EP4191347A1 - Watch case comprising a bottom oriented in a predetermined angular position - Google Patents

Abstract

The invention relates to a watch case (10) comprising a back (30) driven into a middle part (20) via a seal (40), the back (30) comprising a body (31) from which extends radially a lip (32), said body (31) comprising an axial annular bearing surface (310) and said lip (32) comprising a radial annular bearing surface (320), the middle part (20) comprising an axial opening (21) and has an axial annular bearing (200) extending opposite the axial annular bearing (310) of the body (31) of the bottom (30), and a radial annular bearing (201) resting against the annular bearing radial (320) of the lip (32), the seal (40) being interposed between the axial annular bearing surfaces (200, 310) of the middle (20) and of the back (30), the axial annular bearing surfaces (200, 310) of the caseband (20) and the back (30) having peripheral profiles of complementary shapes, substantially circular, both comprising a first portion in the shape of an arc of a circle having a first radius (R1, R2 ), and a second portion in the shape of an arc of circle to which the first portion is connected, having a second radius (r1, r2) whose value is lower than that of the first radius (R1, R2).

Description

Technical field of the invention

The invention relates to the field of watchmaking, and in particular to the components of a watch case.

More particularly, the invention relates to a watch case comprising a back oriented in a predefined angular position.

Technology background

The watch cases have a middle part on either side of which are fixed a crystal and a back.

The back can be fixed to the caseband by screwing, by assembly of the bayonet type or by tight fitting by press fitting, that is to say by driving in.

In the case of fixing the back to the middle by driving in, a seal is arranged in the middle and is compressed radially by the back against the middle when driving the back into the middle. The seal has the effect of giving the box a desired level of water and air tightness, as well as ensuring the mechanical strength of the assembly.

When it presents, on a visible surface, a pattern such as a brand logo, it is desirable that the background be oriented so that said pattern is aligned with respect to a vertical axis 6 o'clock - 12 o'clock, to reasons of perceived quality in particular.

The orientation of the back in relation to the middle part is generally carried out manually by appropriate pre-positioning of the back part in relation to the middle part before mounting on the press, using visual markers present on the middle part or the back part, by example thanks to a notch for the adjustment rod.

In the case of this type of fixing of the back to the middle, the precision of the orientation of the back therefore essentially depends on the skill of the operator carrying out the pre-positioning of the back with respect to the middle.

It is well understood that the level of quality of the assemblies produced can vary significantly.

There is therefore a need to produce assemblies of watch cases in which the orientation of the back relative to the middle part is controlled, so as to obtain a high and constant level of quality.

Summary of the invention

The invention solves the aforementioned drawbacks by proposing a solution making it possible to control the orientation of the back relative to the caseband when it is fixed by press fit.

To this end, the present invention relates to a watch case comprising a back driven into a middle part by means of a seal, the back comprising a body from which a lip extends radially, said body comprising an axial annular bearing surface and said lip comprising a radial annular bearing surface.

The caseband has an axial opening and has an axial annular bearing extending opposite the axial annular bearing of the back body, and a radial annular bearing bearing against the radial annular bearing of the lip.

The gasket is interposed between the axial annular bearing surfaces of the middle part and the back, said axial annular bearing surfaces having peripheral profiles of complementary, substantially circular shapes, both comprising a first portion in the form of an arc of a circle having a first radius R1, R2, and a second portion in the form of an arc of circle to which the first portion is connected, having a second radius r1, r2 whose value is lower than that of the first radius R1, R2.

In particular embodiments, the invention may also include one or more of the following characteristics, taken separately or in all technically possible combinations.

In particular embodiments, the value of the second radius r1, r2 is greater than half the value of the first radius R1, R2.

In particular embodiments, the peripheral profile of the axial annular bearing surfaces of the middle part and the back comprise first and second portions in the form of arcs of circles distributed alternately, one after the other.

In particular embodiments, the axial annular bearing surfaces of the middle part and the back are configured so that the arrows of the first and second portions in the form of circular arcs are separated from each other by an angle of 60 degrees.

In particular embodiments, the axial annular bearing surfaces of the middle part and the back are configured so that the arrows of the portions in the form of arcs of a circle define secant line segments at a point materializing the center of the opening.

In particular embodiments, the shape defined by the peripheral profile of the axial annular bearing surfaces is convex.

In particular embodiments, the seal has a profile complementary to those of the axial annular bearing surfaces of the caseband and the back.

Brief description of figures

• la figure 1 représente une vue en coupe selon un plan radial d'une partie d'une boite selon un exemple préféré de réalisation de l'invention ;
• les figures 2 et 3 représentent respectivement une vue de dessus d'un fond de la boite de la figure 1 et une vue de dessous d'une carrure de la boite de la figure 1.

Other characteristics and advantages of the invention will appear on reading the following detailed description given by way of non-limiting example, with reference to the appended drawings in which:

• there figure 1 shows a sectional view along a radial plane of part of a box according to a preferred embodiment of the invention;
• THE figures 2 and 3 represent respectively a top view of a bottom of the box of the figure 1 and a view from below of a middle part of the case of the figure 1 .

