Clutch device for a watch

Abstract

To provide a clutch device for timepieces that does not require a large space for installation because of a simple structure, and with which it is possible to set the hands of a timepiece to zero without difficulty.SOLUTION: The clutch device for timepieces comprises: a clutch input wheel 1 located on a shaft 2 that supports a clutch output wheel to be incapable of relative rotation; and a clutch disk 3 for the clutch input wheel 1 coaxial on shaft 2, in which a counter clutch disk 4 displaceable in the axial direction is loaded by a spring force to come into contact with a clutch disk 3 in a frictional engagement manner and is graspable from below by a claw 8, the counter clutch disk 4 is liftable to a decoupling position by the claw 8 at a position that is in contact with a joining position with the clutch disk 3, and the claw 8 is movable by a manually operable decoupling pusher from a non-acting position where no load occurs to an acting position at which the counter clutch disk 4 is raised from the clutch disk 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a clutch device for a timepiece, comprising: a clutch input wheel that is rotatably driven by a movement, the clutch input wheel being rotatably driven and fixed in the axial direction, and arranged on an axis that supports a clutch output wheel so that it cannot rotate relative to the clutch output wheel; and a clutch disc of the clutch input wheel that is coaxial with the axis, the clutch disc having an axially displaceable counter clutch disc that is coaxially arranged on the clutch disc, the counter clutch disc being loaded by a spring force to abut frictionally on the clutch disc and being grippable from below by a pawl, the counter clutch disc being able to be lifted by the pawl at a position where it abuts at an engaged position with the clutch disc to a decoupling position (unengaged position), the pawl being movable by a manually operable decoupling pusher from an inoperative position where no load is applied to it to an engaged position where it lifts the counter clutch disc from the clutch disc. [Background technology]

[0002] In such known chronograph clutch devices, friction between the rotatable parts can prevent the hands from being zeroed. Summary of the Invention [Problem to be solved by the invention]

[0003] SUMMARY OF THE INVENTION The object of the present invention is therefore to provide a clutch device for a timepiece as described at the outset which is simple in design, requires little installation space and allows for unhindered zero setting of the hands of the timepiece. [Means for solving the problem]

[0004] To solve this problem, the clutch device for a timepiece according to the present invention is characterized in that when the decoupling pusher is partially operated, the counter clutch disc can be lifted by a pawl from the clutch disc by a first decoupling stroke (first uncoupled stroke) to a first decoupling position that can be locked by the locking device, and when the decoupling pusher is then fully operated, the pawl can be lowered from the counter clutch disc by a second decoupling stroke that is opposite to the first decoupling stroke, and when the decoupling pusher is then partially released, the counter clutch disc can be raised by the pawl from the second decoupling stroke to a third decoupling stroke, and in this case the locking device is unlocked, and when the decoupling pusher is then fully released, the counter clutch disc is returned to the coupled position by a spring force.

[0005] With this configuration according to the invention, if the counter clutch disc has been lifted by the pawl from the clutch disc by the first decoupling stroke due to partial actuation of the decoupling pusher into a first decoupling position that can be locked by the locking device, the clutch device remains open and can be easily rotated by lowering the pawl when the decoupling pusher is fully actuated in order to zero the clock hands. Partial actuation of decoupling pusher When the decoupling pusher is subsequently fully actuated, the pawl can be lowered from the counter clutch disc in a second decoupling stroke opposite to the first decoupling stroke, and when the decoupling pusher is subsequently partially released, the counter clutch disc can be raised by the pawl from the second decoupling stroke to a third decoupling stroke, thereby unlocking the locking device, and when the decoupling pusher is subsequently fully released, the counter clutch disc is returned by the spring force to the engaged position and again to the deactivated position.

[0006] The counter clutch disc may be formed by the bottom of a cup-shaped clutch sleeve, the clutch sleeve having a radially projecting collar at its end remote from the bottom.

