HK1172941B - Assembly of a part that has no plastic domain - Google Patents

Description

Assembly of components without plastic zones

Technical Field

The invention relates to an assembly formed by assembling a component made of a material without plastic zones (plastic range) to a member comprising another material.

Background

Current assemblies including silicon-based components are typically secured by bonding. However, the adhesion is not satisfactory in terms of long-term retention. Also, the operation requires very precise coating, which makes the operation expensive.

EP patent No. 1850193 discloses a first silicon-based component assembled on a metal mandrel using intermediate metal components. However, the shape change proposed in this document is not satisfactory, which results in the silicon parts breaking during assembly, or the parts bonding to each other insufficiently.

Disclosure of Invention

The object of the present invention is to overcome all or part of the above drawbacks by providing an adhesive-free assembly that can secure a part made of a material without plastic zones to a structure comprising a ductile material, such as a metal or a metal alloy.

The invention therefore relates to an assembly formed by a component made of a first material assembled inside a circular opening of a part made of a second material without plastic zones using an intermediate part made of a third material, the intermediate part being mounted between the component and the part, characterized in that the intermediate part is a continuous cylinder comprising a hole for receiving the component, so that the intermediate part absorbs at least part of the axial pressing force of the component radially and in a uniform manner by elastic and/or plastic deformation, and in that the part comprises perforations distributed around the circular opening of the part for absorbing any said radial force not absorbed by the intermediate part, so as to fix the assembly in a manner not to cause damage to the part.

This configuration advantageously enables an assembly comprising a part-intermediate part-member to be secured without bonding to a conventional precision-controlled member, while ensuring that the part is not subjected to damaging stresses even if the part is formed from, for example, silicon.

According to other advantageous features of the invention:

-said perforations are formed at a distance from and around the circular opening, said perforations being formed by two sets of diamond/diamond-shaped holes distributed in a quincunx arrangement so as to form a beam arranged as a secant/cross (secant) V-shape;

-said perforations comprise a third group of holes between the first two groups of holes and the circular opening, said third group of holes being formed by diamond-shaped holes and being arranged in a quincunx arrangement with one of the holes of the first two groups of holes so as to form a secant X-shaped distributed beam;

-said member comprises slots allowing the third set of holes to communicate with the circular opening;

-said perforations are formed at a distance from and around the circular opening, said perforations being formed by a first set of elongated holes and a second set of triangular holes, the first and second sets of elongated holes being distributed in a quincunx arrangement, the second set of holes being closest to the circular opening, each triangular hole communicating with the circular opening through a notch so as to form a beam that is radially movable according to the thickness of the elongated hole;

said perforations comprise a third set of triangular holes, each hole of the third set of holes being distributed between two triangular holes of the second set of holes and communicating with the circular opening through a slot, so as to form a beam having two independent arms, said beam being able to move radially according to the thickness of the elongated holes and tangentially according to the thickness of the slot;

-said set of holes extends over a width of between 100 μm and 500 μm from the edge of the circular opening;

-said circular opening has a diameter between 0.5mm and 2 mm.

Furthermore, the invention relates to a timepiece, characterized in that it comprises an assembly according to any one of the preceding variants.

Finally, the invention relates to an assembly method, wherein a component made of a first material is pressed axially into a component made of a second material without plastic zones. The method comprises the following steps:

a) forming a member having a circular opening and perforations distributed around the circular opening to form elastic deformation means;

b) inserting a continuous cylindrical intermediate part made of a third material and comprising a hole into the circular opening without any stress;

c) rolling and elastic and/or plastic expansion of the intermediate part with the member via the hole of the intermediate part in order to apply uniform radial stress to the wall of the part surrounding the circular opening by means of the elastic deformation mechanism of the part.

The method advantageously allows the member to be pressed in axially without applying any axial stress to the component. Indeed, advantageously, according to the invention, only a uniform radial elastic deformation is applied to said component. Finally, the method integrates an assembly comprising a component-intermediate-member assembly by accommodating variations in the manufacture of the various component parts.

According to other advantageous features of the invention:

-in step b) the difference between the diameter of the circular opening and the diameter of the outer section of the intermediate part is about 10 μm;

-in step c), said crushing and spreading operation applies a clamping displacement between 8 μm and 20 μm;

-in step b) and step c), the intermediate part is held in the circular opening by using a shoulder;

-the second material is silicon-based;

-the third material is formed of a metal or metal alloy base;

said component may be, for example, a wheel set of a timepiece, a pallet fork of a timepiece, a balance spring of a timepiece, a resonator or even a MEMS.

