Timepiece device for transforming a first rotation into a second rotation

Abstract

The invention relates to a timepiece device comprising an input rotary member (2), an output rotary member (3), a fixed or movable cam surface (15), an elastic member (8, 9) and a cam follower (6) arranged to be controlled by the input rotary member (2) and to engage with the cam surface (15) under the action of the elastic member (8) in order to drive the output rotary member (3), the output rotary member (3) and the cam follower (6) being surrounded by the cam surface (15). The output rotary member (3) and the cam follower (6) are coplanar.

Description

[0001] Clockwork device for transforming a first rotation into a second rotation

[0002] The present invention relates to a timepiece device for transforming a first rotation into a second rotation. The second rotation is, for example, at least partly jerky. Such a device can be used, for example, for the jumping display of a time quantity such as hour, minute, second, date, day, week or other, or for driving an automaton.

[0003] It is well known in watchmaking (see for example patent CH 702137) to transform a continuous rotation into a jerky rotation by continuously driving a snail cam on which a lever rests under the action of a spring, this lever carrying a pawl which advances a jumping wheel by one step each time the lever falls from the upper part to the lower part of the snail cam. A jumper acts on the jumping wheel to hold it angularly between two actuations by the pawl. A disadvantage of this type of device is that there is a risk of double jumping, that is to say that under the effect of its inertia the jumping wheel can move an additional step after its actuation by the pawl.

[0004] Clock devices for transforming a continuous rotation into a jerky rotation which overcome this drawback have been proposed in patents CH 707181, CH 707182 and CH 707183 of the present applicant and in patent application CH 709375.

[0005] In the device according to the three aforementioned patents, a continuously driven second wheel meshes with an intermediate wheel which itself meshes with a jumping second wheel. The intermediate wheel is carried by a lever whose beak cooperates with a blocking wheel to immobilize it. This blocking wheel is integral with a pinion which meshes with the jumping wheel. The continuously driven second wheel transmits its rotation to the intermediate wheel. As long as the jumping second wheel is blocked by the action of the beak of the lever on the blocking wheel, the rotation of the intermediate wheel causes the rotation of the lever until the beak leaves the tooth of the blocking wheel against which it was resting.Each time the beak leaves a tooth of the locking wheel, the latter becomes free and the lever returns to its initial position under the action of a return spring, which brings the intermediate wheel back to its initial position and makes the jumping second wheel jump, the jump stopping when the beak of the lever meets the next tooth of the locking wheel. This device is efficient but it is bulky both in height (parallel to the axes of rotation) and in projection in a plane perpendicular to the height.

[0006] The device described in patent application CH 709375 comprises a continuously driven seconds wheel and a pawl carrier coaxial with this seconds wheel. On this pawl carrier is articulated a pawl around a pin. The pawl carrier is connected to the seconds wheel by a balance spring. At one of its two ends, the pawl comprises a beak engaged in an internal toothing of a fixed crown. At its other end, it carries a pin engaged in an oblong hole of the seconds wheel, allowing the pawl to oscillate when the seconds wheel rotates. The seconds wheel, rotating continuously, winds the balance spring and at the same time actuates the pawl. When the pawl leaves a tooth of the crown, it jumps and stops against the next tooth. The pawl carrier thus moves in jumps. This device is bulky both in height and in projection in a plane perpendicular to the height.

[0007] The present invention aims to propose a watch device for transforming a first rotation into a second rotation which is relatively compact, at least in height.

[0008] To this end, there is provided a timepiece device according to claim 1, particular embodiments being defined in the dependent claims. The present invention also provides a timepiece, for example a watch, more particularly a wristwatch, comprising such a timepiece device.

[0009] Other characteristics and advantages of the present invention will appear on reading the following detailed description made with reference to the appended drawings in which:

[0010] - figures 1 to 7 show in plan view from above a clockwork device for transforming a first, continuous rotation into a second, at least partly jerky rotation, according to respectively the first to seventh embodiments of the invention;

[0011] - figure 8 shows in plan view from above a clockwork device for transforming a first, continuous rotation into a second, continuous rotation but at variable speed, according to an eighth embodiment of the invention;

[0012] - figure 9 shows partially, in plan view from above, a clockwork device for transforming a first rotation into a second rotation according to a ninth embodiment of the invention.

[0013] In the various embodiments described below and illustrated in the drawings, the same references are used to designate similar elements.

