CH710892B1 - Chronograph mechanism for watch movement. - Google Patents

Abstract

The present invention relates to a chronograph mechanism, particularly "in-flight", comprising a driving kinematic chain for connecting a driving wheel to a chronograph counter (6), a clutch device (8) comprising a transmission member (10) movable between a first disengaged position in which the driving kinematic chain is interrupted and a second engaged position in which the driving kinematic chain is operative; a movable brake (30) for locking the chronograph counter (6), a reset hammer (50) movable between a first resting position and a second reset position, and comprising a first neutralizing portion (80) capable of cooperating with the transmission member (10) forcing it to leave its engaged position when the reset hammer (50) is actuated, a second neutralizing portion (84) capable of cooperating with the brake (30) to force it to leave its locking position when the reset hammer (50) is actuated.

Description

Description

Technical Field The present invention relates to a chronograph mechanism for a watch movement, comprising a kinematic drive chain capable of establishing a kinematic link between a mobile for driving the watch movement and at least one chronograph counter, a clutch device comprising at least one movable transmission member between a first position, disengaged, in which the drive kinematic chain is interrupted and a second position, engaged, in which the drive kinematic chain is functional, a movable brake between a first position, in which it acts on the chronograph counter to lock it, and a second position, in which it is located at a distance from the chronograph counter to leave it free to rotate, at least one mobile reset hammer between a first position, of rest, and a second position, of reset, d in which it cooperates with the chronograph counter to place it in a predefined configuration, first and second control members arranged to respectively control, on the one hand, the clutch device and the brake and, on the other hand, the reset hammer.

STATE OF THE ART [0002] Such chronograph mechanisms have been known for a long time and can have various constructions.

For example, the work entitled "Clock Theory", by C.-A. Reymondin et al., Published by the Federation of Technical Schools (Switzerland), ISBN 2-940 025-10-X provides examples, in particular on pages 232 to 244.

In these chronograph mechanisms, of the current type, the resetting of the chronograph counters can only be carried out when the mechanism is stopped, in STOR configuration For this purpose, the resetting hammer generally has a spout arranged to cooperate with the control member of the clutch and brake device and prevent actuation of the hammer when the measurement of a time is in progress. In addition, the hammer generally cooperates with the brake to lift it when actuating the reset.

An alternative embodiment of these mechanisms is known, thanks to which a reset is also possible during the measurement of a time. These mechanisms are called "flyback".

In this case, it is necessary to provide a device intended to act on the clutch device if the reset is actuated while the measurement of a time is in progress, to neutralize it and thus avoid causing damage to the mechanism.

The present invention relates to such a mechanism in which the reset hammer is arranged in such a way that it is capable of being actuated independently of the respective positions of the transmission member and of the brake, of forcing the brake. to leave its first position, and to force the transmission member to leave its engaged position.

Patent CH 183 262 presents an example of the construction of a chronograph mechanism of the "return to flight" type. In this mechanism, the reset hammer is arranged to act directly on the brake, if necessary during reset operations, as in standard chronograph mechanisms, while a specific rocker is provided to act on the device clutch and place it in its disengaged configuration if a reset is activated during the measurement of a time. In fact, the reset hammer is generally distant from the clutch device, in chronograph mechanisms, and the implementation of a specific intermediate rocker is necessary to transmit the movements of the hammer to the clutch device. . In the construction presented in this patent, the reset hammer carries a pin passing right through it to act, on one side, on the brake and, on the other side, on the intermediate rocker.

However, such a construction results in an increase in the number of components of the chronograph mechanism and makes it difficult to develop the latter. In addition, the increase in the number of components implies that these are distributed over several levels, depending on the thickness of the chronograph mechanism, which also results in an increase in the total thickness of the mechanism, this being already significant. by default.

Disclosure of the invention A main object of the present invention is to provide an alternative construction to the constructions known from the prior art, by proposing a chronograph mechanism of the "return to flight" type having a thickness and a difficulty. of development limited with reference to known constructions.

To this end, the present invention relates more particularly to a chronograph mechanism of the type described above, characterized in that the hammer comprises a first neutralization portion capable of cooperating with the transmission member when the hammer is actuated , a second neutralization portion capable of cooperating with the brake when the hammer is actuated.

