Oscillator for a timepiece movement and timepiece comprising such an oscillator

Abstract

The invention relates to a balance wheel-hairspring oscillator (10) comprising: a balance wheel shaft (18) intended to be pivotably mounted on a frame of a timepiece; a balance wheel (12) secured to the balance wheel shaft (18); a hairspring (14) comprising an inner end (14a) secured to the balance wheel shaft and an outer end (14b) intended to be connected to a connecting member (16) to said frame, and a transmission member (20, 22) arranged to interact with an escapement. The balance wheel (12) and the hairspring (16) are arranged on either side of the transmission member.

Description

technical field

[0001] The present invention relates to a watch movement comprising a balance-spring type oscillator, as well as a timepiece comprising such a watch movement. The present invention also relates to a stop-seconds device arranged to cooperate with the oscillator. State of the art

[0002] Several oscillators already exist that stand out from traditional oscillators by their arrangement in relation to the dial of a watch, thus giving the watch an original visual appearance.

[0003] As an example, CH713649 discloses a timepiece comprising a cover device having at least one moving part and a control mechanism driving the moving part between a closed position in which part of the regulating organ, such as the balance wheel and hairspring, is hidden by the cover device, and an open position in which the balance wheel and hairspring are fully visible. The moving part is located between the balance wheel and the hairspring when in the closed position. The cover device is configured so that only the balance wheel is visible when the moving part is in the closed position. To this end, the balance wheel and hairspring are mounted on the balance staff so as to be separated by a sufficient axial distance to be located on either side of the moving part when the latter is in the closed position.

[0004] EP0520218 discloses a timepiece comprising a dial with an opening in which is arranged a balance-spring type oscillator so that the oscillator is arranged substantially in the plane of the dial.

[0005] DE202012002284U1 discloses a timepiece comprising a dial with a circular aperture within which a tourbillon mechanism is mounted. This mechanism includes a balance wheel and hairspring, an escapement, and an escape wheel mounted in a tourbillon cage. A display hand is mounted integrally with the cage so as to rotate within the circular aperture in the dial. The tourbillon mechanism is configured so that the balance wheel and hairspring are elevated relative to the dial and oscillate above the display hand.

[0006] In addition, there are many stop-seconds mechanisms that allow the seconds hand to be stopped for precise time setting.

[0007] As an example, EP1422579 discloses a time-setting system comprising a lever having a first part placed on an upper part of the plate and a second part orthogonal to the first part and passing through the upper plate so as to come into contact with the rim of the balance wheel.

[0008] However, this system is difficult to integrate into the watch movement because of the shape of the lever, which is dictated by the location of the balance wheel in the movement.

[0009] Document US2209172A discloses a balance wheel in which the balance wheel rim is positioned at a distance from the balance spring.

[0010] One aim of the present invention is to provide a watch movement in which the location of the balance wheel simplifies the construction of a stop-seconds device.

[0011] Another objective of the present invention is to provide a timepiece comprising an oscillator arranged to give the timepiece an original visual appearance. Brief summary of the invention

[0012] These goals are achieved, thanks to a clockwork movement comprising a balance-spring type oscillator, according to one aspect of the invention, comprising A balance staff intended to be pivotally mounted on the frame of a timepiece, a balance wheel fixed to the balance staff, a balance spring having an inner end fixed to the balance staff and an outer end intended to be connected to a linkage to said frame, and a transmission mechanism arranged to cooperate with an escapement. The balance wheel and balance spring are arranged on either side of the transmission mechanism, in which the movement includes a mainplate, the oscillator being mounted in the timepiece so that the balance wheel and balance spring are arranged on either side of the mainplate.

[0013] According to one form of execution, the balance wheel and the balance spring are mounted respectively at a first and a second end of the balance shaft.

[0014] According to one embodiment, the transmission organ is in the form of a double plate comprising a pin intended to cooperate with an escapement anchor.

[0015] According to one embodiment, the inner end of the spiral is attached to a ferrule mounted at the other end of the balance staff.

[0016] According to one embodiment, a spacer is mounted on the balance shaft between the ferrule and the transmission member.

