CH719702A2 - Chronograph module equipped with a removable wheel. - Google Patents

Abstract

The invention relates to a chronograph module (1) comprising a plate and/or a plate bridge, a primary shaft (3) extending along a longitudinal axis around which it is movable in rotation, the primary shaft (3) ) carrying a primary mobile (4) extending in a plane substantially orthogonal to the longitudinal axis of the primary shaft (3), the primary shaft (3) being mounted on the plate and/or the plate bridge, so that the primary mobile (4) is engaged with a gear train of the chronograph module (1), characterized in that the chronograph module (1) comprises a removable wheel (2) mounted on the primary shaft (3 ), the removable wheel (2) comprising a peripheral meshing structure, as well as a first and a second elastic arm forming a clamp configured to grip the primary shaft (3), the primary shaft (3) comprising a surface radial support on which the first and second elastic arms come to rest, so as to assemble the removable wheel (2) on the primary shaft (3), the chronograph module (1) comprising at least one overlapping part arranged in a lower stage of the chronograph module (1), the arrangement and dimensions of the removable wheel (2) in the chronograph module (1) producing an overlap of the removable wheel (2) and said overlapping part, so that the assembly of said overlapping part required the absence of the removable wheel (2) while the primary shaft (3) is mounted on the chronograph module (1).

Description

Technical field of the invention

[0001] The invention relates to a chronograph module provided with a removable wheel.

[0002] The invention also relates to a watch movement comprising at least one such chronograph module.

[0003] The invention relates to the field of watch mechanisms, and more particularly cogs.

Technology background

[0004] Certain watch movements include complications, which require specific assembly of the movement. For example, in the case of a clutch chronograph, it is necessary to assemble a gear wheel, such as a wheel or pinion, on a shaft already mounted on the movement.

[0005] Indeed, in classic chronographs, it is usual to arrange an additional wheel on the second mobile shaft of the primary module of the movement, in order to take and bring the movement movement to the chronograph module in order to activate it.

[0006] For other types of chronographs, the removable wheel is arranged on an intermediate shaft of a transmission mobile connecting the mobile of the seconds counter of the chronograph to the mobile of the minutes counter of the chronograph.

[0007] Other chronograph module configurations are possible. In addition, there are other complications, which require the assembly of such a removable wheel on a shaft.

However, the assembly of this wheel is not easy, because the shaft on which it must be fixed is necessarily already mounted on the movement. In fact, the shaft is held in a bearing at each end, which are fitted into the plate or plate bridges, which cannot be added later if the removable wheel is present on the shaft. In other words, mounting the shaft with the removable wheel already attached is not possible. The wheel must be assembled to the shaft, after the latter has been at least partially mounted on the plate.

[0009] For this purpose, a hub is generally used passing through the wheel in its center, a conical end of the shaft being embedded in the hub to carry the wheel.

[0010] However, the embedding operation has several drawbacks.

[0011] On the one hand, there is a notable risk of premature wear of certain parts. In particular, the shaft and/or the removable wheel may undergo unwanted buckling or bending, which may harm the proper functioning of the movement.

[0012] On the other hand, the hub being generally thick enough to support the embedding and the support of the wheel, the latter requires resizing at the time of assembly, in order to be able to integrate into the movement. Furthermore, if necessary, the dismantling of the additional wheel and the movement parts, the dismantling of which depends on that of the additional wheel, is difficult, since it is necessary to remove the hub from the shaft. These operations waste time and require special tools and skills.

Summary of the invention

[0013] The invention aims to remedy the aforementioned drawbacks, and aims to provide a chronograph module comprising a removable wheel, the assembly and disassembly of which is facilitated.

[0014] To this end, the invention relates to a chronograph module for a watch movement, the chronograph module comprising a plate and/or a plate bridge, a primary shaft extending along a longitudinal axis around which it is mobile in rotation, the primary shaft carrying a primary mobile extending in a plane substantially orthogonal to the longitudinal axis of the primary shaft, the primary shaft being mounted on the plate and/or the plate bridge, so that the primary mobile is in mesh with a gear train of the chronograph module.

