CH687284B5 - Declic push for a timepiece. - Google Patents

Description

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CH 687 284G A3

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Description

The present invention relates to a snap button for a timepiece.

This type of device is particularly advantageous for watches using one or more pushers, such as chronograph watches.

The advantage of snap-action pushers is that they indicate to the user whether the desired function has been activated or not. Errors in use are thus minimized. In addition, the manipulation is enhanced by the effect of the click. On the other hand, snap-action pushers for watches of known type are often of complex construction. In addition, an additional element is necessary to produce the click. It may be a circlip, a retaining ring, etc., usually arranged along the rod or at the end of the latter. This element complicates the assembly of the assembly. The cost of the resulting pusher is therefore increased by these features. Furthermore, it is frequent that the click occurs only once, for example only when the pusher is pressed, rather than when it is pressed and released.

Patent EP 426 941, for example, describes a known double click plunger. The actuation of the pusher causes the crushing of a return spring as well as an ejection spring. By pressing harder on the pusher, it causes the spacing of a ring engaged in a peripheral groove on the head of the actuator of the pusher. When the ring is sufficiently far apart, the actuator is suddenly released under the action of the ejection spring, causing the first click and exerting on the watch mechanism the action provided for the pusher. The return spring then returns the pusher and the actuator to the initial position, causing a second click when the actuator head returns to its position in the ring. This device requires two separate springs as well as multiple parts that fit telescopically; it is therefore difficult to implement.

The main purpose of the present invention is to provide a snap-action push button of simple and economical construction, easy to mount in the middle of a timepiece. The snap-action pusher has the features of claims 1 to 9. The timepiece using the pusher has the features of claims 10 and 11.

Thanks to the elimination of one element of the pusher, a simple assembly is obtained, and very easy to assemble. The elements simply fit into each other. The particular conformation has the advantage that the click occurs twice; when the pusher is pressed and when it is released. Thus, the user is assured of the exact position of the pusher and of its proper functioning.

The invention is set out below in more detail, using the attached drawing comprising the following figures:

fig. 1 shows a longitudinal section of the pusher according to the invention;

fig. 2 shows a similar partial view of another embodiment of the pusher according to the invention.

The pusher is designed to be placed on the rim of the middle part of a timepiece. For this purpose, the middle part includes a hole giving access to the internal part of the case. A ring 3 is arranged axially in the bore. It is advantageous to provide a fixing of this ring by tightening, but any other method of fixing of known type, such as for example by screwing or welding, can also be used.

A central rod 2, preferably cylindrical, is disposed in the ring 3. It is slidably mounted and can thus carry out a translation movement towards the inside or towards the outside of the middle, along the axis of the ring. 3.

A seal can optionally be placed in a circumferential groove provided for this purpose around the periphery of the rod, in order to seal the rod-ring interface.

A head 1 is fixed to the portion of the rod 2 located towards the outside of the middle part. This head can be entirely prominent with respect to the middle part or even be partially embedded thanks to a recess provided at the edge of the middle part. Alternatively, the rod and the head can also be in one piece.

The end of the rod 2 located inside the middle ends with a flange 4. This flange is located in a housing 6 of substantially corresponding shape, provided at the end of the ring 3. The curved profile of the collar provides a holding effect in place which causes the pusher to remain in the rest position until pressure is exerted on the head 1.

In order to allow the push-button movement back and forth, the flange must be able to disengage from the housing 6 in which it is in the rest position. For this purpose, at least one of the interlocking elements (either the flange 4 and / or the end of the ring 3) is elastically deformable. To do this, different means allow, depending on the embodiment, either to temporarily reduce the diameter of the flange 4, or to temporarily increase that of the housing 6, or a combination of these two means.

According to the first case, illustrated in fig. 1, an axial groove 5 made substantially centrally at the end of the rod 2, makes it possible to release at least two flexible portions 2a of the rod. These portions provide flexibility which makes it possible to temporarily bring the flange portions 2a towards the central axis. Thus, when a force is exerted on the head 1, the flexible portions 2a approach towards the central axis until the widest part of the diameter of the flange 4 has crossed the extreme edge of the housing 6. From that this passage is crossed, the flexible portions 2a return almost instantaneously to their initial position, thereby producing a click.

