Method for manufacturing carbon-carbon watch components

Abstract

The manufacturing method comprises at least one processing step of a part (100, 200) made of carbon-carbon composite material. In a first variant, the method comprises a machining step and a processing step of the part. In a second variant, the method comprises a grinding step of the part before the processing step and a shaping step after the processing step. It is applied to the manufacture of watch components (170, 270).

Description

[Technical Field]

[0001] The present invention relates to the technical field of watchmaking.

[0002] The present invention relates to a watch component made from composite materials.

[0003] The invention also relates to a method for manufacturing a composite watch component. [Background technology]

[0004] Watch components are traditionally made from metallic materials such as stainless steel, titanium, or precious metals such as gold, platinum, or silver.

[0005] For reasons of lightness and aesthetics, composite materials are increasingly replacing metallic materials for the manufacture of some watch components. Summary of the Invention [Problem to be solved by the invention]

[0006] According to a first aspect, the object of the invention is a method for manufacturing a timepiece component from a part made of carbon-carbon composite material.

[0007] More precisely, the method for manufacturing a watch component includes steps for processing a part made of carbon-carbon composite material.

[0008] Carbon-carbon composites are highly valued for their excellent heat resistance, excellent thermal shock resistance, and excellent wear resistance during high temperature friction. For these reasons, carbon-carbon composites are used in the manufacture of: - Brake pads or discs for racing vehicles, automobiles, or motorcycles - Aircraft brake discs - Space Shuttle Tiles - Rocket Jet Nozzle - Friction discs for clutch systems in racing vehicles.

[0009] The article "Carbon / Carbon Composites" by Jacques Thebault and Pierre Olry, published in the journal l'actualite chimique - March-April 2006 - Issues 295-296, describes carbon-carbon composites as the result of fusion between a fibrous reinforcement and a bonding matrix, both of which have the same chemical properties.

[0010] The fibrous reinforcement consists of woven carbon fibres obtained by mechanical means used in the textile industry. The binding matrix is ​​a carbonaceous matrix whose role is to fill the porosity of the fibrous structure. [Means for solving the problem]

[0011] According to a first aspect of the invention, a method for manufacturing a timepiece component comprises the step of treating a part made from a carbon-carbon composite material.

[0012] According to a first variant of the first aspect of the invention, the manufacturing method comprises machining and treating steps of said part.

[0013] According to one feature of the method according to the first variant, the processing step is preceded by a first machining step of the carbon-carbon composite part and followed by a second machining step of said part.

[0014] The first machining step consists of a pre-machining operation by milling that allows the surface of the part to be prepared before the processing step. In particular, spaces with portions exceeding a predefined thickness are provided on said surface. Depending on the desired timepiece component, spaces with portions below the predefined thickness can also be provided on said surface.

[0015] The second machining step consists of a so-called machining operation by milling the same face of said part after the treatment step.

[0016] According to another feature, the method according to the first variant comprises at least one additional machining step after the second machining step, which may be a step of shaping the part, a step of milling another face of the part, a finishing step.

[0017] The processing steps include a resinization operation, which consists of pouring a liquid resin onto the surface of the part that has undergone the preliminary machining operation. The resin may be a thermosetting resin, such as an epoxy resin or a phenolic resin. The resin may also be a thermoplastic resin.

[0018] The processing steps then include a vacuum operation performed simultaneously with a heat curing operation. The processing steps finally include a post-cure operation. The vacuum operation has the effect of favoring the penetration of the resin into the pores of the material. The heat curing has the effect of initiating the polymerization of the resin. The post-cure has the effect of bringing the resin to its maximum hardness.

[0019] Thus, according to a first variant of the method, an initial part made of carbon-carbon composite material is first prepared by pre-machining and then subjected to a treatment in which the carbon-carbon composite material is impregnated with resin, after which the watch component is obtained by machining the treated part to the desired shape.

[0020] Resin infiltration into carbon-carbon composites increases the mechanical strength and hermeticity of the part, which also has the benefit of improving its aesthetics.

[0021] According to a second variant of the first aspect of the invention, the manufacturing method comprises the steps of grinding the carbon-carbon composite part into small pieces, followed by a processing step of the resulting ground material, and finally a shaping step of the ground material that has been subjected to the processing step.

[0022] The processing step involves resinification, which involves pouring resin onto the grounds of the carbon-carbon material and mixing them together, as well as heating the mixture of grounds and resin.

