1 for pinning up to the stud and setting the active length of the balance-spring 2 further comprises a push-piece support 22 which bears the push-button 6, and a balance 24 forming part of a spring balance assembly 26. The push-piece support 22 is arranged to be capable of pivoting about a pivoting axis D of the spring balance assembly 26 of the horological movement.

[0052] In this aim, the push-piece support 22 is provided with an opening 28 the internal diameter of which is adjusted to the external diameter of the pivoting axis D of the spring balance assembly 26. The device 1 according to the invention thus advantageously fulfils both the function of balance-spring stud and of stud support.

[0053] As shown in FIGS. 1 and 2, the spring balance assembly 26 is preferably pivoted in a shock-absorbing bearing 30 conventionally comprising a setting 32, a stone with a hole 34, an endstone 36 and a spring 38.

[0054] It goes without saying that the present invention is not limited to the embodiment described hereinabove, and that various simple alternatives and modifications can be considered by a person skilled in the art without leaving the scope of the invention as defined by the accompanying claims. It will be noted in particular that to facilitate the setting of the active length of the balance-spring 2, a portion at least of the spiral strip forming this balance-spring 2 can be provided with a scale 40 of which each graduation represents for example a variation of 0.1 s as seen in FIGS. 3 and 4. To adjust the active length of the balance-spring 2, it is simply necessary to press the button 8 of the push-button 6 to momentarily release the balance-spring 2, then pivot the balance 24 by the desired angle to correct a known gain or loss. For example, if the horological movement gains 1 second per day, the spring balance assembly 26 is moved to induce a loss by moving 10 graduations of 0.1 s in front of an index 42. Then the pressure is released on the button 8 of the push-button 6 to once again stop the spring balance 2. The pivoting of the balance 24 will also trigger the movement of a guide-mark which can then be realigned by turning the device 1 which is composed of the push-button 6 and the push-piece support 22 bearing the push-button 6. It will obviously be understood that this operation is not possible in the case of the simplified embodiment of the invention illustrated in FIG. 5. It will also be noted that, in the sense of the invention, push-button denotes an assembly formed from a cylinder and tube inside which the cylinder is capable of sliding against the elastic return force of a spring. It will similarly be noted that, as already mentioned above, the stopping of the balance-spring 2 is performed along two points located for one on the terminal curve and for the other in the region where the scale can be provided.

NOMENCLATURE

[0055] 1. Device [0056] 2. Balance-spring [0057] 3. Outer last coil [0058] 4. Point [0059] 6. Push-button [0060] 8. Button [0061] 10. Tube [0062] 12. Elastic organ [0063] 14. Head [0064] 16. Foot [0065] 18. Groove [0066] 21. Screw [0067] 22. Push-piece support [0068] 24. Balance [0069] D. Pivoting axis [0070] 26. Spring balance assembly [0071] 28. Opening [0072] 30. Shock-absorbing bearing [0073] 32. Setting [0074] 34. Stone with hole [0075] 36. Endstone [0076] 38. Spring [0077] 40. Scale [0078] 42. Index