EP1565794B1 - Watch case - Google Patents

Abstract

The watch case (16) has a screwed (30) element (28) which bears the rotatable glass (22) frame (18). An annular chamber (36) separates the glass frame and watch case and is connected to atmosphere by an interstice. The chamber contains an annular elastic collar with a U shaped cross section which houses an undulating spring and positioning ring. Under high water pressure the rings act to open the collar and make it watertight An Independent claim is also included for a watertight joint which includes an annular collar with two lips made from a highly elastic material and a spring ring and positioning ring which act on the lips under water pressure

Description

Technical area

The present invention relates to the field of sealed watch boxes. It relates more particularly to a box with a rotating bezel, of the type commonly used in underwater diving watches. The rotating bezel provides a marker next to the needles, especially to set a maximum dive time.

State of the art

It is obvious that watches intended to be immersed in water must be equipped with a waterproof box. This quality is achieved through the presence of seals disposed between the constituent parts of the watch case, namely: the bezel, the middle part, the bottom and the glass, which together form a housing protecting the movement. For example, the document EP 0 628 895 discloses a watch case with watertight glass-bezel having a seal sandwiched between the bezel and the middle part.

In watches equipped with a rotating bezel, it is frequently arranged on the middle, around the ice, but totally outside the housing. The bezel can rotate freely, but it is relatively far from the needles. The indications she carries may sometimes not be clear. Moreover, being not protected, their readability can deteriorate with time.

To overcome this drawback, it has been proposed to make a box in which the bezel carries the ice and is rotatably mounted on the middle part, with the interposition of a toroidal seal.

Unfortunately, because the seals used have a very large ratio between their perimeter and the diameter of their section, local deformations can be generated by turning the telescope. As a result, the quality of the contact between the joint and the walls of the middle and the bezel is reduced and the seal can be affected.

In addition, it is problematic to have a seal that allows a flexible rotation of the telescope at a pressure close to atmospheric pressure while remaining tight at large depths.

The present invention aims to overcome these disadvantages by providing a watch case equipped with a rotating bezel rotating smoothly and whose sealing remains good, even at high pressures.

Disclosure of the invention

More specifically, the invention relates to a watch case having a caseband, a bezel mounted rotatably on the middle part and defining between them an annular chamber and a gap open towards the outside of the case, a glass mounted so sealed on the bezel, a seal inserted between the bezel and the middle part and disposed in said chamber.

• une bague de forme annulaire, en matériau de type fortement déformable élastiquement et dont la section comprend deux lèvres, l'une en appui contre la lunette, l'autre contre la carrure; et
• un organe de compression disposé dans la chambre du côté de l'interstice, intercalé entre et coopérant avec les lèvres pour les compresser respectivement contre la lunette et contre la carrure.

According to the invention, the seal comprises:

• a ring of annular shape, of a material of strongly elastically deformable type and whose section comprises two lips, one resting against the bezel, the other against the middle part; and
• a compression member disposed in the chamber on the side of the gap, interposed between and cooperating with the lips to compress respectively against the bezel and against the middle part.

The lips are connected to one another by an intermediate portion. They are arranged so as to form an acute angle between them. The chamber is defined by side walls, upper and lower. The lips have, on the side of their free end, a contact surface intended to bear on the side walls of the chamber, while the intermediate portion is flat and marries the lower wall of the room. For sealing to be ensured, it is necessary that the gap is not closed.

The compression member comprises an annular spring placed directly in contact with the lips. Advantageously, this spring has regular undulations, distributed on either side of a circle of diameter substantially equal to the median diameter of the chamber, the undulations being folded by the line formed by the median circle, the angle of the fold being slightly greater or equal to that formed by the lips. This spring may advantageously be made of stainless steel.

The compression member may further comprise a positioning ring interposed between the spring and one of the walls of the chamber. It is advantageously arranged opposite the bezel and has positioning studs supported on it so as to maintain the intermediate portion bearing against a wall of the chamber.

Brief description of the drawings

• la figure 1 est une vue simplifiée en coupe transversale des éléments d'une boîte de montre selon l'invention,
• la figure 2 montre, à une plus grande échelle, la structure que présente la boîte de la figure 1 à l'interface entre la lunette et la carrure, sans le joint, en a et avec, en b, et
• les figures 3, 4a et 4b illustrent des détails relatifs au joint d'étanchéité que comporte la boîte selon l'invention.