[0023] The molding step involves filling a mold having the final shape of the desired part with a mixture made up of ground material and resin, followed by pressing and finally demolding.

[0024] According to one feature of the second variant of the method, the heating operation of the treatment step and the pressing operation of the molding step are carried out simultaneously, having the effect of polymerizing the resin.

[0025] According to one feature of the second variant, the method comprises an optional step of washing the pieces constituting the grounds, preceding the treatment step.

[0026] According to another feature of the second variant, the method comprises an optional step, preceding the treatment step, of screening the pieces constituting the ground product.

[0027] Thus, according to a second variant of the method, the initial part made of carbon-carbon composite material is first prepared by grinding into small pieces, which are then subjected to a treatment in which the carbon-carbon composite material is impregnated with resin, after which the watch component is obtained by molding the treated pieces into the desired shape.

[0028] In either the first or second method variant, the treatment step includes a resinification step in which the carbon-carbon composite material is impregnated with resin. In the first method variant, the impregnation of the carbon-carbon material is carried out by infiltration of the resin through the pre-machined surface. In the second method variant, the impregnation of the carbon-carbon material is carried out by mixing the ground carbon-carbon material with the resin. This impregnation has the advantage of improving the properties of the carbon-carbon material, including mechanical strength, hermeticity, UV resistance, aesthetics, and dermatological compatibility.

[0029] Preferably, the carbon-carbon composite part is made from a brake pad or disc for a race car, or a brake disc for an aircraft, or a tile for a space shuttle.

[0030] The carbon-carbon composite part may be a new part, or advantageously, the carbon-carbon composite part is a used part, in which case the method according to the invention contributes to meeting the ninth of the 17 United Nations Sustainable Development Goals.

[0031] According to a second aspect, the present invention is directed to a timepiece component obtainable by a method according to the first aspect of the invention.

[0032] The timepiece components according to the invention may in particular be the case, back cover, middle case, bezel, but also the dial, hands, band links, the entire band, the plate, bridges, in particular the main bridge, the wheel train bridge, the escapement bridge, the anchor bridge, the balance bridge and the crown.

[0033] The invention will be better understood upon reading the following detailed description of two particular embodiments, given entirely by way of non-limiting example, of a method for manufacturing a horological component consisting of a single-moulded case-middle-dial assembly according to the invention. [Brief explanation of the drawings]

[0034] [Figure 1] 1 shows a top perspective view of an initial part made of carbon-carbon composite material before the implementation of the first or second variant of the method. [Figure 2] 1 shows a digitally controlled machine tool for implementing a first variant of the method, in a top perspective view, the machine tool with a first machining support used for the first, second and third machining steps. [Figure 3] 3A and 3B represent a digitally controlled machine tool for the implementation of a first variant of the method, and 4A and 4B show a machine tool with a second machining support used for the fourth machining step in a perspective top view. [Figure 4]1A and 1B represent a digitally controlled machine tool for the implementation of a first variant of the method, and 1C show a top perspective view of the machine tool with a third machining support used for the fifth machining step. [Figure 5] 2 to 4 show a digitally controlled machine tool for the implementation of a first variant of the method, and in a bottom perspective view show parts of the machine tool not shown in FIGS. [Figure 6] 1 shows a first machining support in an exploded perspective view. [Figure 7] 1 shows a perspective view of an initial part held by a first machining support before a first machining step; [Figure 8] 2 shows a perspective view of the part obtained after the first machining step of the first variant of the method; [Figure 9] FIG. 9 is an enlarged view of zone X in FIG. 8. [Figure 10] 1 illustrates in perspective view the resinification operation of the treatment step of a first variant of the method; [Figure 11] 2 shows a perspective view of the part obtained after the second machining step of the first variant of the method; [Figure 12] FIG. 12 is an enlarged view of zone X in FIG. [Figure 13] 1 shows a perspective view of the part obtained after the third machining step. [Figure 14] 4 shows the second machining support of FIG. 3 in an exploded perspective view. [Figure 15] 14 shows in perspective view the part of FIG. 13 mounted on a second machining support for the fourth machining step. [Figure 16] 1 illustrates in perspective view a fifth machining step performed on the part resulting from the fourth machining step. [Figure 17] The final watch component obtained after the fifth machining step is shown in a perspective view from below. [Figure 18] 1 illustrates the grinding step of a second variant of the method in a perspective view. [Figure 19]1 illustrates in perspective view the filling operation of the molding step of a second variant of the method; [Figure 20] FIG. 1 is an exploded top perspective view of a die used for the forming step. [Figure 21] FIG. 1 is a partially exploded bottom perspective view of a die used for the forming step. [Figure 22] 1 illustrates in perspective view the pressing operation of the molding step of a second variant of the method; [Figure 23] 1 illustrates in perspective view the demolding operation of the molding step of a second variant of the method; DETAILED DESCRIPTION OF THE INVENTION

[0035] A first variant embodiment of the method will be described with reference to FIGS.

