EP0873543B1 - Watch frame comprising a case and a supporting device - Google Patents

Description

The present invention relates to a watch case comprising a waterproof envelope composed of several stacked rooms, which together define a dwelling intended to contain a watch movement, and a support device which holds said assemblies together parts of the envelope, the envelope having one side transparent upper, the support device comprising at least one rigid flange composed of a part upper and lower part which are fixed to each other in a removable manner by organs assembly arranged to produce a clamping of the casing between the two parts of the flange in a axial direction, perpendicular to said face superior.

The invention applies more particularly to watch cases including the outer envelope containing the movement consists mainly of parts in hard materials and therefore difficult to machine, such as sapphire, "hard metals" or metallic carbides, ceramics or even mineral glass.

In US patent 4,390,288, there is described a box watch of this kind, of which the crystal and the back are made of a hard material such as sapphire and are pressed against the middle part by external flanges provided with screws Tightening. The upper and lower surfaces of the middle have each, for their junction respectively with the glass or the bottom, a rebate and a groove for a seal. The build also has two pairs of lugs for fixing a bracelet. It is clear that a middle part thus shaped cannot be economically made from a material hard. In addition, the fact that the seals are clearly visible through the crystal and the sapphire crystal back aesthetics.

Another such watch case is described in publication CH 622 151, where it is mentioned that the use of scratch-resistant hard materials to achieve various parts of watch cases pose many manufacturing problems. As the machining of these materials is difficult, the design and execution of the assembly of the various parts of the box, the tightness and the aesthetics of the box, especially when transparent or translucent materials are used, require special solutions. In a general way, we seek to reduce the machining of recesses to a minimum or holes, which is particularly expensive, and at use simple exterior shapes, which are more easy to polish.

The watch case described in the publication CH 622 151 consists essentially of three parts stacked axially, namely a metal bottom substantially flat with four horns for fixing a bracelet, an annular middle made of a material hard, and a crystal consisting of a sapphire plate fully flat. The middle part is fixed to the bottom by means of of axial screws passing through holes in these two parts. Then the glass, provided with a metallic strip along from the edge of its underside, is glued to the middle so as to cover the heads of the screws and ensure waterproof connection. The seal at the bottom is ensured by a conventional annular seal housed in a recess of the metal bottom.

One drawback of this construction is obviously in the cost of machining the through holes the whole build. In addition, the numerous machining operations necessary on the bottom do not allow to realize it economically in a hard material, for example the same material than the middle, which would be more aesthetic. Yes the middle material is translucent, you can unfortunately see the screws it contains, as well as the seal. Finally, the fact that the horns of bracelet fastening are located at the bottom east harmful to aesthetics.

Publication CH 632 374 describes a watch case whose envelope consists of two pieces of material transparent or translucent mineral, one of which is hollow part forming the crystal and the middle part, and the other is a flat bottom ensuring a tight closure of the box thanks to a seal fitted in a groove of the middle. These two pieces are kept together by means of two opposite metal elements each having two horns for fixing the bracelet. Each element has a top claw and a lower claw between which the two pieces of the envelope are kept tight using a spring. Each element is glued against the lateral face of the middle, so it cannot be dismantled and must bear the pull of the bracelet. You cannot open and close the by sliding the bottom sideways, which risk of damaging the seal. Others disadvantages are that the packing is visible through the transparent pieces and that the making the groove would be very difficult if the middle should be made of a hard material such as sapphire.

The present invention aims to avoid so substantial the aforementioned drawbacks, by creating a waterproof watch case having an envelope capable of being manufactured at an acceptable cost in hard materials and which can be sealed by simple and safe means. A particular purpose is to create a box with a high aesthetic level, especially if the envelope is made mainly of materials transparent or translucent such as sapphire or mineral glass, which lets you see the movement of watchmaking, but as few other elements as possible such as fastening or sealing members to inside the box.

According to the invention, there is provided a watch case of the kind indicated in the preamble, characterized in that said parts of the envelope are made of materials porosity zero or closed and have, one opposite the other, mutual contact surfaces which are flat or of revolution and are polished, no trim not being interposed between them.

In this way, the manufacture of the parts of the envelope is particularly simplified, since the machining of flat or revolving contact surfaces is more simple and less expensive than any other form of area. However, the axial tightening achieved perpendicular to these surfaces by the device external support, which preferably includes screws arranged in the axial direction, guarantees good envelope behavior and reliable sealing on the contact surfaces. Especially with materials hard with zero or closed porosity, the tightness of the envelope is ensured simply by the fact that the mutual contact surfaces of the envelope parts are non-porous and polished, no packing not being interposed between them. Not only machining is simplified thanks to the absence of nesting bodies or grooves in the areas of mutual contact of the parts, but in addition the aesthetics are much better since we do not not see, through the ice or other parts transparent, such bodies or a trim seal such as an O-ring.

