Mounting system using a conical elastic blocking element

Description

Field of invention

[0001] The invention relates to an assembly system using a conical elastic locking element allowing the assembly of a part whose material does not have a usable plastic domain, that is to say with a very restricted plastic domain, with a member comprising another type of material. Background of the invention

[0002] Current assemblies involving a silicon-based part are generally held together by gluing. This operation requires extremely fine application, which makes it expensive.

[0003] Document EP 2 273 322 discloses an assembly with an intermediate part deforming plastically between the bearing surface of an axis and housings of a silicon part to make the assembly integral.

[0004] Document EP 1 705 533 discloses an assembly with a cover comprising lugs intended to be received in housings of a silicon part to make the assembly integral.

[0005] Document CH 703 961 discloses an assembly with a cover provided with a rubber ring elastically deforming against a silicon part to press the silicon part against the bearing surface of an axis.

[0006] Document FR 419 826 discloses an assembly with an intermediate part provided with two shoulders and driven onto an axis, a first shoulder receiving the balance wheel and the second shoulder receiving the spiral collet.

[0007] GB 1 035 315 discloses a fixing of a dowel passing through a hole in a plate by means of stamping a plastic ring onto the through-hole portion of the dowel.

[0008] Document FR 1 259 251 discloses a fixing of a part provided with a rod passing through the hole of a plate using the force fitting of an elastomer ring on the rod of the part. Summary of the invention

[0009] The aim of the present invention is to overcome all or part of the drawbacks mentioned above by proposing an assembly without glue capable of securing a part whose material does not include a plastic domain with a member comprising a ductile material such as, for example, a metal or a metal alloy.

[0010] For this purpose, the invention relates to an assembly system according to the appended claim 1.

[0011] The configuration of the system advantageously makes it possible to secure the assembly consisting of the organ - part - locking element or even the locking washer without gluing with a conventional organ with controlled precision while guaranteeing that the part is not subject to destructive forces even if it is formed, for example, from a silicon-based material. Indeed, the Applicant was surprised to be able to secure the assembly consisting of the organ - part - washer, in particular in relative rotation, with such great structural simplicity because the prejudices regarding the mechanical resistance of parts, in particular those made from a silicon-based material, required until now that axial forces should not be applied to a part made from a material with little or no plastic domain.

[0012] In accordance with other advantageous characteristics of the invention: the third material comprises a metal or a metal alloy whose resistance to relaxation, after 10,000 hours at a temperature of 70°C, is at least equal to 50% of the applied force representing 75% of the stress necessary to obtain 0.2% of plastic deformation of the third material in order to maintain the solidarity of the organ - part - locking element assembly; the third material comprises copper, brass, nickel silver, Cu-Be alloy; the section along an axial cutting plane of the locking element has a ratio of the height to the width of between 0.1 and 5; the section along an axial cutting plane of the locking element has a ratio of the width of the part which flares out to the total width of between 0.1 and 0.95; the section along an axial cutting plane of the locking element has a ratio of the height of the part which flares out in relation to the total height of between 0.1 and 0.95;the internal wall of the locking element comprises, symmetrically to the substantially straight part, a second part which flares conically away from the substantially straight part; the locking element is chamfered in order to avoid any breakage of the second material; the second material is based on silicon such as silicon, quartz, silicon oxide, silicon nitride or silicon carbide; said at least one first material comprises a metal or a metal alloy; the axis and the bearing surface are formed.

[0013] Furthermore, the invention relates to a timepiece characterized in that it comprises at least one assembly system according to one of the preceding variants, the part not comprising a plastic domain which could be a wheel, an anchor or a hairspring.

[0014] Finally, the invention relates to a method of manufacturing an assembly system according to the appended claim 14.

[0015] The method of claim 14 advantageously makes it possible to simply, elastically and without possible relative displacement secure the assembly of the member - part - locking element, or even the washer. Indeed, advantageously according to the invention, only one locking element is added and deformed to induce a purely elastic peripheral pinching. It is also understood that such a method makes it possible to secure the assembly of the member - part - locking element by adapting to the manufacturing dispersions of the different constituents.

[0016] Finally, surprisingly, the axial force exerted by the peripheral part of the locking element during the process does not cause breakage of the second material based on material having little or no plastic domain. This technical advantage makes it possible to considerably simplify the assembly of a part based on material having little or no plastic domain on a pivoting axis. It is understood in particular that it is not necessary to provide glue, an additional locking cover or complementary overlapping shapes to secure the parts together and, in particular, with regard to the relative movements around the axis of rotation of the pivoting axis.