CH 710 892 B1 Thanks to these characteristics, the hammer is shaped so that it can act directly on the clutch device, without the need to provide an intermediate rocker, thus limiting the number of components required with reference to known mechanisms.

According to a preferred embodiment, the reset hammer comprises a flight return arm carrying the first and second neutralization portions.

Advantageously, it can be provided that the reset hammer is substantially planar, the first and second neutralization portions being formed on a section of the return flight arm.

We can then provide that the transmission member and the brake each carry a substantially cylindrical stud intended to cooperate with one of the neutralization portions.

According to a preferred embodiment, when the reset hammer has a rotational movement to pass from one to the other of its first and second positions, the first and second neutralization portions may advantageously have the form d '' circular arcs centered on the axis of rotation of the reset hammer. In this case, it can be expected that, in a plan view, the reset hammer is intended to be arranged substantially in the first quarter of the watch movement, while the transmission member and the brake are intended to be arranged substantially in another quarter of the watch movement. The flight return arm then advantageously has a curved shape intended to bypass the center of the watch movement.

According to an alternative embodiment, it can be provided that the reset hammer comprises a base comprising a hole, defining its axis of rotation, as well as an actuating surface arranged to cooperate with the second control member, and from which extend at least a first arm carrying a reset surface arranged to cooperate with the chronograph counter, and the flight return arm, the latter comprising, from the base and towards its end free, a rest surface, a first inclined surface, the first neutralization portion, a second inclined surface and the second neutralization portion, and that the flight return arm is arranged in such a way that the rest surface is arranged in look of one among the transmission member and the brake, and that the first neutralization portion is arranged facing the other among the transmission member and the brake, da ns the rest position of the reset hammer, and that the first neutralization portion is arranged opposite one of the transmission member and the brake, and that the second neutralization portion is arranged opposite the 'other among the transmission member and the brake, in the reset position of the reset hammer. In general, the chronograph mechanism advantageously includes a chronograph minute counter, the reset hammer comprising an additional arm carrying an additional reset surface arranged to cooperate with the chronograph minute counter for the place in a predefined configuration.

The invention also relates to a timepiece movement comprising a chronograph mechanism meeting the characteristics which have just been exposed, as well as a timepiece comprising such a timepiece movement.

BRIEF DESCRIPTION OF THE DRAWINGS Other characteristics and advantages of the present invention will appear more clearly on reading the detailed description of preferred embodiments which follows, made with reference to the accompanying drawings given by way of non-limiting examples and wherein:

fig. 1 shows a simplified top view of a timepiece movement comprising a chronograph mechanism according to a preferred embodiment of the present invention, in a first configuration;

fig. 2 shows a simplified top view of the watch movement of FIG. 1 in a second configuration, and FIG. 3 shows a simplified top view of the watch movement of FIG. 1 in a third configuration.

Mode (s) of Carrying Out the Invention Figs. 1,2 and 3 show the same simplified top view of a timepiece movement 1 comprising a chronograph mechanism according to a preferred embodiment of the present invention, in respective first, second and third configurations, corresponding to the three operating modes of the chronograph mechanism, that is to say respectively stop, start and reset.

CH 710 892 B1 The watch movement 1 comprises a frame comprising a plate 2 and conventional bridges not shown in the figures for clarity. The watch movement 1 is represented here in a view from its platinum side, a winding stem 4 being assembled with a winding and time-setting mechanism (not visible) in a conventional manner, in the three o'clock position (according to the convention based on the hour positions on a watch face).

The chronograph mechanism is arranged on the plate 2, on its side facing the dial side.

Conventionally, a training mobile (not visible) is provided to rotate, on demand, the mobiles of the chronograph mechanism to measure a time.

A kinematic chain is provided for transmitting, on request, the rotational movement of the driving mobile to a chronograph 6 seconds counter. The kinematic chain comprises a clutch device comprising a rocker 8 pivotally mounted on the frame of the watch movement between a first position, disengaged, and a second position, engaged.

