CH713389B1 - System for connecting a shaft to a part. - Google Patents

Abstract

The invention relates to a connecting system for a timepiece comprising: a shaft (2) on which a component (1) of a timepiece is intended to be mounted, said shaft (2) having a first structure of 'axial stop (23), and a rotation stop structure (20), having a geometry to ensure a stop in rotation, an axial stop member (3) with an opening (30) shaped for allow, in at least one angular position of said axial stop element (3) relative to the shaft (2), a translational engagement on the shaft (2) and the passage of the first axial stop structure ( 23), and a bearing on said first axial stop structure (23) in at least one other angular position, called the stop position, a radial retaining element (4), arranged to cooperate integrally with the element of stop and provided with an opening (40) shaped to cooperate with the rotation stop structure (20) of said shaft (2) to prevent rotation of the shaft retaining element around said shaft (2).

Description

Technical area

The present invention relates to the field of watchmaking. It relates, more particularly, to a connecting system making it possible in particular to assemble a part and a shaft, with a movement in relative translation between the part and the shaft, while limiting this movement. This connection system may relate to the assembly of a component on a shaft forming an axis for the component, or the assembly of a pusher with reference to a pusher tube fixed to a box. The component may or may not be free to rotate with respect to the shaft.

State of the art

[0002] Certain pivoting elements making up a watch movement are rigidly assembled on a shaft pivoted between two bearings. The bearings are arranged in elements of the frame (in a bridge and a plate or in two bridges) of the timepiece. Such an assembly occupies a relatively large volume, because of the frame elements to be arranged. In addition, when a bridge has bearings for several separate pivots, assembly can be tricky. Such an arrangement has other drawbacks associated with the setting of the bearings. Indeed, the stones forming the same level must be perfectly aligned. In the event of an impact, we cannot exclude the risk that a stone will unravel.

[0003] As an alternative, some mobiles are assembled freely in rotation on a shaft mounted rigidly on a frame element or on another mobile element. The component on the shaft can advantageously be mounted flywheel in order to reduce the bulk of the construction, that is to say on a shaft with a free end. We must then position the mobile in translation on its shaft, taking into account a play allowing its rotation, while ensuring that it is located in its operating plane. By positioning the mobile in translation is meant to limit its stroke to an operating position, with or without play, or with a given stroke to perform a function, as is the case for example for a pusher.

[0004] To position the mobile on its shaft, various solutions exist. For example, you can remove a cork from the end of the tree. Such a solution requires controlling the depth of the drive and the force of the latter, in order to have an effective clamping resistant to shocks. However, disassembly is then difficult and frequently destructive, wear resulting from several assembly / disassembly cycles being able to reduce the strength irreversibly. The aesthetic appearance obtained is sometimes also unsatisfactory. Another solution lies in the use of split washers of the circlip type, allowing relatively easier disassembly, but still difficult given the size of the washers and the difficulty in handling them. Such a solution is not very reliable in terms of security either.

[0005] The present invention aims to provide a compact, lightweight, easy to implement connection system, both during assembly and during disassembly.

Disclosure of the invention

[0006] More specifically, the invention relates to a connection system for a timepiece comprising: a shaft on which a component of a timepiece is intended to be mounted, said shaft having a first axial stop structure, and a rotation stop structure, preferably having a non-circular geometry, an axial stop element provided with an opening shaped to allow, in at least one angular position of said axial stop element relative to the shaft, a translational engagement along the axis of the shaft and the passage of the first axial stop structure, and of a bearing surface to cooperate with said first axial stop structure in at least one other angular position, called the stop position, a radial retaining element, arranged to cooperate integrally with the axial stop element and provided with an opening shaped to cooperate with the structure for preventing rotation of said shaft to prevent rotation of the retaining element around said shaft .

[0007] The connecting system may further comprise a second axial stop structure, said axial stop element being positioned between the first and second axial stop structures.

[0008] Advantageously, the second axial stop structure is formed by the surface of a part attached to the axis, which can in particular be chosen from a member of a barrel, a regulating member, a disk of display, a mobile, a cam, or a part of a watch case such as a middle part or pusher tube, the shaft possibly in this case being that of a pusher, a corrector or a rod winder.

[0009] The second axial stop structure can also be formed by a projecting portion of the shaft.

