EP0716360A1 - Watch case with a recessed case and fitting means and watch provided with such a case - Google Patents

Abstract

The watch casing comprises an electroformed box (2) made of precious metal with thin walls, inside which is a casing (5) of cheaper material which holds the watch components (7, 8, 11, 14). The inner casing is held by compression between a first horizontal bearing surface (21) and a second horizontal bearing surface (22) on the upper part. To allow the insertion of the casing circle within the box, it is possible to reduce its thickness and enlarge it again once it is placed inside the box. In one version, truncated cone fixing keys are provided for this purpose, whilst in another version the cheaper material is synthetic and allows a degree of deformation to enable its insertion.

Description

The present invention relates to a watch case according to the preamble of claim 1, and a watch equipped with said watch case. More specifically, this invention relates to a watch case comprising a thin-walled case, more particularly made of precious metal, into which casing means can be introduced to support the other components of the watch. In particular, this invention relates to the problem of fixing the housing with the fitting means.

Such watch cases are well known. In order to reduce the quantity of precious metal used, cases, or moldings, are produced by electroforming, stamping or molding, which are instead hollowed out. This simultaneously reduces the weight and the price of the box. Casing means, for example a casing circle, are then fixed on this case and maintain the movement of the watch and the other internal components. These fitting means can be made of a more economical material than the metal of the box. The hollow space between the housing and the casing circle remains hollow or can also be filled with reinforcing inserts making it possible to improve the rigidity of the housing, or at equal rigidity to further reduce the thickness of the housing.

Precious metal machining operations are generally very expensive. We therefore seek to obtain a housing that can be performed with a minimum of machining operations, even if it means transferring the manufacturing difficulties to the casing circle. The invention relates in particular to the problem of fixing the precious metal case with the fitting means.

Prior art

Various solutions have been made in the prior art to this problem.

Direct screwing

Patent CH79203 describes a thin housing screwed onto the casing ring directly by its internal peripheral surface. A large diameter thread, very expensive to machine, must therefore be made on the precious metal case. This solution is therefore not suitable for watches to be manufactured at low cost.

Screwing in the housing

Patent CH667966 teaches to screw the box, or cap, onto the body of the box by means of several screws passing through the bottom and the body of the box and engaged in threaded holes in the box. This solution therefore requires carrying out several tappings in the housing, which must therefore have a fairly large thickness. This solution is therefore not suitable for watches comprising a precious metal case and having to be produced at a minimum price.

Patent CH343939 uses the same principle of screwing the case, but in order to save material on the case suggests screwing the casing ring on four studs pierced with a tapped hole. The manufacture of these studs, as well as keeping them integral with the housing, constitute an additional obstacle. In addition, to deserve the name gold box, these studs must also be made of gold.

Screwing in the casing circle

The patents CH427658 and GB2157029 describe a housing in which screws pass through the thin metal housing and are engaged in threaded holes in the casing ring. This avoids performing tapping operations in the noble metal of the housing. In the example described, the screw heads appear on the lateral surfaces of the housing, which is generally considered to be unsightly. Patent CH681414 constitutes a variant in which the case is screwed to the casing means from below the watch, which makes it possible to hide the screws. However, in this case, the case must be extended under the underside of the watch, which leads to a waste of precious metal. In addition, through holes for the screws must be drilled through the precious metal case, which also increases the cost of the case.

Support by studs

Patent EP379974 describes a housing hollowed out towards the inside of the box. The housing is held by at least three studs shaped to position the components axially in the housing. The fitting means are therefore held by their periphery by means of the studs. This solution therefore requires the use of pots to be specially manufactured, and does not allow very easy mounting or dismounting of the watch case.

Bottom support

Patent application EP626625 describes a housing constituted by a peripheral body, of noble metal, removably attached to a central body of inexpensive material. The housing is held on the casing circle by the bottom, itself fixed by notches. A similar solution is found in patent EP150746, in which the housing cap is simply pinched between the front plate and the back of the watch. This solution makes it difficult to disassemble the back of the watch, for example to replace the watch battery in the case of a battery watch. Indeed, it is not possible to disassemble the case without disassembling the entire watch, and the replacement of the battery must therefore generally be carried out by a specialist.