[0015] The invention is remarkable in that the chronograph module comprises a removable wheel mounted on the primary shaft, the removable wheel comprising a peripheral meshing structure, as well as a first and a second elastic arm forming a configured clamp to grip the primary shaft, the primary shaft comprising a radial bearing surface on which the first and second elastic arms come to rest, so as to assemble the removable wheel on the primary shaft, the chronograph module comprising at less one overlapping part arranged in a lower stage of the chronograph module, the arrangement and dimensions of the removable wheel in the chronograph module producing an overlap of the removable wheel and said overlapping part, so that the assembly of said overlapping part required the absence of the removable wheel while the primary shaft is mounted on the chronograph module.

[0016] Thanks to the elastic arms forming a clamp, the removable wheel can easily be mounted and disassembled from the primary shaft. Thus, we avoid carrying out a fitting, which can cause defects in the parts, when the module is mounted on the watch movement. In addition, the removable wheel can be easily disassembled and reassembled without using a specific tool, in particular to have access to the parts which require the removal of the removable wheel.

[0017] According to a particular embodiment of the invention, the overlap is between one tenth and half of the diameter of the removable wheel.

[0018] According to a particular embodiment of the invention, the end of the primary shaft comprises a radial bearing surface for the clamp.

[0019] According to a particular embodiment of the invention, in the free state, said clamp is circumscribed by a cylinder with a radius smaller than that of a cylinder circumscribed by said radial bearing surface.

[0020] According to a particular embodiment of the invention, the radial bearing surface is counter-conical.

[0021] According to a particular embodiment of the invention, the two arms each have a central notch, so as to form an orifice for the end of the primary shaft, preferably substantially circular.

[0022] According to a particular embodiment of the invention, the chronograph module comprises a secondary shaft and a chronograph driving pinion arranged on the secondary shaft, a tertiary shaft and a minute counter wheel arranged on the tertiary shaft .

[0023] According to a particular embodiment of the invention, the chronograph module comprises a quaternary shaft and a second wheel arranged on the quaternary shaft, the quaternary shaft being arranged around a part of the secondary shaft

According to a particular embodiment of the invention, the primary mobile is a drive wheel of the minute counter meshing with the seconds mobile of the chronograph arranged on the secondary shaft.

[0025] According to a particular embodiment of the invention, the removable wheel meshes with the mobile of the chronograph minute counter.

[0026] According to a particular embodiment of the invention, the chronograph module comprises a clutch flange sliding around the secondary shaft above the second wheel, between a rest position where the chronograph is not actuated, and an operating position in which it is driven by the second wheel to actuate the secondary shaft.

[0027] According to a particular embodiment of the invention, the primary shaft comprises an axial stop bearing surface arranged to maintain the removable wheel in a position along the longitudinal axis of the primary shaft.

[0028] According to a particular embodiment of the invention, the overlapping part(s) are the clutch flange and/or a hammer and/or a rotating pan.

The invention also relates to a watch movement comprising such a chronograph module.

Brief description of the figures

[0030] Other particularities and advantages will emerge clearly from the description given below, for information only and in no way limiting, with reference to the appended drawings, in which: – Figure 1 is a perspective view from above of 'a chronograph module comprising a removable wheel and a primary shaft on which the wheel according to the invention is mounted, - Figure 2 is a perspective view from below of the chronograph module of Figure 1, - Figure 3 is a view of top of the chronograph module of Figure 1, – Figure 4 is a sectional view of the chronograph module of Figure 1, – Figure 5 is a perspective view of the removable wheel and the end of the primary shaft, and – Figure 6 is a top view of a watch movement comprising a chronograph module according to the invention.