• la figure 1 représente un premier mode de réalisation d'une boíte de montre selon l'invention, vue en coupe suivant la ligne I-I de la figure 2;
• la figure 2 est une vue de dessus de la boíte de la figure 1;
• la figure 3 est une vue éclatée des principaux composants de la boíte des figures 1 et 2;
• la figure 4 représente un deuxième mode de réalisation d'une boíte de montre selon l'invention, vue en coupe suivant la ligne IV-IV de la figure 5;
• la figure 5 est une vue de dessus de la boíte de la figure 4;
• la figure 6 représente un troisième mode de réalisation d'une boíte de montre selon l'invention, vue en coupe suivant la ligne VI-VI de la figure 7, et
• la figure 7 est une vue de dessus de la boíte de la figure 6.

Other characteristics and advantages of the invention will appear in the following description of different embodiments, presented by way of nonlimiting examples with reference to the appended drawings, in which:

• Figure 1 shows a first embodiment of a watch case according to the invention, seen in section along line II of Figure 2;
• Figure 2 is a top view of the box of Figure 1;
• Figure 3 is an exploded view of the main components of the box of Figures 1 and 2;
• 4 shows a second embodiment of a watch case according to the invention, seen in section along the line IV-IV of Figure 5;
• Figure 5 is a top view of the box of Figure 4;
• FIG. 6 represents a third embodiment of a watch case according to the invention, seen in section along line VI-VI of FIG. 7, and
• Figure 7 is a top view of the box of Figure 6.

The watch case illustrated in Figures 1 to 3 has an envelope 1, made of several pieces in hard materials, and a support device 2 arranged for hold together the parts of the envelope and for connect the box to a fixing means which, in the case present, is a bracelet 3 whose ends are fixed to the box using traditional bars 4. The envelope 1 here has a circular shape and defines a sealed cylindrical housing 5 intended to contain a watch movement 6 provided with its display members, for example of needles (not shown).

In this case, envelope 1 consists of three pieces, namely a transparent top plate constituting a window 7, a lower plate constituting a bottom 8, and an annular intermediate piece constituting a middle part 9 and preferably comprising a lateral hole 10 for the passage of a control rod (not shown) of movement 6. In plan, the three parts 7, 8, 9 here have the same circular shape and the same exterior dimensions. In one embodiment preferred, offering a particularly aesthetic appearance attractive, these three pieces are made of sapphire, so transparent. The bottom 8 can advantageously be identical to ice 7.

The three parts 7, 8, 9 have external shapes particularly simple, in order to facilitate their manufacturing and in particular reduce and simplify machining and polishing operations. The middle 9 is a annular cylinder obtained by transverse sawing of a tube sapphire made by extrusion. Its inner wall 11 and its outer wall 12 are cylindrical and do not have no recesses, apart from hole 10. Its faces upper and lower are flat and polished to constitute contact surfaces 13 and 14 on which the glass 7 and the bottom 8 are applied respectively. lower face 24 of the glass 7 is entirely flat; at near its outer edge, it is polished to constitute a contact surface 15 which is applied sealingly on the contact surface 13 of the middle part 9. Similarly, the flat upper face 16 of the bottom 8 is polished near its outer edge to form a contact surface 17 sealingly applied against the contact surface 14 of the middle part. So, the envelope 1 is sealed at the joints between parts 7, 8 and 9 as long as these parts are kept tight together, thanks to the absence of porosity of the material and the polishing of their contact surfaces mutual 13 and 15, 14 and 17, without it being necessary to interpose a seal, or to glue the pieces to each other.

To avoid the appearance of interference fringes (Newton's rings) by reflection on the middle transparent 9, an anti-reflective coating 40 (FIG. 3) is applied to the polished contact surfaces 13 and 14. In in addition, it is possible to add a decoration embedded in part of these same surfaces, provided that side of the decoration a portion of continuous and polished surface, capable of guaranteeing tight contact with the glass 7 or the bottom 8.

The upper face 18 of the glass 7 and the face bottom 19 of bottom 8 are also flat and perpendicular to the central axis 20 of the envelope, but in this example they each have two grooves parallels 21, 22 in which the device engages support 2, as will be described later. These grooves preferably have a rectangular cross section and can be machined relatively little expensive. Furthermore, a frustoconical chamfer 23 is formed around the glass 7 and the bottom 8.