The axial stop element may have a shaped profile, with which a profile of the radial holding element can cooperate to block it in rotation.

The rotational stop structure and the radial retaining element are arranged so as to lock the axial stop element in a stop position.

[0012] Such a connection system can advantageously be applied in a timepiece in which the component is mounted flywheel on the shaft which has a free end.

Brief description of the drawings

Other details of the invention will emerge more clearly on reading the following description, made with reference to the appended drawing in which: FIGS. 1 to 4 show a preferred embodiment of a connection system according to the invention, in different positions that its elements occupy during its assembly, FIG. 5 illustrates an alternative for the implementation of the invention, and FIG. 6 proposes a second embodiment.

Embodiment of the invention

The invention relates to a connecting system for a timepiece allowing, in a first embodiment mainly described, to easily assemble a part on a shaft, on which the part in question is intended to be mounted mobile.

The connecting system comprises a shaft 2. In the example, the shaft 2 is a barrel shaft. It is intended to be assembled to a component 1 of a timepiece. In the example proposed by way of simple non-limiting illustration, component 1 is a power reserve mobile arranged to allow the display of the power reserve of the barrel, and which is mounted to rotate freely on the shaft.

[0016] The shaft 2 has a first axial stop structure 23, formed by a projecting element or advantageously by a groove. This first axial stop structure 23 is intended to provide a support preventing the translation along the axis of the shaft 2, of an element 3 which will be described below.

Advantageously, the groove is delimited, on the side of the end of the shaft 2, by a flange, particularly forming the axial stop structure 23 and on which the aforementioned element can bear, and the side of component 1, by a rib, which defines a second axial stop structure 24.

The shaft 2 further comprises a rotation stop structure 20, having a non-circular geometry 21. This rotation stop structure 20 is intended to provide a support preventing rotation around the axis of the 'shaft 2 of a second element 4 which will be described below. Advantageously, the axial stop structure 23 and the rotation stop structure 20 are contiguous along the shaft 2. It will be noted that the rotation stop structure could be circular with a rotation blocking effected by a pin taking place in a transverse hole.

The geometric dimensions of the axial and rotating stop structures depending on the elements with which they are intended to cooperate, these will be explained later.

The connection system also comprises an axial stop element 3 provided with an opening 30 shaped to allow, in at least one angular position of said axial stop element 3 relative to the shaft 2, an engagement in translation on the shaft 2 and the passage of the first axial stop structure 23 through the opening 30, and a first bearing surface 33 on said first axial stop structure 23 in at least one other angular position , called the stop position. Advantageously, the opening 30 also allows the passage of the rotation stop structure 20. When it is in the groove, the axial stop element 3 is guided in rotation on the shaft 2. This guide rotation can advantageously be facilitated by respective circular surfaces 35 and 25 cooperating together.

[0021] In the preferred embodiment, the axial stop element 3 takes the form of a plate. In terms of thickness, the axial stop element 3 is dimensioned so that, once the rotation stop structure 20 has passed through the opening 30, it is positioned in the groove of the shaft 2, between the first 23 and the second 24 axial stop structures, supported by a second bearing surface 34, located on the side opposite to the first bearing surface 33.

Thus, the difference between, on the one hand the distance between the first 23 and second 24 axial stop structures and, on the other hand, the thickness of the axial stop element 3, defines the clearance of this element. However, the axial stop element 3 is intended to hold the component 1 of the timepiece on the shaft 2. The play of the element 3 can therefore also make it possible to define the play of the watch component on the shaft 2, if the component 1 is dimensioned to come flush with a surface 14 at the level of the second axial stop structure 24.

It may be noted that, advantageously, the axial stop element 3 could comprise a second level of thickness defining a third bearing surface 34 ', as shown in Figure 5, intended to be able to cooperate with the watch component. To do this, the plate could be bordered by a rib 38 or studs projecting parallel to the shaft 2. It is thus possible to define by two different surfaces, on the one hand the play of the axial stop element 3 in the groove of the shaft 2, and on the other hand the play of the watch component 1, and use this means for other purposes, such as for example a pairing which may be made necessary by complex chains of dimensions. As proposed in FIG. 5, by turning the axial stop element 3 upside down, two different heights can be defined, making it possible to adapt to a component of different dimensions.

