WRISTWATCH CASE WITH ROTATING OUTER RING

Description

[0001] The present invention relates to a watch case with a rotating bezel, that is to say a watch case comprising a case middle and a bezel mounted to rotate relative to the case middle.

[0002] Such a rotating bezel can have various functions. For example, it can control a mechanism or display graduations or markings to show information in conjunction with a hand. A well-known example is the rotating bezel on diving watches, which is used to indicate dive time.

[0003] A classic method for attaching a rotating bezel to a case without preventing it from rotating involves using a bent wire or an elastic ring that engages with a groove in the case and a groove in the bezel. With this method, removing the bezel is tricky. It requires inserting a tool between the case and the bezel and forcing the bezel to detach it from the case, potentially damaging the wire or ring. Besides the risk of damaging a component, such removal can cause damage to both the bezel and the case, including scratches. Another drawback of this type of assembly is the significant axial play between the case and the bezel due to the tight fit of the bezel. This puts pressure on the wire or ring, necessitating lowering the bezel sufficiently to allow the wire or ring to relax within the grooves in the case and bezel.This axial play is problematic, particularly because it can allow impurities to enter.

[0004] Also known, from US patent application 2014 / 0098650 A1, is a watch case with a rotating bezel in which the bezel is secured by screws, allowing for easy and damage-free disassembly. The screws, accessible on the outer periphery of the bezel, are screwed into radial holes in the bezel and terminate in a groove in a mount into which the watch crystal is set. The interaction between the screws and the groove axially holds the rotating bezel without preventing it from rotating. This rotating bezel mounting system has the disadvantage of being relatively shock-resistant. Indeed, the linear contact between each screw and the groove in the mount can mark the groove wall during impacts oriented along the watch's axis, creating notches that the user will feel when rotating the bezel. Furthermore, this system is not very aesthetically pleasing due to the visible screws in the upper part of the watch.Furthermore, the coefficient of friction between the screws and the wall of the groove can hardly be optimized.

[0005] Another watch case with a rotating bezel is proposed in patent application IT MI20121844 A1. The rotating bezel here consists of two assembled annular parts—an inner and an outer part—and the outer part, which is manipulated by the user, includes an axial extension on its inner periphery in which a groove is machined. Screws accessible on the outer periphery of the case, in the two lugs intended to receive the strap, extend radially into the case wall to terminate in this groove. These screws thus axially retain the rotating bezel without preventing it from rotating. This system is also not very shock-resistant due to the linear contact between each screw and the wall of the groove, which can create notches in the latter that are perceptible to the user during the rotation of the bezel.This system is also not designed to facilitate optimization of the coefficient of friction between the screws and the scope.

[0006] Document JP S5995279 shows another watch case with a rotating bezel where the rotating bezel is held axially by a shoulder formed in a protective ring that surrounds and is screwed onto the case middle. This construction is bulky and significantly impacts the aesthetic appearance of the watch case.

[0007] The present invention aims to remedy, at least in part, the aforementioned drawbacks.

[0008] To this end, a watch case is proposed according to claim 1, particular embodiments being defined in the dependent claims.

[0009] Other features and advantages of the present invention will become apparent from the following detailed description, made with reference to the accompanying drawings, in which: THEfigures 1 and 2 are exploded perspective views of a watch case according to a particular embodiment of the invention, comprising a case middle, a back, a crystal, a rotating bezel, removable assembly elements and intermediate assembly parts; the figure 3 is a partial exploded perspective view of the watch case according to the particular embodiment of the invention; the figure 4 is a partial cross-sectional view of the watch case according to the particular embodiment of the invention, to which a strap is attached; the figure 5 shows in perspective an intermediate assembly part which, in one variant, can replace the intermediate assembly parts visible in figures 1 to 4 ; there figure 6 shows in perspective another variant of the intermediate assembly parts.