[0017] In accordance with other advantageous characteristics of the invention: step d) is stopped when the force applied by said tool is between 20% and 90% of the elastic limit stress of the third material; the third material comprises a metal or a metal alloy whose resistance to relaxation, after 10,000 hours at a temperature of 70°C, is at least equal to 50% of the force applied during step d) representing 75% of the stress necessary to obtain 0.2% of plastic deformation of the third material in order to maintain the solidarity of the organ - part - locking element assembly; the third material comprises copper, brass, nickel silver or Cu-Be alloy; the section along an axial cutting plane of the locking element has a ratio of the height to the width of between 0.1 and 5; the section along an axial cutting plane of the locking element has a ratio of the width of the part which flares out to the total width of between 0.1 and 0.95;the section along an axial cutting plane of the locking element comprises a ratio of the height of the part which flares out relative to the total height of between 0.1 and 0.95; the internal wall of the locking element comprises, symmetrically to the substantially straight part, a second part which flares out conically away from the substantially straight part; the locking element is chamfered in order to prevent any breakage of the second material; the second material is silicon-based such as silicon, quartz, silicon oxide, silicon nitride or silicon carbide; said at least first material comprises a metal or a metal alloy; the part is a watch mobile, a watch anchor or a watch balance spring. Summary description of the drawings

[0018] Other features and advantages will become clear from the description given below, for informational purposes only and in no way limiting, with reference to the attached drawings, in which: there Figure 1 is a perspective view of a blocking element according to the invention; Figure 2 is a sectional view along an axial plane of a locking element of the Figure 1 ; there Figure 3 is a graphical representation of the force applied during the process as a function of the axial position of the tool exerting said force; figures 4 to 8 are schematic sectional views of successive steps of the method according to the invention; Figure 9 is a sectional view along an axial plane of a locking element according to an alternative of the Figure 2 ; THE figures 10 And 11 are partial schematic views of a watch movement comprising assembly systems according to the invention. Detailed Description of Preferred Embodiments

[0019] As explained above, the invention relates to a system for assembling a part whose material does not have a usable plastic domain, that is to say with a very restricted plastic domain, with a member comprising another type of material.

[0020] This assembly system was designed for applications in the watchmaking industry. However, other fields are also suitable, such as aeronautics, jewelry, automotive, and tableware.

[0021] In the watchmaking field, this assembly is made necessary by the increasing share of fragile materials such as those based on silicon such as monocrystalline (or polycrystalline) silicon, doped or not, silicon oxide such as quartz or silica, monocrystalline or polycrystalline corundum or more generally alumina, silicon nitride and silicon carbide. For example, one can consider forming the balance spring, the balance wheel, the anchor, the bridges or even the mobiles such as the escape wheels totally or partially based on fragile materials.

[0022] However, the fact of always being able to use conventional steel axles whose manufacture is controlled, is a constraint which is difficult to reconcile with the use of parts which do not have a plastic domain. Indeed, during tests carried out, driving out a steel axle is impossible and systematically breaks fragile parts, i.e. parts which do not have a usable plastic domain. For example, it appeared that the shear generated by the entry of the metal axle into the opening of a silicon part systematically breaks the latter.

[0023] This is why the invention relates to an assembly system 1, 101, 121, 201 comprising a member 3, 103, 123, 203 made of at least a first material comprising an axis 2, 102, 122, 202 and a bearing surface 4, the axis 2 of the member being received in the opening 6 of a part 5, 105, 205 made of a second material based on a material having little or no plastic domain.

[0024] It is therefore understood that the axis 2, 102, 122, 202 and the bearing surface 4 may be formed using a single first material or that the axis 2, 102, 122, 202 and the bearing surface 4 of the member 3, 103, 123, 203 may be formed from several materials and / or several parts.

[0025] Advantageously according to the invention, the assembly system 1, 101, 121, 201 comprises a locking element 9, 19, 109, 129, 209 made of a third material arranged to elastically attach the part 5, 105, 205 between the bearing surface 4 of the member 3, 103, 123, 203 and the locking element 9, 19, 109, 129, 209. As best seen in the figure 8, advantageously according to the invention, the part 5 is pinched against the bearing surface 4 of the member 3 by the elastic force of the locking element 9. We immediately understand the simplicity of the assembly system 1, 101, 121, 201 according to the invention which does not require glue, an additional locking cover, complementary overlapping shapes or even plastic deformation such as creep.

