Winding device, in particular for a timepiece barrel, with a disconnectable winding gear train - Patents.com

Abstract

To provide a winding device provided with a system for limiting the winding of a spring, which replaces a system based on the sliding of a blade against notches formed in an inner wall of a drum.SOLUTION: A winding device 1, in particular for a barrel 2 provided with a spring, comprises: a ratchet 3 fixedly mounted on a rotary winding shaft; and a winding gear train 4 meshing with the ratchet. The rotary winding shaft is, for example, a winding shaft of the barrel. Rotation of the rotary winding shaft winds the barrel. Rotation of the winding gear train causes the ratchet and the winding shaft to rotate by applying a torque to the ratchet. The winding gear train is movable between a coupled position, where the winding gear train drives the ratchet, and a disconnected position, where the winding gear train does not drive the ratchet. The winding gear is mounted on a spring 5 exerting a return force on the winding gear train to keep the winding gear train in the coupled position.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a winding device, in particular for a timepiece barrel, with a disconnectable winding gear train.

[0002] The invention further relates to a timepiece movement equipped with such a winding device. [Background technology]

[0003] Most of today's mechanical watches with automatic winding (e.g. wristwatches, pocket watches) generally have an oscillating weight that drives a gear train by gravity. Thanks to the rotation of this oscillating weight, a blade spring can be wound, while a barrel spring is wound around a shaft in a drum by driving this shaft. Generally, a pawl prevents reversal and ensures that it can only rotate in one direction.

[0004] However, when the spring is fully wound, it is important to avoid overwinding, which can cause the spring to break or the resonator to knock, during which the amplitude of vibration increases until the balance abuts against the horn of the pallet lever, causing the balance to rebound against this abutment, resulting in rate fluctuations.

[0005] To avoid this risk, such barrels typically have a system for limiting the winding of the barrel spring.

[0006] This restraint is usually accomplished by the outermost coil of the spring against the inner wall of the drum, which when the spring is fully wound and wrapped around the winding shaft of the barrel, presses against the outer wall of the drum.

[0007] Thus, if the winding torque is greater than the friction torque against the wall of the outermost coil, this blade will begin to slip. Thanks to the notches, it is possible to stop the slippage of the blade end once the winding torque is sufficiently reduced to prevent uncontrolled slippage.

[0008] However, such a system presents a challenge in the sliding friction process of the outermost coil inside the drum. Indeed, when the driving mechanism requires high torque, the bearing force and friction between the spring blades and the wall become large, which leads to wear and deterioration of the barrel's performance, even if grease is present. This grease eventually disappears from the friction area after a certain time.

[0009] Also, in an automatic barrel, conflicting demands must be met, such as reducing friction between the coils to maximize efficiency, and increasing friction between the spring and drum to ensure good winding torque.

[0010] Also, damage to the drum must be avoided, such as peeling of the coating, sludge build-up, and wear of the walls under the pressure of the blades of a fully wound spring. Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention aims to overcome all or some of the above problems by providing a winding device with a system for limiting the winding of the spring, replacing the system based on the slippage of a blade against a notch formed in the inner wall of a drum. [Means for solving the problem]

[0012] To this end, the invention relates to a winding device, in particular for a barrel equipped with a spring, comprising a ratchet attached to a rotating winding shaft and a winding gear train meshing with said ratchet, said rotating winding shaft being, for example, the winding shaft of said barrel, such that rotation of said rotating winding shaft winds said barrel and rotation of said winding gear train applies a torque to said ratchet which rotates said ratchet which rotates said winding shaft, said winding gear train being movable between an engaged position in which it drives said ratchet and a disengaged position in which it does not drive said ratchet.

[0013] The invention is innovative in that the wound gear train is attached to a spring which provides a return force on the wound gear train to hold it in the engaged position.