[0014] In the context of the present invention, two elements are said to be coplanar when they have substantially the same thickness (height) and substantially the same median plane perpendicular to this thickness.

[0015] Figure 1 shows a watch device 1a for transforming a first rotation into a second rotation, at least partly jerky, according to a first embodiment of the invention. This device 1a is intended to be integrated into a movement of a timepiece, typically a watch. It comprises a rotary input member 2, a rotary output member 3, a fixed crown 4 having internal teeth 5, a lever 6 and an intermediate member 7 movable relative to the rotary input and output members 2, 3 and to the crown 4.

[0016] The rotary input member 2, the rotary output member 3, the ring gear 4 and the intermediate member 7 are coaxial. The rotary output member 3, the lever 6 and the intermediate member 7 are part of a monolithic part which is coplanar with the rotary input member 2 and the ring gear 4, the rotary input member 2 being located at the center of the device 1a and the ring gear 4 constituting the periphery of the device 1a.

[0017] The lever 6 is connected, in the monolithic part, to the intermediate member 7 by a first flexible guide 8, here a simple elastic blade. The rotary output member 3 and the intermediate member 7 are connected, in the monolithic part, by a second flexible guide 9, here consisting of two RCC elastic blades (“Remote Center Compliance”; flexible guide with offset center of rotation). Thus, the lever 6 can pivot relative to the intermediate member 7 about a pivot point P, which is located approximately one third of the length of the blade 8 measured from the lever 6, and the intermediate member 7 can pivot about the common imaginary axis A of the members 2, 3, 4, 7 while being guided by the rotary output member 3. The rotary output member 3 is integral with a display disc (for example of the type of disc 17 illustrated in FIG. 2) which is guided in rotation about the axis A by the shaft on which the rotary input member 2 is mounted.For its assembly with the display disc, the rotary output member 3 comprises ears 10 capable of receiving pins glued, welded or otherwise fixed to the display disc.

[0018] The rotary input member 2 is continuously driven in rotation around the axis A in the clockwise direction by the driving member of the movement. A rotation which is timed to the rhythm of the oscillations of the regulating member of the movement, as is the case here, is in fact considered to be continuous in the present invention. For its drive, the rotary input member 2 is integral with a pinion or a wheel (not shown) kinematically connected to the going train of the movement. The rotary input member 2 comprises two meshing teeth 11 which receive between them a first meshing tooth 12 of the lever 6. A second meshing tooth 13 of the lever 6, diametrically opposite to the first with respect to the pivot point P, is engaged between two meshing teeth 14 of the rotary output member 3.

[0019] The internal toothing 5 is composed of wave-shaped teeth each comprising a stop flank 15 against which a beak 16 of the lever 6 can bear under the action of the flexible guides 8, 9. The rotation of the rotary input member 2 causes the beak 16 to slide onto the stop flank 15 on which it is located and to pivot the lever 6 around its pivot point P in the counterclockwise direction by deforming the flexible guides 8, 9 until the beak 16 leaves the toothing 5. As soon as the beak 16 leaves the toothing 5, the lever 6 is released and the restoring force of the flexible guides 8, 9 causes it to fall onto the stop flank 15 of the next tooth, carrying with it the rotary output member 3 by its second meshing tooth 13. The rotary output member s and the display disc move thus by jumps, which allows for example to digitally display the current time, the units and the tens of the current minutes (cf.the display of the units of the minutes by the disc 17 in figure 2), a measured time, a countdown, the date, the day, the week, the power reserve, or other.

[0020] This device 1a is space-saving in height thanks to its flat structure, in particular thanks to the coplanar arrangement of the rotary output member 3 and the lever 6. In addition, the monolithic nature of the lever 6 - intermediate member 7 - rotary output member 3 - flexible guides 8, 9 assembly, an assembly which can be manufactured for example by the LIGA or DRIE process, allows high operating precision.

[0021] Thanks to the floating member constituted by the intermediate member 7, the pivot point P of the lever 6 moves relative to the crown 4, to the rotary output member 3 and to the frame on which the device 1a is mounted during the sliding of the beak 16 on the stop flank 15. Thus, it is not only the rotation of the lever 6 around the pivot point P but also the displacement of the pivot point P which allows the lever 6 to escape from the stop flank 15. This makes it possible to reduce the amplitude of rotation of the lever 6 around the pivot point P, therefore the height of the teeth of the internal toothing 5, therefore the size of the device 1a in its plane. A reduced amplitude of rotation of the lever 6 also reduces the energy consumption of the device 1a.The mobility of the pivot point P also makes it possible to reduce the stresses applied in the return spring of the lever 6, namely here the first flexible guide 8, or to reduce the dimensions of the return spring without increasing the stresses to which it is subjected.