The connecting system according to the invention further comprises a radial retaining element 4, arranged to cooperate integrally with the axial stop element 3 and provided with an opening 40 shaped to cooperate with the stop structure in rotation 20 of said shaft 2 to prevent rotation of the retaining element around said shaft 2. The opening 40 may be through or blind.

The radial retaining element 4 can take the form of a cap when it is intended to take up position at the end of the shaft 2. It comprises a first level provided with a non-circular housing 42 in which can be adjusted a corresponding profile 32 of the axial stop element 3. It also comprises a second level comprising said opening 40. The shape of the latter is corresponding to that of the rotational stop structure 20, in order to bind in rotation, the rotational retaining element 4 and the shaft 2 when the retaining element is positioned with its second level in the plane of the rotational stop structure 20. Various respective shapes for the opening 40 and the rotation stop structure 20 can be envisioned by those skilled in the art to prevent rotation of the radial retaining element 4.

We can choose to link the radial retaining element 4 to the axial stop element 3 or to the shaft 2, the connection with the other of the two elements can then be achieved with a game, for s 'ensure the isostatism of the system. It is possible to provide for a driving in, a clipping, for example using combined profiles of the dovetail type with a very low slope but sufficient to ensure the maintenance, or any fixing between the two elements, the holding element axial 3 being secured by its adjustment in the housing 42 and in the groove (23, 24, 25) of the shaft 2.

In terms of dimensional ratios, those skilled in the art will be able to adapt the shapes of the openings of the axial stop element 3 and of the radial retaining element 4, with respect to the axial and radial stop structures of so that: the axial stop element 3 can take position in the groove of the shaft 2 by passing the stop structure in rotation 20; for this passage, the axial stop element 3 occupies at least a first angular position relative to the shaft 2; once in the groove, the axial stop element 3 can be pivoted about the axis of the shaft 2, and can be arranged to bear against the flange 23 of the axial stop structure; the radial retaining element 4 can be adjusted on the rotation stop structure 20, to limit the rotation of the radial retaining element 4 on the shaft 2; and can cooperate with the axial stop element 3 to also keep the latter in rotation, this cooperation being obtained by adjusting the axial stop element 3 in the housing 42 of the radial holding element 4.

Advantageously, one can use oblong shapes for the opening 30 of the axial stop element 3 and the opening 40 of the radial holding element 4, as well as for the stop structure in rotation 20.

We can define l1 and L1, as respectively the small and the large dimensions of the oblong forming the stop structure in rotation 20, l2 and L2 as respectively the small and the large dimensions of the oblong formed by the section of shaft 2 at throat level. It can be noted that the shaft 2 may not be oblong at the level of the groove with l2 = L2. For the sake of clarity, it is further specified that l1 and l2 are dimensions along parallel lines, and L2 and L1 also, with 11 perpendicular to L1 and therefore 12 perpendicular to L2.

In the example, for reasons of simplification of manufacture, the oblong of the rotational stop structure 20 is a truncated cylinder, having two opposite sides 21 parallel, and defining the length l1. The sides extend to the level of the throat.

We can define L3 and L3 as respectively the small and the large dimensions of the oblong forming the opening 30 of the axial stop element 3.

In order to allow the engagement of the axial stop element 3 and the passage of the stop structure in rotation 20, we l3> l1 and L3> L1. As in the example, the shape of the opening 30 may be a similarity to the shape of the stop structure, with a ratio slightly greater than 1.

Obviously we have l3> l2 and L3> L2 and also L3> 12 to allow the engagement of the axial stop element 3 in the groove and its rotation around the shaft. For the locking in translation of the axial stop element 3, l3 <L1.

For the assembly and use of the connecting system which has just been described, the component 1 of the timepiece which is to be mounted is arranged on the shaft 2 (Fig. 1). The axial stop element 3 is positioned opposite the shaft 2, with the opening 30 oriented in a position which allows the engagement of the rotational stop structure 20 in the opening 30. The element axial stop 3 is engaged on the shaft 2, in the groove, until it comes to bear against the second axial stop structure 24 (Fig. 2).

The axial stop element 3 is pivoted along the axis of the shaft 2, so that it occupies a stop position. The rotation is, according to the example, about 90 °, to prepare the next step and the cooperation with the radial holding element 4 (Fig. 3).

