Winding devices and clock movements

Abstract

To provide a winding device equipped with a system for limiting the winding of a spring, which replaces a system based on the sliding of a blade against notches in an internal wall of a drum.SOLUTION: The invention relates to a winding device 1 of a barrel 2 provided with a spring. The winding device 1 includes a ratchet 3 mounted integrally on a rotary winding shaft, and a winding gear train 4 meshing with the ratchet 3. The rotary winding shaft is, for example, a winding shaft of the barrel 2, the rotation of which winds the barrel 2. The rotation of the winding gear train 4 causes the rotation of the ratchet 3 and the rotation of the rotary winding shaft by application of a torque to the ratchet 3, where the ratchet 3 is deformable in order to be able to disconnect the ratchet 3 from the winding gear train 4.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a winding device, in particular a watch barrel, fitted with a releasable ratchet.

[0002] The invention also relates to a clock movement including such a winding device. [Background technology]

[0003] Modern automatic watches typically include an oscillating weight that uses gravity to drive a gear train, which rotates a drum that in turn drives a rod to wind a spring blade or barrel spring that is wound on the drum around the rod.

[0004] However, once this spring is fully wound, it is important to avoid over-winding, as this can cause the spring to break or the oscillator to knock. During knocking, the amplitude of vibration increases to a point where the balance hits the back of the anchor horn and reaches stops, causing a drift in motion due to the balance rebounding against these stops.

[0005] To avoid these risks, such barrels generally have a system for limiting the winding up of the barrel spring.

[0006] This restriction is typically accomplished by sliding the last outer blade of the spring against the inside wall of the drum. When the spring is fully coiled around the barrel winding shaft, the last coil is forced against the outer wall of the drum.

[0007] Therefore, when the winding torque exceeds the friction torque of the last coil against the wall, the last coil will start to slide. To prevent uncontrolled sliding, the notches allow the blade ends to stop sliding as soon as the winding torque drops sufficiently.

[0008] However, the drawback of such a system lies in the sliding friction process of the last coil inside the drum: when the driven mechanism requires high torque, the bearing force and friction of the spring blade against the wall is increased, causing wear even in the presence of grease that is expelled from the friction track after a certain time, resulting in a deterioration of the barrel's performance.

[0009] Furthermore, automatic barrels must meet conflicting criteria, such as low friction between the coils to maximize efficiency, and high friction between the spring and drum to ensure good winding torque.

[0010] Additionally, damage to the drum, such as peeling of the coating, sludge formation, and wall wear under the pressure of a fully wound spring blade, must be avoided. Summary of the Invention

[0011] The object of the present invention is to overcome all or some of the above mentioned drawbacks by providing a winding device equipped with a system for limiting the winding of the spring, replacing the system based on the sliding of a blade against a notch in the inner wall of a drum.

[0012] To this end, the invention relates to a winding device, in particular for a watch barrel provided with a spring, comprising a ratchet attached to a rotating winding shaft, for example a barrel winding shaft, the rotation of which winds the barrel, and a winding gear train meshing with the ratchet, the winding gear train exerting a torque on the ratchet, thereby driving the rotation of the ratchet and of the rotating winding shaft.

[0013] The present invention is notable in that the ratchet is modifiable so that it can be disconnected from the hoisting gear train.

[0014] That is, once the ratchet is deformed, it is no longer driven by the winding gear train because the winding gear train is no longer meshing with the ratchet. For example, if too much torque is applied to the ratchet, especially if the barrel is fully wound, the ratchet will deform and become disconnected from the winding gear train. This means that the winding gear train will continue to rotate, but the ratchet will no longer rotate, since it will no longer be able to transmit its rotational torque to the ratchet.

[0015] The present invention avoids the risk of premature wear of the barrel, since the limiting device is arranged upstream and outside the barrel, and also avoids the use of conventional winding limiting devices based on spring friction inside the cylinder.

[0016] According to a particular embodiment of the invention, the ratchet includes first peripheral teeth that cooperate with second teeth of the winding gear train when the torque exerted on the ratchet is substantially below a threshold value.

[0017] According to a particular embodiment of the invention, the ratchet deforms such that the first peripheral toothing no longer cooperates with the second toothing when the torque exerted on the ratchet substantially exceeds a threshold value, in particular when the barrel is fully wound up.