The stroke of the released push rod depends on the clearance A available between the head 1 and the adjacent part of the ring 3. By moving towards the inside of the middle part, the end of the rod actuates an element

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CH 687 284G A3

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of the watch movement, such as a contact or a switch (not shown). A return spring 8, disposed between the head 1 and the adjacent part of the ring 3 or even between the head and the middle part, allows the pusher to return to its initial position as soon as the actuating force is no longer applied to the pusher head. The return force of this spring is such that when the flange joins the edge of the housing 6, the flexible portions 2a approach towards the central axis, allowing the flange to reposition in the housing. The pusher is repositioned almost instantaneously, thus producing a new click when entering the housing 6.

According to various variants, several axial grooves 5 are provided, at different angles, separating more than two flexible portions 2a of rod. The higher the number of grooves, the narrower they can be, while retaining sufficient elasticity.

According to the embodiment illustrated in FIG. 2, at least one flexible portion 3a is provided at the level of the ring 3. The portion of the ring 3 situated towards the inside of the middle part is thinned so that its external diameter D2 is less than the maximum diameter D1 of the ring 3 , and by the same fact, to that of the drilling of the middle part. This thinning extends over a given distance, sufficient to provide the flexibility required for said portions 3a. At least two flexible portions 3a, separated from one another for example by grooves, are thus provided.

For best results and the most advantageous cost, it is preferable to use a pusher, all of the elements of which are made of synthetic material. It is however possible to use other types of material, such as for example metal alloys, for one or more elements of the pusher.

The mounting of the pusher according to one or the other embodiment is very simple. Thus, the ring 3 is inserted into the middle of the receiving part; all that remains is to add the rod 2 / head 1 assembly with the spring 7. More simply still, the head / rod / ring / spring assembly already assembled can be inserted into the receiving part. In the case of the embodiment illustrated in FIG. 2, this second mode must be used since the central rod does not have a flexible portion.

Claims (10)

Claims 1. Snap-action push-piece for a timepiece, comprising a head (1), a rod (2) extending longitudinally from the head through a ring (3) in which said rod (2) can perform a movement translation in one direction or the other along the axis of said ring, a return spring (8), disposed between the head (1) and the adjacent end of the ring (3), characterized in that a flange (4) is shaped in the end portion of the rod (2) remote from the head (1), the end of the ring (3) remote from the head (1) comprises a housing (6) intended to house said collar (4), the shape of said housing corresponding substantially to the profile of the collar, and in that at least one of the interlocking elements (4, 6) is elastically deformable so as to allow said collar ( 4) to be released from the housing (6) when a given force is exerted against the head (1) and to be engaged again under the effect of u return spring when said force is no longer exerted. 2. Snap-action push piece for a timepiece according to claim 1, in which the end portion of the rod (2) remote from the head (1) comprises at least one axial groove (5) defining at least two flexible portions (2a) of the rod (2) which allow said collar (4) to be released from the housing (6) when a given force is exerted against the head (1) and to be engaged again under the effect of the return spring when said force is no longer exerted. 3. Snap-action plunger for a timepiece, according to one of claims 1 or 2, in which the external diameter (D2) of a portion of the end of the ring (3) remote from the head (1) is less than the maximum external diameter (D1) of the ring (3), defining at least two flexible portions (3a) of the ring (3) separated by axial grooves which allow said flange (4) to be released from the housing (6) when a given force is exerted against the head (1) and to be engaged again under the effect of the return spring when said force is no longer exerted. 4. Snap-on push-button according to one of claims 1 to 3, in which the rod (2) is of cylindrical shape. 5. Snap-on push-button according to one of claims 1 to 4, in which the rod (2) and the head (1) are formed in one piece. 6. Click plunger according to one of claims 1 to 5, comprising a seal (8) disposed in a circumferential groove provided on the periphery of the rod (2). 7. Snap-on push-button according to one of claims 1 to 6, in which the elements (1, 2, 3) are made of synthetic materials. 8. Push button according to one of claims 1 to 6, wherein the elements (1, 2, 3) are made of metallic materials. 9. Timepiece comprising a pusher according to one of claims 1 to 8. 10. Timepiece according to claim 9, wherein the pusher is fixed in a bore giving access to the inner part of the housing. 5 10 15 20 25 30 35 40 45 50 55 60 65 4