[0017] According to one form of execution, the watch movement includes a dial and a stop-seconds device arranged entirely on the upper part of the plate on the dial side.

[0018] In one embodiment, the stop-seconds device comprises a rocker mounted on the upper part of the mainplate. The rocker has a lever portion arranged to cooperate with a sliding pinion of a winding mechanism and an engagement portion arranged to cooperate with a portion of the balance wheel rim. The lever and engagement portions are arranged on either side of the rocker's pivot axis.

[0019] In one embodiment, the distal end of the lever portion of the rocker arm is arranged to cooperate with a pull-out lever of the winding mechanism. The pull-out lever is pivoted when the winding stem is moved from a first axial position to a second axial position corresponding to the time-setting position. The pivoting of the pull-out lever rotates the rocker arm around its pivot axis so that, on the one hand, the distal end of the engagement portion abuts against a portion of the balance wheel rim to immobilize the balance wheel, and on the other hand, the sliding pinion engages with the gears and the minute wheel to drive the hands for setting the time of the movement.

[0020] Another aspect of the invention relates to a timepiece comprising a watch case incorporating the watch movement as described above. The balance wheel is arranged at the dial level, while the balance spring is arranged on the back of the watch case. Brief description of the figures

[0021] Examples of implementation of the invention are given in the description illustrated by the accompanying figures, in which: there Figure 1 represents a perspective view of the balance-spring type oscillator according to one embodiment of the invention; the Figure 2 represents a cross-sectional view at the level of the oscillator's balance shaft Figure 1 ; there Figure 3 represents a perspective view of a clock movement with a dial containing the oscillator of the Figure 1 ; there Figure 4 represents a view similar to the Figure 3 without the dial; the Figure 5represents a partial view from below of the clockwork mechanism at the level of the oscillator; the Figure 6a represents a perspective view of a portion of the upper part of the mainplate of the watch movement, which includes a stop-seconds device in a non-operational configuration, and the Figure 6b represents a view similar to the Figure 6a when the stop-seconds device is activated. Example(s) of an embodiment of the invention

[0022] According to the Figures 1 and 2 The oscillator 10 includes a balance wheel 12, a balance spring 16 and a balance shaft 18. The balance wheel 12 includes a rim 13, a hub 15 and several arms 14 connecting the rim 13 to the hub 15. The hub 15 of the balance wheel 12 is mounted at a first end of the balance shaft 18 at the level of a first segment 18a of the shaft 18 and against a shoulder 24 in order to ensure that the balance wheel 12 oscillates in a plane perpendicular to its axis of rotation.

[0023] The balance spring 16 is mounted at a second end of the balance shaft 18 at a second segment 18b of the shaft 18. The inner end 16a of the balance spring is attached to a ferrule 28. The ferrule 28 is mounted on the second segment 18b of the balance shaft 18 by means of a spacer 26. This spacer has a first portion 26a having a first diameter and a second portion 26b having a second diameter greater than the first diameter 26a.

[0024] The ferrule 28 is mounted on the first portion 26a of the spacer 26, for example by pressing or riveting, while the second portion 26b of the spacer 26 is arranged between the ferrule 28 and a transmission member fixed to the balance staff 18. This transmission member is preferably in the form of a double plate 20 having a pin 22 intended to cooperate with an escapement lever (not shown) to regulate the rate of a clock movement. In one embodiment, the spacer 26 is integral with the transmission member. In the embodiment of the Figures 1 and 2 The balance wheel 12 and the balance spring 16 are arranged on either side of the transmission organ. In other words, the transmission organ and the balance spring 16 are on the same side of the balance wheel 12.

[0025] THE Figures 3 to 5show a watch movement comprising a mainplate 80. The oscillator is mounted in the watch movement so that the balance wheel 12 and the balance spring 16 are arranged on either side of the mainplate 80. For example, the balance wheel 12 is arranged on the display side of the mainplate 80 and the balance spring is arranged on the opposite side (caseback side) of the mainplate 80. In the example of the Figure 3The watch movement includes a dial 70. The oscillator 10 is mounted in the watch movement so that the balance wheel 12 is positioned at the level of the dial 70, for example, in a circular opening 72 made in the dial 70. The balance wheel 12 can also be positioned above the dial 70. The balance spring 16, on the other hand, is positioned on the opposite side of the mainplate. For example, the balance spring 16 is positioned so as to be on the case back side of a watch case (not shown) when the movement is incorporated into the watch case of a timepiece. According to a variant, the timepiece has no dial or only a partial dial with an arc-shaped cutout so as to only partially surround the balance wheel of the movement.

