CH709162B1 - Clutch device for watch movement. - Google Patents

Abstract

The invention relates to a clutch device for a watch movement (1) comprising first and second rotary clutch mobiles (6, 18) arranged in a substantially coaxial manner and in such a way as to be able to present a relative displacement in their axial direction, between a first relative position, engaged, in which they are in contact with each other, and a second relative position, disengaged, in which they are disjointed. The first and second clutch mobiles (6, 18) comprise respective first and second shafts (10, 20) independent of each other and one of which is carried by a clutch bridge (26). ) intended to be assembled to the watch movement (1) so as to be able to present a displacement in the axial direction in response to a predefined action of a user.

Description

TECHNICAL FIELD [0001] The present invention relates to a clutch device for a watch movement comprising first and second rotary clutch mobiles arranged substantially coaxially and so as to be able to present a relative displacement in their axial direction, between a first relative position, engaged, in which they are in contact with each other, and a second relative position, disengaged, in which they are disjointed.

The present invention also relates to a watch movement comprising such a clutch device, and a timepiece provided with such a watch movement.

State of the art [0003] Clutch devices meeting the above characteristics, commonly referred to as vertical clutches, are already known from the prior art.

By way of example, patent EP 2015 145 B1 describes an example thereof, in a variant to improve the nature of the contact between the two mobile clutch with reference to previously known mechanisms.

Typically, a vertical clutch device comprises a first clutch mobile connected to a first gear train of the watch movement, and a second clutch mobile connected to a second train of the watch movement. When the device is in its engaged configuration, the two gear trains are connected to each other, while they are disassociated from one another when the device is in its disengaged configuration. Both mobiles are mounted free to rotate on a common shaft, the latter being pivoted in two frame members by its ends, usually the plate and a bridge. One of the clutch movers comprises a spring arranged to act on a first clutch pad and push it towards a second clutch pad forming part of the other clutch mobile, in the engaged configuration. This same mobile also has inclined flanks intended to cooperate with clutch clamps arranged to move away from the other mobile, in the disengaged configuration, in response to an action of a user and overcoming the spring force .

The patent cited above discloses that the spring intervening in the clutch must generally be strong, to ensure a good bond without sliding between the two pads of the clutch device. Also, a solution to reduce the strength of this spring is proposed.

However, it should be noted that the clutch mobile having a fixed axial position with reference to the frame of the watch movement is directly connected to the work train. However, it appears that with a construction of the type just described, regardless of the spring force, the shaft is stressed when the clutch device is in its disengaged configuration. These constraints are likely to be transmitted to the finishing gear and may affect the accuracy of the watch movement. Indeed, neither the spring nor the release claws are perfectly symmetrical and these components therefore apply stresses on the shaft when the clamps are closed and compress the spring.

Disclosure of the invention [0008] The main object of the present invention is to propose an alternative construction clutch device which makes it possible to totally eliminate the disturbances experienced by the finishing gear train in the constructions of the state of the art.

For this purpose, the clutch device according to the invention, of the type having the characteristics set out above, is characterized in that the first and second clutch mobiles comprise respective first and second shafts, independent of each other. one of the other and, one of which is carried by a clutch bridge intended to be assembled to the watch movement so as to be able to present a displacement in the axial direction in response to a predefined action of a user.

Thanks to these features, the shaft carrying the clutch mobile having a permanent connection with the work train does not undergo any constraint in the disengaged configuration since it is completely independent of the other mobile clutch in this configuration.

Preferably, it can be provided that the clutch device according to the invention further comprises a movable control member between neutral and active configurations, in response to the predefined action, and arranged to position the mobile devices. clutch in one of the first and second relative positions in the active configuration and to leave them free to take the other relative position, by default, in the neutral configuration, and an elastic member arranged to maintain the clutch mobiles in the default relative position when the controller is in its neutral configuration.

In addition, it can be advantageously provided that the control member and the elastic member are intended to be arranged on the watch movement to act on the clutch bridge.

Thanks to these features, the components involved in the implementation of the clutch device according to the present invention are less delicate than in conventional clutches and both its assembly and its development are facilitated. In addition, the construction according to the invention also makes it possible to reduce the overall thickness of the clutch device with reference to known clutches, the axial dimensions of which constitute a significant disadvantage generally.

It can be advantageously provided that each of the first and second mobiles comprises a clutch pad arranged to cooperate with the clutch pad of the other clutch mobile in the relative position engaged, each of the clutch pads being integral in rotation with the corresponding shaft, and a wheel, also integral in rotation with the corresponding shaft and intended to present a kinematic connection with a gear train of the watch movement.

In this case, it can be provided that the clutch bridge comprises a base, carrying a first pivot bearing of the corresponding clutch mobile, and a board, secured to the base and, carrying a second pivot bearing of the mobile clutch corresponding.