The clutch lever 8 carries a transmission member comprising, in this preferred embodiment by way of nonlimiting illustration, a vertical reference 10 including a first wheel (not visible) is intended to mesh or not with the mobile drive and a second wheel 12 is intended to mesh or not with a wheel 14 of the chronograph seconds counter 6. In known manner, the wheel 14 is integral with a shaft 16 of the chronograph seconds counter 6 intended to carry a display device for the seconds of a timed time (not shown).

Thus, the kinematic chain between the driving mobile and the chronograph counter 6 is interrupted in the first position, disengaged, of the clutch lever 8 and functional in its second position, engaged.

The clutch lever 8 includes an elongated spout 18 arranged to cooperate, on one of its sides, with a rotary control member 20 having an operating mode similar to that of a conventional column wheel.

The control member 20 has for this purpose a first toothing 22, control, and a second toothing 24, actuation, produced by the assembly of two stars, here one with four teeth and the other with eight teeth. The first toothing 22 is intended to allow a rotation of a pitch of the control member 20 in response to a user action on a control lever 26. The second toothing 24 cooperates with the spout 18 of the clutch lever 8 to define the angular orientation of the latter. A return spring 28 acts on the clutch lever 8 so that its spout 18 is arranged in abutment against the control member 20.

When the second toothing 24 has a tooth facing the spout 18, it acts on the spout to move it away from the center of the control member 20 (disengaged position), opposing the action of the spring 28. When the second toothing 24 has a gap, located between two teeth, facing the spout 18, the clutch lever 8 pivots in the counterclockwise direction of rotation, so as to bring its spout 18 closer to the center of the control member 20 (engaged position).

Furthermore, the chronograph mechanism also includes a brake 30 rotatably mounted on the frame of the watch movement and intended to act directly on the periphery of the wheel 14 of the chronograph seconds counter 6, to lock it angularly in the configuration stopped. To this end, a spring 32 is arranged to act on the brake 30 and push it in the direction of the wheel 14.

The brake 30 is shaped so that it can cooperate with a screw 34 carried by the clutch lever 8 so that the latter lifts the brake 30 from its disengaged position to its engaged position.

This operation occurs when the chronograph mechanism changes from its stopped configuration to its running configuration, as shown by a comparative examination of FIGS. 1 and 2. When the clutch lever 8 moves from its disengaged position to its engaged position, it raises the brake 30 while its wheel 12 engages with the wheel 14 of the chronograph seconds counter 6.

Conversely, when the measurement of a time is stopped, the clutch rocker returns to its disengaged position as illustrated in FIG. 1 and releases the brake 30, at the same time, which again locks the wheel 14 whatever its orientation.

In known manner, the illustrated chronograph mechanism also includes a chronograph minute counter 36 driven from the chronograph second counter 6. To this end, the chronograph mechanism includes a reference 38 arranged in permanent engagement with the wheel 14 and carrying an elastic actuating finger 40, intended to cooperate with the teeth of a wheel 42 of the chronograph minute counter 36, to drive it one step at each minute of a timed time. The wheel 42 is integral with a shaft 44 of the chronograph minute counter 36 intended to carry a member for displaying the timed minutes (not shown).

Furthermore, the chronograph mechanism according to the present invention comprises various return springs and long necks which will not be described in detail, as well as their functions, since they are well known to those skilled in the art.

CH 710 892 B1 The chronograph mechanism comprises a reset device comprising in particular two cams at the heart of reset 46, 48, respectively integral with the shafts 16 of the chronograph seconds counter and 44 of the minutes counter chronograph.

The cams 46, 48 are intended to cooperate with a reset hammer 50, in a conventional manner.

The reset hammer 50 is pivotally mounted on the frame of the watch movement, by means of a bearing screw 52, to pivot between a first position, at rest (fig. 1 and 2), and a second position, reset (fig. 3). For this purpose, the hammer 50 comprises a base 54 in which is a hole (not visible) defining the axis of rotation of the hammer and through which the screw 52 is arranged.

The base 54 carries an actuating surface 56 intended to cooperate with a hammer control member having the shape of a control lever 58 pivotally mounted on the frame of the watch movement, between a rest position and a position actuation, intended to ensure the reset of the chronograph counters in response to pressure exerted by a user on the control lever 58.