[0026] The ends of the balance staff 18 are mounted in a first and second bearing (not visible) arranged respectively on a first and second balance bridge 30, 36 mounted on the mainplate 80 on the dial side and case back side, respectively. The ends of the first balance bridge 30 are fixed to the mainplate 80 by two screws 34. These screws are also screwed into two retaining cylinders 33 arranged between the ends of the first balance bridge 30 and the mainplate 80. The height of the retaining cylinders 33 has been adjusted so that the balance wheel 12 of the oscillator 10 is arranged in the opening 72 at the level of the dial 70. Note that a decoration can be machined on the first balance bridge 30, on the dial side, to improve the aesthetic appearance of the watch movement including the oscillator 10.

[0027] According to the Figure 5The second balance bridge 36 has a stud holder 38 in which a stud 17 is fixed, attached to the outer end of the balance spring 16. A regulator system is also mounted on the second balance bridge 36. The regulator system includes a regulator 39 for adjusting the active length of the balance spring 16 in order to correct rate deviations during quality control. The regulator 39 comprises, for this purpose, an arm supporting a pin 39a having a slot inside which a segment of the balance spring 16 is arranged. The regulator 39 is fitted by friction onto the second balance bridge 36. As visible in the Figures 4 and 5 A recess 81 is provided in the plate 80 to allow the passage of the oscillator 10 during its assembly in the movement. The recess 81 has a semi-circular shape, open at the periphery of the plate 80, but can also have any other shape suitable for assembling the oscillator 10 in the movement.

[0028] According to the Figures 6a, 6b The watch movement includes a stop-seconds device that cooperates with the winding stem 40 of the watch movement. The stop-seconds device has a rocker 50 which has the advantage of being arranged in a countersink 59 made on the upper plate 80 on the dial side, which simplifies the integration of the stop-seconds device into the watch movement.

[0029] The rocker 50 is mounted pivotally around a tenon 58 inside the countersink 59. This rocker is made by an assembly of two separate parts, a lever 52 arranged to cooperate with the winding stem 40 and an engagement arm 56 having at its distal end a shoe 57 arranged to come against a part of the perimeter of the rim 13 of the balance wheel 12 when the stop-seconds device is activated.

[0030] The engagement arm 56 is connected to the lever 52 of the rocker 50 so as to pivot in a plane parallel to the plane in which the lever 52 is arranged. To this end, a spacer 60 is mounted between the lever 52 and the engagement arm 56 so that the foot 57 of the engagement arm is at the same height as the rocker arm 12. Furthermore, the engagement arm 56 and the lever of the rocker 50 are arranged on either side of the tenon 58 around which the rocker 50 pivots and form an angle between them between 30° and 60°. In one embodiment, the rocker 50 is formed as a single piece comprising an engagement portion and a lever portion. In another embodiment, the spacer 60 is integral with the lever 52 and the engagement arm 56.

[0031] The lever 52 of the rocker arm 50 engages with a sliding pinion 46 arranged against the winding pinion 44 during the operation of the watch movement. The distal end of the lever 52 has a finger 54 arranged to cooperate with a pull-out 42 of the winding mechanism of the watch movement. The pull-out 42 is arranged to pivot about its pivot axis when the winding stem 40 is actuated from a first axial position to a second axial position corresponding to the position for setting the time.