Detailed description of the invention

The invention relates to a chronograph module 1 for a clock movement. The chronograph module 1, shown in Figures 1 to 4, comprises a primary shaft 3, here a transmission shaft, a secondary shaft 5, here a chronograph seconds shaft, a tertiary shaft 8, here a minute counter shaft of the chronograph, and a quaternary shaft 7, here a seconds shaft.

[0032] In this embodiment, the secondary shaft 5 is arranged inside the quaternary shaft 7. Thus, the secondary shaft 5 and the quaternary shaft 7 are coaxial. The quaternary shaft 7 can rotate independently of the secondary shaft 5. In an operating mode of the chronograph, the secondary shaft 5 and the quaternary shaft 7 rotate simultaneously, the quaternary shaft 7 driving the secondary shaft 5.

The primary shaft 3 is arranged between the secondary shaft 5 and the tertiary shaft 8, with an offset relative to the plane passing through the three shafts. Thus, the primary 3, secondary 5 and tertiary 8 shafts are arranged at the vertices of a triangle, substantially at the same level.

The chronograph module 1 further comprises a minute counter wheel 9 arranged on the tertiary shaft 8, a chronograph driving pinion 13 arranged on the secondary shaft 5, and a second wheel 6 arranged on the shaft quaternary 7. The minute counter wheel 9 and the second wheel 6 are arranged at a higher level of their respective shaft, while the chronograph driving pinion 13 is arranged at a lower level of the secondary shaft 5.

The chronograph module 1 also includes a clutch flange 15 configured to transmit the movement of the second wheel 6 to the driving pinion of the chronograph 13.

The clutch flange 15 is arranged on the secondary shaft 5, above the second wheel 6. The clutch flange 15 slides longitudinally around the secondary shaft 5, between a rest position where the chronograph module 1 is not activated, and an operating position in which it is driven by the second wheel 6.

[0037] In the operating position, the secondary shaft 5 is driven by the clutch flange 15 with the quaternary shaft 7. Thus, the driving pinion of the chronograph 13 is rotated by the second wheel 6 via the clutch flange 15.

The chronograph module 1 also comprises a primary mobile 4, here a driving mobile of the minute counter, which is arranged on the primary shaft 3, at a lower level of the primary shaft 3. The primary mobile 4 meshes with the driving pinion 13 of the chronograph. Thus, in the operating position of the clutch flange 15, the chronograph driving pinion 13 rotates the primary mobile 4 and the primary shaft 3.

The chronograph module 1 also includes a hammer 17 and a rotating peg 11 carried by the hammer 17.

The chronograph module 1 comprises a first core 14 of the chronograph wheel arranged on the secondary shaft 5, above the clutch flange 15, and a second core 12 of the minute counter arranged below the wheel chronograph minute counter 9.

[0041] Furthermore, the chronograph module 1 comprises a removable wheel 2 arranged at an upper end of the primary shaft 3. The removable wheel 2 is a transmission mobile meshing with the minute counter wheel 9 of the tertiary shaft 8. Thus, when the primary shaft 3 is rotated, the removable wheel 2 activates the rotation of the minute counter wheel 9 and the tertiary shaft 8.

In this embodiment, the removable wheel 2 is a transmission wheel, shown in Figure 5, the wheel comprising a peripheral meshing structure 21, which is annular and comprises gear teeth.

This removable wheel 2 further comprises at least one first radially elastic arm 22, and at least one second radially elastic arm 23. Preferably, the arms 22, 23 are symmetrical with respect to each other and substantially parallel. The arms 22, 23 are arranged inside the ring and each connect two opposite points of the peripheral meshing structure 21.

[0044] The primary shaft 3 comprises an axial stop bearing surface 29 which is arranged to maintain the removable wheel 2 in stop support on the primary shaft 3. The axial stop 29 makes it possible to define a precise position of the removable wheel 2 on the primary shaft 3 along the longitudinal z axis, unlike a fitting where the position of the wheel in this direction is more difficult to control.

