HK1197765A - Timepiece housing with composite frame - Google Patents

Description

Watch case with combined frame

The application is a divisional application of an invention patent application with the application date of 2007, 9 and 5, and the application number of 200780035819.X, and the invention name of the invention is 'watchcase with combined frame'.

Technical Field

The invention relates to a watch case with a composite middle part comprising an outer part and an inner part. The outer portion is made of a hard mineral material selected to both provide protection against external attack such as corrosion, friction or scratching, and also to contribute to the overall attractiveness of the watch. The inner part is made of a material that is easy to machine and enables all the other components to be assembled on the watch.

Background

Timepieces are known whose case comprises the following intermediate part: the intermediate portion is made of a hard natural or synthetic mineral such as sapphire, ceramic, or natural or regenerated gem stone. These materials do not withstand mechanical stresses well and therefore attempts have been made to reduce as far as possible the machining operations, or to limit them to the machining of the case for the timepiece movement and of the through passage for the stem of the control element.

According to one embodiment, the CH patent No.517963 discloses an outer part of the bezel-middle part type, made of a metal carbide based material with a hardness close to topaz, while emphasizing the very difficulty in forming the threads in this material in order to assemble all the other watch parts. The same difficulties are encountered if the material used is topaz or any other natural or synthetic mineral material. In order to overcome this problem of assembling the parts, the patent proposes to use an internal metallic intermediate part on which the bezel-intermediate part is fitted, while compensating any variation in dimensions by adhesive bonding, while ensuring waterproofing.

U.S. patent No.4620798 also discloses a construction that includes an inner intermediate portion and an outer intermediate portion. The inner metallic middle part, which fixes the back cover by screws and fixes the bezel by adhesive bonding, further comprises an adhesive joint for fixing the crystal. The back cover and bezel extend slightly radially beyond the inner middle portion and hold the outer middle portion in place, which is made of natural or synthetic mineral material.

Us patent No.4853910 also discloses a construction of the aforementioned type in which the single parts, made of hard mineral material, which simultaneously form the dial, bezel and middle part, are assembled by bonding on the inner metallic middle part.

As can be seen from the above prior art, the adhesive bonding appears to be an inevitable step in any case for assembling the outer intermediate part and the inner metallic intermediate part made of mineral or synthetic material.

However, the adhesive bonding technique has well-known drawbacks. First is the selection of a suitable binder for two different materials, e.g. metallic and ceramic materials. Secondly, the aging of the adhesive, which may lead to a loss of adhesion or to cracks which, over time, impair the waterproofness of the watch case. These drawbacks are unacceptable for medium-high-range timepieces that should have a long life.

Disclosure of Invention

It is therefore an object of the present invention to overcome the aforementioned drawbacks of the prior art by providing a watch case: the watch case has an outer middle part made of natural or synthetic mineral material, such as ceramic, which is assembled without being subjected to mechanical stresses.

The invention therefore concerns a watch case with a composite middle part consisting of two basic parts, one being an external middle part made of mineral material and the other being an internal middle part made of metal that is easy to machine, so as to be able to assemble all the other watch parts. The invention is characterized in that the inner intermediate part itself is made in two parts, i.e. is formed by two rings designed to be mechanically assembled to each other, so as to be able to lock the outer intermediate part with a slight clearance.

Each ring comprises a radial peripheral extension, the opposite shoulders of which can lock the outer intermediate portion, for example by screwing the two rings one inside the other. The only machining of the outer intermediate portion made of hard mineral material sensitive to mechanical stresses involves the through passage for the control element. These through channels can be made with slight clearance, provided that the mechanical assembly is transferred to the internal middle part of the metal.

Drawings

Further characteristics and advantages of the invention will become better apparent from the following description of exemplary embodiments, given by way of non-limiting example, with reference to the accompanying drawings, in which:

figure 1 shows a top view of a precision chronograph watch housed in a watch case according to the invention;

FIG. 2 is a partial section at 12 along the line II-II of FIG. 1;

figure 3 is a partial section through the push-button along the line III-III of figure 1; and

figure 4 is an exploded perspective view of the case of the chronograph watch corresponding to figure 1.

Detailed Description

Fig. 1 shows, as an example, a chronograph watch comprising, in a known manner, a winding/time-setting stem 3 and two push-buttons 5a, 5b, whose stem controlling a timepiece movement 4 must pass through an intermediate part 1, this intermediate part 1 having a corner 2 for fixing a bracelet or wristband. The current time and timing data of the usage counter are displayed on the dial 9 in a conventional manner. It is clear that the concept of an outer intermediate portion made of natural or synthetic mineral material, to be described hereinafter, can equally be applied to watches having only one crown, or conversely watches having a greater number of buttons.

With reference now to figures 2, 3 and 4, it will be explained how the construction according to the invention provides a watch case with an external middle portion 20 having: the outer intermediate part is for example made of a ceramic material, on which no mechanical stresses are exerted, and does not require any adhesive joints for assembly.