Drawings

Further features and advantages will be apparent from the following description, given by way of non-limiting example with reference to the accompanying drawings, in which:

fig. 1 is a schematic partial view of a timepiece movement including three components according to the invention;

FIG. 2 is an enlarged view of a portion of FIG. 1;

fig. 3 to 6 are views of a modification of the first embodiment of the elastic deformation mechanism according to the present invention;

fig. 7 and 8 are views of a modification of the second embodiment of the elastic deformation mechanism according to the present invention;

fig. 9 to 11 are schematic views of successive steps of an assembly method according to the invention;

fig. 12 is a schematic view of a part of a timepiece balance spring including an assembly according to the invention.

Detailed Description

As described above, the present invention relates to an assembly formed of a brittle material, i.e., a material without a plastic region, such as a silicon-based material, fixed to a ductile material, such as a metal or metal alloy, and a method of assembling the assembly.

The assembly is designed for application in the field of horology. However, other applications are readily conceivable, such as, for example, use in the aerospace, jewelry, automotive industry or tableware.

In the horology field, said components are required because of the increasing importance of brittle materials, such as silicon-based materials, quartz, corundum or, more generally, ceramics. As an example, it is possible to envisage forming the balance spring, balance, pallet, bridge or even the wheel set, such as the escape wheel, entirely or partially from a silicon base. However, the fact that it is often necessary to use a common steel mandrel whose manufacture is well understood is a constraint that is difficult to reconcile with the use of components without plastic zones. In fact, it is not possible to press in the steel mandrel, which would systematically damage the fragile parts, i.e. the parts without plastic zones.

This is why the assembly of the invention is proposed, in which a member made of a first material, for example a ductile material such as steel, is pressed axially into a circular opening of a part made of a second material, for example a silicon-based material, free of plastic zones, by using an intermediate part made of a third material more ductile than the first material, said intermediate part being mounted between said member and said part.

According to the invention, the intermediate part is a continuous cylinder with a bore for receiving the component, so that the intermediate part absorbs part of the axial pressing-in force of the component in the radial direction and in a uniform manner by elastic and/or plastic deformation. Indeed, when studying, it is clear that the intermediate element must distribute the radial stresses induced by the rolling and spreading operations in a uniform manner on the wall around said circular opening.

Therefore, a continuous cylinder, i.e. a cylinder without radial slots or axial perforations, is required to prevent any local stresses on the part of the wall of the opening of the brittle member that could damage said brittle member.

This explanation also gives the reason that no collar is used on the top or bottom of the continuous cylinder. In effect, such a collar transfers part of the axial force from the member to the top (or bottom) of the brittle component during crushing and expansion operations. Thus, the shear applied, in particular, by the corners of the collar on the top (or bottom) of the brittle member also generates localized stresses that can damage the brittle member.

Thus, if the cylinder cross-section is circular, a continuous cylinder with holes may be interpreted as a full ring with continuous inner and outer walls, i.e. without any grooves or more generally any discontinuous material. The continuous cylinder thus generates a uniform radial stress on the wall surrounding the circular opening only by elastic and/or plastic deformation, without having to respect a specific axial direction for pressing in the component.

Furthermore, the component comprises perforations forming elastic deformation means, said perforations being distributed around and at a distance from said circular opening, said perforations being intended to absorb any said radial forces not absorbed by the intermediate component in order to secure said assembly in a manner that does not cause damage to said component. The brittle member is fixed to the assembly comprising the intermediate member-member fixed by plastic deformation of the continuous cylinder by elastic deformation of the brittle member due to the perforation.

The assembly according to the invention can be better understood with reference to fig. 1 to 8, which show an exemplary application in the field of horology. Fig. 1 shows a timepiece escapement comprising a pallet 1 and an escape wheel 3.

As an example, pallet 1 comprises two assemblies 2, 12 according to the invention, assemblies 2, 12 being used respectively to fix a dart (dart)7 and a pivot pin 17 to lever 5. As seen in fig. 1, each assembly 2, 12 comprises an intermediate part 4, 14 in the form of a full ring, the intermediate part 4, 14 cooperating between the dart 7 or pivot pin 17 and the lever 5 of the pallet fork 1. Furthermore, each assembly 2, 12 comprises a perforation 6, 16, the perforation 6, 16 being made on the rod 5 around the circular opening 8, 18 and intended to form an elastic deformation mechanism. It is therefore clear that the components 2, 12 are sufficiently resistant to avoid relative movement between their constituent parts.

