CH715720A2 - Adjustable back for a timepiece. - Google Patents

Abstract

The present invention relates to a back (1) for a watch case (50), the back (1) comprising a first element (10) arranged to be screwed onto the watch case (50), and a second element (20) comprising an end face bearing a pattern the second element (20) being mounted so as to be able to rotate about an axis (C) passing through the center of the box (50), characterized in that the second element (20) comprises braking means arranged to maintain it relative to the first element (10) in different angular positions around the axis of rotation (C), the braking means being arranged between the first and second elements (10, 20).

Description

The present invention relates to funds for timepieces and more particularly to such funds comprising a pattern or a logo on their outer face and in which said pattern or logo can be oriented as desired.

TEHNOLOGICAL BACKGROUND

It often happens that, when the face of a watch case back on the caseband of the latter, we realize that, when the back is completely screwed on, the inscriptions or decorative patterns which may have been for example struck by stamping or engraved on the back face located on the wrist side of the wearer of the watch, are not suitably aligned with the vertical axis 12 o'clock to 6 o'clock of said watch, which, of course, adversely affects the aesthetic aspect of this watch.

[0003] This defect in appearance, while it can be tolerated for inexpensive watches, constitutes a very annoying drawback for more expensive watches.

To remedy this drawback, the only solution known to date is to match a case back with a watch case determined during machining, so that we can be sure that once fully screwed, the back is perfectly aligned with the 12h-6h axis of the watch. This solution is however only unsatisfactory because we are exposed to problems if ever the original case back of the watch is lost or damaged and it is necessary to replace it with another case that is not. sure that once screwed on the caseband, it always aligns properly with the vertical axis 12h-6h.

SUMMARY OF THE INVENTION

The present invention aims to remedy this drawback as well as others by providing a system allowing, after screwing a caseback on the middle part of a watch case, to adjust in a simple and effective orientation of the back with respect to the watch, so as to ensure a suitable arrangement of the inscriptions and other decorative motifs which have been transferred to the face of the back of the watch directed towards the wrist of the wearer of this watch.

[0006] To this end, the present invention relates to a back for a watch case, the back comprising a first element arranged to be screwed onto the watch case, and a second element comprising an end face bearing a pattern, the second element being mounted so as to be able to rotate around an axis passing through the center of the box, characterized in that the second element comprises braking means arranged to hold it relative to the first element in different angular positions around the axis of rotation, the braking means being disposed between the first and second elements.

[0007] Thanks to these characteristics, the present invention provides a device for fixing a watch case back which simultaneously allows this case back to be completely screwed onto the caseband of the watch so as to ensure the tightness of this last and to avoid as much as possible any risk of losing said back, then, although the back is fully screwed, to pivot a movable element of this back relative to the caseband to make up for any misalignment of the inscriptions or patterns applied to the face visible from said bottom.

[0008] In accordance with other advantageous variants of the invention: <tb> - <SEP> said braking means act by friction; <tb> - <SEP> said braking means comprise at least one elastic annular element; <tb> - <SEP> said at least one annular element is elastic in a direction parallel to the axis of rotation of the second element; <tb> - <SEP> said braking means are formed by an annular seal made of compressible material; <tb> - <SEP> the first element and the second element comprise additional clipping means; <tb> - <SEP> the second element comprises a pin arranged to cooperate with an annular groove formed in the first element; <tb> - <SEP> the second element comprises two resilient annular elements housed in facing first and second annular grooves formed in the first element; <tb> - <SEP> said annular grooves are arranged on either side of the circular groove; <tb> - <SEP> the second annular groove has two levels, a first level forming the bottom and arranged to receive an elastic annular element, and a second level arranged to receive the edge of the second element; <tb> - <SEP> an O-ring is inserted in an annular groove made at the base of the watch case to guarantee the seal between the back and said case.

[0009] The invention also relates to a timepiece comprising a moon phase mechanism according to the invention.

BRIEF DESCRIPTION OF THE FIGURES

The goals, advantages and characteristics of the striking watch will appear better in the following description on the basis of at least one non-limiting embodiment illustrated by the drawing in which: <tb> - <SEP> Figure 1 is a sectional view of a watch case equipped with a back according to the invention; <tb> - <SEP> Figures 2a and 2b are respectively a bottom view and a sectional view of the first element of a bottom according to the invention; <tb> - <SEP> Figures 3a and 3b are respectively a bottom view and a sectional view of the second element of a bottom according to the invention; <tb> - <SEP> FIG. 4 is an exploded perspective view of a bottom according to the invention.

