Device for securing a timepiece dial

Abstract

A watch is delimited by a case formed of a back cover and of a middle part. A timepiece movement is disposed in a casing ring housed inside the watch case. The watch also includes a dial disposed on top of the casing ring and held by a fixing ring. The fixing ring has an S-shaped cross-section. An upper branch of the fixing ring is supported on the dial and a lower branch of the fixing ring is supported on the casing ring. The lower branch of the fixing ring is clamped between the middle part and the casing ring, so as to grip the dial between the upper branch of the fixing ring and the casing ring.

Claims

1. A watch comprising: a watch case formed of a back cover and of a middle part; a timepiece movement disposed in a casing ring housed inside the watch case; a dial disposed in contact with a top face of the casing ring and held by a fixing ring, wherein the fixing ring has an S-shaped cross-section, wherein an upper branch of the fixing ring is supported on the dial, and a lower branch of the fixing ring is supported on the casing ring, and wherein the lower branch of the fixing ring is clamped between the middle part and the casing ring, so as to grip the dial between the upper branch of the fixing ring and the casing ring.

2. The watch according to claim 1, wherein the casing ring includes a peripheral rim on which the dial is supported.

3. The watch according to claim 2, wherein the upper branch and the lower branch of the fixing ring are connected to each other by an intermediate branch, wherein the height of the intermediate branch is lower than a sum of the thicknesses of the dial and of the peripheral rim of the casing ring.

4. The watch according to claim 3, wherein the casing ring includes an outer peripheral shoulder on which the lower branch of the fixing ring is supported.

5. The watch according to claim 4, wherein the middle part includes internally a surface complementary to the outer peripheral shoulder of the casing ring, wherein the lower branch of the fixing ring is clamped between the outer peripheral shoulder of the casing ring and the complementary surface of the middle part.

6. The watch according to claim 5, wherein the middle part includes internally a peripheral groove which forms a recess, wherein the recess houses the upper branch of the fixing ring with some play and, wherein the recess is delimited by an outer edge supported on the dial.

7. The watch according to claim 4, wherein the middle part includes internally a peripheral groove which forms a recess, wherein the recess houses the upper branch of the fixing ring with some play and, wherein the recess is delimited by an outer edge supported on the dial.

8. The watch according to claim 3, wherein the middle part includes internally a peripheral groove which forms a recess, wherein the recess houses the upper branch of the fixing ring with some play and, wherein the recess is delimited by an outer edge supported on the dial.

9. The watch according to claim 2, wherein the casing ring includes an outer peripheral shoulder on which the lower branch of the fixing ring is supported.

10. The watch according to claim 9, wherein the middle part includes internally a surface complementary to the outer peripheral shoulder of the casing ring, wherein the lower branch of the fixing ring is clamped between the outer peripheral shoulder of the casing ring and the complementary surface of the middle part.

11. The watch according to claim 10, wherein the middle part includes internally a peripheral groove which forms a recess, wherein the recess houses the upper branch of the fixing ring with some play and, wherein the recess is delimited by an outer edge supported on the dial.

12. The watch according to claim 9, wherein the middle part includes internally a peripheral groove which forms a recess, wherein the recess houses the upper branch of the fixing ring with some play and, wherein the recess is delimited by an outer edge supported on the dial.

13. The watch according to claim 2, wherein the middle part includes internally a peripheral groove which forms a recess, wherein the recess houses the upper branch of the fixing ring with some play and, wherein the recess is delimited by an outer edge supported on the dial.

14. The watch according to claim 1, wherein the casing ring includes an outer peripheral shoulder on which the lower branch of the fixing ring is supported.

15. The watch according to claim 14, wherein the middle part includes internally a surface complementary to the outer peripheral shoulder of the casing ring, wherein the lower branch of the fixing ring is clamped between the outer peripheral shoulder of the casing ring and the complementary surface of the middle part.

16. The watch according to claim 15, wherein the middle part includes internally a peripheral groove which forms a recess, wherein the recess houses the upper branch of the fixing ring with some play and, wherein the recess is delimited by an outer edge supported on the dial.

17. The watch according to claim 14, wherein the middle part includes internally a peripheral groove which forms a recess, wherein the recess houses the upper branch of the fixing ring with some play and, wherein the recess is delimited by an outer edge supported on the dial.

18. The watch according to claim 1, wherein the middle part includes internally a peripheral groove which forms a recess, wherein the recess houses the upper branch of the fixing ring with some play and, wherein the recess is delimited by an outer edge supported on the dial.

19. The watch according to claim 1, wherein two complementary circular grooves are arranged respectively at the base of the middle part and of the casing ring so that, when the casing ring, which houses the timepiece movement, is inserted into the watch case, the joining of the two circular grooves forms a groove in which a sealing gasket is placed.

20. The watch according to claim 1, wherein the watch comprises means of positioning the dial on the casing ring.

21. The watch according to claim 20, wherein the positioning means includes a guide lug positioned on the casing ring and a notch arranged in the dial, wherein the guide lug penetrates the notch so as to ensure the angular positioning of the dial.

