HK1239843B - Composite component with stressed resilient means - Google Patents

Description

Composite component with elastic device for bearing force

Technical Field

The present invention relates to a timepiece assembly using an amorphous metal alloy and in particular to such an assembly comprising timepiece components whose material has no usable plastic domain, ie a very limited plastic domain.

Background Art

Existing components, including silicone-based parts, are typically fastened together using adhesive bonding. This type of operation requires extreme precision, making it costly.

Summary of the Invention

The object of the present invention is to overcome all or part of the above-mentioned drawbacks by proposing a timepiece component that does not use adhesives to fix or fasten a component, in particular made of brittle material, to an arbour.

To this end, the present invention relates to a method for producing a composite component, comprising the following steps:

a) forming a member having an opening into which the elastic means extends;

b) placing a tool between the elastic means of the elements so as to load the elastic means;

c) coating the element at least partially with an amorphous metal alloy so as to limit the elastic means to which the forces are applied;

d) Removing the tool to form a composite component between the resilient means provided with passages having a shape corresponding to the tool.

The method thus allows obtaining a fully automatically centered composite component. In fact, the sheathing step makes it possible to hold the elastic means on the tool with a centering stress, which guarantees a very high positioning accuracy.

Furthermore, the coating makes it possible to protect the component against plastic deformation, which allows the use of "brittle" materials. Thus, the composite component obtained using this method can be pressed, i.e., press-fitted, onto a metal mandrel with minimal risk of fracture, even if the component is, for example, silicon-based. Indeed, at least some of the amorphous metal alloy may be subject to plastic deformation.

Finally, the use of an at least partially amorphous metal alloy allows disassembly after manufacturing or press-fitting the composite component. In fact, the at least partially amorphous metal alloy can advantageously be heated to a predetermined temperature that makes it soft enough to have no mechanical resistance.

According to other advantageous variations of the invention:

- the elastic means form at least two deformable strips integrally connected to the walls of the opening in the element;

- at least one end of one of the at least two deformable strips is integrally connected to at least one end of another of the at least two deformable strips;

- at least two deformable strips connected to each other form a V-shaped structure, a polygonal structure or a Y-shaped structure;

- in step c), heating at least part of the amorphous metal alloy blank to a temperature between its glass transition temperature (Tg) and its crystallization temperature (Tx) in order to coat the elastic means;

- in step c), the at least partially amorphous metal alloy cladding layer forms a protrusion of the element so as to provide a thickness of the composite element formed entirely of the at least partially amorphous metal alloy;

- In step c), a mould is placed on the component to define the area of the component which can be clad with the at least partially amorphous metal alloy.

Furthermore, the invention relates to a composite component comprising an element having an opening into which a compression-resilient device confined within a volume of at least partially amorphous metal alloy projects, said composite component comprising a passageway centred relative to said compression-resilient device.

The embedded elastic means make it possible to obtain a completely automatic centering path. In fact, since the elastic means are covered while being subjected to the stress from the tool, they can ensure a very high positioning accuracy.

Furthermore, even if the element were to accidentally break at one of its elastic means, for example due to an impact on the timepiece, its retention would still be ensured by the coating. Any part of the element that might break would in fact be held in place by the coating, thus preventing it from being released into the timepiece movement.

Finally, the use of an at least partially amorphous metal alloy allows for disassembly of the composite component.In fact, the at least partially amorphous metal alloy can advantageously be heated to a predetermined temperature that makes it soft enough to have no mechanical resistance.

According to other advantageous variations of the invention:

- the elastic means form at least two deformable strips integrally connected to the walls of the opening in the element;

- at least one end of one of the at least two deformable strips is integrally connected to at least one end of another of the at least two deformable strips;

- the at least two interconnected deformable strips form a V-shaped structure, a polygonal structure or a Y-shaped structure;

a volume of at least partially amorphous metal alloy forming a protruding portion of the element so as to provide a thickness of the composite element formed entirely of the at least partially amorphous metal alloy;

- the component comprises doped or undoped single-crystalline silicon, doped or undoped polycrystalline silicon, silicon dioxide, quartz, silica, single-crystalline corundum, polycrystalline corundum, aluminum oxide, ruby, silicon nitride, or silicon carbide;

- the component comprises an at least partial coating formed of silicon oxide, silicon nitride, silicon carbide or an allotrope of carbon;

- the volume of at least partially amorphous metal alloy is formed of a magnesium-based alloy, a titanium-based alloy, a zirconium-based alloy, an iron-based alloy, a cobalt-based alloy, a gold-based alloy, a palladium-based alloy, or a platinum-based alloy;

A volume of at least partially amorphous metal alloy is formed by an alloy of the ZrTiCuNiBe, PdCuNiP or PtCuNiP type.