[0018] According to a particular embodiment of the invention, the ratchet includes a plurality of flexible pawls forming first teeth of the ratchet, which engage second teeth when the torque is below a threshold value.

[0019] According to a particular embodiment of the invention, the flexible pawl bends when the torque is substantially greater than a threshold value, such that the flexible pawl no longer engages the second toothing and rotation of the winding gear no longer drives the ratchet.

[0020] According to a particular embodiment of the present invention, the ratchet includes a hub having a flexible pawl disposed thereon, the flexible pawl extending around the hub.

[0021] According to a particular embodiment of the invention, each pawl comprises a flexible blade and teeth arranged at a free end of said flexible blade, the teeth of the flexible blade cooperating with the second teeth.

[0022] Angularly, according to certain embodiments of the present invention, a plurality of flexible pawls are angularly distributed around the ratchet.

[0023] According to a particular embodiment of the invention, the ratchet includes a peripheral rim attached to the first toothing, the peripheral rim being preferably rigid.

[0024] According to a particular embodiment of the invention, the ratchet comprises a hub to which a peripheral rim is connected by at least one spring, preferably several connecting springs.

[0025] According to certain embodiments of the invention, the connecting spring or springs contract or expand when the torque is substantially greater than a threshold value, causing the peripheral rim to move away from the winding gear train so that rotation of the winding gear train no longer drives the ratchet.

[0026] According to a particular embodiment of the invention, the connecting springs are angularly distributed around the hub.

[0027] According to a particular embodiment of the invention, the connecting spring or springs are one or more flexible blades.

[0028] According to a particular embodiment of the invention, the ratchet is attached to the barrel and the rotating winding shaft is the barrel winding shaft that is used to wind the barrel spring.

[0029] The invention also relates to a clock movement including a barrel, which clock movement includes such a barrel winding device. [Brief description of the drawings]

[0030] The objects, advantages and features of the present invention will become apparent on reading some embodiments thereof, given by way of non-limiting example only and with reference to the accompanying drawings, in which:

[0031] [Figure 1] 1 shows a schematic top view of a winding device according to a first embodiment of the invention in a coupled position; [Diagram 2] 2 shows a schematic top view of the winding device according to the first embodiment of the invention in FIG. 1 in a disconnected position, in particular with the barrel spring fully wound up; FIG. [Diagram 3] FIG. 2 shows a schematic top view of a winding device according to a second embodiment of the invention in a coupled position; [Figure 4] 4 shows a schematic top view of the winding device according to the second embodiment of the invention in FIG. 3 in the disconnected position, in particular with the barrel spring fully wound up; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] 1 and 2 show a first embodiment of a winding device 1, here a watch barrel 2, according to the invention.

[0033] The winding device 1 of the barrel 2 includes a ratchet 3 and a winding gear train 4. The winding gear train 4 meshes with the ratchet 3 such that rotation of the winding gear train 4 in a first direction causes the ratchet 3 to rotate in a second direction opposite to the first direction.

[0034] The ratchet 3 is integrally attached to a winding shaft, which winds up the barrel 2. The winding shaft is preferably cylindrical.

[0035] In this example, the winding shaft is the winding shaft of the barrel 2, and the ratchet 3 is arranged on the barrel 2. The ratchet 3 includes a hub 7 that is integrally attached to the winding shaft.

[0036] In one variant not shown in the drawings, the winding shaft is not attached to the barrel and includes a pinion which meshes with a wheel that drives the barrel winding shaft to wind the spring when the ratchet is not attached to the barrel.

[0037] The ratchet 3 comprises a first external toothing 11 distributed around the ratchet 3. The first toothing 11 cooperates with a second toothing 12 arranged on the winding gear train 4. The winding gear train 4, which in this embodiment is for example a pinion, is provided with the second toothing 12 arranged on its periphery.

[0038] Barrel 2 contains a spiral spring (not shown in the drawings) arranged inside barrel 2. This spring needs to be wound up either by an automatic or a manual winding system.

[0039] To this end, the winding device 1 further comprises a gear train system 13, which is driven, for example, by the automatic winding weight (not shown in the drawings) of the watch movement. The gear train system 13 may also be driven by a winding rod (not shown in the drawings) which, in the case of manual winding, may be actuated by the crown.

[0040] The wheel 21 of the gear train system 13 meshes with the second toothing 12 of the winding gear train 4. That is, by actuating the gear system 13, a torque is exerted on the ratchet 4, which is transmitted to the winding shaft, at least in part, via the winding gear train 4 driven by the wheel 21 and via the ratchet 3 driven by the winding gear train 4.