[0007] If the pawl is displaceable axially relative to the shaft between its inoperative and operative positions, friction losses between the pawl and the opposing clutch disc are avoided, resulting in smooth operation of the clutch device.

[0008] The pawl can be driven to move with a stroke crown wheel by a pawl pin parallel to the axis and firmly arranged on the pawl, one of the end faces of the pawl pin abutting against its teeth, and the stroke crown wheel can be advanced stepwise around the crown wheel axis by a decoupling pusher.

[0009] In this case, a simple configuration is realized in that the stroke crown wheel has several alternating pairs of first and second teeth, the first teeth being smaller in height than the second teeth, and the pawl pin raises the pawl to a first decoupling stroke by means of the first tooth, after which, when the decoupling pusher is fully actuated, the pawl pin can be lowered to a second decoupling stroke in a first gap after the first tooth, after which, when the decoupling pusher is partially released, the pawl pin and the pawl together with it can be raised to a third decoupling stroke by means of the second tooth, after which the pawl pin can be lowered to a second gap after the second tooth and the pawl can be lowered to the coupling position.

[0010] The stroke crown wheel can be rotated stepwise by the decoupling pusher.

[0011] The configuration is simplified if the locking device has a claw that is pivotably arranged on the opposing clutch disc around a claw axis that is parallel to the shaft, and the claw is capable of engaging with the locking recess of the shaft when the first decoupling stroke is reached and disengaging from the locking recess when the third decoupling stroke is reached.

[0012] In this case, the claw can be held in elastic radial inward contact on the outer circumferential surface of the shaft during the first decoupling stroke, and can engage radially inward with a circumferential locking recess on the outer circumferential surface of the shaft after reaching the first decoupling position.

[0013] A good locking is achieved if the first side wall of the locking recess, which is closer to the clutch disc, extends radially, and an easy locking is achieved if the second side wall of the locking recess, which is further away from the opposing clutch disc, is a sliding wall that is inclined to enlarge the opening of the locking recess.

[0014] In this case, the claw abuts the second side wall of the locking recess by the first sliding ramp on the path from the second decoupling stroke to the third decoupling stroke, and is movable to exit the locking recess while sliding along the second side wall, and is movable away from the shaft to an unlocked position and is retainable in the unlocked position.

[0015] The claw may be movable to slide on the outer circumferential surface of the shaft in the path of the opposing clutch disc from the third decoupling position to the engagement position so as to immediately position itself again in a position where the decoupling process can take place.

[0016] In a simple configuration, the claw can have a claw arm extending radially from the claw shaft, a free end of the claw arm not engageable with the locking recess of the shaft being roof-shaped to have an engagement tip directed radially relative to the claw shaft, a side surface of the engagement tip extending in a radial plane relative to the claw shaft, the claw having a second sliding ramp formed on the claw arm, the second sliding ramp completely or partially surrounding the shaft concentrically and sloping from an area closer to the claw shaft to an area farther away from the claw shaft, when the counter clutch disc is moved from the third decoupling position to the engaged position, a conical portion firmly positioned on the shaft and directed away from the clutch input wheel abuts on the second sliding ramp, and the claw slides along the second sliding ramp while pivoting around the claw shaft, and in this case the claw spring moves from the second side of the engagement tip, which urges the claw out of the locking recess, to the first side of the engagement tip, which urges the claw into the locking recess.

[0017] An embodiment of the present invention will now be described in more detail with reference to the drawings. [Brief explanation of the drawings]

[0018] [Figure 1] 10 is a cross-sectional view showing the clutch device in transition from a third decoupling position to an engaged position. FIG. [Figure 2] 2 is a plan view of the clutch device of FIG. 1 in an engaged position. [Figure 3] 2 is a cross-sectional view of the clutch device of FIG. 1 in a second decoupling position. [Figure 4] 2 is a plan view of the clutch device of FIG. 1 in a second decoupling position. [Figure 5] 2 is a cross-sectional view of the clutch device of FIG. 1 in a first decoupling position. [Figure 6] 2 is a plan view of the clutch device of FIG. 1 in a third decoupling position. [Figure 7] 2 is a cross-sectional view of the clutch device of FIG. 1 in a third decoupling position. [Figure 8] 2 is a side view showing a claw and a reset pin of the clutch device in FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0019] The illustrated clutch device includes a clutch input wheel 1, which is arranged on an axially fixed shaft 2 so as to be freely rotatable and axially displaceable.