[0022] It will also be noted that, by means of gear ratios adapted between the rotary input member 2 and the lever 6 and between the lever 6 and the rotary output member 3, the meshing between the lever 6 and the rotary output member 3 can be likened to a simple rolling of the lever 6 on the rotary output member 3 (hypocycloidal movement) which keeps the latter stationary. The cooperation between the second meshing tooth 13 of the lever 6 and the two meshing teeth 14 of the rotary output member 3 therefore immobilizes the rotary output member 3 between two jumps and allows the rotary output member 3 to be driven by the lever 6 during each jump.

[0023] It will be appreciated that with such a device, any double jump or incomplete jump of lever 6 is avoided.

[0024] Another important advantage of this device 1a is that it offers great freedom as to the movement that one wishes to produce at the output. By playing on the profile of the internal teeth 5 and on the gear ratios between the rotary input member 2 and the lever 6 and between the lever 6 and the rotary output member 3, it is in fact possible to move the rotary output member 3 according to a purely jerky rotation (jumps only) or partially jerky rotation (combination, for example alternation, of continuous rotations and jumps). It is thus possible to display information instantaneously, as described above, or semi-trailing. It is also possible to control an automaton according to an irregular rotation pattern.

[0025] Device 1a can be considered as a differential in which one of the two inputs controls the other to allow only one rotation scenario. The rotating input member 2 is an input planetary gear of the differential, the lever 6 is a satellite, the intermediate member 7 is the planet carrier and the rotating output member 3 is the output planetary gear. The advantage here is that the differential is flat and there is no element that can get skewed and seize up the system.

[0026] Considering such a differential, it is also possible to move the meshing between the lever 6 and the rotating output member 3 closer to or further away from the pivot point P to give the lever 6 the function of a wheel-pinion satellite.

[0027] Crown 4 is typically fixed, as already indicated, but it could be rotated to, for example, vary the display speed and / or the stop positions of lever 6.

[0028] The stop flanks 15 of the teeth of the crown 4 together form a cam surface which is followed by a cam follower, in this case the lever 6 with its beak 16, and which surrounds the cam follower, the rotary input member 2, the rotary output member 3 and the intermediate member 7.

[0029] A second embodiment of the timepiece device according to the invention is illustrated in Figure 2 and designated by the reference 1b. It differs from the first embodiment essentially in that the rotary input member 2 and the lever 6 mesh by two toothed sectors and in that the lever 6 and the rotary output member 3 also mesh by two toothed sectors.

[0030] According to a third embodiment of the timepiece device according to the invention, shown in Figure 3 and designated by the reference 1c, the display disc 17 is replaced by a hand 18, for example a dead second hand, secured to the rotary output member 3 and guided in rotation around the axis A by the shaft of the rotary input member 2. According to a fourth embodiment, shown in Figure 4, the timepiece device 1d comprises two levers 6a, 6b controlled by the rotary input member 2 and the rotary output member 3 is in two parts 3a, 3b secured by the display disc or other display member.Two monolithic parts, coplanar and symmetrical with respect to the axis A, each comprise one of the two levers 6a, 6b, one of the two parts 3a, 3b of the rotary output member 3, an intermediate member 7a, 7b, an elastic blade 8a, 8b articulating the lever 6a, 6b to the intermediate member 7a, 7b and an elastic blade 9a, 9b connecting the intermediate member 7a, 7b to the rotary output member 3 for guiding the rotation of the intermediate member 7a, 7b. The levers 6a, 6b cooperate with the internal toothing 5 in a phase-shifted manner. A greater number of levers and corresponding monolithic parts can of course be provided. Providing several levers makes it possible to reduce the number of teeth of the crown 4 and to guarantee good repositioning of the levers on the stop flanks 15.