The object of the present invention is therefore to propose a watch case which does not have the drawbacks mentioned of the solutions of the prior art.

In particular, an object of the present invention is to provide a watch case comprising a thin-walled case, especially made of precious metal, requiring a minimum of machining operations, in particular drilling and tapping, for fixing to the fitting means. So general, the object of the present invention is to reduce all the costs of manufacturing the housing.

Another object is to propose a watch case comprising a removable thin-walled case. Preferably, it should be possible to access the movement, for example by dismantling the base, without dismantling the case.

Another object is to propose a watch case comprising a thin-walled case fixed to the fitting means without screws appearing outside the case. This makes it possible to produce more aesthetic watches that are not subject to disassembly or accidental loosening.

Watch cases deserve the name gold box only under certain conditions specified by national laws. In particular, the middle or the case, the bezel and the back must have a fine gold content in accordance with the indication of the title mentioned by the work to deserve this coveted appellation. In addition, the back, if it is separate from the middle part, must partially cover it. Another object of the invention is therefore to propose a construction of a watch case which, if it is made of gold, deserves the name and the hallmark punch of gold.

These objectives are achieved thanks to the elements of the characterizing part of claim 1. Preferential particular embodiments are described in the dependent claims.

In particular, these aims are achieved by maintaining the fitting means in the housing only by compression between two horizontal bearing surfaces formed on the upper and lower parts of the internal face of the housing. Preferably, the fitting means comprise a one-piece fitting circle, and their thickness can be reduced to facilitate insertion into the housing.

• la figure 1 une coupe en profit d'une boîte de montre dans une première variante de l'invention, selon un premier demi-diamètre,
• la figure 2 une coupe en profit d'une boîte de montre dans la même première variante de l'invention, selon un deuxième demi-diamètre différent du premier,
• la figure 3 une vue en perspective d'une clé de fixation.
• la figure 4 une coupe en profit d'une boîte de montre dans une deuxième variante de l'invention
• la figure 5 une coupe en profit d'une boîte de montre dans une troisième variante de l'invention
• la figure 6 une coupe en profit d'une boîte de montre dans une quatrième variante de l'invention

   Les figures 1 et 2 illustrent chacune une coupe en profit d'une moitié de boîte de montre selon un diamètre différent. Seuls les éléments essentiels à la compréhension de l'invention proprement dite ont été représentés. La boîte de montre 1 comporte un boîtier, ou carrure, 2 en métal, de préférence en métal noble tel que or, argent ou platine. Afin d'économiser de la matière, les parois du boîtier 2 sont aussi minces que la résistance du matériau le permet. Le boîtier est fabriqué par des opérations d'étampage, de moulage ou de préférence d'électroformage. La forme externe du boîtier est choisie en fonction de considérations d'ordre esthétique et de manière à optimiser la résistance aux chocs mécaniques pour une épaisseur donnée. La face interne 20 du boîtier est évidée et présente donc un profit principalement concave. Un bracelet 4 est fixé par n'importe quels moyens connus au boîtier, par exemple grâce à des cornes 3. Si nécessaire, le boîtier comporte des renforcements à proximité des cornes.The invention will be better understood using the description given by way of example and the figures, which illustrate:

• FIG. 1 is a section taken advantage of a watch case in a first variant of the invention, according to a first half-diameter,
• FIG. 2 is a cross-section in favor of a watch case in the same first variant of the invention, according to a second half-diameter different from the first,
• Figure 3 a perspective view of a fixing key.
• Figure 4 a section in favor of a watch case in a second variant of the invention
• Figure 5 a section in favor of a watch case in a third variant of the invention
• Figure 6 a section in favor of a watch case in a fourth variant of the invention