[0032] The pivoting of the pull-out 42 exerts a force against the finger 54 of the rocker 50 in order to cause the latter to rotate around the tenon 58. The pivoting of the rocker 50 allows, on the one hand, the shoe 57 of the engagement portion 56 to be brought against a portion of the circumference of the rim 13 of the balance wheel 12 in order to immobilize the balance wheel and, on the other hand, to move the sliding pinion 46 away from the winding pinion 44 until it engages with the gears and the timer for the control of the hands for setting the time of the movement. List of references

[0033] Oscillator 10 Balance 12 Serge 13 Arm 14 Hub 15 Spiral 16 Inner end 16a Outer end 16b Piton 17 18-inch balance shaft First segment 18a Second segment 18b Transmission unit Double Tray 20 Platform pin 22 Shoulder 24 Spacer 26 First portion 26a Second portion 26b Ferrule 28 First swing bridge 30 First level Fixing cylinders 33 Screw 34 Second balance bridge 36 Second level 38mm eye bolt holder Racket 39 Pin 39a Winder Winding stem 40 Pull tab 42 Winding pinion 44 Sliding sprocket 46 Stop-second device Rocker 50 lever 52 Finger 54 Engagement arm 56 Sabot 57 Tenon 58 Countersink 59 Spacer 60 Dial 70 Opening 72 Platinum 80 clearance 81

Claims

1. Watch movement comprising a balance wheel-spiral oscillator (10) comprising: a balance wheel shaft (18) designed to be mounted pivotally on a frame of a timepiece; a balance wheel (12) integral with the balance wheel shaft; a balance spring (16) comprising an inner end (16a) integral with the balance staff (18) and an outer end (16b) intended to be connected to a connecting member (17) to said frame, and a transmission member (20, 22) arranged to cooperate with an escapement; the balance wheel (12) and the balance spring (16) being arranged on either side of the transmission member, and the transmission member being in the form of a double plate (20) comprising a pin (22) intended to cooperate with an escapement anchor; wherein the movement comprises a plate (80), the oscillator (10) being mounted in the watch movement such that the balance wheel (12) and the balance spring (16) are arranged on either side of the plate (80).

2. The watch movement according to claim 1, wherein the balance wheel (12) and the balance spring (16) are mounted respectively at a first and a second end (18a, 18b) of the balance staff (18).

3. The watch movement according to one of the preceding claims, wherein the inner end (14a) of the balance spring (14) is integral with a collet (28) mounted at the second end (18b) of the balance staff (18).

4. The watch movement according to the previous claim, wherein a spacer (26) is mounted on the balance staff (18) between the collet (28) and the transmission member (20, 22).

5. The watch movement according to claim 4, wherein the spacer (26) is formed integrally with the transmission member.

6. The watch movement according to one of the preceding claims, wherein the plate (80) comprises a recess (81).

7. The watch movement according to any of claims 1 to 6, comprising a dial (70) and wherein the balance wheel (12) is arranged at or above the dial (70).

8. The watch movement according to one of claims 1 to 7, comprising a stop-seconds device integrally arranged on the upper part of the plate (80).

9. The watch movement according to the previous claim, wherein the stop-seconds device comprises a lever (50) mounted on said upper part of the plate (80) and comprising a lever portion (52) arranged to cooperate with a sliding pinion (46), which is arranged to move along a winding stem (40), and an engagement portion (56) arranged to cooperate with a portion of the circumference of the serge (13) of the balance wheel (12), said lever portion (52) and engagement portion (56) being arranged on either side of the pivot axis of the lever (50).

10. The watch movement according to the previous claim, wherein the distal end of the lever portion (52) of the lever (50) is arranged to cooperate with a pull-out piece (42) of the winding mechanism, the pull-out piece (42) being pivoted when the winding stem (40) is actuated from a first axial position to a second axial position corresponding to the time-setting position, the pivoting of the pull-out piece (42) actuating the lever (50) in rotation about its pivot axis so that, on the one hand, the distal end of the engagement portion (56) comes into contact with a portion of the circumference of the serge (13) of the balance wheel (12) in order to immobilize the balance wheel, and, on the other hand, the pinion gear (46) meshes with the gear trains and the minute wheel for controlling the hands for setting the time of the movement.

11. Timepiece comprising a watch case incorporating the watch movement according to one of claims 7 to 10, wherein the balance wheel (12) is arranged at or above the dial (70) and wherein the balance spring (16) is arranged on the back side of the watch case.

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