This first arm 22 and second elastic arm 23 together form a clamp 30, which is arranged to clamp a radial bearing surface 28 which the primary shaft 3 comprises in the vicinity of the axial stop bearing surface 7. Friction is thus ensured between the removable wheel 2 and the primary shaft 1.

[0046] The clamp 30 is configured to grip the end 25 of the primary shaft 3. To this end, the primary shaft 3 comprises at its end 25 a radial bearing surface 28 on which the first 22 and the second elastic arms 23 come to rest. The elasticity of the arms 22, 23 allows them to be spread apart to introduce the end 25 of the primary shaft 2 between the arms 22, 23, then to let the arms 22, 23 tighten the radial bearing surface 28 by friction. Thus, we can assemble the additional wheel on the primary shaft.

The radial bearing surface 28 is preferably inverted counter-conical in order to hold the removable wheel 2 on the end 25, against a stop arranged under the cone. The inverted cone has its base at the end of the end 25 and its top oriented towards the middle of the primary shaft 3.

[0048] For the assembly of the removable wheel 2 on the shaft 1, the elasticity of the arms 22, 23 of the removable wheel 2 is used, to allow correct installation, and, preferably, snap-fastening in position.

The primary shaft 3 comprises an introduction ramp 27 arranged to radially push back the first elastic arm 22, and the second elastic arm 23 to facilitate the introduction of the removable wheel 2 onto the primary shaft 3. The ramp of the introduction 27 is for example a chamfer arranged at the end of the primary shaft 3

Advantageously, in the free state, the clamp 30 is circumscribed by a cylinder whose radius is less than that of a cylinder circumscribed by the radial bearing surface 28.

[0051] For this, the two arms 22, 23 each have a central notch 24, so as to form an orifice for the end 25 of the primary shaft 3, the orifice preferably substantially circular

The chronograph module 1 comprises at least one overlapping part mounted in a lower stage of the chronograph module 1. The arrangement and dimensions of the removable wheel 2 in the chronograph module 1 produces an overlap of the removable wheel 2 above of said overlapping piece.

[0053] In the embodiment described, there are several overlapping parts, which require the absence of the removable wheel 2 to be able to be assembled in the chronograph module 1.

[0054] Here, the overlapping parts are the clutch flange 15, the rotating pan 11 and the hammer 17. When assembled on the primary shaft 3, the removable wheel 2 overlaps the overlapping parts. In other words, the projection of the removable wheel 2 orthogonal to its plane of extent and parallel to the primary shaft 3 on the overlapping parts.

The clutch flange 15 has a radius greater than the result of subtracting the radius of the removable wheel 2 from the distance between the primary shaft 3 and the secondary shaft 5, so that a peripheral part of the flange clutch 15 is arranged below a peripheral part of the removable wheel 2 when they are assembled in the chronograph module 1.

The rotating pan 11 is arranged near the primary shaft 3. A portion of the rotating pan 11 passes directly below the removable wheel 2. A portion of the hammer 17 also passes directly below the wheel removable 2.

[0057] In this case, the assembly of these overlapping parts requires the absence of the removable wheel 2 while the primary shaft 2 is mounted on the chronograph module 1. In fact, it is not possible to assemble these parts overlapping in the chronograph module 1 if the removable wheel 2 is already mounted on the primary shaft 3.

[0058] Thanks to the clamp 30, the removable wheel 2 can easily be removed or assembled to the primary axis 3. It facilitates in particular the repair or cleaning of a part of the chronograph module 1, which requires the removal of the removable wheel 2.

[0059] Figure 6 shows a watch movement in which the chronograph module according to the invention is mounted. We notice on the upper face, the minute counter wheel 9, the second wheel 6, and the removable wheel 2 meshing with the minute counter wheel 9.

This figure clearly illustrates the need to remove the removable wheel 2 in order to be able to assemble certain overlapping parts, such as the clutch flange 15 or the rotating pan 11.