It should be noted that parts 7, 8 and 9 of envelope 1, thanks to their simple geometric shapes described above, can be made of materials hard in an economically bearable way. In particular, these parts are devoid of parts protruding and / or recessed intended to achieve sockets. Also they don't need a throat to accommodate seals.

The support device 2 comprises, apart from the two bars 4, two rigid metal flanges 25 arranged parallel in vertical planes, that is to say parallel to the central axis 20 of the envelope 1. Each flange 25 includes an upper part 26 and a part lower 27 which are assembled by means of two screws axial 28 tending to clamp the envelope 1 between the two parts of the flange, thus forming a closed frame. As seen in Figure 2, the four screws 28 can advantageously be outside the envelope 1, therefore they do not require a hole in the envelope. Their head is preferably embedded in the underside of the flange. The overlapping ends of the two parts 26 and 27 of each flange constitute horns 29 for the fixing the bracelet 3, the ends of the bars 4 engaging in holes preferably made in the lower part 27 of the flange.

As shown in Figure 3, the middle part of the upper part 26 of each flange has the shape of a rectangular bar 31 which is housed in the groove 21 of glass 7 and has the same dimensions as this groove, so that the flange 25 is flush with the face upper 18 ice. The thicker ends of the part 26 each have a vertical shoulder 32 obliquely arranged to press against surfaces external devices 33 and 12 of glass 7 and of middle 9, which keeps these two pieces in alignment axial. Similarly, the lower part 27 of each flange 25 has a central bar 34 which is housed in the groove corresponding 22 of the bottom 8, and oblique shoulders 35 which lean against the peripheral surfaces 36 and 12 respectively of the back 8 and the middle part 9. As the two flanges 25 are sufficiently spaced to allow appear between them the watch face, their oblique shoulders 32 and 35 are distributed over the around the envelope 1 and therefore hold the parts of the envelope in any lateral direction. Thus, the support device 2 fills a triple function: axial clamping of stacked pieces of envelope 1, lateral support of these three parts, and connection between the two ends of the bracelet and the envelope.

In Figures 1 and 2, we also see that annular metallized zones 37 and 38 are provided respectively on the underside 24 of the glass 7 and on the upper face 16 of the bottom 8, near the periphery of the housing 5, to allow to stick to this location some classic positioning organs of the movement 6, for example a casing circle and a flange (not shown). These metallic areas play also an aesthetic role by hiding the elements cited above. Other metallized elements can be provided, in particular the frame 39 shown in the figure 2 and intended to cover the edge of a window provided in the dial of the movement 6.

When the control rod passes through hole 10 in the middle part 9, the watertightness can be ensured by a classic O-ring system.

Although the example described above refers to a envelope 1 entirely made of sapphire (or corundum), one similar construction can be used with other materials, high hardness or not. For example, ice 7 could be made of any other transparent crystal, or in mineral glass. The middle 9 could also be in mineral glass, ceramic, hard metal or one way general in any kind of hard material manufactured in particular by molding and sintering. Similar materials are usable to make the bottom 8. Insofar as these materials can be polished to form dishes optical, i.e. very smooth surfaces with porosity zero or closed, it is possible to guarantee watertightness of the envelope without packing, as we have described above. In addition, it should be noted that the middle 9 could be in one piece with glass 7 or with the bottom 8. For example, a case back made by molding and sintering should only be machined for polishing the contact surface 13 and the drilling of hole 10. This hole could even be deleted if a means of contactless time setting, for example by radio or magnetic drive.

Another embodiment of a watch case according to the invention is illustrated by Figures 4 and 5, where we used the same reference numbers as in the previous example for equivalent elements, even if their forms or arrangements are different. In in this case, the glass 7 and the bottom 8 are curved, but only for aesthetic reasons. The middle 9 is identical to that of the previous example. On the other hand two flanges 25 have a different shape from the example previous, because each of them carries one of the bars 4 by its ends bent at right angles to form two horns 29. Its two bars 31 and 34 are parallel to the bar 4, as well as the corresponding grooves 21 and 22 of the glass 7 and the bottom 8. The tension of the bracelet is thus transmits from one flange 25 to the other by through the ice and the bottom.

Compared to the previous example, this construction has the advantage of clearing the central part of the envelope 1, in particular to reveal the movement 6.

