EP0064950A1 - Water-proof watch case - Google Patents

Abstract

The bottom of the waterproof watch case is composed of a metal piece (1), with an edge (2) folded at right angles, and a thin layer (3), made of an elastomer, which lines the internal face of the part (1), to which it strongly adheres by a metal / elastomer bond. This base is fixed to the middle part (9) by screws (24), which press the edge (2) of the base against the middle part (9), compressing the thicker rim of the layer (3) against the middle (9), so as to ensure the seal between the bottom and the middle of the case. The layer (3) is molded with two studs (6), which replace the usual movement fixing keys (22) in the box, and four pillars (7), which press the dial (18) against the bottom of a housing (17).

Description

In boxes of the type defined by the preamble of claim 1, the seal between the base and the middle part is an independent part which must therefore be put in place separately (US - A - 4,015,422) .

If, to reduce the overall height, we choose to use a flat packing, it is important that it is all the more flexible than it is thin, in order to ensure the tightness of a joint. However, the establishment of a very flexible lining is not easy. Even if the trim is carefully placed in the housing to be fitted for it, for example in the middle part, it may happen that the installation of the bottom produces a displacement of this trim, folds a part over itself or goes so far as to cause wrinkling. In all these cases, the watch will obviously no longer be waterproof. As the lining is no longer visible, once the case is closed, each watch must then be checked in a vacuum to make sure it is waterproof. Furthermore, by manufacturing the seal and the parts of the box each for itself, this seal will hardly be able to fulfill its function as it should be, due to manufacturing tolerances, in cases where it is by pressing the base against the middle part that the shape and dimensions of the seal housing are determined. If it is, on the contrary, the lining which limits the approximation between the base and the middle part, the closing of the box is likely to stress the seal beyond its elastic limit. It follows, in all these cases that the quality of the water resistance is not regular in watches of the same production series.

Boxes are also known in which the seal, made of an elastomer, has the shape of a cap and establishes with the glass a sealed capsule inside the case proper (CH - A - 2363/69). The latter is however not waterproof, so that water can seep between the inner capsule and the outer case and then flow in the movement when the box is opened for touch-up or repair.

The box defined by the characteristic of claim 1 avoids the aforementioned drawbacks of the fact that the seal is integral with the bottom, to the metal part from which it strongly adheres by a metal / elastomer bond. When closing the box, the seal will certainly occupy the space provided for it. In addition, this operation is simplified by the fact that the seal does not have to be handled as an independent part. The risk of stressing the seal beyond its elastic limit is also eliminated, since the formation of a metal / elastomer bond involves the polymerization of the elastomer under pressure in a closed mold and, of course, in contact with the metal part of the bottom, so that the shape and dimensions of the assembly thus obtained is as precise as if it had been machined on a machine tool.

The special embodiments defined by claim 2 make it possible to precisely determine the degree of compression of the elastomer layer.

As for those defined by claims 3 and 4, they bring out the possibility, as remarkable as it is unexpected, of forming the layer covering the metal part of the back with organs removing the usual fixing keys from the movement of the watch in the box. . The casing is thereby simplified: it suffices to let the movement of the watch descend into the middle of the case, to place the case back on top and to screw it, these operations being able to be mechanized without difficulty.

The special embodiments defined by claim 5 are advantageous, in particular in the case where the box is intended to receive an electronic movement. In these movements, the thickness depends notoriously on the pile. Now, the metal piece at the bottom can be stripped at this location and allow contact with the ground without intermediary.

Those defined by claim 6 show that the bottom fixing screws do not hinder the location of the area of the elastomer layer which seals the joint between the bottom and the middle of the box, since these screws can pass through this area without prejudice to sealing.

It finally appears from claim 7 that the screws for fixing the back to the middle part can also be used to fix the glass to it, without appearing on the visible face of the watch, since they are engaged in sockets, that their means of fixing to the glass camouflage in their turn.

• la Fig. 1 est une vue en perspective du fond, qui est commun aux deux formes d'exécution;
• la Fig. 2 est une vue en plan d'une montre dont les parties visibles de la boîte sont communes aux deux formes d'exécution, certaines de ces parties étant arrachées et d'autres coupées et vues dans le sens des flèches II-II de la Fig. 3;
• la Fig. 3 est une coupe selon la ligne III-III de la Fig. 2, mais à plus grande échelle, représentant les particularités de la prèmière forme d'exécution;
• la Fig. 4 est une vue de dessous de la montre de la Fig. 2, certaines parties de sa boîte étant arrachées, d'autres coupées et vues dans le sens des flèches IV-IV de la Fig. 3;
• la Fig. 5 est une coupe analogue à celle de la Fig. 3 de la seconde forme d'exécution et d'une variante, et
• la Fig. 6 est une coupe partielle, semblable à celle de la Fig. 5, d'une autre variante.