Figures 1 and 2 each illustrate a section in favor of half a watch case with a different diameter. Only the elements essential for understanding the invention proper have been shown. The watch case 1 comprises a case, or middle part, 2 made of metal, preferably of noble metal such as gold, silver or platinum. In order to save material, the walls of the housing 2 are as thin as the strength of the material allows. The housing is manufactured by stamping, molding or preferably electroforming operations. The external shape of the case is chosen according to aesthetic considerations and so as to optimize the resistance to mechanical impact for a given thickness. The internal face 20 of the housing is hollowed out and therefore has a mainly concave advantage. A bracelet 4 is fixed by any known means to the housing, for example by means of horns 3. If necessary, the housing includes reinforcements near the horns.

In the variant illustrated in FIG. 1, the case has an opening in the bottom through which the various components of the watch, in particular movement 11, can be introduced. Casing means 5,12 are introduced through this opening, which make it possible to support the other components. In the literature, these means, or similar means, are also referred to as the container, the reinforcement structure, the body of the box, the circle, the frame or the casing ring, casing or movement holder. . When these fitting means 5, 12 are essentially constituted by a monobloc element having approximately the shape of the part 5 in FIGS. 1 and 2, one generally speaks of a fitting circle 5.

A bottom 6 closes the opening in the lower part of the housing. The bottom is fixed to the casing circle 5 by screws 60 (Figure 2) or by any other known method of fixing the bottom. A bottom seal 10 prevents water infiltration between the casing ring 5 and the bottom 6. On the upper face of the frame, the dial 14 is visible through the glass 7 supported by the flange 8. A seal of glass 9 is kept compressed between the glass 7, the casing circle 5 and the housing 2. To avoid compressing the glass seal in two different directions, it could also be placed only between the casing circle 5 and the periphery of the ice 7.

During assembly of the watch, the casing circle 5 is first introduced by the bottom of the case 2, and abuts against a first bearing surface 21 formed by the upper part of the internal face 20 of the housing 2. The casing means 5,12 comprise, in addition to the monobloc casing circle 5, fixing keys or truncated fixing keys 12 (FIG. 3) engaged in threaded openings in the casing circle 5. The circle socket 5 is held at the bottom of the housing using these keys 12. The head of said keys is housed in a recess 50 provided for this purpose in the socket circle 5. By tightening each truncated fixing key 12, the upper face 13 of the keys rests on a second bearing surface 22 provided in the internal face 20 of the housing 2. The casing means 5, 12 are thus firmly compressed between the two bearing surfaces 21 and 22. No drilling or tapping is only necessary in the case r 2 in precious metal, which considerably reduces manufacturing costs.

The housing can have different shapes and structures depending on aesthetic considerations and in order to limit the weight of raw material. Preferably, the thin walls of the housing are curved in order to improve the resistance to mechanical shock. Preferably, the internal face 20 of the housing 2 comprises ribs 23 (illustrated only in FIGS. 4 and 5 in relation to the second and third variant embodiments of the invention). These ribs may for example have a honeycomb structure, or another pattern adapted to the particular shape of the housing.

The housing 2 can be provided with optional guide means 25 making it possible to facilitate the introduction of the casing circle 5 into the housing 2. In the case of an open housing as illustrated in FIGS. 1 and 2, these means are by example constituted by a guide ring 25 offering a guide surface 26 substantially perpendicular to said bearing surfaces 21, 22. This ring 25 can either be continuous all around the periphery of the casing circle 5, or be made of pins discontinuous guide between which the casing circle is inserted. Other configurations of the guide means 25 can of course be imagined.

In this variant illustrated by way of example, the watch does not include a bezel, and the crystal 7 comes almost flush with the one-piece case 2. Those skilled in the art are able to adapt the invention to cases also comprising a scope, fixed or removable. In this case, the fitting means could be supported on a bearing surface 21 formed by the base of the bezel previously fixed to the body of the case. The bezel is therefore considered here as an integral part of the case. The fitting means are however removable independently of the telescope.

