Method for manufacturing a sealing gasket from this component

Abstract

The invention relates to a method for manufacturing a sealing gasket, characterized in that the method comprises producing a plurality of cuts in an assembly (10) by means of a machining operation, the assembly (10) being produced from at least two identical joined tubes (20), each tube (20) extending along a longitudinal axis between two ends, the end of one tube (20), referred to as the "first end" (21), having a shape complementary to the shape of the end of the other tube (20), referred to as the "second end" (22), so that the first end (21) and the second end (22) cooperate by virtue of the complementarity of shape.

Description

Technical Field

[0001] The invention belongs to the field of micro-engineering and is particularly advantageously applied in the field of horology.

[0002] More particularly, the present invention relates to a method for manufacturing a sealing gasket from the assembly. Background Art

[0003] The sealing gasket intended to be arranged in a watch case is produced by cutting, generally by machining an assembly of tubes joined together in a colinear manner by means of a cutting tool, for example by milling or by turning.

[0004] These tubes have a cylindrical shape and comprise a transverse section which defines the shape of the gasket obtained after machining.

[0005] In order to fix them without any degree of freedom relative to one another, the tubes can be welded at their opposite ends. For example, for this purpose, two tubes are arranged supported by one of their ends against a hot plate until their melting temperature is reached, and the ends are then held against one another until cooled.

[0006] Instead of welding, it is also possible to glue two adjacent tubes at their junction by applying a layer of glue on their respective ends and by holding them in place on a template until the glue dries.

[0007] However, in addition to having the disadvantage of pose difficulties with respect to collinearity tolerances, such solutions also produce beads of solder or glue, respectively, forming burrs on the inner and outer surfaces of the component.

[0008] Alternatively, the pipes may be connected together by means of dedicated components such as connecting sleeves (eg threaded), which is well known to those skilled in the art.

[0009] Besides incurring additional costs due to the addition of extra components to the assembly, such solutions are often lengthy and cumbersome to implement. Summary of the Invention

[0010] The present invention solves the aforementioned drawbacks by proposing a solution that makes it possible to ensure the collinearity of the tubes joined together, to control the appearance of the outer surface of the assembly, and to avoid the need for assembly templates or additional components other than the tubes for producing the assembly.

[0011] To this end, the invention relates to a method for manufacturing a sealing gasket, comprising producing, by means of a machining operation, a plurality of cuts in an assembly produced from at least two identical joined tubes, each tube extending along a longitudinal axis between two ends, the end of one tube (referred to as the "first end") having a shape complementary to the shape of the end of the other tube (referred to as the "second end"), so that said first and second ends cooperate by virtue of the complementarity of shape.

[0012] Advantageously, the assembly makes it possible to ensure the colinearity of the tubes relative to one another and thus eliminate any risk of imbalance that could be harmful during machining of said assembly.

[0013] Furthermore, these features make it possible to avoid any burrs on the outer surface of the component.

[0014] Another advantage of the invention is that it makes it possible to control the dimensions of the tubes and therefore of the assembly.

[0015] In certain embodiments, the present invention may further include one or more of the following features, either alone or in any technically possible combination.

[0016] In a particular embodiment, the manufacturing method comprises a preliminary step of producing the assembly before performing the machining operations, wherein the tubes are obtained by molding and then joined together in order to obtain said assembly.

[0017] In a particular embodiment, the manufacturing method comprises, before performing the machining operations, a preliminary step in which, for each tube, a cylindrical body is produced by extrusion and a first end is produced by molding, said first end then being fixed to said cylindrical body and finally the tubes thus formed are joined together in order to obtain said assembly.

[0018] In a particular embodiment, during the preliminary step, the first end portion is overmolded onto the cylindrical body.

[0019] In certain embodiments, when joining the tubes, the tubes are threaded together at their respective opposing first and second ends.

[0020] In certain embodiments, when joining the tubes, the tubes are glued or chased together at their respective opposing first and second ends.

[0021] According to another aspect, the invention relates to a watch comprising a sealing gasket obtained by implementing the method described above, and comprising a case formed by a centerpiece, a crystal and a bottom cover. The gasket is arranged against the centerpiece so as to be interposed between the bottom cover and the centerpiece, between the crystal and the centerpiece, or between the bezel and the centerpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other characteristics and advantages of the present invention will become apparent on reading the following detailed description, given by way of non-limiting example, with reference to the accompanying drawings, in which:

[0023] - Figure 1 shows a cross-sectional view of an assembly intended to be machined to produce a sealing gasket, said assembly comprising four joined tubes;

[0024] - Figure 2 Shown Figure 1 a cross-sectional view of a tube of an assembly;

[0025] - Figure 3 A cross-sectional view of a tube according to another alternative embodiment of the present invention is shown.