In the embodiment illustrated by the figures 6 and 7, the outer shape of the envelope 1 is substantially rectangular in plan. However, the wall inner 11 and the outer wall 12 of the middle 9 in this case also have generators parallel to the axis 20 of the casing, so that the middle part can be made from a tubular piece. Ice 7 is convex and the bottom 8 is concave, both following a spherical profile, so that their contact surfaces with the middle 9 also have the same spherical shape, which can be machined and polished without any particular difficulty.

The support device here comprises four flanges 45 each composed of an upper part 46 supported on the ice, from a lower part 47 resting under the bottom and an axial screw 48 which crosses the three parts 7, 8, 9 of the casing 1 and ensures the axial tightening of these parts, as well as the retaining of the flange 45 on the envelope. The flanges 45 are arranged in parallel two by two on opposite ends of the envelope to form two pairs of horns 49 supporting the bars 4. The upper 46 and lower 47 parts of each flange have respective prongs 50 and 51 which are preferably engaged in grooves corresponding exterior of the glass 7 and of the bottom 8, as in the example in Figures 1 to 3. However, these grooves are not essential, since the positioning of each flange 45 can be ensured by support against the envelope and by the screws 48 engaged in the corresponding holes in the envelope. The device support shown here is advantageous when ice and background are both transparent, since it does not hide at all the housing 5 containing the movement 6, or when some of the parts of the envelope are not in hard material and can therefore be pierced easily.

Claims (16)

1. Watch case including a water resistant casing (1) formed of several stacked parts, which together define a housing (5) intended to contain a watch movement (6), and a support device (2) which keeps said casing parts assembled, the casing having a transparent upper face, the support device (2) including at least one rigid clamp (25, 45) formed of an upper portion and a lower portion which are removably fixed to each other by assembly means (28) arranged to produce gripping of the casing (1) between the two portions of the clamp in an axial direction, perpendicular to said lower face,
      the case being characterized in that said casing parts (7, 8, 9) are made of materials having zero porosity or a closed structure and have, facing each other, mutual contact surfaces (13, 14, 15, 17) which are flat or generated by revolution and are polished, no sealing gasket being inserted between them.
2. Watch case according to claim 1, characterized in that said parts of the casing (1) include a transparent upper plate forming a crystal (7), a lower plate forming a back cover (8), and an annular intermediate part forming a middle part (9).
3. Watch case according to claim 1, characterized in that said assembly means include screws (28, 48) arranged in the axial direction.
4. Watch case according to claim 1, characterized in that the clamp (25) also abuts against external peripheral surfaces (12, 33, 36) of each casing part, so that it holds these parts laterally.
5. Watch case according to any of claims 1 to 4,
   characterized in that the support device includes attachment means (4, 29, 49) for attaching a wristlet or other fixing means to the case.
6. Watch case according to claim 5, characterized in that the clamp (25) forms a closed frame which extends substantially in a plane parallel to the axial direction.
7. Watch case according to claim 5, characterized in that the lower portion (27, 47) of the clamp (25, 45) extends in at least one groove (22) arranged in the lower face (19) of the casing and is substantially flush with this face.
8. Watch case according to claim 5, characterized in that the upper portion (26, 46) of the clamp (25, 47) extends in at least one groove (21) arranged in the upper face (18) of the casing and is substantially flush with said face.
9. Watch case according to claim 6, characterized in that the support device (2) includes two of said clamps (25), arranged parallel to each other and in that said attachment means include two lugs (4) arranged perpendicular to the clamps, each lug being fixed to ends of the two clamps.
10. Watch case according to claim 7, characterized in that the support device includes two of said clamps (25), each having two bent ends which together carry one of the attachment means (4).
11. Watch case according to claim 2, characterized in that all the casing (1) parts are made of sapphire.
12. Watch case according to claim 2, characterized in that the middle part (9) is made of sapphire, hard material, ceramics or glass.
13. Watch case according to claim 2, characterized in that the back cover (8) is made of sapphire, hard metal or glass.
14. Watch case according to claim 2, characterized in that the middle part (9) is transparent and includes an antireflective coating (40) at least over its contact surface (13) on the side of the crystal.
15. Watch case according to any of claims 11 to 14, characterized in that the middle part (9) has a cylindrical or prismatic annular shape and inner (11) and outer (12) lateral walls which have generatrices parallel to the axial direction and have no projections or recesses.
16. Watch case according to claim 15, characterized in that the crystal (7) and the back cover (8) have, in plane, substantially the same shape and the same external dimensions as the middle part (9).

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