[0026] According to the invention, the locking element 9, 19, 109, 129, 209 is a washer comprising an internal wall comprising a substantially straight portion 10, 20 on a portion HT -HE of the height HT of the locking element 9, 19, 109, 129, 209 which radially clamps the axis 2, 102, 122, 202 of the member 3, 103, 123, 203, the internal wall comprising, adjacent to the straight portion 10, 20, a portion 16, 26 which flares conically as it approaches the part 5, 105, 205 made of a second material so that only the peripheral portion 12, 13, 22, 23 of the locking element 9, 19, 109, 129, 209 exerts an axial and elastic force directly above the bearing surface 4 of the member 3, 103, 123, 203 in order to make the assembly of member 3, 103, 123, 203 - part 5, 105, 205 - locking element 9, 19, 109, 129, 209 integral.

[0027] To Figures 1 and 2, it can also be seen that the locking element 9, 19, 109, 129, 209 comprises an upper surface 11 intended to come into contact with a preferably flat tool 15 and a lower surface 12 intended to come into contact with the upper surface of the part 5, 105, 205.

[0028] Indeed, as explained below, surprisingly, the axial force exerted by the peripheral part 12, 13, 22, 23 of the locking element 9, 19, 109, 129, 209 during the process does not cause breakage of the second material based on material having little or no plastic domain. This technical advantage makes it possible to considerably simplify the mounting of part 5, 105, 205 on an axis 2, 102, 122, 202, for example, pivoting. This advantage is obtained in particular because the peripheral part 12, 13, 22, 23 of the blocking element 9, 19, 109, 129, 209 presses on the bearing surface 4 and does not overhang the bearing surface 4. It is therefore important that the surface of the blocking element 9, 19, 109, 129, 209 does not exceed that of the bearing surface 4.

[0029] In the example illustrated in Figures 1 and 2 , the blocking element 9 is asymmetrical, that is to say that the surfaces 11 and 12 cannot be indifferently the upper or lower one. However, this asymmetry is only optional.

[0030] Indeed, according to another variant illustrated in the Figure 9 , preferably applied to avoid handling errors during manufacturing, the locking element 19 can also be symmetrical. In this variant the internal wall around the hole 18 comprises, symmetrically to the straight part 20, a first part 26 which flares conically and a second part 28 which flares conically, both moving away from the straight part 20.

[0031] The elastic mounting of the locking element 9, 19, 109, 129, 209 is advantageously obtained by using a third material which comprises a metal or a metal alloy whose resistance to relaxation is at least equal to 50% of the applied force. The tests making it possible to determine this percentage were carried out after 10,000 hours at a temperature of 70°C and under a force of 75% of the stress necessary to obtain 0.2% of plastic deformation, i.e. substantially 75% of the elastic limit of the third material.

[0032] This resistance higher than 50% was observed when the third material included copper, brass, nickel silver, arcap alloy and even higher than 85% when the third material included pfinodal alloy, spinodal alloy, durnico alloy, durimphy alloy, Cu-Be alloy and 20AP steel.

[0033] For considerations specific to watchmaking, the blocking element 9, 19, 109, 129, 209 is, even more preferably, chosen from the above materials which do not have ferromagnetic properties in order to be relatively insensitive to magnetic fields, i.e. copper, brass, nickel silver, arcap alloy, pfinodal alloy, spinodal alloy, Cu-Be alloy and durimphy alloy.

[0034] As best visible to the Figures 1 and 2, preferably according to the invention, the section along an axial cutting plane of the locking element 9, 19, 109, 129, 209 has a ratio (HT / LT ) of the height HT relative to the width LT of between 0.1 and 5. Thus, it is important to choose the length LT carefully to have a peripheral part 12, 13, 22, 23 sufficiently far from the center of the axis D to obtain a lever arm high enough to provide sufficient pinching for securing. At the same time, a height HT must also be chosen carefully to have a minimum height to sufficiently protect the second material based on material having little or no plastic domain and a maximum height to always obtain the intermediate deformation explained below. It is therefore understood that the ratio HT / LT must be adapted according to the intended applications.

[0035] In addition, the geometry of the flared portion 16, 26 of the locking element 9, 19, 109, 129, 209 also provides the possibility of customizing the height HE and the width LE over which the portion 16, 26 flares from the straight portion 10, 20. It is immediately understood that the peripheral portion 13, 23 in contact with the part 5, 105, 205 can thus be directly limited to the lower face 12, 22 by the value of the width LE chosen for the flared portion 16, 26.