[0041] According to the invention, the ratchet 3 is deformable so as to be able to disengage the ratchet 3 from the winding gear train 4. In particular, the ratchet 3 deforms in such a way that the first peripheral toothing 11 no longer cooperates with the second toothing 12 when the torque exerted on the ratchet 3 substantially exceeds a threshold value, in particular when the barrel 2 is fully wound up.

[0042] To this end, the ratchet 3 includes a number of flexible pawls 15 extending outwardly from the hub 7. These flexible pawls 15 are angularly distributed around the hub 7 in the plane of the ratchet 3. The flexible pawls 15 cooperate with the second toothing 12 such that rotation of the winding gear train 4 causes rotation of the ratchet 3 and thus of the winding shaft as the barrel 2 is wound.

[0043] Each pawl 15 includes a flexible blade 16 extending from the hub 7 of the ratchet 3. At the free end of each flexible blade 16 there is a tooth 17 capable of cooperating with the second toothing 12 of the winding shaft. The tooth 17 of the pawl 15 forms a first toothing 11 which cooperates with the second toothing 12. During winding, the tooth 17 of the flexible pawl 15 is inserted into the first toothing 11 to rotate the ratchet 3.

[0044] The decoupling gear means 10 preferably comprises at least eight flexible pawls 15, preferably at least 15 flexible pawls 15. The number of flexible pawls 15 depends on the flexibility of the flexible blade 16 and on the torque threshold value that the decoupling gear means 10 is configured to exceed in order to decouple the ratchet 3 and the winding shaft.

[0045] In this embodiment, the ratchet 3 includes 32 flexible pawls 15 distributed around the hub 7 and the winding shaft.

[0046] The flexible blade 16 is configured to bend when a torque threshold normally required to wind up the barrel is exceeded, i.e., above the threshold the torque becomes too high and the flexible blade 16 bends, causing the teeth 17 of the flexible pawl 15 to move back out of the path of the second tines 12 so that the flexible pawl 15 is no longer driven by the second tines 12.

[0047] In other words, when the winding gear train 4 presses hard against one or more of the flexible pawls 15, the flexible pawls 15 bend and move away from the second toothing 12. As a result, the ratchet 3 no longer rotates, despite the rotation of the winding gear train 4.

[0048] 1 in the winding configuration, the winding torque exerted on the ratchet 3, and in particular on the flexible pawl 15, is below a threshold value and the flexible blade 16 of the flexible pawl 15 remains substantially straight. That is, the flexible pawl 15 and the ratchet 3 are driven by the winding gear train 4. When the torque exerted on the ratchet 3 is substantially below a threshold value, the first peripheral toothing 11 cooperates with the second toothing 12 of the winding gear train 4.

[0049] 2 when the barrel 2 is fully wound up, the winding torque exerted on the ratchet pawl by the winding gear train 4 becomes greater than a threshold value, causing the flexible blade 16 of the flexible pawl 15 to bend. In other words, the torque required to rotate the ratchet 3 becomes too great for the flexible pawl to remain straight.

[0050] As a result, the teeth 17 of the flexible pawl 15 in contact with the winding gear train 4 spread apart and the second toothing 12 of the winding gear train 4 no longer engages with the first teeth 11 to drive the ratchet 3. The first peripheral toothing 11 no longer cooperates with the second toothing 12. The winding gear train 4 continues to rotate, but the ratchet 3 no longer rotates.

[0051] These disconnect gear means protect the cylinder 2 from excessive winding and prevent premature wear on the inside of the cylinder 2.

[0052] The barrel 2 further comprises a third peripheral toothing 18 adapted to cooperate with a fourth toothing 19 of a wheel 20 of the clock movement. The wheel 20 may for example be a central or intermediate wheel or a striking mechanism wheel. Once wound, the barrel 2 provides the energy required to operate the clock movement via the wheel 20.

[0053] 3 and 4 show a second embodiment of a winding device 1 according to the invention, in this case a watch barrel 2.

[0054] The winding device 1 of the barrel 2 includes a ratchet 30 and a winding gear train 4. The winding gear train 4 meshes with the ratchet 30 such that rotation of the winding gear train 4 in a first direction causes the ratchet 30 to rotate in a second direction opposite the first direction.

