EP3765918A1

EP3765918A1 - System for blocking a ratchet of a timepiece barrel

Info

Publication number: EP3765918A1
Application number: EP19712151.0A
Authority: EP
Inventors: Christophe Lyner
Original assignee: Hublot SA
Current assignee: Hublot SA
Priority date: 2018-03-12
Filing date: 2019-03-12
Publication date: 2021-01-20
Also published as: CH714741B1; CH714741A1; WO2019175153A1; JP2021517644A; CN112105993A; CN112105993B; JP7410044B2

Abstract

A system (1) for blocking a ratchet (3) of a timepiece barrel (2), the system comprising: • - a frame (50); • - a lever (4) pivotally mounted on the frame; • - a gear chain (20) comprising at least one first toothed wheel (6) pivotally mounted on the lever and/or on the frame; and • - a spring (5) returning the lever to a rest position, in which the gear chain is meshed with the ratchet (3).

Description

Locking system of a clock ratchet.

The invention relates to a locking system of a ratchet watch clock. The invention also relates to a clock mechanism comprising such a system. The invention also relates to a timepiece comprising such a system or such a clock mechanism.

Timepieces including a mechanical mechanical winding movement include barrels whose ratchets can only rotate in one direction about their axis due to the action of a locking system. Locking systems are ratchets.

The pawls absorb some of the energy transmitted to the barrel and generate rattling noises when winding the barrel.

The object of the invention is to provide a locking system to overcome the disadvantages mentioned above and to improve the systems known from the prior art. In particular, the invention proposes a locking system for optimizing the transmission of energy to the barrel and to limit the noise of the locking system during winding of the barrel.

A system according to the invention is defined by claim 1.

Different embodiments of the component are defined by dependent claims 2 to 9.

A mechanism according to the invention is defined by claim 10.

A timepiece according to the invention is defined by claim 1 1. The appended figures represent, by way of example, an embodiment of a timepiece according to the invention. Figure 1 is a schematic view of an embodiment of a timepiece in a first configuration of the locking system.

Figure 2 is a schematic view of the embodiment of the timepiece in a second configuration of the locking system.

Figure 3 is a schematic view of the embodiment of the timepiece in a third configuration of the locking system. An embodiment of a timepiece 200 is described below with reference to FIGS. 1 to 3. The timepiece is for example a watch, in particular a wristwatch. The timepiece comprises a watch mechanism, in particular a mechanical watch movement 100. The watch movement is for example of the manual winding type or the self-winding type.

The movement comprises a barrel and a locking system 1 of the barrel to prevent the barrel spring from relaxing or unwinding, but still allowing to raise the barrel or tighten the barrel spring.

The barrel is rotatably mounted about an axis 32 on a frame 50 of the movement. The barrel comprises mainly a barrel shaft, a drum and a spring, the shaft and the drum being mechanically connected to each other by the spring wound on itself and contained in the drum. The barrel shaft is mechanically linked to a manual or automatic winding chain.

During reassembly of the timepiece, the barrel shaft is rotated about the axis 32 relative to the frame and the drum in order to raise or strain or constrain the spring. To do this, the barrel shaft is rotated via a ratchet 3.

When driving the movement, the barrel drum is rotated about the axis 32 relative to the frame and the shaft to drive the gear of the timepiece. To do this, the barrel drum comprises a toothing meshing with a first wheel of the wheel of the timepiece. In the embodiment shown, the locking system allows in its first configuration of Figure 1 to allow the rotation of the ratchet around the axis 32 in the clockwise direction. This allows to remount the timepiece. In the embodiment shown, the locking system allows in its second configuration of Figure 2 to prohibit the rotation of the ratchet about the axis 32 in the counterclockwise relative to the frame 50. This prevents the spring barrel does not relax otherwise than by driving the wheel of the timepiece.

Thus, the locking system allows the unidirectional blocking of the barrel, in particular the shaft or the barrel ratchet. It also allows a free unidirectional rotation, relative to the frame, the barrel, including the shaft or the barrel ratchet. As seen above, the blocking system 1 thus allows a conditional locking of the ratchet 3 of the watch cylinder 2.