[0036] Preferably, the section along an axial cutting plane of the locking element 9, 19, as visible in Figures 2 and 9 , has a ratio (HE / HT) of the height HE of part 16, 26 which flares out in relation to the total height HT of between 0.1 and 0.95. In addition, the same section visible at Figures 2 and 9 has a ratio (LE / LT) of the width LE of the part 16, 26 which flares out in relation to the total width LT of between 0.1 and 0.95.

[0037] The variant illustrated in the Figure 9 being applied preferentially to avoid handling errors during manufacturing, the HE' / HT and LE' / LT ratios of the second part 28 which flares conically away from the straight part 20 are therefore identical respectively to the HE / HT and LE / LT ratios of the second part 26 which flares conically away from the straight part 20.

[0038] However, by losing the advantage of being able to mount the lower face 22 and the upper face 21 indifferently, the variant of the Figure 9 can be modified so that the locking element 19 is not symmetrical, i.e. does not have identical flared portions 26 and 28 on each side of the straight portion 20 of the internal wall around the hole 18.

[0039] According to another preference, the locking element 9, 19, 109, 129, 209 is chamfered in order to avoid any breakage of the second material based on material having little or no plastic domain. Indeed, as explained below depending on the geometry of the intermediate deformation, a chamfer can prevent the locking element 9, 19, 109, 129, 209 from coming into contact on the upper surface of the part 5, 105, 205 by a sharp edge capable of generating too much stress and / or pressure on a minimal surface.

[0040] Thus, advantageously according to the invention, said at least one first material formed for the member 3, 103, 123, 203 can comprise a wide variety of materials such as, for example, a metal or a metal alloy.

[0041] The method of manufacturing a first embodiment of assembly system 1 according to the invention illustrated in Figure 10 is explained below with reference to the figures 3 to 8 .

[0042] The method comprises a first step a) consisting of forming each part of the assembly system 1. Thus, step a) comprises a phase intended to form a member 3 in at least a first material comprising an axis 2 and a bearing surface 4 which may or may not be shaped and a second phase intended to form a part 5 in a second material based on a material which does not or does not have a plastic domain with an opening 6.

[0043] Finally, step a) comprises a third phase intended to form a locking element 9 in the form of a washer based on a third material whose hole 8 is smaller than the axis 2 of the member 3 and whose internal wall comprises a substantially straight part 10 on a part HT -HE of the height HT of the locking element 9 and a part 16 which flares conically away from the straight part 10. It is understood that during step a), the order of execution of the phases has no importance.

[0044] The process continues with a second step b) consisting of passing without constraint the axis 2 of the member 3 into the opening 6 of the part 5. This step b) can be seen at Figure 4 .

[0045] Step c) continues the process and includes a first phase intended to place the axis 2 against the hole 8 of the locking element 9, taking the precaution that the part 16 which flares is opposite the part 5. In fact, a reverse assembly does not allow assembly. This first phase of step c) can also be seen at Figure 4 .

[0046] At this Figure 4 , we also notice a tool 15. This tool 15 is preferably flat, that is to say has a substantially flat surface 14 intended to come into contact with the upper face 11 of the blocking element 9. We thus note that only the variant of the blocking element 19 which is symmetrical as illustrated in Figure 9, allows to eliminate assembly errors between the upper face 11 and the lower face 12.

[0047] Step c) continues with a second phase intended to forcefully slide the locking element 9 against the axis 2 using the tool 15 in order to deform the locking element 9 so that the peripheral part 13 of the locking element 9 is closest to the part 5 as illustrated in Figure 5 We understand that this second phase could be likened to a hunt.

[0048] This elastic intermediate deformation, which can cause point plastic deformations at the level of the straight part 10, gives the impression that the locking element 9 is a Belleville washer. However, this geometry is not stable, that is to say not a plastic deformation like creep, and only induced by the force of the tool 15. This elastic intermediate deformation is made maximum by the use of the hole 8 of the locking element 9 smaller than the axis 2 of the member 3 and the use of the tool 15 whose surface 14 is substantially flat.