Outer intermediate portion 20 is somewhat sandwiched by inner intermediate portion 10 of metal, inner intermediate portion 10 being made of steel or brass, for example. The inner intermediate part is made in two parts, i.e. formed by a top ring 12 and a bottom ring 14, the two rings 12, 14 being mechanically assembled to each other. In the example shown, this mechanical assembly is achieved by screwing the top ring 12 into the inner wall of the bottom ring 14. It will be clear that the top ring can also be screwed into the outer wall of the bottom ring 14.

The top ring 12 comprises a radial peripheral extension 13, which extension 13 extends beyond the wall of the bottom ring 14. The top ring 12 further comprises an annular axial extension 16, which extension 16 abuts a corresponding shoulder 18 of the bottom ring 14. Opposite the ring formed by the shoulder 18, the top ring 12 comprises a groove 22 for placing a sealing gasket 23 between the two rings 12, 14.

The top ring 12 is also provided for fixing the bezel 7, the crystal 8 and the dial 9, this bezel 7 being made in two parts 7a, 7b in this example. Bezel 7 is secured to top ring 12, while ring 7b may, for example, change the aesthetic appearance of a given design, or be used to add legends.

The bottom ring 14 also includes a peripheral extension 15, the extension 15 extending approximately the same distance as the extension 13 extends from the top ring 12. As can be easily understood from the exploded perspective view of fig. 4, the assembly of the outer intermediate portion 20 is very simple: the outer intermediate portion 20 is mounted on the bottom ring 14 and the top ring 12 is then screwed in until the axial extension 16 of the top ring 12 abuts against the shoulder 18 of the bottom ring, at which time the radial extensions 13, 15 of the rings 12, 14 press against the top and bottom edges of the outer intermediate portion 20. In order not to exert mechanical stress on the ceramic material of the outer intermediate portion 20, the distance between the opposite shoulders of the extensions 13 and 15 must be slightly greater than the height of the outer intermediate portion 20. For the same reason, a certain clearance is also provided between the outer wall of the inner intermediate portion 10 and the inner wall of the outer intermediate portion 20. Furthermore, the outer wall of the bottom ring 14 comprises an annular groove 19, which groove 19 accommodates the sleeve 17 for radially centering the outer intermediate portion 20.

Similar to top ring 12, bottom ring 14 is provided for assembling other watch components, such as back cover 6 and timepiece movement 4. In the example shown, the base of the bottom ring 14 comprises an annular recess 24, this recess 24 being intended to accommodate a sealing gasket 25 between said ring 14 and the snap-on rear cover 6. It is clear that any other means for assembling the rear cover known to the person skilled in the art may be used, for example using screws. To secure the cartridge 4, as shown in fig. 2, this may be accomplished using techniques known in the art by forming a counterbore 30 in the inner wall of the bottom ring 14 into which a flange 31 is engaged and secured by screws 32.

With reference to fig. 3, which shows a cross section of the push-button 5b, and with reference to fig. 4, it will now be described how the invention allows the stem of the control elements 3, 5a and 5b to pass without applying mechanical stress to the outer intermediate portion 20 (outer intermediate portion 20). The bottom ring 14 has a through channel 26, which through channel 26 is arranged opposite to a through channel 28 of the outer intermediate part 20. In the preferred embodiment shown, it can be seen that the through-passages 28 have a semicircular shape open towards the bottom, each through-passage 26 comprising a collar 27, which collar 27 can be engaged in the through-passage 28 and makes the outer intermediate portion 20 oriented at a single angle. The through channel 26 comprises a thread which allows a bushing 29 to be screwed therein, which bushing comprises a push-button mechanism known to the person skilled in the art and therefore not described here again.

In the example just described above, it should be noted that the bottom ring 14 is the most important and plays a "decisive" role. It is clear that the roles of the top ring 12 and the bottom ring 14 can be interchanged without departing from the scope of the invention: the top ring 12 can be decisive by making the necessary adjustments, which are within the ability of the person skilled in the art.

Similarly, the example relates to a circular watch case, but the invention is not limited to this shape. The watch case may have an oval or rectangular shape. The only adjustment to be made is to change the mechanical assembly of the rings 12, 14, for example by using a snap-on type device, which has the advantage of making the watch case completely impossible to disassemble. The snap-fit technique can of course also be used for round watchcases.

For a round watch case, the rings 12, 14 can also be assembled using a bayonet (bayonet) device.

Other variations and modifications may be devised by those skilled in the art without departing from the scope of the present invention.

