Device for fastening and orienting a back cover on an intermediate piece of a timepiece

Abstract

The present invention relates to a device for fastening a back cover (1) to a middle part (2) of a watch, the back cover (1) comprising a cover (10) configured to form a support surface with the middle part (2) and a body (12) configured to rest within the middle part, the device comprising an indexing ring (3) disposed between the back cover and the middle part, characterized in that the indexing ring comprises at least one lower latch (32) and at least one upper latch (33), the lower latch being configured to engage with the back cover and ensure indexing positioning with the back cover, the upper latch being configured to engage with the middle part (2) and ensure indexing positioning of the back cover-ring assembly relative to the middle part (2), the height of the at least one upper latch (33) being greater than the height of the at least one lower latch (32), or vice versa.

Description

Technical Field

[0001] The present invention relates to an apparatus and method for fastening one element of a watch relative to another element at an adjustable angle, and more specifically, to a fastening device for a watch case including a back cover whose centering is adjustable relative to a vertical axis from 12 o'clock to 6 o'clock.

[0002] The present invention also relates to a clock or watch, particularly a wristwatch, that includes such a device. Background Technology

[0003] External components of watches and similar instruments are subject to many restrictions, particularly in terms of water resistance, robustness, and appearance, and must be manufactured to prevent any irreversible accidental disassembly that would necessitate after-sales intervention such as gasket replacement, cleaning, lubrication, or even repair.

[0004] Some external or control components must also be angularly indexed relative to each other for positioning of initial reference, rest, or actuation positions, or to aid in reading indications or scales, or to ensure the continuity of curved surfaces and / or decorations. Such angular indexing is often difficult to achieve well, given the combination of good component securing and perfect waterproofing of the gaskets.

[0005] As described in document CH 423 637 or patent CH 447 046, it is known to use resilient closure elements independent of the mechanism to be assembled. The main disadvantage of the resilient elements proposed in these documents lies in their overall size. It is also known from document CH 512769 to use columnar members made of compressible material surrounded by crown sections that mate with milled portions arranged at the corners of square or rectangular housings. Such devices can only be used on molded housings, and the elasticity is provided by a compressible material of the elastomeric type, which may change significantly during aging. Summary of the Invention

[0006] The present invention proposes to manufacture a waterproof and robust component for an external part, which has an easily adjustable angular scale.

[0007] Therefore, the present invention relates to a device for fastening a rear cover to an intermediate member according to claim 1.

[0008] The present invention also relates to a clock or watch that includes such a fastening device. Attached Figure Description

[0009] Other features and advantages of the invention will become more apparent from the following description of specific embodiments thereof, given by way of simple illustrative and non-limiting examples and accompanying drawings, wherein:

[0010] -Figure 1 An exploded perspective view of the fastening device with an indexing ring according to the present invention is shown, wherein the rear cover is flipped relative to its original position.

[0011] - Figure 2 A cross-sectional view of the fastening device according to the present invention is shown. Detailed Implementation

[0012] This invention proposes the manufacture of a waterproof and robust assembly for external components, which has easily achievable angular indexing and is positioned securely, has a minimal number of parts, and reduces manufacturing costs. Furthermore, by using an indexing ring independent of the gasket seal, functional separation is made possible, with the waterproofing function performed solely by the gasket.

[0013] Figure 1 and 2 A non-limiting example of mounting the back cover and angular division relative to the watch centerpiece is shown.

[0014] The present invention relates to a fastening device 100 for fastening a back cover 1 to a middle part 2 of a watch. The back cover 1 includes a cover 10 configured to form a support surface with the middle part 2, and a body 12 configured to be assembled into the middle part 2. The fastening device includes an indexing ring 3 disposed between the back cover 1 and the middle part 2.

[0015] Although the indexing element 3 can also take other forms, the ring is preferred because it is easy to produce by machining or injection molding and is inexpensive due to its very small size.