[0010] With reference to figures 1 to 4A watch case according to a particular embodiment of the invention comprises a case middle 1, a case back 2, a crystal 3, and a rotating bezel 4. The case back 2 is assembled to the case middle 1 in a known manner, but it could also be a single piece with the case middle 1. At 6 o'clock and 12 o'clock, the case middle 1 has two pairs of lugs 5 in its lower part for attaching a strap 6. The upper part of the case middle 1, surrounded by the rotating bezel 4, constitutes a fixed mount or bezel 7 in which the crystal 3 is set. In the example shown, the case middle 1 is a single piece, but it could be made of several assembled parts, comprising, for example, a main part and the mount 7 assembled to the main part. The watch case is sealed by a gasket 8 placed between the crystal 3 and the mount 7 and by another gasket 9 placed between the case back 2 and the case middle 1.The interior space delimited by the case 1, the base 2 and the glass 3 forms a sealed area 10 in which the watch movement, the hands and the dial (not shown) are housed.

[0011] The rotating bezel 4 can be a single piece, as shown, or made of several assembled parts, in particular several coaxial annular parts. It is guided in rotation about the axis A of the watch case by the mount 7 and may have on its lower surface unidirectional teeth 4a cooperating with a ratchet (not shown) carried by the case middle 1 to allow its rotation in only one direction. The rotating bezel 4 is held axially relative to the case middle 1 by an assembly device comprising removable assembly elements 11, such as screws or pins, which can be manipulated with a tool from outside the watch case, and first and second intermediate assembly pieces 12.

[0012] The removable assembly elements 11 extend radially (relative to axis A) within the case wall 1, accessible from the two lugs 5a designed to receive the strap 6. Thus, the removable assembly elements 11 are concealed by the strap 6 when the latter is assembled to the case 1, as visible at the figure 4 .

[0013] The first and second intermediate connecting pieces 12 are located at 6 o'clock and 12 o'clock in recesses 13 formed in the side of the case 1 and open at the top. Each of these intermediate connecting pieces 12 is an annular segment having a collar 14 at the top and two drilled feet 15 at the bottom. These drilled feet 15 fit into the corresponding recess 13 in the case 1, and their holes 16 are aligned with two respective holes 17 in the side of the case 1, which open on one side into the lug 5a and on the other side into the recess 13. The removable connecting elements 11 extend into the holes 17 in the case 1 and into the holes 16 in the feet 15 and terminate in holes 18 in the side of the case 1.

[0014] The housings 13 are used to position the intermediate assembly pieces 12 before they are fixed to the case 1 by the removable assembly elements 11. The removable assembly elements 11 thus block the intermediate assembly pieces 12 axially (i.e. along the axis A), the intermediate assembly pieces 12 being prevented from rotating around the axis A by the removable assembly elements 11 and / or by the housings 13.

[0015] Advantageously, the removable assembly elements 11 are offset from the holes 17 and 18 of the wall of the case 1 and their end 19 received in the holes 18 has a conical shape and cooperates with a wall, also conical, of the holes 18 to press the intermediate assembly pieces 12 against the bottom 20 of their housing 13. In this way, a precise axial positioning of the intermediate assembly pieces 12 can be obtained.

[0016] Preferably, as illustrated in the drawings, the removable assembly elements 11 are set screws with conical ends screwed into the holes 16 of the feet 15, which are therefore tapped for this purpose, and can be manipulated with a simple screwdriver.

[0017] The flange 14 of the intermediate assembly parts 12 is engaged in a groove 21 formed in the inner periphery of the bezel 4, which holds the bezel 4 axially without preventing its rotation. The reverse is of course possible, namely that the axial holding of the bezel 4 can be achieved by the interaction between an inner flange of the bezel 4 and a groove in the intermediate assembly parts 12.

[0018] In one embodiment of the invention, the conical holes 18 could be replaced by a notch formed on the periphery of the case 1 and having a radial V-shaped section or at least an inclined surface arranged to cooperate with the conical end 19 of the removable assembly elements 11. In another embodiment of the invention, also, a single intermediate assembly piece 12 could be provided, which would be in the form of a split ring (cf. figure 5 ) almost completely surrounding mount 7. Yet another variant is shown at the figure 6 , where the intermediate assembly parts 12 are annular segments longer than those of the figures 1 to 4 to, together, almost completely surround mount 7.