[0055] The ratchet 30 is integrally attached to a winding shaft, which winds up the barrel 2. The winding shaft is preferably cylindrical.

[0056] In this example, the winding shaft is the winding shaft of barrel 2 and the ratchet 30 is arranged on barrel 2. The ratchet 30 includes a hub 7 that is integrally attached to the winding shaft.

[0057] In one variant not shown, the winding shaft is not attached to the barrel, and includes a pinion that meshes with a wheel that drives the barrel winding shaft to wind the spring if the ratchet is not attached to the barrel.

[0058] The ratchet 30 comprises a first external toothing 11 distributed around the ratchet 30. The first toothing 11 cooperates with a second toothing 12 arranged on the winding gear train 4. The winding gear train 4 comprises a pinion provided with the second toothing 12 arranged on its periphery.

[0059] Barrel 2 contains a spiral spring (not shown in the drawings) arranged inside barrel 2. This spring needs to be wound up either by an automatic or a manual winding system.

[0060] To this end, the winding device 1 also includes a gear train system 13, which is driven, for example, by the automatic winding weight (not shown in the drawings) of the watch movement. The gear train system 13 may also be driven by a winding rod (not shown in the drawings) which, in the case of manual winding, may be actuated by the crown.

[0061] The wheel 21 of the gear train system 13 meshes with the second toothing 12 of the winding gear train 4. That is, by actuating the gear system 13, a torque is exerted on the ratchet 4, which is transmitted to the winding shaft, at least in part, via the winding gear train 4 driven by the wheel 21 and via the ratchet 30 driven by the winding gear train 4.

[0062] According to the invention, the ratchet 30 is deformable so as to be able to disengage the ratchet 30 from the winding gear train 4. In particular, the ratchet 30 deforms in such a way that the first peripheral toothing 11 no longer cooperates with the second toothing 12 when the torque exerted on the ratchet 30 substantially exceeds a threshold value, in particular when the barrel 2 is fully wound up.

[0063] To this end, the ratchet 30 includes a preferably rigid hub 27 and a peripheral rim 8, the hub 27 being arranged inside the peripheral rim 8. The hub 27 and the peripheral rim 8 have a circular toroidal shape, the radius of the hub 27 being smaller than the radius of the peripheral rim 8. The hub 27 and the peripheral rim 8 preferably extend in the same plane.

[0064] The peripheral rim 8 includes a first external toothing 11 distributed along the peripheral rim 8 around the ratchet 30 .

[0065] The hub 27 and the peripheral rim 8 are connected by at least one connecting spring 9, preferably several connecting springs, angularly distributed around the hub 27. The connecting spring or springs 9 are, for example, one or more flexible coil blades.

[0066] The number of flexible arms 15 depends on the flexibility of the flexible blade 16 and on the torque threshold beyond which the disconnecting gear means 10 is configured to disconnect the ratchet 30 and the winding shaft. In this embodiment, the ratchet 30 comprises four connecting springs 9 arranged at four base points.

[0067] The connecting spring or springs 9 are configured to contract or expand when a torque greater than a threshold torque value normally required to wind the barrel 2 is applied, causing the peripheral rim 8 to move away from the winding gear train 4.

[0068] In other words, when the winding gear train 4 presses hard against the peripheral rim 8 , the peripheral rim 8 moves away from the second toothing 12 .

[0069] As a result, the rotation of the winding gear train 4 no longer drives the ratchet 30, since the first toothing 11 is no longer in mesh with the second toothing 12.

[0070] 3 in the winding configuration, the winding torque exerted on the ratchet 30 is below a threshold value and the connecting spring 9 does not change shape, i.e. the first toothing 12 and the ratchet 30 are driven by the winding gear train 4.

[0071] 4 when the barrel 2 is fully wound up, the winding torque exerted by the winding gear train 4 on the ratchet 30 exceeds a threshold value, causing the connecting spring 9 to contract or expand depending on its arrangement. In other words, the torque required to rotate the ratchet 30 becomes too great for the connecting spring 9 to remain in its initial shape.

[0072] In this example, the two connecting springs 9 arranged on one side of the winding gear train 4 contract, whilst the two connecting springs arranged on the other side of the hub 27 expand.

[0073] As a result, the rim 8 moves away from the winding gear train 4 and the second toothing 12 of the winding gear train 4 no longer engages the first toothing 11 to drive the ratchet 30. The winding gear train 4 continues to rotate, but the ratchet 30 no longer rotates.