[0026] It should be noted that the drawings are not to scale. DETAILED DESCRIPTION

[0027] Figure 1 An assembly 10 is shown which is intended to be processed to produce a sealing gasket according to the invention.

[0028] The assembly 10 comprises a plurality of tubes 20 , preferably identical, joined to form a strip extending along a longitudinal axis merging with the longitudinal axis of each tube 20 .

[0029] like Figure 2 and Figure 3 As illustrated in various alternative embodiments of the tubes 20, each tube 20 extends between a first end 21 and a second end 22 having complementary shapes, such that the first end 21 of one tube 20 mates with the second end 22 of another tube 20 by shape complementarity.

[0030] Thus, the assembly 10 is composed of a plurality of tubes 20 that are continuously joined together by each of their first end 21 and second end 22 , except for the tubes 20 arranged at the ends of the assembly 10 .

[0031] These tubes 20 are fixed together without degrees of freedom, for example by fitting and / or by gluing at their junctions.

[0032] The first end 21 of each tube 20 advantageously comprises a stud 210 extending from a radial surface 211 along the longitudinal axis of the tube 20 , the stud 210 forming an annular shoulder with the radial surface 211 .

[0033] like Figure 1As shown in the figure, the second end 22 is formed by an axial opening 220 opening on an end surface 221 and the column 210 of the adjacent tube 20 is engaged therein, so that the radial surface 211 extending from the column 210 is supportedly arranged against the end surface 221, and this contact defines the axial positioning of the two tubes 20 adjacent to each other.

[0034] The radial positioning of two adjacent tubes 20 is defined by the engagement of the studs 210 in the openings 220 .

[0035] More specifically, in Figures 1 to 3 In the embodiment of the invention shown in , between its first end 21 and second end 22 , each tube 20 comprises a hollow cylindrical body 23 defined between an outer surface 230 and an inner surface 231 , the opening 220 being realized by the inner surface 231 of the second end 22 .

[0036] The inner surface 231 of the second end portion 22 may advantageously receive a possible layer of glue mentioned herein above, in order to increase the fixation between the two tubes 20 , without the glue protruding beyond the outer surface 230 .

[0037] Alternatively, a glue layer may be applied to the outer surface of the posts 210 .

[0038] In the preferred embodiment of the invention shown in the drawings, each tube 20 is monolithic in that it is formed in one piece.

[0039] The cylindrical body 23 may or may not have a solid of revolution shape.

[0040] exist Figure 1 and Figure 2 In the embodiment, the tube 20 is blind, since the opening 220 is open only at its second end 22; Figure 3 In the alternative embodiment shown in , the tube 20 has a through opening 220 which also opens at the first end 21 .

[0041] Advantageously, the second end 22 may include a chamfer or necking 222 defined between the end surface 221 and the inner surface 231 to facilitate engagement of the post 210 of the tube 20 in the opening 220 of the other tube 20 and thereby facilitate production of the assembly 10 .

[0042] In order to improve the form fit between the first end 21 and the second end 22, the first end 21 may include a chamfer or necking 212 defined between the radial surface 211 and the post 210. The necking 212 of the first end 21 of each tube 20 is then opposite the chamfer or necking 222 of the second end 22 of the adjacent tube 20 with which the first end 21 mates, except for the tube 20 constituting one end of the assembly 10; for example, Figure 1 The end tube 20 on the right side of the assembly 10 is visible.

[0043] like Figure 3 As shown in FIG, the post 210 may include a chamfer or necking 213 at its free end for this same purpose.

[0044] Advantageously, the complementary shapes of the first end 21 and the second end 22 are not solids of revolution, so as to prevent any possible rotation between the tubes 20. The assembly 10 is therefore better resistant to torsional forces, in particular to those experienced during the processing of the assembly 10. This feature makes it possible to significantly reduce the risk of fracture of the assembly 10, that is to say the risk of separation of two adjacent tubes 20 during the processing of the gasket.

[0045] More specifically, the cross-sections of the pillars 210 and the openings 220 may be polygonal, such as square, triangle, etc., or curved, such as elliptical, multi-petal, etc.