[0014] Thus, by moving the winding gear train to the disconnected position, the ratchet is no longer driven by the winding gear train because the winding gear train is no longer driven. For example, if too much torque is applied to the ratchet, especially when the barrel is fully wound, the winding gear train will move and no longer transmit rotational torque to the ratchet, causing the ratchet to stop rotating.

[0015] Thanks to the invention, the risk of premature barrel wear is avoided, as the limiting device is located upstream and outside the barrel, and the use of traditional winding limiting devices based on spring friction inside the cylinder is avoided.

[0016] In certain embodiments of the invention, the ratchet has a first peripheral row of teeth that interlock with a second row of teeth of the winding gear train when a torque applied to the ratchet is substantially less than a threshold value.

[0017] In certain embodiments of the invention, the winding gear train moves to a cut-off position when the torque applied to the ratchet substantially exceeds a threshold value, particularly when the barrel is fully wound.

[0018] In certain embodiments of the invention, the winding gear train meshes with the winding actuating wheel when in the engaged position and does not mesh with the winding actuating wheel when in the disengaged position.

[0019] In a particular embodiment of the invention, the winding gear train is disposed next to the ratchet when in the coupled position, and preferably extends in the same plane as the ratchet.

[0020] In certain embodiments of the invention, the winding gear train undergoes lateral movement between an engaged position and a disengaged position.

[0021] In certain embodiments of the invention, the wound gear train undergoes a rotational motion to move from an engaged position to a disengaged position and vice versa.

[0022] In a particular embodiment of the invention, the spring has a flexible guide forming a virtual pivot, the wound gear train is suspended by the flexible guide, and the flexible guide exerts a radial return force on the wound gear train in the direction of the actuating wheel.

[0023] In a particular embodiment of the invention, the flexible guide has two non-intersecting flexible blades and a rigid movable element that carries the winding gear train, the two flexible blades connecting the rigid movable element to a fixed support of the winding device.

[0024] In a particular embodiment of the invention, the ratchet is fixedly attached to the barrel and the rotating winding shaft is a barrel winding shaft making it possible to wind the spring of the barrel.

[0025] The invention further relates to a timepiece movement comprising a barrel and a barrel winding device such as previously described. [Brief description of the drawings]

[0026] The objects, advantages and features of the invention will become apparent on reading the description of several embodiments thereof, given by way of example only and with reference to the accompanying drawings, in which:

[0027] [Figure 1] FIG. 1 is a schematic top view of a winding device according to an embodiment of the invention in a coupled position. [Diagram 2] 2 is a schematic top view of the winding device according to the embodiment of the invention of FIG. 1 when the barrel is being wound. FIG. [Diagram 3] 2 is a schematic top view of the winding device according to the embodiment of the invention of FIG. 1 when the barrel is fully wound. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] 1 to 3 show one embodiment of a winding device 1, in this case a barrel 2 for a timepiece, according to the invention.

[0029] The winding device 1 for the barrel 2 comprises a ratchet 3 and a winding gear train 4. The winding gear train 4 meshes with the ratchet 3 so that when the winding gear train 4 rotates in a first direction, the ratchet 3 rotates in a second direction opposite to the first direction.

[0030] The ratchet 3 is fixedly attached to the winding shaft, which makes it possible to wind the barrel 2. The winding shaft is preferably cylindrical.

[0031] In the example, the winding shaft is the winding shaft of the barrel 2, and the ratchet 3 is disposed on the barrel 2. The ratchet 3 has a hub 7 fixedly attached to the winding shaft.

[0032] In one variant not shown, the winding shaft is not attached to the barrel and the winding shaft is provided with a pinion which meshes with a wheel which drives the winding shaft of the barrel to wind the spring when the ratchet is not attached to the barrel.

[0033] The winding gear train 4 is arranged next to the ratchet 3 and preferably extends in the same plane as the ratchet 3 .

[0034] The ratchet 3 has a first external row of teeth 11 distributed around the ratchet 3. The first row of teeth 11 interlock with a second row of teeth 12 formed on the winding gear train 4. The winding gear train 4 comprises a pinion having the second row of teeth 12 formed on its circumference.