[0020] The clutch input wheel 1 is rotatably driven by a chronograph movement (not shown).

[0021] The clutch input wheel 1 has a clutch disc 3 that cannot rotate relative to the clutch disc 3, and an opposing clutch disc 4 that can be displaced in the axial direction is arranged coaxially with the clutch disc 3. The opposing clutch disc 4 is loaded by the spring force of a compression spring 5 so as to abut in a frictional engagement with the clutch disc 3 at the engagement position.

[0022] The counter clutch disc 4 is formed by the bottom of a clutch sleeve 6 and in the engaged position frictionally abuts against the clutch disc 3. At its end remote from the counter clutch disc 4, the clutch sleeve 6 has a circumferential collar 7 extending radially outward.

[0023] The collar 7 can be gripped from below by a claw 8, which can be moved by a manually operable decoupling pusher (not shown) from an inoperative position in which the collar 7 is not loaded to an operative position in which the counter clutch disc 4 is lifted from the clutch disc 3.

[0024] By means of the pawl 8, the clutch sleeve 6, and therefore the counter clutch disc 4, can be lifted from the clutch disc 3 against the spring force of the compression spring 5 by activating a decoupling pusher.

[0025] A decoupling pusher (not shown) allows the stroke crown wheel 9 to be advanced stepwise around the crown wheel axis.

[0026] A pawl pin 10 extending parallel to the axis 2 and displaceably mounted is rigidly connected to the pawl 8 and rests with its end face remote from the pawl 8 against the stroke crown wheel 9 .

[0027] The stroke crown wheel 9 has alternating pairs of first and second teeth 11, 12, with the first teeth 11 being smaller in height than the second teeth 12. During the first step of the decoupling pusher, the first teeth 11 of the pawl pin 10 allow the pawl 8 to be lifted from the clutch disc 3 in a first decoupling stroke, and the counter clutch disc 4 and the clutch sleeve 6 can be locked by the locking device 15. When the decoupling pusher is then fully actuated, the pawl pin 10 can descend into the gap 13 of the stroke crown wheel 9, resulting in a second decoupling stroke in which the pawl 8 is moved further below the clutch sleeve 6, thereby releasing the contact between the pawl 8 and the collar 7. When the decoupling pusher is then partially released, the pawl pin 10 moves onto the teeth 12 in a third decoupling stroke. The clutch sleeve 6 is then lifted by the pawl 8 in a third decoupling stroke that is greater than the first decoupling stroke. This causes the locking device to be unlocked, and the clutch sleeve 6 is returned to the coupled position by the compression spring 5 unless the decoupling pusher is subsequently actuated.

[0028] The locking device 15 has a claw 17 which is pivotably arranged on the clutch sleeve 6 about a claw axis 16 parallel to the shaft 2 and which is engageable with a locking recess 18 on the shaft 2 which is configured as an annular groove when the first decoupling stroke is reached.

[0029] In this case, the claw 17 is held in elastic radial inward contact on the outer circumferential surface of the shaft 2 during the first decoupling stroke, and after reaching the end of the first decoupling stroke, engages radially inward with the locking recess 18.

[0030] A first side wall 26 of the locking recess 18, closer to the clutch disc 3, extends radially, and a second side wall 27 of the locking recess 18, further away from the counter clutch disc 4, is a sliding wall that is inclined to enlarge the opening of the locking recess 18.