The hammer comprises a first arm 60, carrying a first reset surface 62 intended to cooperate with the cam 48 of the chronograph minute counter 36, as well as a second arm 64 carrying a second reset surface 66 intended to cooperate with the cam 46 for resetting the chronograph seconds counter 6 to zero.

Note that the reset hammer 50 does not interact with the first control member 20 as is generally the case in simple chronograph mechanisms, which allows it to be operated independently of the angular position of the control member 20 and therefore of the current operating mode, that is to say whether the measurement of a time is in progress or not. As mentioned above, this type of chronograph mechanism is called "flyback".

A return spring 67 cooperates with the reset hammer 50 so as to push it back towards its rest position. The spring 67 has a recess 70 in which is housed a pin 72 secured to the reset hammer 50 in the rest position of the latter. The recess 70 allows at the same time to define a notch during the actuation of the reset hammer 50. When the control lever 58 is actuated and released by a user, the return spring 67 acts on the reset hammer to zero 50 to push it back into its rest position.

As has been explained in connection with the prior art, a chronograph mechanism of the "return to flight" type requires the implementation of an arrangement making it possible to separate the brake 30 and the clutch lever. 8 of wheel 14 during reset operations to avoid any damage that the chronograph mechanism could otherwise suffer.

For this purpose, the reset hammer according to the present invention comprises a flight return arm 68 intended to act both on the clutch lever 8 and on the brake 30, when the hammer 50 is actuated to go from its rest position to its reset position.

The flight return arm 68 extends substantially in a plane and comprises on its outer edge, or edge, from the base 54 towards its free end 74, a rest surface 76 followed by a first inclined surface 78 , a first neutralization portion 80, a second inclined surface 82 and a second neutralization portion 84.

In the stopped configuration of the chronograph mechanism (Fig. 1), the rest surface 76 is located opposite a stud 86 secured to the clutch lever 8, the latter however being out of reach of the hammer 50 due to its cooperation with a tooth of the control member 20. In this configuration, the first neutralization portion 80 is located opposite a stud 88 secured to the brake 30, without however being pressed against it. The brake 30 is thus free to position itself in abutment against the wheel 14 to lock it. The second neutralization portion 84 is free from any interaction in the configuration of FIG. 1.

It is noted that, advantageously without limitation, the stud 86 is here directly constituted by a portion of the shaft on which the wheels of the clutch device are pivoted extending slightly beyond the hub of the second wheel 12.

When the measurement of a time is initiated by actuation of the control member 20, as illustrated in FIG. 2 in the running configuration, the clutch lever 8 pivots to drive the wheel 14. The reset hammer 50 then has an unchanged position relative to the position of FIG. 1.

It can be seen that the rest surface 76 does not intervene in the rotation of the clutch lever 8, the distance between them at rest being sufficiently great. The brake 30 is then lifted by the clutch lever 8 and is moved away from the first neutralization portion 80 which consequently does not always play any role in the operation of the chronograph mechanism.

If the control lever 58 is actuated from the running configuration of the chronograph mechanism (fig. 2), the latter goes into the reset configuration, as illustrated in fig. 3.

The action of the control lever 58 causes the reset hammer 50 to pivot in the counterclockwise direction of rotation.

CH 710 892 B1 The reset surfaces 62 and 66 then come into contact with the cams 46 and 48 to reset the two counters in a predefined angular orientation corresponding to a zero measured time, in a conventional manner.

During the fall of the reset hammer 50 to its reset position, the flight return arm 68 has the same rotational movement as the hammer to, at first, push the clutch lever 8 and the brake 30 if necessary, by means of its first and second inclined surfaces acting on the pads 86 and 88, then, in a second step, positioning the first and second neutralization portions 80 and 84 opposite the pads 86 and 88 and thus keep the clutch lever 8 and the brake 30 distant from the wheel 14 of the chronograph second counter 6.

Note that if the zero setting is activated in the stopped configuration of the chronograph mechanism (fig. 1), in which only the brake 30 is arranged in contact with the wheel 14, the brake 30 only is moved by the return flight arm 68, the first neutralization portion 80 coming to be placed opposite the stud 86 of the clutch lever 8 to ensure that the latter cannot pass into its engaged position without it actually being necessary to push it further.