[0016] The cover 10 can be installed on the intermediate part 2, and a gasket seal is inserted between the two parts.

[0017] from Figure 1 and 2 As can be seen, the back cover 1 has three layers. The first layer is formed by the cover 10, the second layer is formed by the first annular portion 11 with a diameter smaller than that of the cover 10, and the third layer is formed by the main body 12 of the cover, with the diameter of the main body 12 being smaller than that of the first annular portion 11.

[0018] The first annular portion 11 forming the second layer is arranged as a receiving ring 3. The ring 3 is placed on the cover, abutting against the edge of the body 12 near the first annular portion 11 and against the shoulder 20 of the intermediate member 2, and the ring 3 is designed to ensure the strength and water resistance of the assembly between the back cover 1 and the intermediate member 2 when the surfaces 14 and 24 of the back cover 1 are in contact with each other in the assembly position on the intermediate member 2.

[0019] The main body 12 of the back cover 1, which forms the third layer, is arranged to cooperate with the intermediate part 2 of the watch case.

[0020] from Figure 1 and 2 As can be seen, ring 3 includes at least one lower catch 32 formed on the lower surface of ring 3 and configured to rest in the bed or hole 15 of the second annular portion of the rear cover 1. This at least one lower catch 32 extends from the lower surface of ring 3. Therefore, for example, when torque is applied to the rear cover 1, ring 3 cannot be rotated. Advantageously, ring 3 includes three lower catches 32 distributed on its lower surface, spaced apart from each other at an angle of 100°. This arrangement effectively holds ring 3 on the rear cover 1 and allows for better force distribution during assembly. The 100° angle also has the advantage of acting as an angular polarizer.

[0021] The ring 3 also includes at least one upper clasp 33 formed on the upper surface of the ring, the upper clasp 33 being arranged to engage with a machined portion 22 formed in the intermediate member 2. This arrangement allows the components of the back cover 1 and the ring 3 to be correctly positioned or indexed relative to the intermediate member 2, which is particularly useful when the back cover 1 is decorated and must be perfectly aligned along the 12h-6h axis of the watch.

[0022] Advantageously, the indexing ring 3 includes at least one first chamfer 30 on its lower surface and at least one second chamfer 31 on its upper surface. The upper surface refers to the surface that contacts the intermediate member 2, and the lower surface refers to the surface that contacts the rear cover 1. The chamfers 30 and 31 facilitate the installation of the ring when the rear cover is pressed onto the intermediate member, with the first chamfer 30 located at the shoulder formed by the body 12 and the second annular portion 11, and the second chamfer 31 located at the intermediate member 2.

[0023] The lower clip 32 is shorter than the upper clip 33 to distinguish the upper and lower surfaces, thus ensuring the ring 3 is positioned correctly. Therefore, clips 32 and 33 also function as polarizers during installation. Furthermore, as shown in the figure, these clips are positioned opposite each other on both sides of the ring 3. Clearly, these clips can be offset.

[0024] Alternatively, one could envision a ring 3 with chamfers on each of its edges, thus eliminating the need to check the ring's installation orientation, and with snaps of the same height.

[0025] The height of the main body 12 is greater than the height of the first annular portion 11, so that the back cover 1 can be easily aligned with the intermediate part 2. During the assembly process, the main body 12 and the ring 3 form the guiding surface of the intermediate part 2.

[0026] exist Figure 1 It will also be noted that the outer diameter of ring 3 corresponds to the inner diameter of intermediate part 2, which ensures that the support diameter of ring 3 on intermediate part 2 is optimal, thereby ensuring the waterproofness of the component.

[0027] Ring 3 is preferably made of a polymer material, such as It is an injection-moldable material and meets the mechanical requirements for waterproofing. Clearly, any other material capable of elastic deformation and possessing sufficient resistance can be used to manufacture ring 3. Ring 3, along with the lower snap 32 and upper snap 33, forms an integral element, thus achieving good resistance against the opening torque (radial opening or release) of the rear cover 1. These snaps can also be conceived as connecting pins, which facilitates the formation of the annular portion with gap holes.