[0031] According to a fifth embodiment of the clockwork device according to the invention, illustrated in Figure 5 and designated by the reference 1e, the assembly comprising the lever 6, the intermediate member 7 and the rotary output member 3 is no longer monolithic. The lever 6 and the intermediate member 7 are here separate parts articulated together by a pivot connection 19 and the intermediate member 7 is guided in rotation around the axis A by an arcuate slide 20 which the rotary output member 3 comprises. The spring of the lever 6, constituted by the first and second flexible guides 8, 9 in the preceding embodiments, is here formed by a blade 21, one end of which is joined to the rotary input member 2 and the other end, free, rests on the back of the lever 6. The rotary input member 2, the rotary output member 3, the crown 4, the lever 6, the intermediate member 7 and the blade 21 are coplanar.

[0032] A sixth embodiment is illustrated in Figure 6. The watch device 1f according to this sixth embodiment is similar to the watch device 1a according to the first embodiment. However, the intermediate member 7 comprises a guide arm 22 which fits a curved portion 23 of the lever 6 concentric with the pivot point P of the lever 6 relative to the intermediate member 7 to ensure precise rotational guidance of the lever 6 relative to the intermediate member 7. This guide arm 22 may comprise projecting parts 24 forming guide pads in contact with the curved portion 23.

[0033] Another characteristic of the watch device 1f is that the internal toothing 5 of the crown 4 extends over less than 360°, being interrupted by a connecting surface 25. Thus, over one rotation of the input rotary member 2, the lever 6 causes the output rotary member 3 to make a series of short jumps (when the lever 6 cooperates with the toothing 5) followed by a long jump (when the lever 6 moves opposite the connecting surface 25). The stop flanks 15 of the toothing 5 together constitute a cam surface with which a cam follower cooperates, namely the lever 6 and its beak 16.

[0034] This sixth embodiment can be modified by making the connecting surface 25 concentric with the axis A so as to transform it into a sliding surface with which the beak 16 of the lever 6 can cooperate to make the rotary output member 3 perform a continuous movement after the series of jumps caused by the teeth 5. In this case, the cam surface is constituted by the stop flanks 15 and by the surface 25.

[0035] A timepiece device 1g according to a seventh embodiment of the invention, illustrated in Figure 7, differs from the timepiece device 1f according to the sixth embodiment in that the intermediate member 7 and the meshing between the lever 6 and the rotary output member 3 are omitted, the lever 6 being connected by the flexible guide 8 directly to the rotary output member 3. The lever 6 therefore rotates around a pivot point which is fixed during the sliding of the beak 16 on the stop flank 15 of an inner tooth of the crown 4. When the lever 6 jumps between two stop flanks 15, the rotary output member 3 is driven by the lever 6 via the flexible guide 8.A 1 h timepiece device according to an eighth embodiment of the invention, illustrated in Figure 8, differs from the 1 f timepiece device according to the sixth embodiment in that the cam surface with which the beak 16 cooperates is constituted by a sliding surface 26 coplanar with the monolithic part 3, 6, 7, 8, 9 and whose distance from the axis A varies. The cooperation between the beak 16 and this sliding surface 26 produces a continuous movement, but at variable speed, of the rotary output member 3.

[0036] A timepiece device 1 i according to a ninth embodiment of the invention, partially illustrated in Figure 9, differs from the timepiece device 1 a according to the first embodiment, from the timepiece device 1 b according to the second embodiment or from the timepiece device 1 c according to the third embodiment essentially in that (i) the first flexible guide 8 which connects the lever 6 to the intermediate member 7 is of the RCC type (to guarantee the position of the pivot point of the lever 6 relative to the intermediate member 7) and (ii) the intermediate member 7 is guided in rotation by the shaft of the rotary input member 2.A consequence of characteristic (ii) is that, in this ninth embodiment, the display member (disc or needle for example) integral with the rotary output member 3 is guided in rotation by the second flexible guide 9 which connects the rotary output member 3 to the intermediate member 7, and no longer directly by the shaft of the rotary input member 2.