Escape wheel 3 (more generally wheel set 3) comprises, as an example, an assembly 22 for fixing a pivot pin 27 to body 25 of wheel 3. As can be seen in fig. 1 and 2, the assembly 22 comprises an intermediate part 24 in the form of a full ring, the intermediate part 24 co-acting between a pivot pin 27 and a body 25 of the wheel 3. Furthermore, the assembly 22 comprises a perforation 26, the perforation 26 being made on the hub around a circular opening 28 in the wheel 3 and intended to form an elastic deformation mechanism.

Thus, it should be apparent that the exemplary assembly 22 may be applied to any type of wheel set. Furthermore, the pivot pin 27 may comprise an integral pinion in order to form the final wheel set.

Examples of perforations are shown in fig. 3 to 8. According to a first embodiment, illustrated in figures 3 to 6, perforations are made at a distance from and around the circular opening, said perforations consisting of two groups of diamond-shaped holes distributed in a quincunx arrangement so as to form secant V-shaped arranged beams.

Fig. 3 is a view of the perforations 6, 16, 26 of fig. 1 and 2. For greater simplicity, only the reference numerals of the wheel 3 have been used again in fig. 3. Fig. 3 shows a perforation 26, the perforation 26 preferably passing through the entire thickness of the body 25 made of brittle material. The perforations 26 are distributed at a distance from the circular opening 28 and surround said circular opening 28, the circular opening 28 also being preferably formed through the entire thickness of the body 25 made of brittle material.

As seen in fig. 3, perforations 26 form a first set of holes 31 and a second set of holes 33, the first set of holes 31 being furthest from opening 28, the first set of holes 31 and the second set of holes 33 being diamond-shaped and arranged in a quincunx pattern. Fig. 3 shows that the perforations 31, 33 thus form V-beams 32 that are secant to each other.

In a first variant of the first embodiment shown in fig. 4, the perforations 26' comprise, in addition to the first and second sets of holes 31, 33 as well, a third set of holes formed by diamond-shaped holes 35, which is located between the first two sets of holes and the circular opening 28, i.e. closest to the opening 28. As seen in fig. 4, the third set of holes 35 is distributed in a quincunx arrangement with one of the first two sets of holes 33 to form an X-shaped secant beam 34.

In a second variant of the first embodiment shown in fig. 5, the perforations 26 "comprise, in addition to the same perforations 26' of fig. 4, slots 36, through which slots 36 the third set of holes 35 communicates with the circular opening 28.

Advantageously, according to the invention, the holes 31, 33 and 35 and the slot 36 are used to form an elastic deformation mechanism able to absorb radial stresses, i.e. forces exerted from the centre of the circular opening 28 towards the wall of the body 25 surrounding said circular opening.

Of course, the two or three sets of holes may be closer or further from each other and/or have different shapes and/or have different sizes, depending on the maximum clearance required and the required stresses for deforming the beams 32, 34.

As an example, fig. 6 shows an alternative to fig. 5. It can be seen that the perforations 26' "are similar to the perforations 26" of fig. 5. However, the three sets of holes are relatively far from each other. Furthermore, it can be seen that the shape and size of the holes and slots are different. It is therefore evident that the alternative of figure 6 changes the stiffness of the elastic deformation mechanism in silicon.

Preferably, the perforations 26, 26', 26 ", 26'" extend over a width of between 100 μm and 500 μm from the edge of the circular opening 28. Furthermore, the slots 36 are between 15 μm and 40 μm. Finally, the diameter of the circular opening 28 is preferably between 0.5mm and 2 mm.

According to a second embodiment, shown in figures 7 and 8, the perforations are formed at a distance from and around the circular opening, the perforations being formed by a first set of elongated holes and a second set of triangular holes, distributed in a quincunx arrangement, the second set of holes being closest to the circular opening, each triangular hole communicating with the circular opening through a notch, so as to form a beam that can move radially according to the thickness of the elongated holes.

Thus, fig. 7 shows a perforation 46 preferably through the entire thickness of the body 25 made of brittle material. The perforations 46 are distributed at a distance from the circular opening 28 and surround said circular opening 28, the circular opening 28 also being preferably formed through the entire thickness of the body 25 made of brittle material.

As seen in fig. 7, the perforations 46 form a first set of elongated apertures 51 and a second set of triangular apertures 53. According to the second embodiment, the two sets of holes 51, 53 are arranged in a quincunx arrangement.