Detailed description of the invention

The present invention relates to a watch case 10, a portion of which is shown in the sectional view along a radial plane of said watch case 10 of the figure 1 .

The watch case 10 comprises a middle part 20 of generally circular shape comprising an axial opening 21 receiving a crystal (not shown) at one of its ends called the "upper end", opposite a bottom 30 driven out at another end of said caseband 20, called "lower end". The crystal, the back 30 and the caseband 20 define a volume inside which a watch movement is arranged, in a manner known to those skilled in the art.

Since the watch movement and the other watch components used in a watch case 10 are known to those skilled in the art and do not form part of the present invention, they are not shown in the figures, nor described below.

The bottom 30 has a generally circular shape and includes a body 31 from which extends radially a lip 32 forming a peripheral shoulder with respect to said body 31. More specifically, as shown in the sectional view of the figure 1 , the shoulder is formed by an axial annular bearing 310 of the body 31 and by a radial annular bearing 320 of the lip 32.

Said axial 310 and radial 320 annular bearing surfaces are provided to constitute bearing surfaces as described in more detail below.

The axial and radial directions are defined in the present text relative to the watch case 10, and in particular relative to the opening 21 of the middle part 20. In a manner known in the field of watchmaking, the axial direction extends from one to the other of the upper and lower ends of the middle part 20 and the radial direction extending perpendicularly to said axial direction.

At its lower end, the caseband 20 has an axial annular bearing 200 extending opposite the axial annular bearing 310 of the back 30. This axial annular bearing 200 is connected to a radial annular bearing 201 bearing against radial annular bearing surface 320 of lip 32. Radial annular bearing surface 201 of middle part 20 forms an end surface of said middle part 20 in the preferred embodiment of the invention shown in the figures.

An annular seal 40 is advantageously interposed between the axial annular bearing surfaces 200 and 310 respectively of the caseband 20 and of the back 30, and is compressed by one and the other of said axial annular bearing surfaces 200 and 310, as represented on the figure 1 . This compression of the seal 40 makes it possible to impart water and air tightness to the watch case according to a desired level and generates a tightening force allowing the fixing of the back 30 on the middle part 20.

Advantageously, the axial annular bearing surfaces 200 and 310 of the caseband 20 and of the back 30 are of complementary shapes, and do not have a shape of revolution. On the contrary, although it has a substantially circular shape, as shown by the figures 2 and 3 , their respective peripheral profile comprises a first portion in the shape of an arc of a circle having a first radius R1, R2 and a second portion in the shape of an arc of a circle connected to the first portion and having a second radius r1, r2 less than the first radius R1, R2. The first portions of the middle part 20 and of the bottom 30 are intended to rest opposite one another, just as the second portions of the middle part 20 and of the bottom 30 are intended to rest opposite one of the other. 'other.

The first and second rays R1, R2 and r1, r2 are represented on the figures 2 and 3 by arrows.

The term “peripheral profile” defines in the present text the projection of the axial annular bearing surfaces 200 and 310 respectively of the caseband 20 and of the back 30 on a plane P perpendicular to the axial direction and parallel to the radial direction. In other words, the plane P is parallel to the radial annular bearing surfaces 201 and 320 of the caseband 20 and of the lip 32, as represented on the figures 1 and 2 .

The term “complementary” means that the shapes of the axial annular bearing surfaces 200 and 310 are identical, only the dimensions of said axial annular bearing surfaces varying relative to each other.

These conformations of the back 30 and the middle part 20, visible respectively on the figures 2 and 3 , make it possible to guarantee the performance of the tightness of the watch case 10 to water and air by preserving the peripheral profile of the axial annular bearing surfaces 200 and 310 from any angle, broken line or stop, etc., by the continuity of the curved surfaces, while playing a keying role in the orientation of the back 30 vis-à-vis the middle part 20 when they are assembled to one another.

Indeed, to drive the bottom 30 into the middle part 20, it is then possible to orient the bottom 30 only according to a position in which the shapes of the axial annular bearing surfaces 200 and 310 are aligned with one another. other, that is to say a position in which the first portions are arranged opposite each other and the second portions are arranged opposite each other.

Advantageously, to guarantee a high level of water and air tightness, the shape defined by the peripheral profile of the axial annular bearing surfaces 200 and 310 of the caseband 20 and of the back 30 is convex, in the sense that said bearing surfaces axial rings 200 and 310 are located respectively entirely on the same side of a tangent line applied at any point of their peripheral profile. The term "convex" is used here in its definition specific to the field of geometry.

Preferably, in a preferred embodiment of the invention, the values of the second radii r1, r2 of the second portions of the axial annular bearing surfaces 200 and 310 of the caseband 20 and of the back 30 are respectively greater than half the values of the first radii R1, R2 of the first portions of the middle 20 and the back 30.

This characteristic contributes to the continuity of the curved surfaces and therefore to preventing the shape of the peripheral profile of the axial annular bearing surfaces 200 and 310 from comprising any broken line or stop angle.