[0036] Referring first to FIG. 1, there is represented an initial part 100 intended for the manufacture of a timepiece component by carrying out a first variant of the method according to the invention or by carrying out a second variant of the method according to the invention.

[0037] According to the invention, the initial part 100 is made of a carbon-carbon composite material.

[0038] In the illustrated embodiment, the initial part 100 is a brake pad for a racing vehicle, consisting of an active part 102 that is subjected to frictional stresses when the vehicle is braking, and a fastener part 104 that is provided to hold the brake pad in the vehicle's caliper. The active part 102 and the fastener part 104 of the part 100 are milled in one piece from a blank block of carbon-carbon composite material.

[0039] 2 to 5 represent a digitally controlled machine tool 10, such as a 4-axis digital milling machine of the ISEL ICP 2015 type, having a spindle 12 allowing high rotational speeds, for example in excess of 15,000 revolutions per minute.

[0040] As shown in more detail in Figure 5, the machine tool 10 also includes a tool holder 14 driven by the spindle 12, and a machining tool, identified by the numeral 16, which is changed as needed as the machining steps progress. The machining tool 16 is diamond coated to reduce tool wear due to friction with dust generated during the machining steps.

[0041] The machine tool 10 also includes a table 18 on which the base 24 of the first machining support 20 (FIG. 2), the second machining support 30 (FIG. 3) and the third machining support 40 (FIG. 4) are sequentially mounted to perform the machining steps of the method.

[0042] The machining supports 20, 30, 40 are adapted not only to the different machining steps, but also to the shapes and dimensions of the parts to be machined in the different steps of the method, and to the shape and dimensions of the desired final watch component.

[0043] The first machining support 20 illustrated in FIGS. 6 and 7 includes a frame 22 and a base 24 .

[0044] The base 24 is fixed to the table 18 (FIG. 2) via the centering cavity 2 (see FIG. 4) using screws, for example two M8 type screws (not shown), which cooperate with two fixing holes 4 present on the table 18 (FIG. 4).

[0045] In use, the frame 22 is positioned on the base 24 by means of a positioning cavity 26 realized on said base 24 (FIG. 6).

[0046] The frame 22 and base 24 are assembled together using assembly screws 50 which cooperate with holes 60 in the frame 22 and holes 62 in the base 24 .

[0047] The frame 22 and base 24 are machined metal components, for example, the frame 22 is made of steel and the base 24 is made of aluminum, that are specifically designed and dimensioned to support the part to be machined during the first, second, and third machining steps described below.

[0048] 7 shows the initial part 100 being forcibly held in the frame 22 by means of set screws 52 which cooperate with threaded holes 64 in said frame 22. In the illustrated embodiment, the set screws 52 are distributed around the periphery of the frame 22 and there are ten of them.

[0049] The assembly constituted by the frame 22 and the initial part 100 is then fitted onto the base 24 and fixed to the base by means of screws 50, of which there are four in the illustrated embodiment, for example CHC M5 type screws.

[0050] The initial part 100 is placed on the first machining support 20. In the illustrated embodiment, this initial part is placed in such a way that its active part 102 is exposed to the machining tool 16 (FIG. 5) under machining conditions on the machine tool 10 (FIG. 2).

[0051] The initial part 100 is subjected to a first machining step illustrated in Figure 8, which consists of a preliminary machining operation by milling the exposed surfaces to carve out the concave shape. The displacement of the machining tool 16 is parameterized in such a way as to machine a blank 110 having the desired shape.

[0052] The parameterization of the displacement of the machining tool 16 is likewise adjusted in such a way as to provide on the blank 110: a surface of said blank 110 that is higher than the reference surface, said surface including a first space 112 having a portion that exceeds a predefined thickness; a surface of said blank 110 lower than the reference surface, said surface comprising a second space 114 having a portion lower than a predefined thickness and a third space 116 having a portion lower than a predefined thickness;

[0053] Preferably, the excess thickness is between 0 mm and 1 mm, and even more preferably, the excess thickness is 0.3 mm.