The wheel of the clutch mobile associated with the clutch bridge is then advantageously arranged between the base and the board.

Furthermore, it can be provided that the base comprises at least two cylindrical feet, axes parallel to the axial direction of the clutch mobile and intended to cooperate with holes adapted to the watch movement to ensure the positioning of the bridge. clutch on the frame of the watch movement and its guiding during changes in relative position between the clutch mobiles.

The present invention also relates to a watch movement, preferably of the type comprising a chronograph function, comprising a clutch device meeting the above characteristics, and a timepiece comprising such a watch movement.

BRIEF DESCRIPTION OF THE DRAWINGS [0019] Other features and advantages of the present invention will appear more clearly upon reading the detailed description of a preferred embodiment which follows, with reference to the accompanying drawings given as non-limiting examples. in which: FIG. 1 represents an exploded and simplified perspective view of a part of a watch movement comprising a clutch device according to a preferred embodiment of the invention; fig. 2 is a plan view and transparency of the watch movement of FIG. 1; fig. 3a is a simplified cross-sectional view of the watch movement of FIG. 1, in a first configuration, along the section line III-III of FIG. 2; fig. 3b is a simplified cross-sectional view similar to that of FIG. 3a, in a second configuration, and FIG. 4 represents an exploded and simplified perspective view of a part of a watch movement comprising a clutch device according to an alternative embodiment.

Embodiment (s) of the invention [0020] FIG. 1 represents an exploded and simplified perspective view of a part of a watch movement 1 comprising a clutch device according to a preferred embodiment of the invention. The watch movement is visible by its bridges side in fig. 1.

In general, only the elements having a direct link with the present invention have been shown for clarity.

The watch movement 1 is here of the chronograph function type, for non-limiting illustrative purposes.

It comprises a plate 2 having a multitude of machining and feet to allow the assembly of the various components of the watch movement 1, in a conventional manner.

The plate 2 comprises in particular a core 4 intended to receive a first clutch mobile 6, including a transmission wheel 8, secured to a shaft 10 and driven from the finishing gear (not shown) of the watch movement 1.

The transmission wheel 8 is pivoted between the plate 2 and a bridge 12 assembled to the plate. The bridge carries two pins 14 for positioning and holding on the plate 2 and is further screwed on it by means of a screw 15.

The shaft 10 has a length such that it passes through the bridge 12 and allows to fix at its free end a first clutch pad 16, integral with the shaft 10 in rotation, and therefore the transmission wheel 8.

The first clutch mobile 6 is surmounted by a second clutch mobile 18 having a shaft 20 carrying a second clutch shoe 22 and a chronograph drive wheel 24, both integral with the shaft. 20 in rotation. The first and second clutch mobiles 6 and 18 are coaxial.

The second clutch mobile 18 is pivoted on a clutch bridge 26, in two parts here, that is to say a base 28 and a board 30. The second clutch pad 22 is arranged movement side of the base 28, while the chronograph drive wheel 24 is arranged between the base 28 and the board 30.

The base 28 comprises two cylindrical legs 32, on its side facing the plate 2, axes parallel to the axial direction of the clutch movers 6 and 18 and intended to cooperate with holes 34 adapted to the plate 2 to ensure in particular the positioning of the clutch bridge 26 on the plate 2.

The base 28 has two studs 36 on its other side, intended to ensure the proper positioning of the board 30 on the base 28. The board 30 is further secured to the base 28 by means of a screw 38 .

The clutch device according to the present invention further comprises an elastic member in the form of an elongated and curved blade spring 40. The base 42 of the spring 40 is made integral with a chronograph bridge 44, by a screw 46, while its free end 48 takes place in a recess 50 substantially complementary to the board 30. The chronograph bridge 44 is assembled to the platinum 2 in a conventional manner not shown in FIG. 1.

The spring 40 is shaped so as to exert a pressure force on the board 30, tending to push the clutch bridge 26 towards the plate, as will be apparent from the explanations of the following figures.

FIG. 2 shows a partial plan and transparency view of the watch movement 1.

The fact that the first and second clutch mobiles 6 and 18 are coaxial appears clearly from the view of FIG. 2.

In addition, a chronograph counter wheel 52 (seconds) is also visible in FIG. 2, the latter being arranged in engagement with the chronograph drive wheel 24 and being intended to carry an indication member seconds timed.

There is shown a broken line of section III-III in FIG. 2 defining the cross-sectional planes of the representations of FIGS. 3a and 3b.

FIG. 3a shows the clutch device according to the preferred embodiment of the invention in its engaged configuration, while FIG. 3b represents it in its disengaged configuration.