[0035] The barrel 2 includes a balance spring (not shown) disposed inside the barrel 2, which must be wound by an automatic or manual winding system.

[0036] For this purpose, the winding device 1 further comprises a gear train system 13, which is driven, for example, by the automatic winding weight (not shown) of a timepiece movement, which in the case of manual winding can also be driven by a winding stem (not shown) which can be operated by the crown.

[0037] An actuating wheel 21 for winding the gear train system 13 has a third tooth row 14 which meshes with the second tooth row 12 of the winding gear train 4. Thus, by actuating the gear train system 13, a torque is applied to the ratchet 3 which transmits the torque at least partially to the winding shaft via the winding gear train 4 driven by the actuating wheel set 4 and via the ratchet 3 driven by the winding gear train 4.

[0038] When the barrel 2 is being wound, rotation of the winding gear train 40 rotates the ratchet 3 and thus the winding shaft.

[0039] To avoid overwinding the barrel, the winding gear train 4 is movable between an engaged position in which it drives the ratchet 3 and a disengaged position in which it is not engaged with the ratchet 3.

[0040] In particular, the winding gear train 4 meshes with the winding actuating wheel 21 when in the engaged position and does not mesh with the winding actuating wheel 21 when in the disengaged position.

[0041] Thus, in the engaged position, the actuating wheel 21 drives the winding gear train 4, which in turn drives the ratchet 3. However, in the disengaged position, the actuating wheel 21 only rotates idle and does not drive the winding gear train 4, which is separated from the actuating wheel 21, and the ratchet 3 is no longer driven by the winding gear train 4.

[0042] According to the invention, the wound gear train 4 is attached to a spring 5 which exerts a force on the wound gear train 4 to hold it in the coupled position.

[0043] In this embodiment, the spring 5 comprises a flexible guide forming a virtual pivot, from which the winding gear train 4 is suspended. The flexible guide has two non-intersecting flexible blades 15 and a rigid mobile element 16 that supports the winding gear train 4. The two flexible blades 15 connect the rigid mobile element 16 to a fixed support 17 of the winding device 1.

[0044] On the fixed support 17 there is for example a bearing for the ratchet 3. The flexible blades 15 are cross-connected to the bearings on the one hand and move away from each other as they approach the ends of the rigid mobile element 16, which here has the shape of a circular arc.

[0045] The flexible guide provides a radial return force to the winding gear train 4 in the direction of the actuating wheel 21 .

[0046] Also, when the torque applied to the ratchet 3 substantially exceeds a threshold value, in particular when the barrel 2 is fully wound, the winding gear train 4 moves to the cut-off position.

[0047] Thus, when the torque substantially exceeds the threshold value, the winding gear train undergoes a rotational movement to move from the engaged position to the disengaged position, the winding gear train 4 undergoes a lateral movement between the engaged and disengaged positions, and the winding gear train 4 undergoes a rotational movement about a virtual pivot to move from the engaged position to the disengaged position and vice versa.

[0048] Above the threshold value, when the torque required to turn the ratchet 3 is greater than the torque required to bend the flexible guide, the winding gear train 4 is pushed back into the disconnected position by the actuating wheel 21, i.e. when the winding gear train 4 presses hard against the ratchet 3, the flexible blade 15 of the flexible guide is bent, causing the rigid movable element 16 and the winding gear train 4 to move.

[0049] As a result, the actuating wheel set 21 continues to rotate, but the winding gear train 4 and ratchet 3 no longer rotate.

[0050] 1, in the wound configuration, the winding torque applied to the ratchet 3 is below a threshold value, and therefore the winding gear train 4 remains in the coupled position and meshes with the actuating wheel 21. In this manner, the ratchet 3 and the winding shaft are driven by the winding gear train 4. The first peripheral tooth row 11 of the ratchet 3 engages with the second tooth row 12 of the winding gear train 4 when the torque applied to the ratchet 3 is substantially less than a threshold value.