[0054] Preferably, the lower thickness is between 0 mm and 0.2 mm, and even more preferably, the lower thickness is 0.1 mm.

[0055] 9 shows the arrangement of the first spaces 112 beyond the thickness, located on the surface that will be visible from the outside on the final watch component obtained by the method. The presence of these spaces makes it possible to avoid the sudden appearance of surface defects when carrying out subsequent machining steps.

[0056] FIG. 9 also shows a second underthickness space 114, positioned on a surface that will become a contact surface of the final watch component obtained by the method, such as a packing support in the case of a middle case.

[0057] Finally, FIG. 9 shows a third underthickness space 116 localized on the surface that is to become the decorative surface of the final timepiece component obtained by the method.

[0058] The initial part 100 on whose surface the blank 110 is formed then constitutes a first intermediate part 120 resulting from the first machining step, which has a pre-machined surface with a number of irregularities.

[0059] The first intermediate part 120 is always maintained in the frame 22 of the machining support 20 by means of set screws 52. The frame 22 is disassembled from the base 24 of the machining support 20, which remains fixed to the table 18 of the machine tool 10 by means of the centering cavity 2.

[0060] The first intermediate part 120 is then subjected to processing steps including a resinification operation, then a vacuum operation with simultaneous heat curing, then a post-curing operation.

[0061] The resinification operation is illustrated in Figure 10. This operation consists of pouring resin 122 into blank 110, for example using a container 124, so as to at least partially fill said blank 110.

[0062] Resin 122 is a thermosetting epoxy resin. Indeed, epoxy resin has excellent mechanical robustness adapted to the stresses exerted on the final watch component during use. Epoxy resin also has a low shrinkage rate compared to other resins. Epoxy resin is also valued for its superior visual appearance of the final watch component due to its excellent UV resistance and the ready availability of transparent epoxy resins.

[0063] Optionally, color additives can be added to the thermosetting resin for decorative purposes.

[0064] The drawing does not illustrate the vacuuming operation, which consists of placing the frame 22 carrying the first intermediate part 120, into which the resin 122 has been poured, in a sealed container and drawing a vacuum inside said container, which can last up to 24 hours at a temperature of approximately 20-25 degrees Celsius inside the container.

[0065] The vacuuming operation has the effect of favoring the penetration of the resin 122 into the carbon-carbon material, while removing any residual air bubbles that may be present in the resin 122 after filling the blank 110 .

[0066] The vacuum operation is complemented by a heat curing operation (not shown), which can be carried out in an open space with the frame 22 removed from the airtight container, or under vacuum with the frame 22 remaining in the airtight container. Depending on the resin used and the desired hardness of the final watch component to be produced, the heat curing operation can last from 3 to 24 hours at temperatures that can reach 150 degrees Celsius. The heat curing operation has the effect of initiating polymerization of the resin.

[0067] The heat cure operation is followed by a post-cure operation which has the effect of bringing the resin 122 to its maximum hardness.

[0068] The first intermediate part 120 into which the resin 122 is poured and hardened during a processing step thereafter constitutes the second intermediate part 130 .

[0069] The resin 122 penetrates into the carbon-carbon composite material. The penetration distance is at least 0.5 millimeters. The presence of the resin 122 makes it possible to remove irregularities resulting from the first machining step and obtain a smoother surface, especially in the second spaces 114 and the third spaces 116, which have an undersized thickness.

[0070] The frame 22 carrying the second intermediate part 130 is reassembled to the base 24 which remained fixed to the table 18 of the machine tool 10. The frame 22 is returned to its original location on the base 24 by means of the locating cavities 26.

[0071] A second machining step similar to the first machining step is then performed on the second intermediate part 130 .

[0072] The second machining step consists of so-called machining by milling, which has the effect of removing the resin 122 poured into the blank 110 and hardened during the processing step.

[0073] The parameterization of the machining tool 16 is now adjusted in such a way as to remove the spaces 112 beyond the first thickness that were left on the blank 110 during the first machining step.

[0074] The parameterization of the machining tool 16 is similarly adjusted to return the second under-thickness space 114 and the third under-thickness space 116 to the reference surface level.