In particular, the difference between the values of the first and second radii R1 and r1 of the axial annular bearing 200 of the middle part 20, as well as the difference the difference between the values of the first and second radii R2 and r2 of the annular bearing axial 310 of the bottom 30, is of the order of a few millimeters or tenths of millimeters.

As shown by the figures 2 and 3 , the shape of the axial annular bearing surfaces 200 and 310 of the caseband 20 and of the back 30 comprises several first and second portions in the form of arcs of circles distributed alternately, one after the other. In other words, two first portions in the form of a successive arc of a circle are connected to each other by a second portion in the shape of an arc of a circle and two second portions in the shape of a successive arc of a circle are connected to each other by a first portion in the form of an arc of a circle.

In the preferred embodiment of the invention, the axial annular bearing surfaces 200, 310 of the caseband 20 and of the back 30 are configured so that the arrows of the first and second portions in the form of arcs of circles are separated from each other. another by an angle of 60 degrees. The concept of an arrow of an arc of a circle is known to those skilled in the art. This angle easily acts as an effective polarizer allowing to orient a background in a case middle. A lack of orientation would be quickly perceptible and correctable for the operator.

In other words, the axial annular bearing surfaces 200 and 310 of the caseband 20 and of the back 30 comprise three first portions and three second portions in the form of arcs of circles alternately distributed one after the other.

Furthermore, the arrows of the portions in the form of arcs of circles define secant line segments at a point materializing the center of the opening 21.

Preferably, the seal 40 has a peripheral profile complementary to those of the axial annular bearing surface 310 of the lip 32 and of the axial annular bearing surface 200 of the middle part 20.

On the figure 1 , the seal 40 has been shown with a rectangular cross section. In other exemplary embodiments of the invention, it may comprise a cross section of circular or other shape.

Advantageously, the radial annular bearing surface 320 of the bottom 30 may comprise an annular extra thickness 321 to receive the seal 40 in support, as shown in the figures 1 and 3 . Thus, the radial annular bearing 201 of the caseband 20 bears against an end portion of the radial annular bearing 320 of the back 30.

The back 30 and the middle part 20 can be made of any suitable material, for example metal, such as steel or precious metal, ceramic, etc.

The seal 40 can also be made of any suitable material, such as polymer, having a hardness of 75 ± 10 Shore D.

More generally, it should be noted that the modes of implementation and embodiment considered above have been described by way of non-limiting examples, and that other variants are therefore possible.

For example, it is conceivable that the peripheral profile of the axial annular bearing surfaces 200 and 310 of the caseband 20 and of the back 30 has more than two portions in the form of arcs of circles whose radii are different and/or that it comprises more of three first portions and more than three second portions in the form of arcs of circles alternately distributed one after the other.

Claims (7)

Watch case (10) comprising a back (30) driven into a middle part (20) via a seal (40), the back (30) comprising a body (31) from which extends radially a lip (32), said body (31) comprising an axial annular bearing (310) and said lip (32) comprising a radial annular bearing (320), the caseband (20) comprising an axial opening (21) and has an axial annular bearing (200) extending opposite the axial annular bearing (310) of the body (31) of the bottom (30), and a radial annular bearing (201) resting against the radial annular bearing (320) of the lip (32), the gasket (40) being interposed between the axial annular bearing surfaces (200, 310) of the caseband (20) and the back (30), said watch case (10) being characterized in that the bearing surfaces axial annular rings (200, 310) of the caseband (20) and the back (30) have peripheral profiles of complementary shape, substantially circular, both comprising a first portion in the form of an arc of a circle presenting a first radius (R1, R2), and a second portion in the form of an arc of a circle to which the first portion is connected, having a second radius (r1, r2) whose value is lower than that of the first radius (R1, R2 ). Watch case (10) according to claim 1, in which the value of the second radius (r1, r2) is greater than half the value of the first radius (R1, R2). Watch case (10) according to one of Claims 1 or 2, in which the peripheral profile of the axial annular bearing surfaces (200, 310) of the caseband (20) and of the back (30) comprise several first and second portions in the shape circular arcs distributed alternately, one after the other. Watch case (10) according to one of Claims 1 to 3, in which the axial annular bearing surfaces (200, 310) of the middle part (20) and of the back (30) are configured so that the arrows of the first and second portions in the form of circular arcs are separated from each other by an angle of 60 degrees. Watch case (10) according to one of Claims 1 to 4, in which the axial annular bearing surfaces (200, 310) of the middle (20) and of the back (30) are configured so that the arrows of the shaped portions circular arcs define intersecting line segments at a point materializing the center of the opening (21). Watch case (10) according to one of Claims 1 to 5, in which the shape defined by the peripheral profile of the axial annular bearing surfaces (200, 310) is convex. Watch case (10) according to one of Claims 1 to 6, in which the gasket (40) has a profile complementary to those of the axial annular bearing surfaces (200, 310) of the caseband (20) and of the back (30) .

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