[0049] This elastic intermediate deformation is of great importance for the future assembly system 1 in that it applies the future axial stress to the part 5 as illustrated in Figure 6, not as close as possible to the axis 2 but, via the lever arm of width LT of the blocking element 9, at the level of the peripheral part 13 of the blocking element 9. It is therefore understood that the section of the bearing surface 4 of the member 3 must also preferably be substantially equal to or greater than that of the blocking element 9 in order to allow the peripheral part 13 to exert an axial and elastic force directly above the bearing surface 4 of the member 3.

[0050] In simple terms, the method ends with step d) consisting of stopping and removing the tool 15 when a predefined force, lower than the elastic limit stress of the third material, is reached between the tool 15 and the bearing surface 4 of the member 3. Indeed, once the elastic pinching has been carried out between the peripheral part 13 of the locking element 9 in line with the bearing surface 4 of the member 3, the tool 15 is used to bring the straight part 10 closer to the internal wall as close as possible to the part 5 without exceeding, at the peripheral part 12, 13, the elastic limit stress of the third material used for the locking element 9.

[0051] It is therefore understood that once the tool 15 has been removed, it is not desired that the entire width (LT -LE) of the lower face 12 of the locking element 9 exerts a stress against the part 5 but only or mainly its peripheral part 13. It is immediately understood that the peripheral part 13, 23 in contact with the part 5, 105, 205 can thus be directly limited to the lower face 12, 22 by the value of the width LE chosen for the flared part 16, 26.

[0052] The joining of the assembly comprising member 3 - part 5 - locking element 9 is therefore exerted solely or mainly by an axial and elastic force of the peripheral part 13 or of the lower face 12 of the locking element 9 in line with the bearing surface 4 of the member 3 combined with the radial clamping of the straight part 10 of the internal wall of the locking element 9 against the axis 2 of the member 3.

[0053] There Figure 3is a graphical representation of the force applied by the tool 15 during the above process as a function of the axial position of the tool 15. From arrow A, the second phase of step c) begins as illustrated in Figure 5 . From arrow B, the peripheral part 13 of the locking element 9 begins to pinch the part 5 as shown in Figure 6 . From arrow C, the straight part 10 of the internal wall of the blocking element 9 is brought as close as possible to the part 5 as illustrated in Figure 7 and any additional force from the tool 15 exerts an internal stress on the locking element 9 without impacting the geometry of the locking element 9.

[0054] It is therefore understood that the steps of the manufacturing process as well as the elements of the assembly system are very simple and very easy to implement. Thus, according to a first embodiment illustrated in Figure 10, it is possible to fix a hairspring 5 on a balance shaft 2, using an assembly system 1 according to the invention. To do this, the collet 7 of the hairspring is secured between the pivot 3 and the locking element 9.

[0055] In order to minimize the risk of plastic deformation of the locking element 9, 109, 129, 209, step d) is stopped when the force applied by the tool 15 is between 20% and 90% of the elastic limit stress of the third material. Of course, the percentage must be adapted according to the intended application. During the tests, it appeared that stopping step d) gave complete satisfaction when the force applied by the tool 15 is substantially equal to 75% of the elastic limit stress of the third material.

[0056] As explained above, the elastic mounting of the locking element 9, 19, 109, 129, 209 is advantageously obtained by using a third material which comprises a metal or a metal alloy whose resistance to relaxation is at least equal to 50% of the applied force.

[0057] The tests to determine this percentage were carried out after 10,000 hours at a temperature of 70°C and under a force of 75% of the stress necessary to obtain 0.2% plastic deformation.

[0058] The resistance higher than 50% was observed when the third material included copper, brass, nickel silver, arcap alloy, and even higher than 85%, when the third material included pfinodal alloy, spinodal alloy, durnico alloy, durimphy alloy, Cu-Be alloy and 20AP steel.

[0059] For considerations specific to watchmaking, the blocking element 9, 19, 109, 129, 209 is, even more preferably, chosen from the above materials which do not have ferromagnetic material in order to be relatively insensitive to magnetic fields, i.e. copper, brass, nickel silver, arcap alloy, pfinodal alloy, spinodal alloy, Cu-Be alloy and durimphy alloy.

[0060] As best visible to the Figures 1 and 2, preferably according to the invention, the section along an axial cutting plane of the locking element 9, 19, 109, 129, 209 has a ratio (HT / LT ) of the height HT relative to the width LT of between 0.1 and 5. Thus, it is important to choose the length LT carefully to have a peripheral part 13, 23 sufficiently far from the center of the axis D to obtain a lever arm high enough to provide sufficient stress for the joining. At the same time, a height HT must also be chosen carefully to have a minimum height to sufficiently protect the second material having little or no plastic domain and a maximum height to always obtain the intermediate deformation explained below. It is therefore understood that the ratio HT / LT must be adapted according to the intended applications.