Two embodiments and variants are described below in detail, but by way of example only, with reference to the drawing, which represents them schematically and in which:

• Fig. 1 is a perspective view of the background, which is common to the two embodiments;
• Fig. 2 is a plan view of a watch the visible parts of the case of which are common to the two embodiments, some of these parts being torn off and others cut and seen in the direction of the arrows II-II of FIG . 3;
• Fig. 3 is a section along line III-III of FIG. 2, but on a larger scale, representing the peculiarities of the first embodiment;
• Fig. 4 is a bottom view of the watch of FIG. 2, certain parts of its box being torn off, others cut and seen in the direction of the arrows IV-IV of FIG. 3;
• Fig. 5 is a section similar to that of FIG. 3 of the second embodiment and a variant, and
• Fig. 6 is a partial section, similar to that of FIG. 5, of another variant.

The bottom of the watch case, which is shown in FIG. 1, comprises a metal part 1, which is generally flat. This part 1 constitutes the external part of the bottom. Its edge 2 is raised at an angle straight by folding. The bottom shown also includes a thin layer 3 of an elastomer, which lines the internal surface of the part 1, to which it strongly adheres. At its periphery, the layer 3 has a rim 4, which is adjacent to the raised edge 2 of the metal piece at the bottom and which extends slightly beyond this edge 2 of the piece 1. Passages 5 are formed at the four corners of the bottom, at through its metal part 1, the layer 3 and its rim 4. Two studs 6 and four pillars 7 are integral with the layer 3. Finally, the layer 3 is interrupted in a circular area 8, so that the internal surface of the part 1 is stripped in this place.

The role of the studs 6, the pillars 7 and the zone 8 is explained in detail below. As for the passages 5, they are intended for the bottom fixing screws, shown in the sections of the following figures.

To avoid excessive variations in the section of the rim 4, the triangular parts, shown at the corners of the bottom, could be reduced. It suffices, in fact, that this rim surrounds the passage 5 of the screws. These passages 5 can also be arranged closer to the corners of the bottom.

As shown in FIG. 1, the layer 3, with its rim 4, the studs 6, the pillars 7, the central opening 8 and the passages for the screws for fixing the bottom, is molded in the part 1 under pressure, so as to form a connection metal / elastomer. The material sold under the brand "VITON" adheres particularly well to the stainless steel of part 1 at the bottom, under the described formation conditions for this layer.

The watch case shown in Figs. 2 to 4 comprises a middle part 9, of which only the external lateral face 10 has undergone fine termination operations, since it is the only visible face of the middle part 9. The upper part of the latter is arranged so as to receive the glass , composed of a plate 11 made of sapphire or tempered mineral glass, which completely covers the upper face of the middle part 9, of a second plate 12, also made of sapphire or tempered mineral glass, which is bonded under the plate 11 to remains, inalienably, and which is forcibly engaged in an opening 13 of the middle part 9 with the interposition of a sleeve 14 forming a seal between the glass and the car rure, and a frame 15, glued under the plate 11 in the same way as the plate 12. This frame 15 can be constituted by a precious or semi-precious stone, which will therefore be visible through the plate 11 of the glass; it can also be made of hard metal or even ordinary metal, by presenting, in the latter case, an upper face treated so as to constitute a decoration visible through the plate 11. Finally, the frame 15 may simply consist of a blank, which would be bonded to a metallization layer formed under the peripheral part of the plate 11 by vacuum evaporation. Such a layer is in any case formed under the plate 11, between the frame 15 and the plate 12, to mask the projection 16 of the middle part 9 and the sleeve 14. The height of this projection 16 is equal to the thickness of the frame 15, so that the latter and the region of the plate 11, extending above the projection 16, both rest on the middle part 9.

In addition to the opening 13, the internal wall of the middle part 9 has a housing 17 for the dial 18, recesses 19 on the long sides of the case, for the passage of the hands 20, and a housing 21, in which the movement 22 of the watch takes place and the shape of which corresponds to that of the internal lateral face of the rim 4 of the layer 3, as seen in particular in FIG. 4, where part of the bottom of the box has been torn off. To receive the bottom fixing screws, the middle part 9 also has four tapped blind holes 23, in the vicinity of its angles. Finally, the underside of the middle part 9 is flat.

As seen in particular in FIG. 3, the bottom of the box is fixed to the middle by screws 24, only one of which appears in this figure. The head 25 of each of these screws is partially embedded in a housing 26 of the part 1 at the bottom. To establish a first baffle of any kind of infiltration, the underside 27 of the head 25 and the bottom of the housing 26 are polished, so as to press one on the other. Between the head and the thread, each screw 24 has a smooth part 28, which passes with play through the part 1 of the bottom.