DETAILED DESCRIPTION

Figure 1 illustrates a back 1 for watch case 50 intended to be screwed by a thread on a middle part 51, the latter having a complementary thread machined at its base and on its inner periphery.

More specifically, the bottom 1 comprises a first element 10 arranged to be screwed onto the watch case 50, and a second element 20 comprising an end face 21 bearing a pattern such as a logo or a mark, the second element 20 being mounted to be movable in rotation around an axis passing through the center of the watch case.

The first element 10 is intended to be screwed onto the watch case 50 and has for this purpose, on its rear face, that is to say the face oriented towards the inside of the case, an annular shoulder 11 comprising a thread 110 on its outer periphery. Thus the shoulder 11 is screwed to the base of the watch case 50 which includes a complementary thread provided for this purpose.

The first element 10 also comprises, on its front face, that is to say the face oriented towards the outside of the box, a base 12 with an inclined wall 13 towards the outside of the box so that said base 12 has a cross-section of substantially trapezoidal shape.

The second element 20 comprises a cavity 22 with an inclined wall 23 complementary to the base 12 to be able to perform a clipping (clipping) or a force interlocking, and thus assemble the two elements 10, 20. So as to facilitate the introduction by force of the second element 20 on the first element 10, the ridges of the base 12 and of the cavity 22 are chamfered.

Advantageously the base 12 of the first element 10 comprises portions 13 'recessed and an annular groove 13 "formed behind the wall 13 so as to facilitate the deformation of the wall during the force fit of the second element 20 on the first element 10.

As can be seen, the diameter of the base 12 and of the cavity 22 are smaller than the diameters of the first and second element 10, 20.

The second element 20 is rotatably mounted on the first element 10 about the axis of rotation C passing through the center of the box 100, the interlocking or the clipping providing sufficient play to rotate the second element 20.

As can be seen in Figures 2a and 2b, the first element 10 successively comprises a first annular groove 14 formed in the base 12, an annular groove 15 formed near the periphery of the first element and a second annular groove 16 also formed in the immediate vicinity of the periphery of the first element 10.

Note in Figure 1 that the second element 20 has an orifice 24 arranged to receive a pin 25, the pin 25 cooperating with the annular groove 15 formed in the first element 10 so as to guide the second element 20 during its pivoting. It will also be noted in FIG. 2a that the annular groove 15 is not continuous and has two ends 150 and 151 close to each other, each defining a stop.

According to the invention, there is provided braking means which act by friction and which are arranged to maintain different angular orientations of the second element 20 relative to the first element 10, and therefore relative to the middle part. Thus, when the first element 10 is screwed into abutment on the caseband, the second element carrying the pattern M can easily be moved angularly into a desired position against the frictional force generated by the braking means and maintained in the desired position. The second element 20 is thus clamped axially between its rear face and the front face of the first element 10. Preferably, the respective dimensions of the second element 20, in particular its thickness, and those of the first element 10 are chosen so that the edge of the second element 20 is flush with the front face of first element 10 to thus form a continuous surface.

[0022] According to a preferred embodiment, the braking means comprise at least one resilient annular element 30 which in particular has elasticity in a direction parallel to the axis of rotation C. Typically the annular element can be produced by a seal made of natural or synthetic compressible material. The annular element 30 is disposed between the first and the second element. According to the invention, the elastic annular element or elements 30 are arranged in the first and second annular grooves 14 and 16 which are formed in the front face of the first element. Those skilled in the art could, without particular difficulty, reverse this assembly and place the resilient annular elements 30 on the rear face of the second element 20, forming therein the grooves 14 and 16 beforehand. The annular grooves 14 and 16 are arranged on either side of the annular groove 15, which allows a better distribution of the friction forces generated by the elastic annular elements 30.

Advantageously, the second annular groove 16 has two levels, a first level forming the bottom of the groove arranged to receive an elastic annular element 30, and a second level forming the opening of the groove arranged to receive the edge of the second element 20. The second level has dimensions greater than the first level so that the edge of the second element 20 can move in translation in the direction of the axis C.

Note that the desired braking force can be controlled by adjusting the compression ratio of the annular element during manufacture.

It will also be noted that the use of a second element attached to a first element allows the manufacturer to have a stock of replacement funds and also to use funds bearing different patterns. This type of background also makes it possible to easily combine various materials to produce the various elements thereof.