FIG. 3a represents the clutching mobiles 6 and 18 in their default relative position, that is to say the one they occupy when the spring 40 is free to exert a pressure force on the clutch bridge 26. In this relative position, the clutch pads 16 and 22 are arranged in contact with each other, the clutch device being in its engaged configuration.

In this configuration, it appears that the rotational movement that the transmission wheel 8 receives from the finishing gear can be transmitted to the chronograph drive wheel 24 via the first shaft 10, the first skate clutch 16, the second clutch shoe 22 and the second shaft 20. The chronograph counter wheel 52 is driven in this configuration, associated with the measurement of a time.

The clutch device according to the present invention also comprises a control member for passing from one of its configurations to the other, in response to a predefined action of a user, typically a pressure on an external control member of the corresponding timepiece.

This control member here has the form of clutch clamps (not visible), similar to clutch clamps known from the prior art.

In the engaged configuration of FIG. 3a, the clutch clamps are typically spaced, in a neutral configuration, while they close to move to the active configuration of FIG. 3b, in which the clutch device is disengaged.

The base 28 of the clutch bridge 26 has a chamfer 54 intended to cooperate with the clutch clamps, when they close, to convert the movement of the clutch clamps in their plane in a movement of the bridge. clutch 26 oriented in the axial direction of the clutch mounts 6 and 18.

Closing the clutch clamps therefore causes a relative distance between the clutch mobile 6 and 18, because the clutch bridge 26 carrying the second clutch mobile 18 is remote from the plate 2.

The mode of cooperation between the cylindrical feet 32 of the clutch bridge 26 and the holes 34 of the plate provides guiding of the clutch bridge 26 during its configuration changes.

At the same time, the spring 40 is deformed, as is apparent from the disengaged configuration as illustrated in FIG. 3b.

In this configuration, the first and second clutch mobile 6 and 18 are completely dissociated, the clutch pads 16 and 22 being disjoint.

When the clutch clamps are again spaced, the clutch bridge 26 is approaching the plate 2 under the effect of the action of the spring 40 on the board 30, the clutch mobiles then taking their close relative position.

It is clearly seen from the view of FIG. 3b that the first clutch mobile 6 is free of any constraint that could come from the chronograph side of the clutch device, in the disengaged configuration, its transmission wheel 8 being driven only by the finishing train.

Unlike the known clutch devices of the prior art, the components of the clutch device according to the present invention do not give rise to any structural parasitic stress that would be applied to the first clutch mobile and would be likely to disturb the operation of the gear train.

A comparative examination of FIGS. 3a and 3b reveals that the chronograph drive wheel 24, in particular its thickness, is dimensioned such that its toothing remains in engagement with the wheel of the chronograph counter 52 in both configurations of the clutch.

It will also be noted that the stone 56, housed in the board 30, defines a stop for the shaft 20 in the engaged position, in order to limit its axial displacement when the second clutch pad 22 exerts a pressure on the first pad 16, under the effect of the action of the spring 40.

Thanks to its construction, the clutch device according to the present invention allows in particular to drive a display member seconds timed without risk of jump start, as is the case with horizontal clutches, but without however, not having the disadvantages of the vertical clutches known from the prior art.

FIG. 4 is an exploded and simplified perspective view of a part of a watch movement comprising a clutch device according to a variant of the preferred embodiment which has just been described.

The general principle of this embodiment is the same as the one just described, the essential differences between the two versions residing in the assembly mode of the clutch bridge to the plate and, in the manner whose elastic member acts on it to push it back to its disengaged configuration.

The components of the clutch device of the embodiment variant of FIG. 4 which do not show a significant difference, with reference to the embodiment which has just been described, bear the same numerical references to facilitate the understanding of the variant.

The base 128 of the clutch bridge 126, carrying a board 130, has, in addition to two cylindrical legs 32 for cooperating with holes 34 of the plate 2, a through hole 160 for engaging on a post 162 secured to the plate 2.

The through hole 160 has two sections in its axial direction, a first section closer to the plate 2 having a smaller diameter than the second section, the farthest from the plate 2. The difference in diameter between the two sections defines a shoulder 164 in the through hole 160.

The post 162 has a tapping provided to cooperate with a screw 166 wide head to make the base 128 integral with the plate 2.

A coil spring 140, whose diameter is between those of the two sections of the hole 160, is housed therein. Thus, when the device is assembled, the spring 140 is supported, on the one hand, on the shoulder 164 and on the other hand, on the head of the screw 166. Insofar as the latter is secured to the plate 2, the spring 140 exerts a pressing force on the base 128 tending to bring it closer to the plate 2, by acting on the shoulder 164.

As in the main embodiment, closing clutch clamps causes a displacement of the clutch bridge 126 as it moves away from the plate 2, overcoming the force exerted by the spring 140 and compressing it. Conversely, when the clutch clamps deviate, the clutch bridge 126 approaches the plate under the effect of the action of the spring 140, the clutch disks 6 and 18 ironing from their position relative remote, in which their pads 16 and 22 are disjoint, their relative position close, in which their pads are in contact with each other.