Finally, the invention relates to an assortment comprising a mandrel driven into a passage of a composite component according to any of the aforementioned variants.

It is therefore clear that the composite component has an increased holding force on the mandrel. Consequently, a mandrel driven into the composite component has a much higher stiffness than a simple elastic structure of the same component without the sheathing. Furthermore, the holding torque depends on the pressure exerted by the deformed material of the hole in the mandrel. It is therefore clear that this pressure is significantly higher in the case of a composite component.

Furthermore, the at least partially amorphous metal alloy volume protects the component from plastic deformation, which allows the use of "brittle" materials. Thus, the composite component can be driven, i.e., press-fitted, onto a metal mandrel with minimal risk of fracture, even if the component is, for example, based on silicon. Indeed, at least a portion of the amorphous metal alloy volume can be plastically deformed.

Finally, the use of an at least partially amorphous metal alloy allows disassembly of the assembly.In fact, the at least partially amorphous metal alloy can advantageously be heated to a predetermined temperature that makes it soft enough to have no mechanical resistance.

According to other advantageous variations of the invention:

- the mandrel is arranged to be pressed only against a volume of at least partially amorphous metal alloy of the composite component;

- the passage is arranged so that the mandrel is pressed only against a volume of at least partially amorphous metal alloy of the composite component;

- the composite member is locked against the shoulder of the mandrel;

The integrated component forms all or part of the gear train, escapement or resonator of a timepiece.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages will emerge clearly from the following description, given by way of non-limiting illustration with reference to the accompanying drawings, in which:

- Figure 1 is a top view of a composite member according to the invention;

- Figure 2 is a bottom view of a composite member according to the invention;

- Figure 3 is a cross-sectional view of a composite member according to the present invention;

- Figures 4 to 6 are diagrams of alternatives of the element according to the invention;

- FIG. 7 is an exploded view of a watch movement according to the invention;

- FIG8 is a view of a gear train according to the invention;

- FIG. 9 is a view of an assembly according to a first embodiment of the invention;

- Figures 10 to 12 are views of further embodiments of an assembly according to the invention.

DETAILED DESCRIPTION

The present invention relates to a composite component and an assembly comprising such a composite component for a timepiece using an amorphous metal alloy. More specifically, the composite component comprises an element made of a material having no usable plastic domain, ie a very limited plastic domain.

In a non-limiting manner, the material may be doped or undoped single-crystalline silicon, doped or undoped polycrystalline silicon, silicon dioxide, quartz, silica, single-crystalline corundum, polycrystalline corundum, aluminum oxide, ruby, silicon nitride, or silicon carbide. The material may include at least one partial coating formed from an allotrope of silicon oxide, silicon nitride, silicon carbide, or carbon. Of course, other types of materials, such as other ceramics, are contemplated, as are other types of coatings.

As mentioned above, current assemblies include an increasing number of silicon-based components, typically joined by adhesive bonding. This is why the composite component of the present invention was developed to form all or part of the gear train 101 of the escapement 103 or resonator 105. However, other applications are possible, not only in the field of watchmaking, without departing from the scope of the present invention.

By way of non-limiting example, a composite component may thus form wheel 102, pinion 104, an oscillating weight, a spring (for example a mainspring), escape wheel 107, fork 108 of pallet lever 109, fork pin 110 of pallet lever 109, fork 111 of pallet lever 109, balance wheel 113, a disc (for example a double disc holding an impulse stud) or balance spring 115. In the figures, the collet of a timepiece balance spring will serve to better compare the alternatives and embodiments described.

1 to 3 , the invention relates to a composite component 1 comprising an element 3 having an opening 4. As mentioned above, the element 3 can advantageously be formed from a material having no usable plastic domain, ie a very limited plastic domain, such as a silicon-based material.

According to the invention, elastic means 5—that is, an elastic structure capable of elastic deformation, which is preferably integral with the wall surrounding the opening 4 of the composite component 3—extend into the opening 4. In the example shown in Figures 1 to 3, element 3 thus comprises a substantially annular collet 6, integral with the inner coil _S1 of the balance spring and whose opening 4 houses the elastic means 5.

Preferably, the elastic means according to the invention form at least two deformable strips integrally connected to the wall of the opening in the element. Thus, in the example of FIG1 , the elastic means 5 comprise three deformable strips L ₁ , L ₂ , L ₃ , interconnected to form an integral triangle joined to the inner wall of the collet 6 at the junction between the strips L ₁ and L ₂ .