[0019] Thanks to the intermediate assembly piece(s) 12, the assembly of the case 1 and the bezel 4 can be particularly robust and shock-resistant since the intermediate assembly piece(s) 12 can be specially shaped for these purposes, typically with, as shown, a planar-on-planar contact between the bezel 4 and the intermediate assembly piece(s) 12 and large contact surfaces.

[0020] The intermediate assembly piece(s) 12 may also be made of a material distinct from those of the case 1 and the removable assembly elements 11, in particular in a material which minimizes friction and promotes sliding between the bezel 4 and the intermediate assembly piece(s) 12. The intermediate assembly piece(s) 12, or only their parts in contact with the bezel 4, may also be coated with an anti-friction coating, such as a DLC (Diamond-Like Carbon) type coating.

[0021] The precise axial positioning of the intermediate assembly piece(s) 12 against the bottom 20 of their housing 13 in the case wall 1 allows the axial play between the case 1 and the bezel 4 to be minimized, by adjusting as closely as possible the play between the collar 14 and the groove 21, and by controlling the gap between said case and bezel.

[0022] It will also be appreciated that all the parts of the assembly device 11, 12 according to the invention are reusable, that the dismantling of the bezel 4 is particularly easy since it is enough to remove, typically unscrew, the removable assembly elements 11 to free the bezel 4, that the bracelet 6 prevents accidental removal of the removable assembly elements 11 and that the assembly device 11, 12 is entirely outside the watertight area 10 used to house the movement, which avoids having to open this watertight area 10 to dismantle the bezel 4.

Claims

1. Watchcase comprising a middle (1) and a bezel (4) mounted in a rotatable manner with respect to the middle (1) about an axis (A), the bezel (4) being held axially with respect to the middle (1) by detachable mounting elements (11) accessible from outside the watchcase and extending radially in the wall of the middle (1), characterised in that it comprises at least one intermediate mounting piece (12) located in a housing (13) formed in the wall of the middle (1) and open in its upper part, the at least one intermediate mounting piece (12) being axially immobilised in the wall of the middle (1) by the detachable mounting elements (11), immobilised against rotation about said axis (A) and cooperating with the bezel (4) in order to hold it axially.

2. Watchcase as claimed in claim 1, characterised in that it comprises horns (5) for the attachment of a bracelet (6) and in that the detachable mounting elements (11) are accessible from the spaces (5a) between the horns (5) intended to receive the bracelet (6) in such a way as to be concealed by the bracelet (6) when it is mounted on the watchcase.

3. Watchcase as claimed in claim 1 or 2, characterised in that, for the purpose of axially holding the bezel (4), the bezel (4) comprises a groove (21) receiving a protruding part (14) of the or each intermediate mounting piece (12).

4. Watchcase as claimed in any one of claims 1 to 3, characterised in that, for the purpose of axially holding the bezel (4), the or each intermediate mounting piece (12) comprises a groove receiving a protruding part of the bezel (4).

5. Watchcase as claimed in any one of claims 1 to 4, characterised in that the or each intermediate mounting piece (12) is an annular segment fixed to the middle (1) by at least two said detachable mounting elements (11).

6. Watchcase as claimed in any one of claims 1 to 5, characterised in that the detachable mounting elements (11) have a conical end (19) which cooperates with an inclined surface of the middle (1) for close axial placement of the at least one intermediate mounting piece (12) against a surface (20) of the middle (1).

7. Watchcase as claimed in any one of claims 1 to 6, characterised in that the bezel (4) surrounds a glass (3) which is driven into the middle (1, 7).

8. Watchcase as claimed in any one of claims 1 to 7, characterised in that the detachable mounting elements (11) and the at least one intermediate mounting piece (12) are located outside a sealed zone (10) of the watchcase serving to house a timepiece movement.

9. Watchcase as claimed in any one of claims 1 to 8, characterised in that the detachable mounting elements (11) are screws, preferably headless screws.

10. Watchcase as claimed in any one of claims 1 to 9, characterised in that it comprises a plurality of intermediate mounting pieces (12).

11. Watch comprising a watchcase as claimed in any one of claims 1 to 10.