It will be noted that the variant embodiment of FIG. 4 allows greater freedom in the design of the chronograph bridge, in that it does not define an anchor point for the spring 140.

The construction illustrated in FIG. 4 has the same advantages as the main embodiment with reference to the clutch devices known in the state of the art.

The foregoing description attempts to describe a particular embodiment by way of non-limiting illustration and, the invention is not limited to the implementation of certain particular features which have just been described,

Claims (10)

as for example the shape of the various components of the clutch device, in particular the clutch bridge, the spring or the clutch clamps. In particular, any other suitable type of control member can be envisaged, replacing the clutch clamps without departing from the scope of the present invention. One can also consider the use of a ball bearing to ensure pivotal mounting of the second clutch mobile in the clutch bridge, the board of the latter is then no longer absolutely necessary. One can then optionally provide a specific stop to limit the axial displacement of the corresponding shaft and limit the axial stresses applied to the ball bearing, during the transition from the disengaged configuration to the engaged configuration. It is advantageously provided that the clutch pads have a fine texturing of the surfaces in contact in the engaged configuration, such as a trimming, to eliminate any risk of sliding (shown schematically by a dark zone on the first pad 16, on Fig. 1). In general, the clutch device according to the present invention may be associated with a chronograph display located on the dial or bottom side without departing from the scope of the invention. Furthermore, it is possible to implement the device of the invention with any other type of clock mechanism requiring a clutch. The skilled person will not encounter any particular difficulty to adapt the content of the present disclosure to his own needs and implement a clutch device in which the clutch mobile have respective independent shafts one the other and, one of which is carried by a movable clutch bridge in the axial direction of the clutch, without departing from the scope of the present invention. claims Clutch device for a watch movement (1) comprising first and second rotary clutch mobiles (6, 18) arranged substantially coaxially and so as to be able to present a relative displacement in their axial direction, between a first position relative, engaged, in which they are in contact with each other, and a second relative position, disengaged, in which they are disjoint, characterized in that said first and second clutch mobiles (6, 18) comprise respective first and second shafts (10, 20) independent of one another and one of which is carried by a clutch bridge (26) to be assembled to the watch movement (1) so as to ability to move in said axial direction in response to a predefined action of a user. 2. A clutch device according to claim 1, characterized in that it further comprises a movable control member between neutral and active configurations, in response to said predefined action, and arranged to position said clutch mobiles (6). , 18) in one of said first and second relative positions in said active configuration and to leave them free to take the other relative position, by default, in said neutral configuration, and an elastic member (40) arranged to hold said mobiles clutch (6, 18) in said default relative position when said control member is in its neutral configuration. 3. A clutch device according to claim 2, characterized in that said control member and said elastic member (40) are intended to be arranged on the watch movement (1) to act on said clutch bridge (26). 4. A clutch device according to one of the preceding claims, characterized in that each of said first and second clutch mobile (6, 18) comprises a clutch pad (16, 22) arranged to cooperate with the clutch pad. clutching the other clutch mobile in said engaged relative position, each of said clutch pads (16, 22) being rotatably connected to the corresponding shaft (10, 20), and a wheel (8.24). , integral in rotation with the corresponding shaft (10,20) and intended to present a kinematic connection with a gear train of the watch movement (1). Clutch device according to claim 4, characterized in that said clutch bridge (26) comprises a base (28) carrying a first pivot bearing of the corresponding clutch mobile (6, 18), and a board (30), integral with said base (28) and carrying a second pivot bearing of the clutch mobile (6, 18) corresponding. 6. A clutch device according to claim 5, characterized in that the wheel (24) of the clutch mobile (18) associated with said clutch bridge (26) is arranged between said base (28) and said board (30). ). 7. clutch device according to claim 5 or 6, characterized in that said base (28) comprises at least two cylindrical feet (32), axes parallel to said axial direction of said clutch mobiles (6, 18). and, intended to cooperate with holes (34) adapted to the watch movement (1) to ensure the positioning of said clutch bridge (26) on the frame (2) of the watch movement (1) and its guiding during the changes of relative position between said clutch mobiles (6, 18). 8. watch movement (1) comprising a clutch device according to one of the preceding claims and first and second gear trains, characterized in that said first gear train has a kinematic connection with said first mobile d clutch (6), while said second gear train has a kinematic connection with said second clutch mobile (18). Clock movement according to claim 8, comprising a chronograph mechanism, said clutch device being arranged to establish or interrupt, on demand, a kinematic connection between said first and second gear trains, one of them being a finishing gear and the other a chronograph wheel. Timepiece comprising a watch movement (1) according to claim 8 or 9.