[0051] 2, during winding of the barrel, when the torque becomes large and approaches a threshold value, the winding gear train 4, thanks to the flexible guide, starts to move laterally, but is still engaged with the third tooth row 14 of the actuating wheel 21. Thus, the ratchet 3 is still driven by the winding gear train 4.

[0052] In FIG. 3, when the barrel 2 is fully wound, the winding torque provided by the winding gear train 4 to the ratchet 3 is greater than a threshold value and, thanks to the flexible guide, the winding gear train 4 moves fully to the cut-off position.

[0053] As a result, the second tooth row 12 of the winding gear train 4 is no longer in engagement with the third tooth row 14 of the actuating wheel 21. As a result, the winding gear train 4 and the ratchet 3 do not rotate.

[0054] This cutting means protects the barrel 2 from overwinding and prevents premature wear within the barrel 2.

[0055] The barrel 2 further has a fourth peripheral toothing 18 adapted to cooperate with a fourth toothing 19 of a wheel 20 of the timepiece movement, said wheel 20 being, for example, an intermediate wheel. When wound, the barrel 2 provides the energy necessary to operate the timepiece movement via the wheel 20.

[0056] The invention further relates to a timepiece movement, not shown, comprising a barrel and a barrel winding device as defined above.

[0057] Naturally, the invention is not limited to the embodiments described with reference to the drawings, and variants are conceivable without departing from the scope of the invention. [Explanation of symbols]

[0058] 1 Winding Device 2 barrels 3. Ratchet 4-turn gear train 5. Spring 13 Gear train system 15 Flexible Blade 16 Robust moving elements 17 Fixed support 20 Timekeeping movement car 21 Actuator Vehicle

Claims

1. A winding device (1) for a barrel (2) equipped with a spring, comprising: A ratchet (3) fixedly attached to a rotating winding shaft, and a winding gear train (4) meshing with the ratchet (3), The rotating winding shaft is the winding shaft of the barrel (2), The barrel (2) is wound by rotating the rotating winding shaft, The rotation of the winding gear train (4) imparts a torque to the ratchet (3), which rotates the ratchet (3) and the winding shaft; said winding gear train (4) being movable between an engaged position in which it drives said ratchet (3) and a disengaged position in which it does not drive said ratchet (3); The wound gear train (4) is attached to a spring (5) which exerts a return force on the wound gear train (4) to hold it in a coupled position; The winding gear train (4) meshes with the winding actuating wheel (21) when in the connected position, and does not mesh with the winding actuating wheel (21) when in the disconnected position; The spring (5) has a flexible guide forming a virtual pivot, The wheels of the winding gear train (4) are suspended by the flexible guide, The flexible guide exerts a radial return force on the wound gear train (4) in the direction of the actuating wheel (21).

13. A winding device comprising:

2. The winding gear train (4) moves to a cut-off position when the torque applied to the ratchet (3) is greater than a threshold value.

2. The winding device of claim 1.

3. The winding gear train (4) moves to a cutting position when the barrel (2) is fully wound.

3. The winding device according to claim 2.

4. The winding gear train (4) is disposed next to the ratchet (3).

2. The winding device of claim 1.

5. A winding device as described in Claim 4, characterized in that the winding gear train (4) extends in the same plane as the ratchet (3) when in the coupled position.

6. The winding gear train (4) performs a lateral movement between an engagement position and a disengagement position.

2. The winding device of claim 1.

7. The winding gear train (4) undergoes a rotational movement to move from an engaged position to a disengaged position and vice versa.

6. A winding device according to claim 4 or 5.

8. The flexible guide has two non-intersecting flexible blades (15) and a rigid movable element (16) that supports the winding gear train (4), The two flexible blades (15) connect the rigid mobile element (16) to a fixed support (17) of the winding device (1).

2. The winding device of claim 1.

9. A barrel (2) and a winding device (1) for said barrel (2) according to claim 1. A timekeeping movement characterized by:

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