When the screws 24 are fully engaged in the tapped holes 23 of the middle part 9, the folded edge 2 of the part 1 of the bottom presses against the underside of the middle part 9. For its part, the part of the rim 4 of the layer 3, which extends beyond the edge 2 of the part 1 at the bottom, is crushed between this part 1 and the flat underside of the middle part 9. In the corners of the box, this rim is compressed against the smooth part 28 of the screws 24, in order to embrace it in a sealed manner. The height of said part of the rim 4 is chosen so that the crushing described produces sealing of the joint between the base and the middle part, but without causing permanent deformation of the rim 4, that is to say without causing a stress in layer 3 exceeding its elastic limit.

Fig. 3 further highlights the role played by the studs 6 and the pillars 7. Like that shown in FIG. 3, each of the pillars 7 is located under an area of the dial 18 which extends beyond the movement 22 of the watch (see also Fig. 4 as well as Fig. 2). These pillars 7 are long enough to press the dial 18 against the rim of the middle part 9, formed by the bottom of the housing 17. As for the studs 6, they enter housings 29 of the movement 22 of the watch, arranged for the keys of usual fixing of the latter in the box. The pads 6 replace the keys in question. They are long enough to keep the thread 30 of the watch movement firmly applied against a flange (not shown) of the middle part, which extends in the middle part of the long sides of the case (Fig. 4, see also Fig. 3 and Fig. 2).

The movement 22, which is intended to be mounted in the described box, is electronic. The pile which feeds it is located precisely to the right of the central part of part 1 of the bottom which is stripped, as can be seen at 8 in FIGS. 1 and 2. As a result, layer 3, which lines the inside of part 1 at the bottom, does not cause any extra thickness of the watch, taking into account that the battery supplying the movement of an electronic watch constitutes the part the thickest of this movement. In addition, the battery in question can rest against part 1 at the bottom and thus establish contact with the ground.

The planar shape of the background, shown in the drawing, is not a necessity. The bottom of the case and the underside of the middle could also be arched according to the curvature of the wrist of the wearer of the watch, provided that these camber are such that the vertical edge of the bottom is pressed against the middle in the closed position.

The applications of the invention are obviously not limited to boxes whose outline has the shape shown in the drawing. It would be equally applicable to boxes, for example square, hexagonal or trapezoidal, and more generally to polygonal boxes whose sides would be arched, and even to round boxes. The invention has, in fact, in all these cases, the advantage of considerably simplifying the fitting of the watch movement. After placing the glass on the case middle, the latter is turned over. It is then enough to deposit the movement there, furnished with its dial and hands, to put the bottom on top, then to screw it. If necessary, the rod carried by the control button 31 will be put in place and locked in the movement before covering the latter by the bottom.

It will be noted, finally, that the metal piece of the bottom can be made relatively thin, especially if it is made of stainless steel, because of the reinforcing ribs 32 which not only break the monotony of a uniformly smooth surface, but also allow besides, a welcome air circulation between the watch and the wrist of its wearer, to eliminate the sweat.

The second embodiment as well as the variants shown in Figs. 5 and 6 comprise an additional simplification, of manufacture and assembly, which is the subject of patent application No. ......... of the applicant (Swiss application No. 2859/81), filed in same time as this and entitled "Watch box". In these cases, the fixing screws at the bottom of the case are used at the same time to fix the glass to the middle.

In the embodiment shown in the left half of FIG. 5, an ornamental frame 33 (precious or semi-precious stone, polished hard metal, finely finished ordinary metal) is glued under the glass 34 and a spacer frame 35 is glued under the frame 33. In the axis of the screws attachment 36 of the bottom 1, 3, the frame 35 has housings 37, hollowed out in its face glued to the frame 33. These housings 37 receive the base 38 of tapped sockets 39, which pass through holes in the frame 35, drilled at center of the bottom of the housings 37 and engage in holes 40 in the middle 41.

By engaging the screws 36 fully into the sockets 39, the middle part 41 is sandwiched between the frame 35 adjoining the glass 34 and the bottom 1, 3 of the box. In the embodiment shown in the drawing, the seal between the glass and the middle part is ensured by a gar niture 42, arranged inside the frames 33 and 35. A metallization zone by evaporation under vacuum, a little wider than the lining 42, is formed under the glass 34 to hide this lining as well as any scratches from the internal edge of frame 33.

In a variant (not shown), the frames 33 and 35 could extend towards the inside of the case up to the right of the opening 43 of the middle part 41 and the seal could be placed in a recess formed in the planar upper face of the middle part 41, below the frame 35. In this case, it would be sufficient for the metallized thread of the glass to be just wide enough to hide any scratches from the internal edge of the frame 33.