Advantageously according to the invention, as will be described below, the compressed, i.e., elastically deformed, elastic means 5 is confined within a volume of at least partially amorphous metal alloy 7. A passage 8, i.e., a region containing no material, can also be seen in the composite component 1. Advantageously according to the invention, the passage 8 is centered relative to the elastic means 5 due to the compressed state of the elastic means 5, as will be described further below.

In the example of FIGS. 1 to 3 , it can also be seen that a volume of at least partially amorphous metal alloy 7 forms a protrusion 9 of the element 3 in order to provide a thickness E of the composite component 1 formed entirely of the at least partially amorphous metal alloy.

According to the present invention, the volume of at least partially amorphous metal alloy 7 is preferably formed from a magnesium-based alloy, a titanium-based alloy, a zirconium-based alloy, an iron-based alloy, a cobalt-based alloy, a gold-based alloy, a palladium-based alloy, or a platinum-based alloy, for example, an alloy of the ZrTiCuNiBe, PdCuNiP, or PtCuNiP type. The term "at least partially amorphous" means that the metal alloy may be partially or completely in the amorphous phase. Preferably, at least 20%, more preferably at least 50%, and most preferably at least 80% of the metal alloy is in the amorphous phase.

It will thus be understood that the constrained elastic means 5 make it possible to obtain a completely self-centring passage 8. In fact, since the elastic means 5 are constrained while being stressed, they ensure a very high positioning accuracy.

Furthermore, the use of an at least partially amorphous metal alloy allows for disassembly of the composite component 1. In fact, a volume of at least partially amorphous metal alloy 7 can advantageously be heated to a predetermined temperature making it soft enough to have no mechanical resistance, ie to be able to creep.

In practice, the viscosity of an at least partially amorphous metal alloy such as that described above, when it is heated to a temperature between its glass transition temperature and its crystallization temperature, decreases to the point where it can creep.

Finally, the press fit inside the composite component 1 has a much higher stiffness than a simple elastic structure 5 of the same element without the sheathing. Furthermore, the holding torque depends on the pressure exerted by the deformed material of the hole. It is therefore obvious that this pressure is significantly higher in the composite component 1 according to the invention.

Of course, other alternatives are possible for the elastic means 5 and, incidentally, the element 3. Thus, generally speaking, at least one end of one of the at least two deformable strips is integrally connected to at least one end of the other of the at least two deformable strips, so that the deformation of the elastic means allows the centering of the component.

For example, a passage may be formed between the inner wall of the collet and the elastic means comprising only two deformable strips.It is therefore obvious that the at least two interconnected deformable strips may form a V-shaped structure.

However, preferably, the at least two interconnected deformable strips form a polygonal structure, ie comprising more than three interconnected strips, such that the passage is completely surrounded by the elastic means.

A first alternative element 13 is shown in FIG4 . Thus, compared to FIG1 , it can be seen that the elastic means 15 is still mounted inside the opening 14 of the collet 16 and comprises three strips forming a triangle, that is, three interlocking V-shaped structures. Note, however, that in this first alternative, each vertex of the triangle, or each base of the V-shaped structure, is integrally connected to the inner wall of the collet 16.

A second alternative element 23 is shown in FIG5 . Thus, compared to FIG1 , it can be seen that elastic means 25 is still mounted inside opening 24 of collet 26 . However, note that in this second alternative element, elastic means 25 comprises four strips forming a square, i.e., four interlocking V-shaped structures. Furthermore, each vertex of the square, or each base of the V-shaped structure, is integrally connected to the inner wall of collet 26 .

It is also conceivable to replace the V-shaped structure with a Y-shaped structure, that is, a V-shaped structure integrally connected via a base. By way of non-limiting example, a third alternative element 33 is thus shown in FIG6 . Thus, compared to FIG1 , it can be seen that the elastic means 35 is still mounted inside the opening 34 of the collet 36 . However, it should be noted that in this third alternative element, the elastic means 35 comprises three Y-shaped structures, each of which comprises two deformable strips L ₁ , L ₂ , L ' ₁ , L ' ₂ and L ' ₁ , L ' ₂ integrally connected to the inner wall of the collet 36 by means of bases B, B', B".

Advantageously, the invention also relates to an assembly 10 comprising a mandrel 2 driven into a passage 8 of a composite component 1 as shown in Figure 9. Furthermore, the composite component 1 can advantageously be locked axially against a shoulder of the mandrel 2 as shown in Figure 9 .

It will therefore be understood that the composite component 1 has an increased holding force on the mandrel. Consequently, the mandrel 2 driven into the composite component 1 has a much higher stiffness than the simple elastic structure 5 of the same element 3 without the sheathing. Furthermore, the holding torque depends on the pressure exerted by the deformed material of the passage 8 on the mandrel 2. It is therefore clear that this pressure is significantly higher in the case of the composite component 1.