Other features of the invention will emerge from the description which follows, given with reference to the appended drawing, in which:

• FIG. 1 is a simplified cross-sectional view of the elements of a watch case according to the invention,
• Figure 2 shows on a larger scale, the structure shows the Figure 1 box at the interface between the bezel and the middle part, without the gasket, has and, at b, and
• Figures 3, 4a and 4b illustrate details of the seal that includes the box according to the invention.

Mode (s) of realization of the invention

• une carrure 16 de forme annulaire, délimitant le volume dans lequel prennent place les différents organes de la montre,
• une lunette 18 montée tournante sur la carrure 16,
• un fond schématiquement représenté en 20 et fermant la boîte de montre 10 sur son côté inférieur 12, et
• un verre 22 fixé de manière étanche sur la lunette 18, fermant la boîte de montre sur sa face supérieure 14 et laissant voir ainsi les moyens d'affichage portés par le mouvement.

FIG. 1 shows, in part, a waterproof watch case 10 according to the invention, having a lower face 12 intended to be in contact with the arm of the carrier and an upper face 14 on the side of which the means for displaying the time are visible. This box essentially comprises:

• a middle part 16 of annular shape, delimiting the volume in which the various organs of the watch take place,
• a rotating bezel 18 mounted on the middle 16,
• a bottom schematically shown at 20 and closing the watch case 10 on its lower side 12, and
• a glass 22 sealingly attached to the bezel 18, closing the watch case on its upper face 14 and thus showing the display means carried by the movement.

More specifically, the bottom 20 is fixed on the middle part 16, generally by screwing or by any means known to those skilled in the art, a seal being interposed between them. The caseband 16 has a structure arranged to mount a watch movement. It further comprises a flat surface 24 and a cylindrical surface 26 ensuring the positioning of a flange 28.

The flange 28 is fixed on the middle part by screws, schematically represented by a center line 30. It ensures the positioning and guiding of the bezel 18, thus allowing it to rotate on the middle part 16.

The glass 22 may be attached to the bezel 18 by gluing or by driving with the interposition of a seal, or by any means known to those skilled in the art.

To ensure the tightness of the box at its interface between the middle 16 and the bezel 18, the latter are shaped so as to define an annular chamber 36 having two side walls 36a and 36b respectively formed by the middle part 16 and the bezel 18 , an upper wall 36c formed by the bezel 18 and a lower wall 36d essentially formed by the middle part 16.

The chamber 36 is connected to the outside of the box 10 by a gap 40.

As can be seen in FIG. 2b, the chamber 36 serves as a housing for a seal 42, comprising a ring 44 with two lips 44a, advantageously made of polyurethane of hardness of the order of 20 to 30 Shore A and a compression member 46.

The ring 44 is annular and its section has an overall shape of U. The lower branch of the U constitutes an intermediate portion 44b connecting the two lips 44a. The width of the U, at its base, is less than that of the chamber 36, while the lips 44a, constituting the lateral branches of the U, form between them an acute angle of the order of 5 ° to 15 °. They have, on the side of their free end, a contact surface intended to bear on the walls of the chamber, leaving free the gap 40. These contact surfaces between the lips 44a and the side walls 36a and 36b of the chamber 36 are continuous, so that they provide the seal at the interface between the middle part 16 and the bezel 18.

The intermediate portion 44b is flat and fits the lower wall 36d of the chamber 36. A space 48 defined between the legs of the U is thus in direct communication with the outside of the watch case 10 via the gap 40 .

Inside the space 48 is housed the compression member 46. It consists of an annular spring 50 placed directly in contact with the lips 44a and a positioning ring 52 interposed between the spring and the upper wall 36c of the room 36.

As illustrated in FIG. 3, the annular spring 50 is in the form of a band of substantially constant width forming regular undulations arranged on either side of a circle of diameter D substantially equal to the median diameter of the chamber 36. The spring 50 is obtained from a machined stainless steel blade chemically.

The corrugations are folded in V on either side of the line constituting the diameter D. The angle formed is slightly greater than that formed by the lips 44a, so that, when it is put in place, it forces the free ends of the lips 44a against the walls 36a and 36b of the chamber. This angle is typically between 10 ° and 20 °. Its summit is rounded. It follows from this conformation that the spring 50 has a high elasticity.

At atmospheric pressure, the pressure applied by the spring 50 on the ring 44 makes it possible to control the torque necessary for the rotation of the telescope 18 and to ensure the contact of the lips 44a all around the walls 36a and 36b.