Naturally, the invention is not limited to the embodiments described with reference to the figures and variants could be considered without departing from the scope of the invention.

Claims (14)

1. Chronograph module (1) for a watch movement, the chronograph module (1) comprising a plate and/or a plate bridge, a primary shaft (3) extending along a longitudinal axis around which it is movable in rotation , the primary shaft (3) carrying a primary mobile (4) extending in a plane substantially orthogonal to the longitudinal axis of the primary shaft (3), the primary shaft (3) being mounted on the plate and /or the plate bridge, so that the primary mobile (4) is engaged with a gear train of the chronograph module (1), characterized in that the chronograph module (1) comprises a removable wheel (2) mounted on the primary shaft (3), the removable wheel (2) comprising a peripheral meshing structure, as well as a first (22) and a second elastic arm (23) forming a clamp (30) configured to grip the primary shaft (3), the primary shaft (3) comprising a radial bearing surface (25) on which the first (22) and the second elastic arm (23) come to rest, so as to assemble the removable wheel (2) on the primary shaft (3), the chronograph module (1) comprising at least one overlapping part arranged in a lower stage of the chronograph module (1), the arrangement and dimensions of the removable wheel (2) in the chronograph module (1) producing an overlap of the removable wheel (2) and said overlapping part, so that the assembly of said overlapping part required the absence of the removable wheel (2) and the presence of the primary shaft (3) in the chronograph module (1). 2. Chronograph module according to claim 1, characterized in that the overlap is between one tenth and half of the diameter of the removable wheel (2). 3. Chronograph module according to claim 1 or 2, characterized in that the end (25) of the primary shaft (3) comprises a radial bearing surface (28) for the clamp (30). 4. Chronograph module according to claim 3, characterized in that in the free state, said clamp (30) is circumscribed to a cylinder of radius less than that of a cylinder circumscribed to said radial support surface (28) . 5. Chronograph module according to any one of the preceding claims, characterized in that the radial bearing surface (28) is counter-conical. 6. Chronograph module according to any one of the preceding claims, characterized in that the two arms (22, 23) each have a central notch, so as to form an orifice for the end (25) of the shaft primary (3), preferably substantially circular. 7. Chronograph module according to any one of the preceding claims, characterized in that it comprises a secondary shaft (5) and a chronograph driving pinion (13) arranged on the secondary shaft (5), a tertiary shaft (8) and a minute counter wheel (9) arranged on the tertiary shaft (8). 8. Chronograph module according to any one of the preceding claims, characterized in that it comprises a quaternary shaft (7) and a seconds mobile (6) arranged on the quaternary shaft (7), the quaternary shaft (7) being arranged around a part of the secondary shaft (5). 9. Chronograph module according to claim 8, characterized in that the primary mobile (4) is a driving mobile of the minute counter meshing with the second mobile (6) of the chronograph arranged on the secondary shaft (5). 10. Chronograph module according to any one of the preceding claims, characterized in that the removable wheel (2) meshes with the minute counter wheel of the chronograph (9). 11. Chronograph module according to any one of the preceding claims, characterized in that it comprises a clutch flange (15) sliding around the secondary shaft (5) above the second wheel (6) , between a rest position where the chronograph is not activated, and an operating position in which it is driven by the second wheel (6) to activate the secondary shaft (5). 12. Chronograph module according to any one of the preceding claims, characterized in that the primary shaft (3) comprises an axial stop bearing surface (29) arranged to maintain the removable wheel (2) in a position along the longitudinal axis of the primary shaft (3). 13. Chronograph module according to any one of the preceding claims, characterized in that the overlapping part(s) are a clutch flange (15) and/or a hammer (17) and/or a rotating part (11) . 14. Clock movement comprising a plate, drive means, characterized in that it comprises a chronograph module (1) according to any one of the preceding claims.