[0046] Alternatively, the respective first end 21 and second end 22 of two adjacent tubes 20 may be mated to each other by means of a screw connection. More specifically, the post 210 may be threaded so as to be engaged by being threaded into a correspondingly tapped opening 220 .

[0047] In another embodiment of the present invention not shown in the drawings, for each tube 20 , the cylindrical body 23 and the post 210 may be formed independently of each other, so that the tube 20 is obtained by fastening the cylindrical body 23 and the post 210 .

[0048] In this case, the cylindrical body 23 and the column 210 may be of different materials and may be fitted and / or glued.

[0049] Insofar as the tube 20 is intended to be formed into a sealing gasket by machining after the successive transverse cutting operations of the assembly 10, only the portion of the tube 20 of the assembly 10 that is outside the junction between the first end 21 and the second end 22 is usable. In other words, the portion of the assembly 10 consisting of the junction between the first end 21 and the second end 22 of the tube 20 is not used and constitutes waste.

[0050] By way of example, each tube 20 may have a length between 20 and 80 centimeters, preferably 30 centimeters.

[0051] These values for the length of the tubes 20 are advantageous because they constitute a good compromise between a length of the tubes 20 that is difficult to produce by a molding operation and a length that is too short to minimize the usable portion of each tube 20 .

[0052] As mentioned above, the method for manufacturing the sealing gasket consists in producing a plurality of transverse cuts in the component 10 by a machining operation with a cutting tool, in particular turning, and in particular profile turning. Cutting may be followed by a complementary machining operation, such as a milling operation, in order to trim the gasket profile obtained.

[0053] The length of the assembly 10 may be several meters and is in practice limited only by the limitations of the processing machine.

[0054] The manufacturing method comprises preliminary steps for producing the assembly 10 before performing machining operations, in which the tubes 20 are obtained by molding and then joined together.

[0055] Alternatively, during a preliminary step, for each tube 20 , the cylindrical body 23 is produced by extrusion and the first end 21 by molding, each first end 21 is then fixed to the cylindrical body 23 and finally the tubes 20 thus formed are joined together.

[0056] More specifically, during a preliminary step, the first end portion 21 may be overmolded onto the cylindrical body 23 .

[0057] The invention is particularly suitable for obtaining a sealing gasket intended to be placed against the centerpiece of a watch case, for example interposed between a bottom cover and the centerpiece, between a watch crystal and the centerpiece, or between a bezel and the centerpiece.

[0058] By way of example, the material of the tube 20 is a polymer, in particular a polyurethane, preferably of the type known to those skilled in the art under the trade name “Asutane”.

[0059] More generally, it should be noted that the embodiments and examples considered above have been described by way of non-limiting examples and that other variants are therefore possible.

Claims

1. A method for manufacturing a sealing gasket, characterized in that: The method comprises producing a plurality of transverse cuts in an assembly (10) by machining operations, and performing complementary machining operations to trim the obtained gasket profile, wherein the assembly (10) is produced from at least two identical joined tubes (20), each tube (20) extending along a longitudinal axis between two ends, the end of one tube (20), referred to as the first end (21), having a shape complementary to the shape of the end of the other tube (20), referred to as the second end (22), so that the first end (21) and the second end (22) cooperate by shape complementarity.

2. The method according to claim 1, comprising a preliminary step of producing the component (10) before performing the machining operation, wherein The tubes (20) are obtained by molding and then joined together in order to obtain the assembly (10).

3. The method according to claim 1, comprising a preliminary step before performing the machining operation, wherein For each tube (20), a cylindrical body (23) is produced by extrusion and a first end (21) is produced by molding, the first end (21) is then fixed to the cylindrical body (23), and finally the tubes (20) thus formed are joined together to obtain the assembly (10).

4. The method according to claim 3, wherein: During the preliminary step, the first end portion (21) is overmolded onto the cylindrical body (23).

5. The method according to any one of claims 2 or 3, wherein When joining the tubes (20), the tubes (20) are threaded together at their respective opposing first and second ends (21, 22).

6. The method according to any one of claims 2 or 3, wherein When joining the tubes (20), the tubes (20) are glued or snapped together at their respective opposing first end (21) and second end (22).

7. A watch comprising a sealing gasket obtained by implementing the method according to any one of claims 1 to 6, and comprising a case formed by a center piece, a watch glass and a bottom cover; the watch is characterized in that the sealing gasket is arranged against the center piece so as to be inserted between the bottom cover and the center piece, between the watch glass and the center piece, or between the bezel and the center piece.

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