[0074] These disconnecting gear means protect the barrel 2 from over-winding and prevent premature wear inside the barrel 2. Thus, the winding shaft can be locked when the barrel spring is fully wound without the risk of damaging the barrel spring 2.

[0075] The barrel 2 also includes a third peripheral toothing 18 configured to cooperate with a fourth toothing 19 of a wheel 20 of the clock movement. The wheel 20 may be, for example, a central or intermediate wheel or a striking mechanism wheel. Once wound, the barrel 2 provides, via the wheel 20, the energy required to operate the clock movement.

[0076] The invention also relates to a clock movement, not shown in the drawings, which movement includes a barrel and a barrel winding device as described above.

[0077] Of course, the invention is not limited to the embodiments described with reference to the drawings, and variants are possible without departing from the scope of the invention.

Claims

1. A winding device (1, 10) for a barrel (2) provided with a spring, comprising: The winding gear train (4) includes a ratchet (3, 30) that is integrally attached to the rotating winding shaft, and a pinion that meshes with the ratchet (3, 30), the rotating winding shaft is a winding shaft of the barrel (2) which winds up the barrel (2) by rotation, and the rotation of the winding gear train (4) exerts a torque on the ratchet (3, 30) thereby causing the rotation of the ratchet (3, 30) and thus the rotation of the rotating winding shaft; A hoisting device characterized in that said ratchet (3, 30) is deformable to enable said ratchet (3, 30) to be disconnected from said hoisting gear train (4).

2. 2. A hoisting device according to claim 1, characterized in that the ratchet (3, 30) comprises a first peripheral toothing (11) which cooperates with a second toothing (12) of the hoisting gear train (4) when the torque exerted on the ratchet (3, 30) is below a threshold value.

3. 3. A lifting device according to claim 2, characterized in that, when the torque exerted on the ratchet (3, 30) exceeds said threshold value, the ratchet (3, 30) is deformed such that the first peripheral toothing (11) no longer cooperates with the second toothing (12).

4. 4. A hoisting device according to claim 3, characterized in that the ratchet (3) comprises a plurality of flexible pawls (15) forming the first peripheral toothing (11) of the ratchet (3), the flexible pawls (15) meshing with the second toothing (12) when the torque is below the threshold value.

5. 5. A hoisting device according to claim 4, characterized in that the flexible pawl (15) bends when the torque is greater than the threshold value, such that the flexible pawl (15) no longer meshes with the second toothing (12) and the rotation of the hoisting gear train (4) no longer drives the ratchet (3).

6. 5. A hoisting device according to claim 4, characterized in that the ratchet (3) comprises a hub (7) on which the flexible pawls (15) are arranged, the flexible pawls (15) extending around the hub (7).

7. 5. A hoisting device according to claim 4, characterized in that each flexible claw (15) comprises a flexible blade (16) and teeth (17) arranged at a free end of said flexible blade (16), said teeth (17) of said flexible claw (15) cooperating with said second toothing (12).

8. 5. A hoisting device according to claim 4, characterized in that the flexible pawls (15) are angularly distributed around the ratchet (3).

9. 4. A hoisting device according to claim 3, characterized in that the ratchet (30) comprises a rigid peripheral rim (8) provided with the first peripheral toothing (11).

10. 10. A lifting device according to claim 9, characterized in that the ratchet (30) comprises a hub (27), the peripheral rim (8) being connected to the hub (27) by at least one connecting spring (9).

11. 11. A winding device according to claim 10, characterized in that the connecting spring or springs (9) contract or expand when the torque is greater than the threshold value, thereby moving the peripheral rim (8) away from the winding gear train (4) so ​​that rotation of the winding gear train (4) no longer drives the ratchet (30).

12. 11. A lifting device according to claim 10, characterized in that a plurality of said connecting springs (9) are angularly distributed around said hub (27).

13. 11. Lifting device according to claim 10, characterized in that the connecting spring or springs (9) are one or more flexible blades.

14. 2. A winding device according to claim 1, characterized in that the ratchet (3, 30) is integrally attached to the barrel (2) and the rotating winding shaft is the winding shaft of the barrel (2) enabling the spring of the barrel (2) to be wound up.

15. A clock movement comprising a barrel (2) and a winding device (1, 10) for said barrel (2) as claimed in claim 1.

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