[0061] In addition, the geometry of the flared portion 16, 26 of the locking element 9, 19, 109, 129, 209 also provides the possibility of customizing the height HE and the width LE over which the portion 16, 26 flares from the straight portion 10, 20. It is immediately understood that the peripheral portion 13, 23 in contact with the part 5, 105, 205 can thus be directly limited to the lower face 12, 22 by the value of the width LE chosen for the flared portion 16, 26.

[0062] Preferably, the section along an axial cutting plane of the locking element 9, 19, as visible in Figures 2 and 9 , has a ratio (HE / HT) of the height HE of part 16, 26 which flares out in relation to the total height HT of between 0.1 and 0.95. In addition, the same section visible at Figures 2 and 9 has a ratio (LE / LT) of the width LE of the part 16, 26 which flares out in relation to the total width LT of between 0.1 and 0.95.

[0063] The variant illustrated in the Figure 9 being applied preferentially to avoid handling errors during manufacturing, the HE' / HT and LE' / LT ratios of the second part 28 which flares conically away from the straight part 20 are therefore identical respectively to the HE / HT and LE / LT ratios of the second part 26 which flares conically away from the straight part 20.

[0064] However, by losing the advantage of being able to mount the lower face 22 and the upper face 21 indifferently, the variant of the Figure 9 can be modified so that the locking element 19 is not symmetrical, i.e. does not have identical flared portions 26 and 28 on each side of the straight portion 20 of the internal wall around the hole 18.

[0065] According to another preference, the locking element 9, 19, 109, 129, 209 is chamfered in order to avoid any breakage of the second material. Indeed, as explained above depending on the geometry of the intermediate deformation, a chamfer can prevent the locking element 9, 19, 109, 129, 209 from coming into contact on the upper surface of the part 5, 105, 205 by a sharp edge likely to generate too much stress on a minimal surface.

[0066] Thus, advantageously according to the invention, said at least one first material formed for the member 3, 103, 123, 203 may comprise a wide variety of materials such as, for example, a metal or a metal alloy. It is therefore understood that the axis 2, 102, 122, 202 and the bearing surface 4 may be formed using a single first material or that the axis 2, 102, 122, 202 and the bearing surface 4 of the member 3, 103, 123, 203 may be formed from several materials and / or several parts.

[0067] It is also understood that, thanks to the method according to the invention, the second material based on material having little or no plastic domain can comprise, in particular, silicon, quartz, corundum, silicon oxide, silicon nitride or silicon carbide without risk of breakage.

[0068] There Figure 11 shows other embodiments of assembly systems 101, 121, 201 according to the invention in the field of watchmaking. An anchor 105, for example, may comprise two assembly systems 101, 121 according to the invention intended respectively to secure the pin 103 and the stem 123, with the rod 107.

[0069] As visible at the Figure 11, each assembly system 101, 121 comprises the rod 107 which is secured between the axis 102 of the dart 103 or the axis 122 of the rod 123 and the locking element 109, 129. It is therefore understood that each assembly system 101, 121 is sufficiently strong not to generate relative movements between its constituents.

[0070] In the same figure, an escape wheel, and more generally the wheel 205, comprises, by way of example, an assembly system 201 intended to secure a pivot 203, with the wheel 205. As visible in the Figure 11 , the assembly system 201 comprises a hub 207 which is secured between the axis 202 of the pivot 203 and the locking element 209.

[0071] It is therefore immediately understood that the example of assembly system 201 can be applied to any type of mobile. In addition, the axis 202 can comprise a pinion in a single piece in order to form a finished mobile.

[0072] Of course, the present invention is not limited to the illustrated example but is susceptible to various variants and modifications which will appear to those skilled in the art. In particular, the blocking element 9, 19, 109, 129, 209 may have a different geometry without departing from the scope of the invention.

[0073] The tool 15 could also comprise a substantially conical surface 14 to substantially follow the Belleville washer shape obtained during the intermediate elastic deformation.

[0074] Furthermore, the opening 6 of the part 5, 105, 205 cannot be limited to a circular shape and / or the part 5, 105, 205 can be partially openworked below the blocking element 9, 19, 109, 129, 209. Thus, by way of example, the spiral 5 of the Figure 10 could be replaced by the spiral 10 comprising a collet 41 whose opening is substantially clover-shaped from document EP 2 363 762 without removing the advantages cited above.