If the reset is actuated in the running configuration of the chronograph mechanism (FIG. 2), in which only the clutch lever 8 is arranged in contact with the wheel 14 by means of its wheel 12, the clutch lever 8 only is moved by the flight return arm 68, the second neutralization portion 84 coming to be placed opposite the pad 88 of the brake 30 to ensure that the latter cannot pass into the locking position, in pressing against the wheel 14. More precisely, as mentioned above, in the running configuration, the brake 30 is lifted from the wheel 14 directly by the clutch lever 8, but the fact that the clutch lever 8 is pushed back by the first neutralization portion 80 implies that the brake 30 could be free to fall on the wheel 14 without the intervention of the second neutralization portion 84 arranged to prevent it.

When the control lever 58 is released, after resetting the chronograph counters, the reset hammer 50 returns to its rest position, under the effect of the action of the return spring 67. In this movement, the flight return arm 68 presents a reverse movement to what has just been described and releases the clutch lever 8 and the brake 30 to return to the configuration of the chronograph mechanism which was in place before handing over at zero, either on or off.

Note that here the outer edge of the flight return arm 68 has different sections substantially in the form of circular arcs centered on the center of rotation of the hammer 50, with the interposition of the two inclined surfaces, to define the portions neutralization. The flight return arm 68 therefore plays the role of a two-level cam arranged to act respectively on the clutch lever 8 and on the brake 30.

This produces a reset hammer construction which provides an optimal level of security for the implementation of the return-to-flight operation of the chronograph mechanism, without however having a complex structure and therefore expensive.

It will be noted in particular that the construction of the chronograph mechanism according to the present invention makes it possible to reduce its bulk in the direction of its thickness. In fact, the reset hammer 50 can be produced substantially along a plane thanks to the particular shape of its flight return arm 68 which allows the latter to cooperate simultaneously with the clutch lever 8 and with the brake 30 In addition, the fact that the reset hammer cooperates directly with the clutch lever rather than via an intermediate lever as is the case in the mechanisms of the prior art, also allows to simplify the development and adjustment operations of the mechanism during its manufacture.

Furthermore, the architecture of the chronograph mechanism according to the preferred embodiment which has just been described is particularly advantageous. Indeed, the control members, respectively for on-off commands and for resetting to zero, are arranged directly opposite the corresponding pushers, as they are typically installed in timepieces with chronograph function. More specifically, it can be seen that the control member 20 is situated at two o'clock, substantially opposite the on-off push-button, while the actuating surface 54 of the hammer 50 is located around five o'clock, ie in the immediate vicinity of the push-button. reset, located at the four o'clock position. Thanks to these characteristics, it is not necessary to resort to the use of elongated intermediate rockers to retransmit the commands from the external pushers as is generally the case in known chronograph mechanisms. This characteristic again contributes to simplifying the development of the mechanism during its manufacture. In addition, it can be seen in the figures that such an architecture makes it possible to arrange the reset hammer substantially in the first quarter of the watch movement, while the components involved in the on and off operating modes, in particular the rocker d 'clutch and brake, are arranged in a second quarter of the watch movement. The flight return arm then has a curved shape, intended to bypass the center of the watch movement, to extend into the quarter in which the clutch lever and the brake are arranged.

The above description attempts to describe a particular embodiment by way of nonlimiting illustration and, the invention is not limited to the implementation of certain particular characteristics which have just been described, such as the shapes specifically illustrated and described for the components of the chronograph mechanism.

CH 710 892 B1

In particular, it will be noted that the reset hammer illustrated has an advantageous shape due to the fact that the junctions between its different arms and its base are refined, thus conferring a certain elasticity on the arms. The operations of adjustment and adjustments during the manufacture of the corresponding mechanism are again simplified.

Those skilled in the art will not encounter any particular difficulty in adapting the content of the present disclosure to their own needs and building a chronograph mechanism of the "return to flight" type and in which the reset hammer is arranged to cooperate directly with the brake and the clutch device when a reset is actuated, without departing from the scope of the present invention.

By way of example, if the chronograph mechanism which has just been described is of the integrated type (with the basic watch movement), the person skilled in the art may decide to adapt the present teaching to produce a mechanism for modular type chronograph without difficulty and without departing from the scope of the invention.