Further, each triangular hole 53 communicates with the circular opening 28 through the notch 57. Fig. 7 shows that the perforations 46 thus form trapezoidal (i.e., trapezoidal) beams 52, the trapezoidal beams 52 being spaced apart from one another by notches 57. It is also noted that each beam 52 is centered on the elongated hole 51, which enables each beam 52 to move radially according to the thickness of the elongated hole 51.

In a variant of the second embodiment shown in fig. 8, the perforations 46' comprise, in addition to the perforations 46 of fig. 7, also a third set of triangular apertures 55. In addition, each hole 55 of the third set of holes is disposed between two triangular holes 53 of the second set of holes and communicates with the circular opening 28 through a slot 56. The perforations 46' thus form a beam 54 having two independent symmetrical and substantially L-shaped arms, said beam 54 being able to move radially according to the thickness of the hole 51 and tangentially according to the thickness of the slot 56.

Of course, as in the first embodiment, the two or three sets of holes may be closer or further from each other and/or have different shapes and/or have different sizes, depending on the maximum clearance required and the stresses required for deforming the beams 52, 54.

Preferably, the perforations 46, 46' extend over a width of between 100 μm and 500 μm from the edge of the circular opening 28. Furthermore, the slot 56 or notch 57 is between 15 μm and 40 μm. Finally, the diameter of the circular opening 28 is preferably between 0.5mm and 2 mm.

The assembly method is explained below with reference to the schematic diagrams of fig. 9 to 11. For greater simplicity, only the reference numerals of the wheel 3 are reused in fig. 9 to 11. According to the invention, the first step consists in forming the part 3 with the circular opening 28 and the perforations 26 from a material without plastic zones, the perforations 26 being distributed around the circular opening 28 and intended to form an elastic deformation mechanism, according to for example the previously described embodiments. As seen in fig. 9, the circular opening 28 has a diameter e₄The perforations 26 comprise a cross-section e₅The hole of (2).

This step can be achieved by dry or wet etching, such as DRI etching.

Further, in a second step, the method comprises forming the pivot pin 27 from a second material, the pivot pin 27 having a largest cross-section e₆. As described above, the second step may be performed according to a conventional mandrel manufacturing process. The pivot pin 27 is preferably metal, and may be made of steel, for example.

In a third step, the method comprises forming a continuous cylindrical intermediate part 24 with holes 23 from a third material, the intermediate part 24 having an inner cross-section e₂And outer section e₃. This third step can thus be achieved by conventional machining or electroforming (electroforming). The intermediate part 24 may thus have a thickness of between 100 μm and 300 μm, and a width I, i.e. an outer cross-section e, also of between 100 μm and 300 μm₃Minus the internal section e₂Is (I ═ e) difference₃-e₂)。

Preferably, the third material is more ductile than the second material of the pin 27 so that the pin 27 does not deform during the crushing and expanding operations. The intermediate member 24 is preferably metallic and may therefore comprise nickel and/or gold. However, any other malleable material may be advantageously added to or substituted for the third material.

Of course, the first three steps need not necessarily follow any particular order, and may even be performed simultaneously.

In a fourth step, the intermediate part 24 is inserted into the circular opening 28 without any contact with the circular opening 28. As seen in fig. 9, this means that the diameter e of the circular opening 28₄Greater than or equal to the outer section e of the intermediate part 24₃。

Preferably, the diameter e of the circular opening 28₄With the outer diameter e of the intermediate part 24₃Is about 10 μm, i.e. about 5 μm thick, which makes the componentThe body 25 of 3 is spaced relative to the intermediate member 24.

Furthermore, preferably, according to the invention, the intermediate part 24 is retained in the circular opening 28 by means of a shoulder 21, the shoulder 21 having a cross-section e₁Drilling the hole.

Finally, the method comprises a fifth step consisting in crushing and elastically and/or plastically expanding the intermediate element 24 by fitting the pins 27 in the axial direction a through the holes 23 of the intermediate element 24, so as to exert a uniform radial force B on the wall of the circular opening 28 by means of the elastic deformation means of the element 3, i.e. the perforations 26.

Thus, firstly, as seen in fig. 10, thanks to the section e of the pin 27₆Larger than section e of the intermediate part₂Thus, when the pin 27 enters (schematically shown) the hole 23 in the direction a, this causes an elastic and/or plastic deformation of the intermediate part 24, the intermediate part 24 being deformed only in the radial direction by abutment against the shoulder 21.