[0028] The rear cover 1 and ring 3 are sized such that when they are forcefully inserted into the intermediate member 2, the rear cover 1 radially presses the ring 3 against the intermediate member 2, which has the effect of squeezing the ring between the wall of the intermediate member and the wall of the rear cover. In response to the squeezing force, the ring 3 will deform, ensuring good retention of the assembly. The squeezing of the ring between the rear cover 1 and the intermediate member 2 ensures no radial gaps between the respective rear cover 1, ring 3, and intermediate member 2, which contributes to the quality (accuracy and rigidity) of the indexing positioning between the rear cover 1 and the intermediate member 2.

[0029] Figure 2 A cross-sectional view is shown of a rear cover 1 and a ring 3 assembled on an intermediate member 2, with the ring 3 pressed between the inner side of the intermediate member 2 and the rear cover 1. By forcibly mounting the rear cover onto the intermediate member, the ring 3 can be kept deformed, and this deformation is clearly within the elastic deformation limit of the material of the ring 3.

[0030] The present invention also relates to clocks or watches that include such fastening devices.

[0031] In summary, the present invention enables the creation of a compact fastening device that maintains the watch's water resistance and prevents any accidental disassembly.

[0032] The invention also enables the near-perfect orientation (±1° angular positioning tolerance) of components that are held locked in their operating position.

Claims

1. A fastening device for fastening a back cover (1) on an intermediate piece (2) of a watch, said back cover (1) comprising a cover (10) arranged to form a resting surface against said intermediate piece (2) and a body (12) arranged to rest inside said intermediate piece, said device comprising an indexing ring (3) arranged between said back cover and said intermediate piece, characterized in that, The indexing ring comprises at least one lower snap (32) arranged to cooperate with the back cover and to ensure the indexing positioning with the back cover, and at least one upper snap (33) arranged to cooperate with the intermediate piece (2) and to ensure the indexing positioning of the back cover-indexing ring assembly relative to the intermediate piece (2), the height of the at least one upper snap (33) being greater than the height of the at least one lower snap (32), or the height of the at least one lower snap (32) being greater than the height of the at least one upper snap (33).

2. The fastening device of claim 1, wherein The indexing ring (3) comprises three lower snaps (32) spaced apart from each other by 100°.

3. The fastening device according to claim 1 or 2, characterized in that The back cover (1) comprises at least one hole (15) arranged to receive the at least one lower snap (32) of the indexing ring (3).

4. The fastening device according to claim 1 or 2, characterized in that The intermediate piece (2) comprises a machined portion (22) arranged to receive the at least one upper snap (33) of the indexing ring (3).

5. The fastening device according to claim 1 or 2, characterized in that The indexing ring (3) is made of a polymeric material.

6. The fastening device of claim 1 or 2, wherein The indexing ring comprises at least one first chamfer (30) on its lower face and at least one second chamfer (31) on its upper face.

7. The fastening device of claim 1 or 2, wherein The back cover (1) has three levels, a first level formed by the cover (10), a second level formed by a first annular portion (11) having a diameter smaller than the cover, and a third level formed by the main body (12) having a diameter smaller than the first annular portion.

8. The fastening device of claim 7, wherein The at least one upper snap (33) and the at least one lower snap (32) are oppositely arranged on the indexing ring.

9. The fastening device of claim 7, wherein The first annular portion forming the second level is arranged to receive the indexing ring (3).

10. The fastening device of claim 7, wherein The height of the main body (12) is greater than the height of the first annular portion.

11. The fastening device of claim 1 or 2, wherein The outer diameter of the indexing ring (3) corresponds to the inner diameter of the intermediate piece (2).

12. A timepiece, characterized by The timepiece comprises a fastening device according to any one of claims 1 to 11. The timepiece comprises a fastening device according to any one of claims 1 to 11.

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