Claims (10)

claims 1. Chronograph mechanism, for a watch movement (1), comprising a kinematic drive chain capable of establishing a kinematic connection between a mobile driving the watch movement and at least one chronograph counter (6), a device for 'clutch (8) comprising at least one transmission member (10) movable between a first position, disengaged, in which said drive kinematic chain is interrupted and a second position, engaged, in which said drive kinematic chain is functional , a brake (30) movable between a first position, in which it acts on said chronograph counter (6) to lock it, and a second position, in which it is located at a distance from said chronograph counter (6) to leave it free to rotate, at least one reset hammer (50) movable between a first position, of rest, and a second position, of reset, in which it cooperates with said chronograph counter (6) to place it in a predefined configuration, first and second control members (20, 58) arranged to respectively control, on the one hand, said clutch device (8) and said brake (30) and, on the other hand, said reset hammer (50), said reset hammer (50) being arranged in such a way that it can be actuated independently of the respective positions of said transmission member (10) and said brake (30), forcing said brake (30) to leave its first position, and forcing said transmission member (10) to leave its engaged position, characterized in that said delivery hammer to zero (50) comprises a first neutralization portion (80) capable of cooperating with said transmission member (10) when said reset hammer (50) is actuated, a second neutralization portion (84) capable of cooperating with l edit brake (30) when said reset hammer (50) is actuated. 2. Chronograph mechanism according to claim 1, characterized in that said reset hammer (50) comprises a flight return arm (68) carrying said first and second neutralization portions (80, 84). 3. Chronograph mechanism according to claim 2, characterized in that said reset hammer (50) is substantially planar, said first and second neutralization portions (80, 84) being formed on a section of said return flight arm (68). 4. Chronograph mechanism according to claim 3, characterized in that said transmission member (10) and said brake (30) each carry a substantially cylindrical stud (86, 88) intended to cooperate with one of said neutralization portions ( 80, 84). 5. Chronograph mechanism according to one of claims 1 to 4, said reset hammer (50) having a rotational movement to pass from one to the other of its first and second positions, characterized in that said first and second neutralization portions (80, 84) have substantially the form of circular arcs centered on the axis of rotation of said reset hammer (50). 6. Chronograph mechanism according to claim 5, characterized in that, in a plan view, said reset hammer (50) is intended to be arranged substantially in a first quarter of the watch movement (1), while said transmission member (10) and said brake (30) are intended to be arranged substantially in a second quarter of the watch movement (1), and in that said flight-back arm (68) has a curved shape intended to bypass the center of the watch movement (1). 7. Chronograph mechanism according to claim 5 or 6, characterized in that said reset hammer (50) comprises a base (54) comprising a hole, defining its axis of rotation, as well as an actuation surface ( 56) arranged to cooperate with said second control member (58), and from which extend at least one first arm (64) carrying a reset surface (66) arranged to cooperate with said chronograph counter ( 6), and CH 710 892 B1 said flight return arm (68), the latter comprising, from said base (54) and in the direction of its free end (74), a rest surface (76), a first inclined surface (78) , said first neutralization portion (80), a second inclined surface (82) and said second neutralization portion (84), and in that said flight-back arm (68) is arranged in such a way that said rest surface (76) is arranged opposite one of said transmission member (10) and said brake (30), and that said first neutralization portion (80) is arranged opposite one of said transmission member ( 10) and said brake (30), in said rest position of said reset hammer (50), and that said first neutralization portion (80) is arranged facing one of said transmission member (10) and said brake (30), and that said second neutralization portion (84) is arranged facing the other of said transmission member (10) and said brake (30), in said reset position of said reset hammer (50). 8. Chronograph mechanism (20) according to one of the preceding claims, characterized in that it comprises a chronograph minute counter (36), said reset hammer (50) comprising an additional arm (60) carrying an additional reset surface (62) arranged to cooperate with said chronograph minute counter (36) to place it in a predefined configuration. 9. Watch movement (1) comprising a chronograph mechanism according to one of the preceding claims. 10. Timepiece comprising a timepiece movement (1) according to claim 9. CH 710 892 B1 CH 710 892 B1