The locking system includes:

the frame 50;

a rocker 4 mounted pivoted on the frame;

a gear chain comprising at least a first toothed wheel mounted pivoted on the rocker and / or on the frame; and

a spring 5 biasing the rocker to a rest position in which the gear chain is engaged with the ratchet 3;

the gear chain comprising a toothing 61; 71 of an irreversible gear 30.

The latch 4 is pivotally mounted on the frame about an axis 8. This axis is for example parallel to the axis 32. Preferably, the latch is of the monostable type. It is therefore recalled to a first position of rest or reminder. This first position of rest or return is shown in Figures 1 and 2. This recall is provided by the spring 5. The spring is advantageously integral with the rocker or monobloc with the rocker. The spring bears on a stop 51 of the frame or, more generally, on the movement to ensure the elastic return in the first position of FIGS. 1 and 2. For example, the spring 5 is a leaf spring 5.

The latch 4 comprises an abutment surface 12 cooperating with an abutment 10 of the frame or, more generally, of the movement. The stop 10 may be a pin. The contacting cooperation of this abutment surface 12 and of this abutment 10 defines the first position of the latch 4 FIG. 1 and 2. The spring 5 previously seen thus makes it possible to return the abutment surface 12 in contact with the abutment 10.

The rocker supports at least a portion of the gear chain 20. In other words, an element or elements 6, 7 making up the gear chain are pivotally mounted on the rocker 4, in particular on an arm 41 of the rocker 4. For example, the single element or all the elements 6, 7 making up the gear chain are mounted pivoted on the rocker 4, in particular on an arm 41 of the rocker 4. In the embodiment shown, the gear chain comprises a first toothed wheel 6 and a second toothed wheel 7. The first and second toothed wheels are arranged on the rocker so as to mesh permanently with each other.

The first toothed wheel 6 is pivotally mounted on the frame 50 about an axis 8. The second toothed wheel 7 is pivotally mounted on the rocker about an axis 9. Preferably, these axes 8 and 9 are parallel to each other and parallel to the axis 32 of the barrel. More preferably, the axis about which the first gear is pivoted on the rocker is also the axis about which the rocker is pivoted on the movement. The first toothed wheel 6 is pivotally mounted about the axis 8. It can therefore also be seen as pivoted on the rocker, especially since it is able to pivot freely relative to this rocker.

In the embodiment shown, the first wheel 6 has a first toothing 61 and the second wheel 7 has a second toothing 71. These first and second teeth are arranged so as to achieve an irreversible gear between the first and second wheels. Thus, when the second wheel is driving and turns counterclockwise, it rotates the first wheel which is driven (see Figure 1), but when the second wheel is driving and rotates clockwise, the gear locks and the rotation of the second wheel is blocked by the first wheel (see Figure 2). Indeed, the geometry of the first and second sets of teeth makes the tops of the teeth of the first and second sets of teeth come into contact when the second clockwise rotating wheel begins to drive the first wheel.

In this embodiment, the irreversibility of the gear is ensured by the particular profiles of the first toothing 61 and second toothing 71 and by the arrangement of the first and second wheels. In addition to the profiles of first and second teeth shown, other tooth profiles can be used to achieve an irreversible gear, particularly the teeth illustrated in publications WO2015193809A1 and CH700806B1.

Preferably, the toothing 31 of the ratchet is quite conventional, in particular the toothing 31 is a toothing whose profile is a standardized clock profile.

Preferably, the first toothing comprises less than 30 teeth or less than 20 teeth or less than 10 teeth and / or the second toothing comprises less than 30 teeth or less than 20 teeth or less than 10 teeth.