FIG. 4 illustrates a second embodiment of a watch case 1 according to the invention. In the figure given by way of example of this variant, the housing 2 is identical to the housing of Figure 1 except that it has the ribs 23 mentioned. The internal face 20 of this box has two identical bearing surfaces 21 and 22 between which the fitting means 5 are inserted. These means can be introduced by the bottom 6. They are essentially constituted by a one-piece casing circle 5 made of metal or of deformable synthetic material. They comprise at least one peripheral lug 28 which comes to bear on the lower bearing surface 22 of the housing 2. It is possible to provide either a single lug 28 continuous over the entire periphery of the casing circle 5, or a plurality of pins pressing in different places on the support surface 22.

The casing ring 5 is inserted into the housing 2 by forcing. The lug (s) 28 have, depending on the elasticity of the material used for the casing ring 5, a thickness which allows them to deform during the forced introduction, then to resume their shape once the circle is in place, thus ensuring effective retention of the casing circle 5 between the bearing surfaces 21 and 22. The thickness of the lug (s) 28 is for example of the order of 40 to 60 microns if the casing circle 5 is made of metal. Disassembly is also by forcing, for example by inserting a blade or a comparable tool between the housing and the casing ring. No screw is necessary to fix the fitting means 5 to the housing 2.

FIG. 5 illustrates a third embodiment of the invention. In this variant, the housing 2 is closed bottom, and is equipped with a bezel 15 removably attached. The casing circle 5 is introduced by the upper face of the watch by dismantling the bezel 15, and comes to bear against the bearing surface 22 on the bottom of the watch. A lug or group of lugs 29, comparable but symmetrical to the lugs 28 of FIG. 4, is provided on the periphery of the casing circle 5. The casing circle 5 is introduced by the upper face of the watch into the case 2 by forcing these pins 29, then is held in place by compression between the bearing surfaces on the middle part 21 and 22.

In another embodiment not shown, the casing ring 5 could be provided with two lugs or groups of lugs 28 and 29, intended to come to bear respectively on the lower support surfaces 22 and upper 21. The casing ring of this variant is then compressed neither against the bottom 6, nor against the bezel 15, but is only held by the bearing surfaces 21 and 22 formed on the edge of the two guide rings 25.

Compared to the first embodiment described in relation to FIG. 1, the embodiments comprising lugs make it possible to dispense with the fixing keys 12, but on the other hand require high manufacturing tolerances both for the casing circle and for for the housing.

FIG. 6 illustrates a fourth embodiment of a watch case 1 according to the invention. As in the variant described in connection with Figure 5, the housing 2 is closed bottom. The housing could however also include an opening in the bottom obstructed by a removable bottom and a seal. The casing circle 5 with the various components of the watch such as the movement are fitted into the case 2 from above. In the variant illustrated, the housing 2 is of the closed shell type, that is to say that the part hollowed out inside the housing is limited by a reinforcement and guide wall 27 preferably pierced with several windows 24. The crushing resistance of the housing is improved by this reinforcement and guide wall. It also offers a vertical guide surface 26 facilitating the introduction and positioning of the casing circle 5 in the housing 2. This type of closed shell housing can naturally also be used in combination with the variant embodiments described in relationship with the previous figures.

The upper part of the internal face 20 of the housing 2 comprises a first surface approximately 21 supporting face when the watch is placed on the bottom or on its crystal. This first bearing face is limited on the one hand by the opening in the housing intended for the glass 7 and on the other hand by the reinforcement and guide wall 27. A second bearing surface 22 is constituted by the periphery of the bottom of the housing, delimited by the reinforcement and guide wall 27.

The casing circle 5 of this variant is made of a deformable synthetic material. It includes a gold element 51 intended to be inserted between the housing 2 and the crystal 7, to hide the plastic parts. The element 51 is fixed by any known means to the casing circle. In a variant, the casing circle could be masked by a bezel removably attached to the housing.