[0031] The claw 17 has a claw arm 19 extending radially from the claw shaft. The free end of the claw arm 19, not engageable with the locking recess 18 of the shaft 2, is roof-shaped to have an engagement tip 20 oriented radially relative to the claw shaft. The side surface of the engagement tip 20 extends in a radial plane relative to the claw shaft. A second sliding ramp 28 arranged on the claw 17 partially concentrically surrounds the shaft 2 and is inclined from a region closer to the engagement tip 20 to a region farther away from the engagement tip 20. When the counter clutch disc 4 is moved from the third decoupling position to the engaged position, the conical portion 22 (of the reset pin 29), which is firmly positioned on the shaft 2 and oriented away from the clutch input wheel 1, abuts against the second sliding ramp 28, and the claw 17 slides along the second sliding ramp 28 while pivoting around the claw shaft. In this case, the claw spring 23 moves from the second side 25 (of the engagement tip 20) which biases the claw 17 out of the locking recess 18 to the first side 24 (of the engagement tip 20) which biases the claw 17 into the locking recess 18.

[0032] In the third decoupling stroke, with the decoupling pusher released, the claw 7 can disengage from the locking recess 18 and the clutch sleeve 6 can return to the coupled position by the compression spring 5 . [Explanation of symbols]

[0033] 1 clutch input wheel 2-axis 3 clutch disc 4 opposing clutch discs 5 compression springs 6 Clutch sleeve 7 Colors 8 Claws 9-stroke crown wheel 10 claw pins 11 First tooth 12 Second tooth 13 First Gap 14 Second gap 15 Locking device 16 Claw shaft 17 Claws 18 Lock recess 19 Claw Arm 20 Engagement tip 21 Sliding ramp 22 Cone section 23 Claw spring 24 First aspect 25 Second aspect 26 First side wall 27 Second side wall 28 Second Sliding Ramp 29 Reset pin

Claims

1. A clutch device for a timepiece, comprising: a clutch input wheel (1) rotatably driven by the movement and arranged on an axle (2) which is rotatably driven and axially fixed and which supports a clutch output wheel in a non-rotatable manner relative to the axle; a clutch disc (3) of the clutch input wheel (1) coaxial with the shaft (2), wherein an axially displaceable counter clutch disc (4) is arranged coaxially with the clutch disc (3), the counter clutch disc (4) is spring-loaded to frictionally engage with the clutch disc (3) and can be gripped from below by pawls (8), and the counter clutch disc (4) can be lifted by the pawls (8) to a decoupling position when it abuts the clutch disc (3) in an engagement position; Equipped with A clutch device in which the pawl (8) can be moved by a manually operable decoupling pusher from a non-operating position where no load is applied to an operating position where the counter clutch disc (4) is lifted from the clutch disc (3), a first decoupling position lockable by a locking device (15) for locking the counter clutch disc (4) from the clutch disc (3) by the pawl (8) by a first decoupling stroke when the decoupling pusher is partially actuated, and thereafter the pawl (8) descends from the counter clutch disc (4) by a second decoupling stroke opposite to the first decoupling stroke when the decoupling pusher is fully actuated, thereby resetting the clock hands to zero and allowing the clutch device to rotate in an released state; a second decoupling stroke when the decoupling pusher is partially released, and the counter clutch disc (4) is raised by the pawl (8) from the second decoupling stroke to a third decoupling stroke when the locking device (15) is unlocked; and a third decoupling stroke when the decoupling pusher is fully released, allowing the counter clutch disc (4) to return to the engaged position by the spring force.

2. 2. A clutch device according to claim 1, characterized in that the counter clutch disc (4) is formed by the bottom of a cup-shaped clutch sleeve (6), the clutch sleeve (6) having a radially projecting collar (7) at its end remote from the bottom.

3. 3. A clutch device according to claim 1 or 2, characterized in that the pawl (8) is axially displaceable relative to the shaft (2) between the inoperative position and the operative position.