[0075] Finally, other "fragile" materials than those based on silicon or alumina are conceivable, such as, for example, ceramics based on zirconium or titanium, or glasses. The blocking element 9, 19, 109, 129, 209 can also be formed from amorphous metals also called metallic glasses.

Claims

1. An assembly system (1, 101, 121, 201) comprising an organ (3, 103, 123, 203) made of at least a first material comprising an axis (2, 102, 122, 202) and a shoulder (4), a part (5, 105, 205) made of a second material, comprising little or no plastic and comprising silicon, quartz, silicon dioxide, silicon nitride or silicon carbide, said second material having an opening (6), the axis (2, 102, 122, 202) of the organ (3, 103, 123, 203) being held in the opening (6) of the part (5, 105, 205), in which the assembly system (1, 101, 121, 201) further comprises a washer (9, 19, 109, 129, 209) made of a third material comprising a metal or a metal alloy whose resistance to relaxation is at least equal to 50% of the applied force, the third material being arranged to elastically attach the part (5, 105, 205) between the shoulder (4) of said organ and the washer (9, 19, 109, 129, 209), and in which the washer comprises an internal wall comprising a substantially straight portion (10) over part of the height (HT) of the washer (9, 19, 109, 129, 209) which radially grips the axis (2, 102, 122, 202) of said organ, said internal wall comprising, adjacent to the substantially straight portion (10), a portion (16, 26, 28) which flares conically towards the part (5, 105, 205) made of a second material so that only the peripheral portion (13, 23) of the washer (9, 19, 109, 129, 209) exerts an axial elastic force vertical to the shoulder (4) of said organ so as to secure the organ (3, 103, 123, 203) - part (5, 105, 205)- washer (9, 19, 109, 129, 209) assembly.

2. The assembly system (1, 101, 121, 201) according to the preceding claim, characterised in that the third material comprises a metal or a metal alloy whose resistance to relaxation, after 10,000 hours at a temperature of 70°C is at least equal to 50% of the applied force representing 75% of the strain necessary to obtain a 0.2% plastic distortion of the third material in order to hold the organ (3, 103, 123, 203) -part (5, 105, 205) -washer (9, 19, 109, 129, 209) assembly together.

3. The assembly system (1, 101, 121, 201) according to the preceding claim, characterised in that the third material comprises copper, brass, nickel silver, or Cu-Be alloy.

4. The assembly system (1, 101, 121, 201) according to any of the preceding claims, characterised in that the cross-section in an axial plane of the washer (9, 19, 109, 129, 209) comprises an (HT / LT) ratio of the height (HT) to the width-(LT) of the washer comprised between 0.1 and 5.

5. The assembly system (1, 101, 121, 201) according to any of the preceding claims, characterised in that the cross-section in an axial plane of the washer (9, 19, 109, 129, 209) comprises an (HE / HT, HE' / HT) ratio of the height (HE, HE') of the flared portion (16, 26, 28) to the total height (HT) comprised between 0.1 and 0.95.

6. The assembly system (1, 101, 121, 201) according to any of the preceding claims, characterised in that the cross-section in an axial plane of the washer (9, 19, 109, 129, 209) comprises an (LE / LT, LE' / LT) ratio of the width (LE, LE') of the flared portion (16, 26, 28) to the total width (LT) comprised between 0.1 and 0.95.

7. The assembly system (1, 101, 121, 201) according to any of the preceding claims, characterised in that the internal wall comprises, symmetrical to the substantially straight portion (10), a second portion (28) which flares conically away from the part (5, 105, 205) made of a second material.

8. The assembly system (1, 101, 121, 201) according to any of the preceding claims, characterised in that the washer (9, 19, 109, 129, 209) is chamfered to prevent any breakage of the second material.

9. The assembly system (1, 101, 121, 201) according to any of the preceding claims, characterised in that the second material is silicon-based.

10. The assembly system (1, 101, 121, 201) according to any of the preceding claims, characterised in that said at least one first material comprises a metal or a metal alloy.

11. The assembly system (1, 101, 121, 201) according to any of the preceding claims, characterised in that the axis (2, 102, 122, 202) and the shoulder (4) are made in one piece.

12. A timepiece characterised in that it comprises at least one assembly system (1, 101, 121, 201) according to any of the preceding claims.