22. The watch according to claim 1, wherein the fixing ring is made in one-piece in a metallic material.

23. The watch according to claim 1, wherein the dial is transparent or semi-transparent.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other features and advantages of the present invention will appear more clearly upon reading the following detailed description of an example embodiment of the invention, this example being given purely by way of non-limiting illustration with reference to the annexed drawing, in which:

(2) FIG. 1 is a cross-section of a watch including a device for fixing a dial according to the invention; and

(3) FIG. 2 is an exploded view of a watch receiving the device for holding the dial according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(4) Designated as a whole by the general reference number 1, the watch case shown in FIG. 1 is delimited by a back cover 2 fixed by any appropriate means onto a middle part 4. A timepiece movement 6 is disposed in a casing ring 8 housed inside watch case 1. For the axial positioning thereof, timepiece movement 6 includes a collar 10 which is supported on an inner peripheral shoulder 12 of casing ring 8. The watch also includes a dial 14 disposed on top of casing ring 8 and held by means of a fixing ring 16 as described in more detail hereafter. Finally, watch case 1 is closed from above by a crystal 18 fixed to middle part 4 with the insertion of a sealing gasket 20.

(5) A through orifice 22 pierced through casing ring 8 is intended to receive (see FIG. 2) a stem 24 of a time-setting crown 26, which simultaneously ensures the axial and radial positioning of timepiece movement 6 inside casing ring 8.

(6) According to a characteristic of the invention, casing ring 8 is surmounted by a peripheral rim 28 on which dial 14 is supported. As can be seen in FIG. 1, fixing ring 16, formed, for example, of a metal part, has an S-shaped cross-section formed of an upper branch 16a and a lower branch 16c connected to each other by an intermediate branch 16b. The upper branch 16a of fixing ring 16 bears on all or part of the periphery of dial 14, whereas the lower branch 16c of the fixing ring 16 bears on casing ring 8. More specifically, casing ring 8 includes, in the median part thereof, an outer peripheral shoulder 30 on which the lower branch 16c of fixing ring 16 is supported. Finally, intermediate branch 16b of fixing ring 16 hugs the respective edges of casing ring 8 and dial 14, which permits the centering of dial 14 with respect to casing ring 8. The inner diameter of fixing ring 16 is made with a slight clearance with respect to the outer diameter of casing ring 8, so that fixing ring 16 can be fitted onto casing ring 8.

(7) According to another characteristic of the invention, middle part 4 includes internally a surface 32 complementary to the outer peripheral shoulder 30 of casing ring 8, the lower branch 16c of fixing ring 16 being clamped between the outer peripheral shoulder 30 of casing ring 8 and complementary surface 32 of middle part 4 during assembly of the watch. Under the effect of this clamping, upper branch 16a of fixing ring 16 presses dial 14 against peripheral rim 28 of casing ring 8, ensuring that dial 14 is held perfectly. For this to be possible, the height of the intermediate branch 16b of fixing ring 16 is slightly smaller than the sum of the thicknesses of dial 14 and of peripheral rim 28 of casing ring 8.

(8) It will be noted that middle part 4 includes internally a peripheral groove 34 which forms a recess which houses upper branch 16a of fixing ring 16 with some play and which is delimited by an outer edge 36 supported on dial 14. The width of peripheral groove 34 is slightly greater than that of upper branch 16a of fixing ring 16 so as to facilitate assembly. However, it must be ensured that the outer edge 36 of peripheral groove 34 is as thin as possible so as to maximise the visible surface of dial 14.

(9) Two complementary circular grooves 38a and 38b are respectively arranged at the base of middle part 4 and of casing ring 8. When casing ring 8, which houses timepiece movement 6, is inserted into watch case 1, the joining of the two circular grooves 38a and 38b forms a groove in which a sealing gasket 40 is placed. When the back cover 2 is fixed, for example by screws, to middle part 4, sealing gasket 40 is compressed and deformed and exerts an upward vertical thrust force on casing ring 8. Under the effect of this thrust force, the outer peripheral shoulder 30 of casing ring 8 presses lower branch 16c of fixing ring 16 against complementary surface 32 of middle part 4. Under the effect of this clamping, upper branch 16a of fixing ring 16 presses dial 14 against peripheral rim 28 of casing ring 8.

(10) During assembly of watch case 1, timepiece movement 6 is inserted from above into casing ring 8, after which dial 14 and fixing ring 16 are placed on top of casing ring 8. The resulting assembly is then slid from back cover 2 into the inner volume of watch case 1. Finally, back cover 2 is fixed to the middle part 4 of the watch.

(11) Such an assembly thus allows dial 14 to be secured in a simple and effective manner without having to use dial feet.

(12) Such an assembly is thus particularly advantageous for watches having a transparent or semi-transparent dial. Of course, this assembly can also be used with watches having an opaque dial.

(13) According to a variant embodiment of the invention illustrated in FIG. 2, watch case 1 includes means for the radial positioning of dial 14 relative to casing ring 8. These positioning means may include, for example, a guide lug 42 positioned on casing ring 8 and a notch 42 arranged in dial 14, guide lug 40 being intended to penetrate notch 44 so as to ensure the angular positioning of dial 14. Of course, any other positioning means known to those skilled in the art may be suitable for positioning dial 14.

(14) It goes without saying that this invention is not limited to the embodiment that has just been described and that various simple modifications and variants of the invention can be envisaged by those skilled in the art without departing from the scope of the invention as defined by the annexed claims. In particular, according to a variant (not shown in the drawing), casing ring 8 is provided at regularly spaced intervals along the base thereof with elastic strips which exert thereon an upward vertical elastic return force. Under the effect of this force, casing ring 8 clamps lower branch 16c of fixing ring 16 against middle part 4. Yet another mode of securing casing ring 8 consists in screwing the casing ring onto back cover 2 of watch case 1.