4. 2. A clutch device according to claim 1, characterized in that the pawls (8) can be driven to move with a stroke crown wheel (9) by means of a claw pin (10) parallel to the axis (2) and firmly arranged on the pawls (8), with one of the end faces of the claw pin (10) abutting on one of its teeth (11, 12), and the stroke crown wheel (9) can be advanced stepwise around the crown wheel axis by means of a decoupling pusher.

5. 5. A clutch device according to claim 4, characterized in that the stroke crown wheel (9) has a plurality of alternating pairs of first and second teeth (11, 12), the first teeth (11) being smaller in height than the second teeth (12), the pawl pin (10) raises the pawl (8) to a first decoupling stroke by means of the first teeth (11), after which, when the decoupling pusher is fully actuated, the pawl pin (10) can be lowered to a second decoupling stroke in a first gap (13) behind the first teeth (11), after which, when the decoupling pusher is partially released, the pawl pin (10) and the pawl (8) together with it can be raised to a third decoupling stroke by means of the second teeth (12), then the pawl pin (10) can be lowered to a second gap (14) behind the second teeth (12) and the pawl (8) can be lowered to an engaged position.

6. 5. A clutch device according to claim 4, characterized in that the stroke crown wheel (9) can be rotated stepwise by the decoupling pusher.

7. 2. The clutch device according to claim 1, wherein the locking device (15) has a claw (17), the claw (17) being pivotably disposed on the opposing clutch disc (4) about a claw axis (16) parallel to the shaft (2), the claw being engageable with a locking recess (18) of the shaft (2) when the first decoupling stroke is reached, and being disengageable from the locking recess (18) when the third decoupling stroke is reached.

8. 8. The clutch device according to claim 7, wherein the claws (17) are held in radially inward elastic contact on the outer circumferential surface of the shaft (2) during the first decoupling stroke, and after reaching the first decoupling position, they engage radially inward with circumferential locking recesses (18) on the outer circumferential surface of the shaft (2).

9. 9. A clutch device according to claim 8, characterized in that a first side wall (26) of the locking recess (18) closer to the clutch disc (3) extends radially, and a second side wall (27) of the locking recess (18) further away from the counter clutch disc (4) is a sliding wall that is inclined to enlarge the opening of the locking recess (18).

10. 10. The clutch device according to claim 9, wherein the claw (17) abuts against the second side wall (27) of the locking recess (18) by a first sliding ramp (21) in a path from the second decoupling stroke to the third decoupling stroke, and is movable to exit the locking recess (18) while sliding along the second side wall (27), and is movable to move away from the shaft (2) to an unlocked position and is retainable in the unlocked position.

11. 11. The clutch device according to claim 8, wherein the claw (17) is movable to slide on the outer circumferential surface of the shaft (2) in the path of the opposing clutch disc (4) from the third decoupling position to the engagement position.

12. 12. The clutch device according to claim 11, wherein the claw (17) has a claw arm (19) extending radially from the claw shaft (16), a free end on an end face side of the claw arm (19) engageable with the lock recess (18) of the shaft (2) is formed in a roof shape to have an engagement tip (20) directed radially relative to the claw shaft (16), a first side surface (24) and a second side surface (25) of the engagement tip (20) extend in a radial plane relative to the claw shaft (16), the claw (17) has a second sliding ramp (28) formed on the claw arm (19), the second sliding ramp (28) completely or partially surrounds the shaft (2) concentrically and extends from a region closer to the engagement tip (20) to a region closer to the engagement tip (20) and when the counter clutch disc (4) is moved from the third decoupling position to the engaged position, a conical portion (22) that is firmly disposed on the shaft (2) and directed away from the clutch input wheel (1) abuts against the second sliding ramp (28), and the claw (17) slides along the second sliding ramp (28) while pivoting about the claw axis (16), and in this case, a claw spring (23) moves from the second side (25) of the engagement tip (20) that urges the claw (17) out of the locking recess (18) to the first side (24) of the engagement tip (20) that urges the claw (17) into the locking recess (18).

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