[0075] The second machining step leaves a residual resin layer 122 filling the second under-thickness space 114 and the third under-thickness space 116. The blank 110 then has a generally uniform surface with certain zones 134, 136 covered with resin. These zones 134, 136 may be destined for contact with other parts, such as the packing support zone 134 of the final watch component. These zones may also be destined for the decorative zone 136 of the final watch component. In the case of the decorative zone 136, the thickness of the resin influences the opacity of the decoration. Color additives, optionally added previously to the resin 122, also contribute to the decorative effect.

[0076] The part resulting from the second machining step is a third intermediate part 140, illustrated in Figures 11 and 12. Depending on the nature of the desired final watch component, several finishing machining operations are performed. In the illustrated embodiment, fixing holes 138 are provided on the machined surface, which will serve to fix other elements onto the final watch component during assembly of the watch.

[0077] The third intermediate part 140 resulting from the second machining stage has the final appearance and final dimensions of the upper surface of the single-moulded case-middle-dial assembly.

[0078] This part is still maintained on the first machining support 20 mounted on the table 18 of the machine tool 10 for the third machining step consisting of a molding operation which results in a fourth intermediate part as illustrated in FIG. 13.

[0079] The fourth intermediate part 150 is then placed on the second machining support 30 to be subjected to a fourth machining step to form the lower face of the final watch component.

[0080] The second machining support 30 is shown in exploded view in Figure 14. It is a machined part specially designed and dimensioned to accommodate the fourth intermediate part 150.

[0081] The second machining support 30 is made up of an approximately parallelepipedal block, one of whose faces is carved to define the counterform 32 of the fourth intermediate part 150, said counterform 32 observing very fine tolerances of the order of hundredths of a millimeter.

[0082] The second machining support 30 comprises two lateral blocks 36 separated by a longitudinal opening 38 which is open on one side and closed on the opposite side, inside which the counterform 32 is located.

[0083] The second machining support 30 also includes a through-hole 34 passing transversely through each of the two side blocks 36. Said through-holes 34 are intended to accommodate clamping means 80, 82, 84 which, in use, serve to bring the two side blocks 36 significantly closer together.

[0084] In the illustrated embodiment, the fastening means 80,82,84 include a fastening screw 84 cooperating with metal inserts 80,82.

[0085] Preferably, the second machining support 30 is made of a material that does not risk modifying the fourth intermediate part 150 when fastened, in particular a plastic material that may be, for example, a plastic material commercially available under the name Delrain®.

[0086] The second machining support 30 is fixed to the table 18 (FIG. 3) via the centering cavity 2 (see FIG. 4) by means of screws, for example two M8 type screws (not shown) which cooperate with threaded holes 72 in the base 70 of said third machining support 30 and with fixing holes 4 present on the table 18 (FIG. 4).

[0087] Figure 15 shows a fourth intermediate part 150 mounted on the second machining support 30. This intermediate part has a lateral surface 152 formed by molding during the third machining step. This intermediate part has a first end surface (not shown in Figure 13) formed by milling during the second machining step and oriented towards the bottom of the longitudinal opening 38 of the second machining support 30. Finally, this intermediate part has a second end surface 154 opposite the first end surface and exposed to the machining tool 16 (Figure 3).

[0088] The fourth intermediate part 150 is placed on the second machining support 30 while being positioned in the counterform 32 of the second machining support 30 and maintained with high precision between the two side blocks 36 of the second machining support 30, which are brought close to each other by the clamping means 80, 82, 84 and the elasticity of the material of which the side blocks 36 are made.

[0089] A fourth machining step is then carried out on the fourth intermediate part 150, consisting of milling its second end face 154, which will become the lower face of the final timepiece component.

[0090] The fourth intermediate part 150 with the second end face machined thereon then constitutes a fifth intermediate part 160, which is placed on the third machining support 40 for being subjected to the fifth machining step, as illustrated in FIG. 16.

[0091] The third machining support 40 is fixed to the table 18 of the machine tool 10 via frame elements 42, 44 (FIG. 4).

[0092] The positioning of the fifth intermediate part 160 on the third machining support 40 is achieved by the presence of counterforms (not shown) on the lateral faces of the fifth intermediate part 160 on the third machining support 40 and by the action of a central screw which is able to separate the counterforms due to the elasticity of the material constituting the third machining support 40, namely aluminium in the illustrated embodiment.