Preferably, according to the invention, the crushing and spreading operation is set so that the clamping force is greater at the gap between the undeformed intermediate part 24 and the wall of the part 3 surrounding the circular opening 28. Preferably, the clamping force is arranged to provide a displacement between 8 μm and 20 μm.

As a result, after the elastic and/or plastic deformation of the intermediate part 24 in the first stage, it is desirable for the crushing and expanding operation to apply an elastic deformation to the body 25 around the circular opening 28 in the second stage, so as to integrate the assembly comprising the pin 27, the intermediate part 24 and the wheel 3, as shown in fig. 11. This elastic deformation allows the assembly comprising pin 27-intermediate part 24 to be self-centering. In this regard, FIG. 11 shows perforations 26 having a cross-sectional area defined by e₇Indicated cross-section, and no longer cross-section e₅。

Advantageously, according to the invention, the pin 27 can be pressed in from either side of the body 25 of the wheel 3. Furthermore, no axial force is exerted on the body 25 of the wheel 3 during the process. Only radial elastic deformation is applied. It should also be noted that the use of a continuous cylindrical intermediate element 24 makes it possible to apply a uniform stress on the wall of the body 25 around the circular opening 28 during the radial deformation of the intermediate element 24, so as to prevent breaking of the brittle material of the wheel 3 and to accommodate any variability in the manufacture of the various constituent parts.

Of course, the invention is not limited to the illustrated examples, but may have various modifications and changes that occur to those skilled in the art. In particular, the perforations of the part made of brittle material may comprise more or fewer sets of holes than the embodiments described above.

Fig. 1 and 2 show an escapement system applied to a timepiece movement, such as a pallet 1 and an escape wheel 3. Of course, the assembly 2, 12, 22 of the present invention may be applied to other elements. By way of example, it is possible to envisage using the assemblies 2, 12, 22 described above to form a balance spring, a balance, a bridge or, more generally, a wheel set.

Thus, as shown in fig. 12, it is possible to use an assembly 62 according to the invention to fix a balance spring 61 to a spindle 67. A perforation 66 may be formed in the collet 63 of the balance spring 61 and the intermediate member 64 may be fitted in the opening 68 of the collet 63 in a similar manner to that described above.

It is also possible to use the assembly 2, 12, 22, 62 instead of the elastic mechanism 48 or cylinders 63, 66 of WO patent No.2009/115463 (which is incorporated herein by reference) in order to fix the single-piece sprung balance resonator to the pivot pin.

Finally, the assembly 2, 12, 22, 62 according to the invention can also integrate, with the arbour, any type of timepiece or other component, for example a tuning fork resonator or more generally a MEMS (micro-electromechanical system), the body of which is formed of a material without plastic zones (silicon, quartz, etc.).

Of course, two parts similar to those described above could also be fixed to the same spindle using two different assemblies 2, 12, 22, 62 to integrate their respective movements.

Claims (20)

1. An assembly (2, 12, 22, 62) of a component (7, 17, 27, 67) made of a first material formed by assembling inside a circular opening (8, 18, 28, 68) of a part (1, 3, 61) made of a second material without plastic zones using an intermediate part (4, 14, 24, 64) made of a third material, the intermediate part (4, 14, 24, 64) being mounted between the component and the part, characterized in that the intermediate part (4, 14, 24, 64) is a continuous cylinder comprising a hole (23) for receiving the component, so that the intermediate part (4, 14, 24, 64) absorbs at least part of the axial pressing-in force (a) of the component radially and in a uniform manner by elastic and/or plastic deformation, and in that the part (1, 3, 61) comprises a ring around the part (1, 3, 61) of the intermediate element (4, 14, 24, 64) is provided with perforations (6, 16, 26, 26', 26 "', 46, 46', 66) distributed over the circular opening (8, 18, 28, 68), said perforations forming elastic deformation means for absorbing any of said radial forces (B) not absorbed by said intermediate element (4, 14, 24, 64) in order to fix said assembly (2, 12, 22, 62) in a manner that does not damage said element.

2. Assembly (2, 12, 22, 62) according to claim 1, characterized in that the perforations (6, 16, 26, 26', 26 "', 66) are formed at a distance from and around the circular opening (8, 18, 28, 68), the perforations being formed by two sets of diamond-shaped holes (31, 33) distributed in a quincunx arrangement so as to form a beam (32) arranged in a secant V-shape.