The radial retaining element 4 is positioned opposite the shaft 2, with the opening 40 oriented in a position which allows the engagement of the rotational stop structure 20 in the opening 40. L The radial retaining element 4 is engaged on the shaft 2, at the same time as the axial stop element 3 takes up position in the housing 42 of the radial retaining element 4. If necessary, the angular position of the axial stop element 3 is adjusted so that it takes position in housing 42 (Fig. 4).

Depending on the fixing method chosen for the radial retaining element 4, the latter is fixed either on the shaft 2 or on the axial stop element 3.

Thus, the assembly formed by the axial stop elements 3 and radial holding 4 has no degree of freedom relative to the shaft 2, nor in translation thanks to the axial stop element 3, nor in rotation thanks to the radial retaining element 4, apart from the games.

The proposed connection system is thus particularly compact, because it allows to have a flywheel assembly of the watch component, that is to say that the shaft 2 has a free end. There is therefore no need to have a frame element such as a bridge to hold the shaft 2 or the component 1. This connection system also makes it possible to guarantee the impact resistance of a part with a large mass, typically of a barrel on its shaft. Indeed, no detachment can occur under the effect of a significant acceleration due to a shock.

The connection system could also be used with a shaft 2 held at both ends, using it along the shaft 2 to adjust the play of the component. The various elements to be pivoted are individually guided, the adjustment of the clearances and lugs is facilitated, insofar as the dimensions of the groove and the thickness of the locking element in translation can be easily controlled.

In addition, the elements can be handled and dismantled easily, without affecting the deformation of elastic parts, except during a possible driving-in.

As proposed in Figure 6, the connection system which has just been described could be used by those skilled in the art to mount a push rod in a push tube. The push rod is then the shaft 2 as defined for the connecting system and the push rod or the middle part to which the push rod is integral, is component 1 of the timepiece within the meaning of claim . It is thus possible to provide a first axial stop structure 23 and a rotation stop structure 20 at the end of the push rod in order to mount therein an axial stop element 3 and a radial retaining element 4, in order to '' assemble the push rod on the push rod. For the passage of the pusher in the pusher tube, one can provide shaped profiles, as shown in section C-C, to prevent rotation of the pusher inside the tube.

A person skilled in the art can also use such a connection system to mount a regulating member (balance or tourbillon cage), a display disc, an element such as an oscillating weight, any mobile, a cam or any element that can advantageously benefit from such an assembly.

[0044] The present description has been given by way of non-limiting illustration of the invention and those skilled in the art may, where appropriate, be inspired by it, the scope of the protection conferred however being delimited by the content of the claims.

Claims (8)

1. Linking system for a timepiece comprising: - a shaft (2) on which is intended to be mounted a component (1) of a timepiece, said shaft (2) having a first axial stop structure (23), and a stop structure in rotation (20), having a geometry making it possible to ensure a stop in rotation - an axial stop element (3) provided with an opening (30) shaped to allow, in at least one angular position of said axial stop element (3) relative to the shaft (2), an engagement in translation on the shaft (2) and the passage of the first axial stop structure (23), and a bearing on said first axial stop structure (23) in at least one other angular position, called the stop position , - a radial retaining element (4), arranged to cooperate integrally with the stop element and provided with an opening (40) shaped to cooperate with the stop structure in rotation (20) of said shaft (2) for preventing rotation of the retaining member around said shaft (2). 2. A connection system according to claim 1, characterized in that it further comprises a second axial stop structure (24), said stop member being positioned between the first and second axial stop structures. 3. Connection system according to claim 2, characterized in that the second axial stop structure (24) is formed by a part attached to the axis. 4. Connection system according to claim 3, characterized in that the attached part is chosen from a member of a barrel, a regulating member, a display disc, a mobile, a cam, a winding member such as an oscillating weight or part of a watch case such as a caseband. 5. Connection system according to claim 2, characterized in that the second axial stop structure (24) is formed by a projecting portion (24) of the shaft (2). 6. Connecting system according to one of the preceding claims, characterized in that the axial stop element (3) has a shaped profile (32), with which a profile (42) of the radial holding element (4) cooperates to block it in rotation. 7. Connection system according to one of the preceding claims, characterized in that the rotational stop structure (20) and the radial holding element (4) are arranged so as to block the axial stop element. (3) in a stop position. 8. Timepiece comprising a connecting system according to one of the preceding claims, wherein the shaft (2) has a free end.