13. The timepiece according to the preceding claim, characterised in that the part made of a second material is a mobile (205), a pallet (105) or a balance-spring (5).

14. A method of manufacturing an assembly system (1, 101, 121, 201) comprising the following steps: a) forming an organ (3, 103, 123, 203) made of at least a first material including an axis (2, 102, 122, 202) and a shoulder (4), a part (5, 105, 205) made of a second material based on material comprising little or no plastic and comprising silicon, quartz, silicon dioxide, silicon nitride or silicon carbide, said second material having an opening (6) and a washer (9, 19, 109, 129, 209) made of a third material comprising a metal or a metal alloy whose resistance to relaxation is at least equal to 50% of the applied force, the washer comprising a hole (8, 18) which is smaller than the axis (2, 102, 122, 202) of said organ, a surface area no larger than that of the shoulder of said organ and whose internal wall has a substantially straight portion (10) over part of the height (HT) of the washer (9, 19, 109, 129, 209) and a portion (16, 26, 28) which flares conically away from the substantially straight portion (10); b) inserting the axis (2, 102, 122, 202) of said organ without strain into the opening (6) of the part (5, 105, 205); c) placing the axis against the hole in the washer, said flared portion (16, 26, 28) facing the part (5, 105, 205), and forcibly sliding the washer (9, 19, 109, 129, 209) against the axis (2, 102, 122, 202) by applying force using a tool (15) in order to distort the washer (9, 19, 109, 129, 209) in the substantially straight portion (10) of its internal wall so that the peripheral portion (13, 23) of the washer (9, 19, 109, 129, 209) is closest to the part (5, 105, 205); d) stopping, then removing said tool when a predefined force that is less than the yield strength of the third material is reached between the tool (15) and the shoulder (4) of said organ.

15. The manufacturing method according to the preceding claim, characterised in that step d) is stopped when the force applied by said tool is comprised between 20% and 90% of the yield strength of the third material.

16. The manufacturing method according to claim 14 or 15, characterised in that the third material comprises a metal or a metal alloy whose resistance to relaxation, after 10,000 hours at a temperature of 70°C is at least equal to 50% of the force applied in step d) representing 75% of the strain necessary to obtain a 0.2% plastic distortion of the third material in order to hold the organ (3, 103, 123, 203) - part (5, 105, 205) - washer (9, 19, 109, 129, 209) assembly together.

17. The manufacturing method according to the preceding claim, characterised in that the third material comprises copper, brass, nickel silver, or Cu-Be alloy .

18. The manufacturing method according to claims 14 to 17, characterised in that the cross-section in an axial plane of the washer (9, 19, 109, 129, 209) comprises an (HT / LT) ratio of the height (HT) to the width-(LT) of the washer comprised between 0.1 and 5.

19. The manufacturing method according to any of claims 14 to 18, characterised in that the cross-section in an axial plane of the washer (9, 19, 109, 129, 209) comprises an (HE / HT, HE' / HT) ratio of the height (HE, HE') of the flared portion (16, 26, 28) to the total height (HT) comprised between 0.1 and 0.95.

20. The manufacturing method according to any of claims 14 to 19, characterised in that the cross-section in an axial plane of the washer (9, 19, 109, 129, 209) comprises an (LE / LT, LE' / LT) ratio of the width (LE, LE') of the flared portion (16, 26, 28) to the total width (LT) comprised between 0.1 and 0.95.

21. The manufacturing method according to any of claims 14 to 20, characterised in that the internal wall of the washer (9, 19, 109, 129, 209) comprises, symmetrical to the substantially straight portion (10), a second portion (28, 26) which flares conically away from the substantially straight portion (10).

22. The manufacturing method according to any of claims 14 to 21, characterised in that the washer (9, 19, 109, 129, 209) is chamfered to prevent any breakage of the second material.

23. The manufacturing method according to any of claims 14 to 22, characterised in that the second material is silicon-based.

24. The manufacturing method according to the preceding claim, characterised in that the second material comprises quartz, silicon oxide, silicon nitride or silicon carbide.

25. The manufacturing method according to any of claims 14 to 24, characterised in that said at least one first material comprises a metal or a metal alloy.

26. The manufacturing method according to any of claims 14 to 25, characterised in that the part is a horology mobile (205).

27. The manufacturing method according to any of claims 14 to 25, characterised in that the part is a horology pallet (105).

28. The method according to any of claims 14 to 25, characterised in that the part is a horology balance-spring (5).