3. An assembly (2, 12, 22, 62) according to claim 2, characterized in that the perforations (26 ', 26 "') comprise a third group of holes between the first two groups of holes (31, 33) and the circular openings (8, 18, 28, 68), said third group of holes being formed by diamond-shaped holes (35) and being arranged in a quincunx arrangement with one group of holes (33) of the first two groups of holes so as to form secant X-shaped distributed beams (34).

4. Assembly (2, 12, 22, 62) according to claim 3, characterized in that said parts (1, 3, 61) have slots (36) allowing the third set of holes (35) to communicate with the circular openings (8, 18, 28, 68).

5. Assembly (2, 12, 22, 62) according to claim 1, characterized in that the perforations (46, 46') are formed at a distance from and around the circular opening (8, 18, 28, 68), the perforations (46, 46') being formed by a first set of elongated holes (51) and a second set of triangular holes (53), the first and second set of elongated holes being distributed in a quincunx arrangement, the second set of holes (53) being closest to the circular opening (8, 18, 28, 68), each triangular hole (53) communicating with the circular opening (8, 18, 28, 68) through a notch (57) so as to form a beam (52) that is radially movable according to the thickness of the elongated hole (51).

6. Assembly (2, 12, 22, 62) according to claim 5, characterized in that said perforation (46') comprises a third set of triangular holes (55), each hole (55) of said third set of holes being arranged between two triangular holes (53) of the second set of holes and communicating with the circular opening (8, 18, 28, 68) through a slot (56) so as to form a beam (54) having two independent arms, said beam (54) being able to move radially according to the thickness of the elongated hole (51) and tangentially according to the thickness of the slot (56).

7. Assembly (2, 12, 22, 62) according to claim 1, characterized in that the perforations extend over a width of between 100 μm and 500 μm from the edge of the circular opening (8, 18, 28, 68).

8. Assembly (2, 12, 22, 62) according to claim 1, characterized in that the diameter of the circular opening (8, 18, 28, 68) is between 0.5mm and 2 mm.

9. Timepiece, characterized in that it comprises at least one assembly (2, 12, 22, 62) according to any one of the preceding claims.

10. An assembly method for assembling a member (7, 17, 27, 67) made of a first material in a circular opening (8, 18, 28, 68) of a part (1, 3, 61) made of a second material that is free of plastic zones by using an intermediate part (4, 14, 24, 64) made of a third material, wherein the intermediate part (4, 14, 24, 64) is mounted between the member and the part, the member (7, 17, 27, 67) made of the first material being pressed in the axial direction into the part (1, 3, 61) made of the second material that is free of plastic zones, the assembly method comprising the following steps:

a) forming a part (1, 3, 61) having a circular opening (8, 18, 28, 68) and perforations (6, 16, 26, 26', 26 "', 46, 46', 66) distributed around said circular opening (8, 18, 28, 68) to form elastic deformation means;

b) inserting a continuous cylindrical intermediate part (4, 14, 24, 64) made of a third material and comprising a hole (23) into the circular opening (8, 18, 28, 68) without any stress;

c) -rolling and elastic and/or plastic expansion of the intermediate part (4, 14, 24, 64) with the member via its hole (23) in order to apply a uniform radial force (B) to the wall of the part (1, 3, 61) surrounding the circular opening (8, 18, 28, 68) by using the elastic deformation mechanism of the part (1, 3, 61).

11. Method of assembly according to claim 10, characterized in that in step b) the difference between the diameter (e4) of the circular opening (8, 18, 28, 68) and the outer diameter (e3) of the intermediate part (4, 14, 24, 64) is 10 μm.

12. Method of assembly according to claim 10, characterized in that in step c) said crushing and spreading operation applies a clamping displacement between 8 μm and 20 μm.

13. Method of assembly according to claim 10, characterized in that in step b) and step c) the intermediate part (4, 14, 24, 64) is held in the circular opening (8, 18, 28, 68) by using a shoulder (21).

14. The method of assembly of claim 10, wherein the second material is silicon-based.

15. The method of assembly of claim 10, wherein the third material is formed of a metal or metal alloy base.

16. Method of assembling according to any one of claims 10 to 15, characterized in that said component is a wheel (3) of a timepiece.

17. Method of assembling according to any one of claims 10 to 15, characterized in that said component is a pallet fork (1) of a timepiece.

18. Method of assembling according to any one of claims 10 to 15, characterized in that said component is a balance spring (61) of a timepiece.

19. Method of assembling according to any of claims 10 to 15, characterized in that said component is a resonator.

20. Method of assembling according to any of claims 10 to 15, wherein said component is a MEMS.