The casing ring 5 is introduced by forcing into the housing through the upper opening intended for the glass 7, and resumes its initial shape once in place, so as to come to bear against the two bearing surfaces 21 and 22. No screw is necessary, the pressure exerted against the two bearing surfaces is sufficient to keep the casing ring 5 in place in the middle part. The casing circle may possibly include protuberances intended to engage in the windows 24 of the reinforcement and guide wall 27. These protuberances prevent in particular a rotation of the casing circle 5 inside the housing 2.

Other variants of the invention are within the reach of ordinary skill in the art. In particular, other means can be provided to reduce the thickness of the fitting means between the bearing surfaces 21 and 22 at the time of insertion, and to widen them again after they have been put in place. inside the housing. For example, the fitting means could be provided with compressible spring means. The fitting means are introduced by compressing these springs. Once in place, these springs exert pressure against the two bearing surfaces 21 and 22.

In addition, the fitting means can, according to the variants, be made from several elements possibly composed of different materials.

Claims (15)

Watch case (1) comprising: - a recessed case (2) whose thin walls define a mainly concave internal face (20), the upper part of said internal face comprising a first approximately horizontal support surface (21) when the watch case is placed on its bottom or on its ice (7), - fitting means (5,12) that can be introduced into said housing (2) to come to bear against said first bearing surface (21), - said fitting means (5,12) being made of a less expensive material than said case (2), - said casing means (5,12) serving to hold the internal components (7, 8, 11, 14) of the watch,
characterized in that
the lower part of said internal face (20) of the housing (2) has a second bearing surface (22) substantially parallel to the first bearing surface (21), said fitting means (5,12) being maintained inside said housing (2) by compression between said first bearing surface (21) and said second bearing surface (22). Watch case according to the preceding claim, characterized in that the fitting means (5,12) are essentially constituted by a monoblock fitting circle (5). Watch case according to one of the preceding claims, characterized in that said fitting means (5,12) can be introduced into the case (2) by temporarily modifying their shape or their thickness between said bearing surfaces (21 , 22). Watch case according to one of the preceding claims, characterized in that a recess is formed between said internal face (20) of the case (2) and said fitting means (5,12). Watch case according to one of the preceding claims, characterized in that said inner face (20) of the case (2) is provided with guide means (25; 27) facilitating the introduction of said fitting means (5,12 ) in the housing (2). Watch case according to one of the preceding claims, characterized in that said thin walls of the case (2) are provided with reinforcing ribs (23). Watch case according to the preceding claim, characterized in that said reinforcing ribs (23) constitute a honeycomb structure. Watch case according to one of the preceding claims, characterized in that said thin-walled case (2) is made of precious metal by electroforming. Watch case according to one of the preceding claims, characterized in that said casing means (5) are made of synthetic material whose deformability makes it possible to introduce them by forcing into the case (2), so that they are held by compression against said first (21) and second (22) bearing surfaces once introduced. Watch case according to one of the preceding claims, characterized in that said fitting means (5) are held inside the case (2) by means of at least one peripheral lug (28; 29) supported against one of the two bearing surfaces (21, 22). Watch case according to one of claims 1 to 8, characterized in that the fitting means (5,12) are maintained compressed between said bearing surfaces (21,22) by means of at least one threaded part (12) engaged in at least one corresponding threaded hole made in the casing means (5,12) and the face of which upper (13) opposite said leg (13) is supported on the second bearing surface (22) in the lower part of the internal face (20) of the housing (2). Watch case according to the preceding claim, characterized in that said threaded piece (12) is constituted by a truncated fixing key. Watch case according to one of the preceding claims, characterized in that said casing means (5,12) can be introduced into the case (2) through an opening in the bottom of the case (2), the watch case further comprising a bottom (6) which can be fixed to said casing means (5,12) to close said opening. Watch case according to one of claims 1 to 11, characterized in that said case (2) is closed on the bottom and in that said casing means (5,12) can be introduced into the case (2) from above. Watch provided with a watch case (1) according to one of the preceding claims.

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