Thus, to orient the bottom the manufacturer (or the wearer) exerts pressure on the second element 20 in the direction of the watch case so as to compress the elastic annular elements 30. Then, while maintaining pressure on the second element, the manufacturer rotates the second element relative to the first element 10 so as to orient the bottom in a desired angular position so that the pattern M is, for example, aligned with the axis 6H-12H of the watch.

So as to facilitate the removal of the second element 20 from the first element 10, the second element 20 comprises a notch 26 adapted to receive a tool for exerting a leverage force and thus dislodge the second element.

The timepiece 100, for example of the wristwatch type, which is provided with the bottom 1 according to the invention is partially shown in Figure 1. This timepiece comprises in particular a middle 51 surmounted by a bezel 52 which can be screwed onto the middle 51 and which serves to hold a crystal 53. The assembly formed by the bezel 52 and the crystal 53 is sealed by interposing a seal 54. The middle 51 also has a bore for the passage of a rod 55 on which is fixed a crown 56. In the example shown in the figures, the wristwatch is of the type with an analog time display and for this purpose comprises a set of hands 58 of the hours and minutes (a single hand has been shown in the drawing) moving above a dial 57. It goes without saying that the present invention could equally well be applied to a watch with a digital time display. comprising, for example, a liquid crystal cell.

It will be understood that various modifications and / or improvements obvious to those skilled in the art can be made to the embodiment described in the present description without departing from the scope of the present invention defined by the appended claims. Provision may in particular be made to use a ring with a wavy spring in place of the annular seal 30 when it has elasticity in compressibility along the axis C. Still in another variant, it would be possible to envisage associating the means braking at indexing notches to position the substrate in a plurality of predefined angular positions.

It will be noted that an O-ring 31 is conventionally inserted in an annular groove 59 made at the base of the middle part 51 to ensure the seal between the first element 10 of the bottom 1 and said middle part 51.

The first and the second element can be made of metals, a metal alloy, ceramic, a composite material or even a plastic material.

It goes without saying that the invention is not limited to the embodiment which has just been described and that various modifications and simple variants can be envisaged without departing from the scope of the invention.

Claims (12)

1. Case back (1) for a watch case (50), the case back (1) comprising a first element (10) arranged to be screwed onto the watch case (50), and a second element (20) comprising a face d 'end bearing a pattern (M), the second element (20) being mounted movable in rotation about an axis (C) passing through the center of the box (50), characterized in that the second element (20) comprises braking means arranged to keep it relative to the first element (10) in different angular positions around the axis of rotation (C), the braking means being arranged between the first and second elements (10, 20). 2. Case back (1) for a watch case (50) according to claim 1, characterized in that said braking means act by friction. 3. Case back (1) for a watch case (50) according to claims 1 and 2, characterized in that said braking means comprise at least one elastic annular element (30). 4. Case back (1) for a watch case (50) according to one of the preceding claims, characterized in that said at least one annular element (30) is elastic in a direction parallel to the axis of rotation (C) of the second element (20). 5. Case back (1) for a watch case (50) according to one of the preceding claims, characterized in that said braking means are formed by an annular seal (30) made of compressible material. 6. Case back (1) for a watch case (50) according to one of the preceding claims, characterized in that the first element (10) and the second element (20) comprise additional clipping means. 7. Bottom (1) for a watch case (50) according to one of the preceding claims, characterized in that the second element (20) comprises a pin (24) arranged to cooperate with an annular groove (15) formed in the first element (10). 8. Case back (1) for a watch case (50) according to claim 3, characterized in that the second element (20) comprises two resilient annular elements (30) housed in first and second annular grooves (14, 16) in look formed in the first element (10). 9. Bottom (1) for a watch case (50) according to claims 7 and 8, characterized in that said annular grooves (14, 16) are arranged on either side of the circular groove (15). 10. Bottom (1) for a watch case (50) according to one of the preceding claims, characterized in that the second annular groove (16) has two levels, a first level forming the bottom and arranged to receive an elastic annular element. (30), and a second level arranged to receive the edge of the second element (20). 11. Bottom (1) for a watch case (50) according to one of the preceding claims, characterized in that an O-ring (31) is inserted in an annular groove (59) formed at the base of the watch case (51) to guarantee the seal between the bottom (1) and said box (50). 12. Timepiece comprising a back for a watch case according to one of claims 1 to 11.