In the rest or return position of the rocker shown in Figures 1 and 2, the gear chain 20, in particular the second wheel 7 meshes with the ratchet. In a second position of the rocker shown in FIG. 3, the rocker has pivoted and the toothing 31 of the ratchet is no longer in contact with the gear chain 20, in particular it is no longer in engagement with the toothing 71 of FIG. the second wheel 7. This second position defines a third configuration of the locking system. The teeth 31 and 71 are in fact at a distance from each other. In this third configuration, the ratchet is free to rotate, especially in the counterclockwise direction, about the axis 32 relative to the frame 50. This second position can be defined by the contact cooperation of a stop surface 1 1 of the rocker and the stop 10. This second position disarms the spring for example for disassembling the movement. The third configuration is shown in FIG.

The rocker has for example a first arm 41 on which is mounted the gear chain. The rocker has for example a second arm 42 on which are provided abutment surfaces 1 1, 12 limiting, in cooperation with one or more stops 10, the pivoting amplitude of the rocker 4. The rocker has for example a third arm 43 constituted by the spring 5. The three arms are for example distributed in T, that is to say that the three arms form substantially two right angles.

Advantageously, the gear chain and the rocker are arranged so that the ratchet driven in the unwinding direction of the mainspring (that is to say in the counterclockwise direction) exerts on the gear chain a driving action. the rocker to the rest position.

In the embodiment described above, the rocker comprises three arms providing the following functions: support of the gear chain, limitation of the pivoting amplitude and elastic return of the rocker. Alternatively, the arms could be organized geometrically differently. Moreover, alternatively, the functions provided by these three arms could be organized differently on the arms, in particular any of these functions could be grouped on the same arm. Thus, the rocker could have only two arms, or even one arm. In the embodiments and variants described above, the first and second teeth present are particular. Alternatively, only the first toothing, respectively the second toothing, may be particular and cooperate with the second toothing, respectively the first toothing, whose profile is a standardized clock profile.

In the embodiments and variants described above, the irreversible gear is made between the second wheel and the first wheel. However, alternatively, the irreversible gear can be made between the gear chain and the ratchet. In this case, the profile of the teeth of the ratchet is preferably a standardized clock profile and the profile of the teeth of the gear chain wheel meshing with the ratchet is a particular profile to achieve irreversibility when it meshes with normalized profile teeth.

In the embodiments and variants described above, the gear chain comprises two wheels. However, alternatively, the gear chain may comprise a single wheel. In this case, the wheel is not rotated on the rocker about the axis about which the rocker is pivoted on the frame. In another variant, the gear chain may comprise more than two wheels, in particular 3 wheels or 4 wheels.

In the embodiments and variants described above, the gear chain comprises a wheel pivoted on the frame at the axis about which the rocker is pivoted on the frame. However, alternatively, the gear chain may comprise a wheel pivoted on the frame other than around the axis about which the rocker is pivoted on the frame. In this case, the gear chain comprises at least two wheels. Moreover, in this case, the meshing between the wheel pivoted on the frame and a wheel pivoted on the rocker can be broken in the second position of the rocker.

By "irreversible gearing", we mean throughout this document a gear of a second toothing with a first toothing in which, when the second toothing is driving, it can cause the first toothing in one direction, the first and second teeth blocking in the other direction. Advantageously, this blockage is obtained by the geometries of the first and / or second teeth. In particular, the blocking may be due to an arching phenomenon.

The operation of the timepiece 200, in particular the movement 100, is described below.

Assume an absence of action on the latch 4, including a lack of action of a watchmaker on the latch 4. The latch is therefore in the first position shown in Figures 1 and 2.