[0037] The above embodiments have been described by way of example only. It is understood that modifications could be made in each of them without departing from the scope of the claimed invention. For example:

[0038] - the rotary input member 2 could be a wheel or pinion meshing with a drive train, located under the lever 6 and cooperating with the latter by a pin and oblong hole system;

[0039] - instead of being a simple elastic blade or two elastic RCC blades, the first flexible guide 8 connecting the lever 6 to the intermediate member 7 could be in the form of two crossed blades, separated or not, that is to say located in two different parallel planes or in the same plane;

[0040] - the second flexible guide 9, for example of the RCC type, could be placed between the intermediate member 7 and the rotary input member 2 rather than between the intermediate member 7 and the rotary output member 3;

[0041] - the second flexible guide 9 could connect the intermediate member 7 and the output rotary member 3 and a third flexible guide, which could also be of the RCC type, could connect the intermediate member 7 to the input rotary member 2;

[0042] - the intermediate member 7 could be guided in rotation non-coaxially to the rotary input member 2 or even be guided in translation;

[0043] - the display member could not be integral with the rotary output member 3 but be, for example, driven directly or indirectly by a wheel integral with the rotary output member 3;

[0044] - the rotation of the rotary input member 2 could be jerky rather than continuous, the device according to the invention then serving to transform, for example, a first jerky rotation into a second jerky rotation, different from the first.

Claims

CLAIMS Clock device (1 a-1 h) comprising - a rotary input member (2), - a rotary output member (3; 3a), - a fixed or movable cam surface (15; 26), - an elastic organ (8, 9; 8a; 9a), and - a cam follower (6; 6a) arranged to be controlled by the rotary input member (2) and to cooperate with the cam surface (15; 26) under the action of the elastic member (8, 9; 8a; 9a) to drive the rotary output member (3; 3a), the rotary output member (3; 3a) and the cam follower (6; 6a) being surrounded by the cam surface (15; 26), characterized in that the rotary output member (3; 3a) and the cam follower (6; 6a) are coplanar. A timepiece device according to claim 1, characterized in that the rotary input member (2) is coplanar with the rotary output member (3; 3a) and the cam follower (6; 6a). Clockwork device according to claim 1 or 2, characterized in that the cam follower (6; 6a) is connected to the rotary output member (3; 3a) by means of at least one flexible guide (8, 9; 8a, 9a) constituting the elastic member (8; 8a).Clockwork device according to any one of claims 1 to 3, characterized in that the cam follower (6; 6a) and the rotary output member (3; 3a) are part of the same monolithic part. Clockwork device according to any one of claims 1 to 4, characterized in that it further comprises an intermediate member (7; 7a) coplanar with the rotary output member (3; 3a) and the cam follower (6; 6a) and movable relative to the rotary input member (2), to the rotary output member (3; 3a) and to the cam surface (15; 26), and in that the cam follower (6; 6a) is articulated to this intermediate member (7; 7a), this articulation defining a movable pivot point (P) of the cam follower (6; 6a) in the timepiece device (1a-1 h). Timepiece device according to claim 5, characterized in that the cam follower (6; 6a) is articulated to the intermediate member (7; 7a) by a first flexible guide (8; 8a). Timepiece device according to claim 6, characterized in that the first flexible guide (8; 8a) is a simple elastic blade or a flexible guide of the type with an offset center of rotation. Clockwork device according to any one of claims 5 to 7, characterized in that the intermediate member (7) is guided by a second flexible guide (9; 9a, 9b).Watchmaking device according to claim 8, characterized in that the second flexible guide (9) is of the type with an offset center of rotation. Watchmaking device according to any one of claims 5 to 9, characterized in that the intermediate member (7) is guided in rotation coaxially with the rotary input member (2) and with the rotary output member (3; 3a). Clockwork device according to any one of claims 5 to 10, characterized in that the cam follower (6; 6a), the intermediate member (7; 7a) and the rotary output member (3; 3a) are part of the same monolithic part. Clockwork device according to any one of claims 5 to 11, characterized in that the cam follower (6; 6a) cooperates by meshing with the rotary output member (3; 3a). Clockwork device according to any one of claims 1 to 12, characterized in that the cam follower (6; 6a) cooperates by meshing with the rotary input member (2).Clockwork device according to claims 5, 12 and 13, characterized in that the cam surface (15) comprises stop flanks of a toothing (5) on each of which a beak (16) of the cam follower (6; 6a) can slide before jumping onto the next stop flank to make the rotary output member (3; 3a) jump, and in that the meshing of the cam follower (6; 6a) with the rotary input member (2) and with the rotary output member (3; 3a) is such that, between two jumps of the cam follower (6; 6a), the latter keeps the rotary output member (3; 3a) stationary. Timepiece according to any one of claims 1 to 14, characterized in that it comprises a display member (17; 18) integral with the rotary output member (3) or arranged to be driven by the rotary output member (3). Timepiece, for example a watch, comprising a timepiece according to any one of claims 1 to 15.

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