[0093] The fifth machining step consists in finishing the fifth intermediate part 160 so as to obtain the final watch component 170. The finishing consists in producing cavities and other indentations and decorations for the cooperation of said watch component 170 with other watch components at the time of final assembly to form a watch.

[0094] In the embodiment illustrated in FIG. 17, the final timepiece component 170 obtained by the first variant of the method according to the invention is a single-moulded case-middle-dial assembly.

[0095] The method according to the first variant illustrated in FIGS. 2 to 17 includes the following steps. - 1st machining step: Pre-machining, milling of the top surface - Processing Steps Resinification work · Vacuuming work · Heat curing work · Post-curing work - Second machining step: so-called milling of the top surface - Third machining step: Impression - Fourth machining step: milling the bottom face - Fifth machining step: finishing

[0096] A second variant embodiment of the method will now be described with reference to Figures 18 to 23.

[0097] According to this second variant, the manufacturing method according to the invention comprises a step of grinding the initial part made of carbon-carbon composite material.

[0098] The crushing step is illustrated in Figure 18. The initial part 200 made of carbon-carbon composite material is crushed in a crusher 210, for example a jaw crusher of the RETSCH BB 400XL type. The initial part 200 breaks into a large number of small pieces 220.

[0099] Preferably, the grinder 210 is adjusted so that the pieces 220 obtained by grinding have a predefined maximum length of, for example, 2 millimeters. The size of the pieces influences the fineness of detail of the final watch component obtained by the second variant of the method.

[0100] The processing steps include resinification and heating operations.

[0101] This processing step is complemented by pouring, pressing and demolding operations.

[0102] The two steps of processing and shaping are combined in the following order: - Resinification work - Pouring work - Heating and pressure application - Demolding work

[0103] The resinification operation (not shown) consists of mixing the pieces 220 obtained by grinding with a thermosetting resin, the selection criteria of which are the same as in the first variant of the method and will not be explained again: epoxy resin is preferred.

[0104] Optionally, the resulting mixture 240 may be enriched with additives such as precious metals or colorants.

[0105] The pouring operation illustrated in FIG. 19 consists of pouring a mixture 240 of ground material pieces 220 and resin into a cavity 250 of a mold 260 using, for example, a container 242 .

[0106] The die 260 is shown in exploded view in Figures 20 and 21. The die is made of hardened steel to provide the ability to withstand deformation during the pressing operation.

[0107] The mold 260 includes a plurality of elements, four in the illustrated embodiment, 262, 264, 266, 268. Each element 262, 264, 266, 268 has a cavity portion 272, 274, 276, 278. More specifically, the bottom element 262 includes a bottom cavity portion 272, the top element 264 includes an top cavity portion 274, and the two side elements 266, 268 each include a side cavity portion 276, 278.

[0108] The lower element 262 is assembled with two lateral elements 266, 268 using assembly screws 254, which makes it possible to realize a cavity 250 into which the mixture 240 is poured (FIG. 19). The cavity 250 is then closed with an upper element 264, as illustrated in FIG. 22.

[0109] In a manner known per se, the upper element 268 is provided with holes 280 for the evacuation of air during the pressurization operation, the diameter of which is selected so as to prevent the escape of resin together with the air.

[0110] The collection of cavity portions 272, 274, 276, 278 constitutes one complete cavity (not shown) having the final dimensions and shape of the watch component that it is desired to obtain.

[0111] Optionally, stiffening inserts (not shown) can be incorporated into cavity 250 of mold 260 to increase the strength and tightness of the final molded watch component. The stiffening inserts can be made of metal, composite material, or any other suitable material within the reach of one skilled in the art.

[0112] The mixture 240 contained in the complete cavity is then subjected to a pressing operation, during which the mixture is compressed in a closed mold (FIG. 22) under pressure, for example in a hydraulic press (not shown). The mixture 240 is subjected to pressures that can range from a few kilograms per square centimeter to several hundred kilograms per square centimeter. The pressing has the effect of increasing the cohesive forces between the components of the mixture 240, namely the ground pieces 220, the resin, and possibly additives.

[0113] Simultaneously with the pressure application, a heating operation is applied which has the effect of polymerizing the resin. This operation is achieved by means of a heating resistor (not shown) located in the transverse hole 282 of the lower element 262 of the mold 260 (FIG. 22). The temperature reached during the heating operation, as well as its duration, depends on the resin used and is similar to the temperatures and durations indicated for the first variant embodiment of the method.