The variant shown in the right half of FIG. 5 differs from the embodiment described above by the fact that the glass 34 carries a single frame 44 at its periphery, which is bonded to a thin metallization layer formed under the edge of the glass by vacuum evaporation. In this case, the base 38 of the sockets 39 is welded into a corresponding housing of the frame 44. Here too, the frame 44 could extend inward to the right of the opening 43 of the middle part 41 and the seal 42 be placed under this frame, in a recess in the upper face of the middle part 41.

In the variant of FIG. 6, the glass 45 does not entirely cover the visible face of the box. It is glued to a hard metal frame 46 which extends to the outer edge of the middle part 41. The sockets 39 are secured to the glass 45 as in the embodiment shown in the left half of FIG . 5, by a spacer frame 35, glued under the frame 46 of hard metal. The frame 35 is however narrower than the frame 46, so that the seal 47 can be housed between the hard metal frame and the middle part 41 and does not press against the glass.

In the executions where the edge of an ordinary metal frame appears on the side face of the box, it is in no way mismatched. The wafer in question can, for example, be knurled and protected by a resistant deposit, thereby contributing to the originality of the part.

When the screws 36 are fully engaged in the sockets 39, the juxtaposition against the upper and lower faces of the middle part, respectively of the lower face of the frames attached to the glass and of the rim 2 of the bottom, does not reveal any day, so that the box seems to form a single compact block.

The separate manufacture of the back, the middle part and the glass with all its adjoining elements, as well as their bonding or welding, is simple and easy. The manufacturing tolerances have practically no influence on the tightness of the boxes of the same production series. During assembly, it suffices to place the glass upside down on a support, to place the gasket there, to engage the holes in the middle on the sockets integral with the glass, to deposit the movement in the middle, put the movement control rod in place and lock it, then cover everything with the base by inserting the studs 6 in the corresponding movement housings and tighten the screws 36 fully, until the frames adjoining the glass and the edge of the metal piece at the bottom are pressed against the middle. The gaskets sealing the joints are then compressed exactly to the desired extent and they occupy the location assigned to them.

Claims (7)

1. Waterproof watch case, comprising an independent bottom, fixed to the case middle by screws passing through it,
characterized
in that this bottom is composed of an external piece (1), metallic, and of a thin internal layer (3) of an elastomer which lines at least the peripheral zone of the internal face of said metallic piece, to which it strongly adheres by a metal / elastomer connection, and the said screws (24, 36) of which compress the periphery between the middle part (9, 41) and the metal part (1) of the bottom, so as to establish a tight seal between these two pieces. 2. Box according to claim 1,
characterized - in that the metal part (1) at its bottom is generally flat, but the edge (2) of which is raised by folding and presses against the underside of the middle part (9, 41), - in that at its periphery, said internal layer (3) has a rim (4) which is adjacent to the raised edge (2) of the metal part (1) of the bottom and which, in its natural state, exceeds this raised edge (2), the projecting part of said layer being crushed by the underside of the middle part (9, 41) up to the level of said raised edge of the metal part of the bottom, when the box is closed - And in that the measurement of the overflow of said rim above the raised edge of the metal piece of the bottom is determined so that the crushing of this rim does not constrain said layer beyond its elastic limit . 3. Box according to claim 1 or claim 2,
characterized
in that at the places usually occupied by the movement fixing keys (22) in the box, the said inner layer (3) has come from manufacture with studs (6) intended to replace the said keys, engage in the housings (29) of the movement (22) provided for these and to exert an axial pressure on the latter to fix it in the box. 4. Box according to either of the preceding claims, intended to receive a movement with a dial extending beyond the latter, at least in certain places,
characterized
in that at said places, said internal layer (3) came from manufacture with pillars (7) intended to press the dial (18) against a shoulder of the middle part (9, 41). 5. Box according to either of the preceding claims, characterized
in that certain zones (8) of the central part of the internal face of the metal part (1) of the bottom are stripped to make room for organs of the watch movement. 6. Box according to either of the preceding claims, characterized
in that the fixing screws (24) of the bottom comprise, on the one hand, a head (25) whose lower face (27), polished, rests against the bottom, also polished, of a housing (26) of the metal part (1) of the bottom, and, on the other hand, a smooth, polished part (28) between said head and their thread, which crosses the metal part (1) of the bottom with play and which is embraced by the compressed rim (4) of said internal layer (3). 7. Box according to either of the preceding claims, characterized
in that the fixing screws (36) of the base pass through openings passing through the middle (41) right through and are engaged in threaded sockets (39), integral with the glass (34, 45).

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