Claims (11)

1. A watch case comprising a combined middle part (1) through which passes the stem of a control element (3, 5a, 5b), a back cover (6) and a bezel (7), said bezel (7) being closed by a crystal (8) so as to jointly define a space accommodating a timepiece movement (4), the timepiece movement (4) is intended to display time data or non-time related data on a dial (9), said intermediate portion (1) being formed by an inner intermediate portion (10) of metal and an outer intermediate portion (20) of natural or synthetic mineral material, characterized in that the inner intermediate portion (10) is formed by a top ring (12) and a bottom ring (14), the top ring (12) is assembled into the inner or outer wall of the bottom ring (14), the top ring (12) comprises an axial extension (16) that abuts a peripheral shoulder (18) of the bottom ring (14); and in that the top ring (12) and the bottom ring (14) each have a radial extension (13, 15) directed towards the outside, so as to stop the external intermediate portion (20) with a slight clearance by mechanically assembling the top ring (12) and the bottom ring (14) to each other, the bottom ring (14) being arranged so as to be able to assemble the back cover (6) and the timepiece movement (4), and the base of the bottom ring (14) comprising an annular recess (24), this annular recess (24) being intended to accommodate a gasket (25) between the bottom ring (14) and the snap-on back cover (6).

2. A watch case comprising a combined middle part (1) through which passes the stem of a control element (3, 5a, 5b), a back cover (6) and a bezel (7), said bezel (7) being closed by a crystal (8) so as to jointly define a space accommodating a timepiece movement (4), the timepiece movement (4) is intended to display time data or non-time related data on a dial (9), said intermediate portion (1) being formed by an inner intermediate portion (10) of metal and an outer intermediate portion (20) of natural or synthetic mineral material, characterized in that the inner intermediate portion (10) is formed by a top ring (12) and a bottom ring (14), the top ring (12) is assembled into the inner or outer wall of the bottom ring (14), the top ring (12) comprises an axial extension (16) that abuts a peripheral shoulder (18) of the bottom ring (14); and in that the top ring (12) and the bottom ring (14) each have a radial extension (13, 15) directed towards the outside, so as to stop the external intermediate portion (20) with a slight clearance by mechanically assembling the top ring (12) and the bottom ring (14) to each other, the bottom ring (14) being arranged so as to be able to assemble the back cover (6) and the timepiece movement (4) and to assemble the back cover using screws.

3. A watch case comprising a combined middle part (1) through which passes the stem of a control element (3, 5a, 5b), a back cover (6) and a bezel (7), said bezel (7) being closed by a crystal (8) so as to jointly define a space accommodating a timepiece movement (4), the timepiece movement (4) is intended to display time data or non-time related data on a dial (9), said intermediate portion (1) being formed by an inner intermediate portion (10) of metal and an outer intermediate portion (20) of natural or synthetic mineral material, characterized in that the inner intermediate portion (10) is formed by a top ring (12) and a bottom ring (14), the top ring (12) is assembled into the inner or outer wall of the bottom ring (14), the top ring (12) comprises an axial extension (16) that abuts a peripheral shoulder (18) of the bottom ring (14); and in that the top ring (12) and the bottom ring (14) each have a radial extension (13, 15) directed towards the outside, so as to stop the external intermediate portion (20) with a slight clearance by mechanically assembling the top ring (12) and the bottom ring (14) to each other, the bottom ring (14) being arranged so as to be able to assemble the back cover (6) and the timepiece movement (4), and a countersink (30) being formed in the inner wall of the bottom ring (14), in which countersink (30) a flange (31) is engaged and fixed by means of screws (32) to fix the timepiece movement (4).

4. Watch case according to any of claims 1 to 3 characterized in that the top ring (12) and the bottom ring (14) are assembled using screws.

5. Watch case according to any one of claims 1 to 3 characterised in that a sleeve (17) is housed in a groove (19) of one of the top ring (12) and the bottom ring (14) of the inner middle part (10) in order to provide a slight clearance between the inner middle part (10) and the outer middle part (20) and to centre the outer middle part (20) in the radial direction.

6. Watch case according to any one of claims 1 to 3 characterised in that the top ring (12) is arranged so as to be able to assemble the crystal (8), the bezel (7) and the dial (9).

7. Watch case according to any one of claims 1 to 3 characterised in that the radial extension (13) of the top ring (12) has a groove (22) for housing a gasket (23) to ensure the waterproofing between the top ring (12) and the bottom ring (14).

8. Watch case according to any one of claims 1 to 3 characterised in that the internal middle part (10) and the external middle part (20) comprise a through channel (26, 28) opposite the stem of the control element (3, 5a, 5 b).

9. Watch case according to claim 8 characterised in that the through channel (28) of the outer middle part (20) has a semicircular shape open towards the bottom of the case and in that the through channel (26) of the inner middle part (10) comprises a collar (27), the collar (27) engaging in the through channel (28) of the outer middle part (20).

10. Watch case according to any one of claims 1 to 3, characterised in that the material of the external middle part (20) is chosen from ceramics and natural or artificial gems.

11. Watch case according to any one of claims 1 to 3, characterised in that the material of the outer middle part (20) is sapphire.