It is assumed that an automatic or manual winding drive train drives the ratchet clockwise. This training causes the constraint or the winding of the mainspring. Due to this rotation of the ratchet, its toothing 31 drives the toothing 71 of the second wheel 7 which rotates counterclockwise. Due to this rotation of the second wheel, its toothing 71 drives the toothing 61 of the first wheel 6 which rotates clockwise. The rotations of the first and second wheels are freely without resistance or almost without resistance. The only resistances to be overcome are the meshing friction at the teeth and the pivoting friction of the wheels on the rocker. These resistances are very weak. It is now assumed that the automatic or manual winding drive train no longer retains the ratchet (either for a manual winding watch when the watch is stopped or for an automatic watch being disassembled): this one has a tendency to to turn counterclockwise under the effect of the mainspring. However, this rotation is prohibited as explained below. Indeed, after a possible rotation of the ratchet 3 counterclockwise in which, due to the meshes of the teeth 31, 71 and 61, the second wheel is driven clockwise and the first wheel is driven counterclockwise, a tooth of the second toothing abuts on the top of the tooth of the first toothing. This creates an arching blocking the rotation of the second toothing which thus forms an obstacle to the rotation of the ratchet counterclockwise. It is buttressed because the force F1 (represented by an arrow) of the first toothing 61 on the second toothing 71 is oriented in a direction passing through the axis 8 around which is rotated the first wheel. As represented in FIG. 2, the force F1 of the first wheel on the second wheel creates a torque around the axis 9 opposing the torque created around the axis 9 by the force F2 (represented by an arrow ) of the ratchet on the second wheel. It should also be noted that the force F2 exerted by the ratchet on the rocker tends to rotate the rocker clockwise about its pivot axis 8, or to remind the rocker in its rest position, including its position in which the abutment surface 12 is in contact against the abutment 10. The spring 5 also tends to rotate the latch in the same direction.

However, during maintenance operations, it is necessary to be able to relax the mainspring and release the energy stored in the barrel. To do this, we (a watchmaker) acts the latch 4 so as to move away from its rest position. To do this, it acts against the force provided by the spring 5 and against the action of the ratchet on the rocker. Once a flip pivot amplitude is reached, the ratchet and second wheel teeth are no longer engaged and the ratchet can then rotate freely counterclockwise. The rocker can in particular be moved to its second position defined by the contact of the abutment 10 with the abutment surface 1 1 as illustrated in FIG.

With a locking system as described above, it is possible to obtain a locking system:

- without ratchet or without ratchet;

- Easily deactivated by a simple action of a watchmaker (rotation of a rocker);

- optimizing the transmission of energy to the barrel; and

- Limiting the noise generated during the winding of the barrel.

Claims

Claims:

1. System (1) for locking a ratchet (3) of a watch cylinder (2), the system comprising:

a frame (50);

a rocker (4) rotatably mounted on the frame;

a gear chain (20) comprising at least a first toothed wheel (6) mounted rotatably on the rocker and / or on the frame; and

a spring (5) biasing the latch to a rest position in which the gear chain is engaged with the ratchet (3);

the gear chain comprising a toothing (61; 71) of an irreversible gear (30).

2. System (1) blocking according to the preceding claim, characterized in that the gear chain comprises the first toothed wheel and a second gear (7), in particular a second gear wheel pivoted on the rocker (4).

3. locking system according to the preceding claim, characterized in that the irreversible gear is formed between the first wheel and the second wheel.

4. Blocking system according to one of the preceding claims, characterized in that the first gear wheel is pivotally mounted, in particular mounted pivotally on the rocker, about an axis (8) on which the rocker is pivoted on the frame.

Locking system according to one of the preceding claims, characterized in that the irreversible gear is formed between the gear chain and the ratchet.

6. locking system according to one of the preceding claims, characterized in that the spring is a leaf spring (5), in particular a leaf spring (5) integrally with the rocker or monobloc with the rocker.

7. Locking system according to one of the preceding claims, characterized in that the system comprises a stop (10) cooperating with a surface (12) of the rocker (4) to define the rest position of the rocker.

8. Blocking system according to one of the preceding claims, characterized in that the gear chain and the rocker are arranged so that the ratchet driven in the unwinding direction of the mainspring spring exerts on the gear chain a action causing the rocker to the rest position.

9. Locking system according to one of the preceding claims, characterized in that it is devoid of pawl.

10. Watchmaking mechanism (100), especially a watch movement, comprising a system (1) according to one of claims 1 to 9.

1. Timepiece (200), in particular a wristwatch, comprising a mechanism according to the preceding claim and / or a system according to one of claims 1 to 9.