The positioning ring 52, shown in FIGS. 4a and 4b, has the same median diameter as the ring 44. It is arranged in contact with the spring 50, facing the telescope 18 and has positioning studs 58 resting on the bezel 18 so as to maintain the spring 50 in contact with the lips.

The studs 58 are of cylindrical shape and have a flat surface intended to be in contact with the telescope. The height of the assembly formed by the ring 52 and by the pads 58 is equal to the distance between the bezel 18 of the annular spring 50. This is precisely held in place while the bezel 18 slides on the pads 58 when she is turned.

When the watch is immersed, the chamber 48 is connected to the external medium by the gap 40 and, thanks to the fact that the positioning pads 58 do not occupy the entire chamber 48, it is at the same pressure as the medium outside. The water then compresses the positioning ring 52 which presses on the seal 42 and strongly applies the lips 44a against the walls of the chamber 36. Thus, the greater the external pressure, the more strongly the lips 44a are. applied against the walls 36a and 36b of the chamber. Under these conditions, the friction forces then created between the lips 44a and the watch case 10 make it impossible to rotate the bezel 18. There is therefore locking underwater, which enhances safety.

In deep water, the diver breathes a gaseous mixture containing helium or hydrogen. These light gases can enter the inside of the watch case. When rising to the surface, the outside pressure may decrease more rapidly than that inside the watch case. If a valve is not provided to regulate this overpressure, the glass can be expelled from its housing. With a box according to the invention, such a valve is not necessary. Indeed, thanks to the shape of the lips 44a, the gas contained inside the box 10 can escape freely.

In other words, the watch case thus produced is perfectly sealed when the external pressure is greater than the internal pressure and it lets out the gas it contains when the internal pressure is greater than the external pressure.

Thus is obtained a waterproof watch case with a rotating bezel, whose sealing qualities are particularly effective. Moreover, these qualities are not at the expense of the flexibility of operation of the rotating bezel.

The box thus described may, of course, be the subject of many variants, without departing from the scope of the invention. Thus, the chamber 36 could have a section other than rectangular. In addition, the seal could be oriented differently, with, for example, the lips in contact with the upper walls 36c and lower 36d, while the intermediate portion would be in contact with the side wall 36a formed on the telescope 18.

The assembly means of the bezel 18 on the middle part 16 could also be considerably modified. The mobile inner part could occupy a much larger space, to allow the display of a maximum of information and thus offer better reading conditions.

Claims (8)

1. A watch case comprising a case middle (16), a bezel (18) mounted so that it can turn on the middle and defining between them an annular chamber (36) and a gap (40) open towards the outside of the case, a glass (22) mounted in sealed fashion on the bezel, a seal (42) inserted between the bezel and the middle and arranged in said chamber (36), said seal comprising

   - a ring (44) of annular shape made of a material of the highly elastically deformable type and the cross section of which comprises two lips (44a), characterized in that one of said lips bears against the bezel (18), the other against the case middle (16), and

   - a compression member (48) arranged in said chamber on the side of the gap, inserted between and collaborating with said lips in order to compress them against the bezel and against the case middle, respectively.
2. Watch case according to claim 1, characterized in that said chamber (36) is defined by lateral, upper and lower walls, the lips (44a) are connected to one another by an intermediate part (44b) and are arranged in such a way as to form an acute angle between them, said lips having, at their free end, a contact surface intended to bear against the walls of said chamber without said gap being filled.
3. Watch case according of claim 2, characterized in that said intermediate part (44b) is flat and hugs the lower wall of the chamber (36), said lips bearing via their contact surface against the lateral walls.
4. Watch case according to claims 2 and 3, characterized in that the compression member (46) comprises an annular spring (50) placed directly in contact with the lips (44a).
5. Watch case according to claim 4, characterized in that the annular spring (50) has regular wave forms distributed on either side of a circle of a diameter more or less equal to the mean diameter of said chamber, said wave forms being bent about the line formed by said circle, the angle of the bend being greater than or equal to the angle formed by said lips.
6. Case according to one of claims 4 and 5, characterized in that said spring is made of stainless steel.
7. Case according to one of claims 4 to 6, characterized in that said compression member comprises, in addition, a positioning ring (52) inserted between said spring and one of the walls of the chamber.
8. Watch case according to claim 7, characterized in that the positioning ring (52) is arranged facing the bezel (18) and comprises positioning studs (58) resting against said bezel in such a way as to keep the intermediate part bearing against a wall of said chamber.

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