[0114] The demolding operation is illustrated in FIG. 23, which shows the final watch component 270 above the lower element 262 of the mold 260 with the lower cavity portion 272 .

[0115] The method according to the second variant includes an optional chip washing step, not illustrated in the figures, following the step of breaking the initial parts 200 into chips and preceding the treatment step. The washing can be carried out, for example, by spraying with a cleaning agent or by immersing the chips in a cleaning bath.

[0116] The washing step makes it possible to remove from the ground material any residues that may be harmful to the molding and that may come from fats and oils that have come into contact with the pieces during the grinding process. The washing agent is chosen for its ability to dissolve fats and oils and for its volatility. Acetone is preferred.

[0117] The method according to the second variant includes an optional sieving step (not shown) following the step of grinding the carbon-carbon composite parts into pieces and preceding the processing step, which can be carried out, for example, using a machine of the TAMISEUSE AS 200 BASIC type.

[0118] The sieving step has the effect of removing any chips of a size greater than 2 millimeters that may be present in the grinding, as well as any impurities that may possibly be present in the initial part 200 in the case of used parts.

[0119] In the illustrated embodiment, the final timepiece component 270 obtained by the second variant of the method according to the invention is a single-moulded case-middle-dial assembly.

[0120] Depending on the nature of the final watch component obtained after demoulding, a finishing step can optionally be envisaged, which may be manual if it is a step of removing resin residues, polishing or even deburring the final watch component, or may use a machining process similar to that of the fifth step of the first embodiment of the first variant of the method if it is a step of creating cavities and other reliefs and decorations for cooperation of said watch component 170 with other watch components at the time of final assembly to form a wristwatch.

[0121] The method according to the second variant illustrated in FIGS. 18 to 23 includes the following steps. - Crushing step - optional washing step and / or optional sieving step - Processing Steps Resinification work Heating work - Molding step Filling work Pressurized work Demolding work - Optional finishing steps by hand or machine [Prior art documents] [Non-patent literature]

[0122] Article "Carbon-carbon composites" by Jacques Thebault and Pierre Olry, published in the magazine l'actualite chimique - March-April 2006 - Issues 295-296 [Explanation of symbols]

[0123] 100 Carbon-carbon composite parts 170 Clock Components 200 Carbon-carbon composite parts 270 Clock Components

Claims

1. 1. A method for manufacturing a watch component (170, 270), comprising a step of treating a carbon-carbon composite part (100, 200) including a resinification operation, characterized in that the carbon-carbon composite part (100, 200) is made from a brake pad or disc of a racing vehicle, or a brake disc of an aircraft, or a tile of a space shuttle, and the carbon-carbon composite part (100, 200) is a used part.

2. The method of any preceding claim, further comprising the step of machining the carbon-carbon composite part (100).

3. 3. The method of claim 2, wherein the processing step is preceded by a first machining step of one face of the part (100), during which spaces (112) are provided having portions exceeding a predefined thickness.

4. 4. A method according to claim 3, characterized in that spaces (114, 116) having a portion below the predefined thickness are likewise provided during the first machining step.

5. 4. The method of claim 3, wherein the processing step is followed by a second machining step applied to the same face of the part (100) as the first machining step.

6. 6. A method according to claim 2, wherein the treatment step comprises, in addition to the resinification operation, a vacuum operation and a heat curing operation simultaneously with the vacuum operation.

7. 7. The method of claim 6, wherein the processing step further comprises a post-cure operation following the simultaneous vacuum and heat curing operations.

8. 8. A method according to any one of claims 5 to 7, characterized in that it comprises at least one additional machining step after the second machining step.

9. 2. The method of claim 1, wherein the processing step is preceded by a step (220) of breaking down the carbon-carbon composite part (200) into pieces so as to obtain a crushed mass, and followed by a molding step.

10. 10. The method of claim 9, wherein the treating step comprises a heating operation.

11. 11. A method according to claim 10, characterized in that during the resinification operation, the grinds are mixed with the resin in such a way as to obtain a mixture (240).

12. 12. The method of claim 11, wherein the molding step comprises the operations of filling the mixture (240) into a mold (260), pressing, and demolding.

13. 13. The method of claim 12, wherein the pressing operation of the molding step is simultaneous with the heating operation of the treating step.

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