Furthermore, the volume of at least partially amorphous metal alloy 7 protects element 3 from plastic deformation, which allows the use of "brittle" materials. Thus, composite component 1 can be driven, i.e., press-fitted, onto metal mandrel 2 with minimal risk of fracture, even if element 3 is, for example, based on silicon. Indeed, the volume of at least partially amorphous metal alloy 7 can undergo plastic deformation.

Furthermore, even if element 3 were to accidentally break at one of the deformable strips L ₁ , L ₂ , L ₃ of elastic means 5 , for example due to an impact on the timepiece, its retention would still be ensured by the coating. Any portion of element 3 that might break would in fact be held in place by the coating, thus preventing it from being released into the timepiece movement.

Finally, the use of a volume of at least partially amorphous metal alloy allows disassembly of the assembly 10. In practice, the at least partially amorphous metal alloy can advantageously be heated to a predetermined temperature as described above, which makes it soft enough not to have any mechanical resistance.

Of course, embodiments other than the integrated component 10 are possible. Thus, for example, it may be desirable for the elastic means 5, 15, 25, 35 not to contact the mandrel. To address this, the mandrel and/or the passageway may be arranged to be pressed only against a certain volume of at least a portion of the amorphous metal alloy of the composite component.

A first alternative embodiment is shown in FIG10 . In this case, the integrated part 50 comprises a mandrel 42 that is tapered so as to be pressed only against the thickness E of the projection 9 of the at least partially amorphous metal alloy 7 of the composite component 1. As can be seen in FIG10 , the passage 8 of the composite component 1 thus remains undriven, in particular with respect to the third strip L ₃ of the elastic means 5.

A second alternative embodiment is shown in Figure 11. In this case, the integrated part 60 comprises a mandrel 52 having a cross section shaped differently from the passage 8 so as to be pressed only against a certain volume of at least part of the amorphous metal alloy 7 of the composite component 1. As shown in Figure 11, it can thus be seen that the passage 8 of the composite component 1 remains undriven, in particular with respect to the elastic means 5.

A third alternative embodiment is shown in Figure 12. In this case, the integrated part 70 includes a passage 68 having a shape different from that of the mandrel 62 so as to be pressed only against a volume of at least partially amorphous metal alloy 67 of the composite member 61. As shown in Figure 12, it can thus be seen that the passage 68 of the composite member 61 remains undriven, in particular with respect to the elastic means 65.

Of course, the invention is not limited to the examples described, but is capable of various modifications and variations that will be obvious to those skilled in the art. In particular, other types of elements (different elastic means, use of a different collet, etc.) or mandrels (mandrels without shoulders, different cross-sections, etc.) could be implemented without departing from the scope of the invention.

An exemplary method for producing a composite member 1, 61 will now be described. According to the invention, the method for producing a composite member comprises a first step a) for forming an element 3, 13, 23, 33 having an opening 4, 14, 24, 34 into which an elastic means 5, 15, 25, 35, 65 extends.

The method continues with step b) of placing a tool inside the opening 4, 14, 24, 34 in the element 3, 13, 23, 33 in order to load the elastic means 5, 15, 25, 35, 65. It will be appreciated that this tool will form the future passage 8, 68. The method then includes step c) of cladding the element 3, 13, 23, 33 with the at least partially amorphous metal alloy in order to constrain the loaded elastic means 5, 15, 25, 35, 65. To facilitate step c), a mold can be placed on the element 3, 13, 23, 33 to better define the area of the element 3, 13, 23, 33 to be clad with the at least partially amorphous metal alloy. In particular, it will be appreciated that this mold can very precisely form the projection 9 of the element 3 that provides the thickness E of the composite component 1 made solely of the at least partially amorphous metal alloy disclosed in Figures 1 to 3.

Finally, the method ends with a step d) for removing the tool in order to form a composite component 1 , 61 provided with passages 8 , 68 having a shape corresponding to that of said tool.

Of course, the invention is not limited to the examples described, but is capable of various modifications and variations that will be apparent to those skilled in the art.In particular, indexing means may be provided to allow the various components to be fully referenced to each other.

Claims (28)

1. A method for manufacturing a composite component (1, 61), comprising the following steps: a) Forming an element (3, 13, 23, 33) having an opening (4, 14, 24, 34) into which an elastic device (5, 15, 25, 35, 65) extends; b) Place the tool between the elastic devices (5, 15, 25, 35, 65) of the elements (3, 13, 23, 33) so that the elastic devices (5, 15, 25, 35, 65) are subjected to force; c) The elements (3, 13, 23, 33) are covered with at least a portion of an amorphous metal alloy in order to limit the force on the elastic device (5, 15, 25, 35, 65); d) Remove the tool to form the composite member (1, 61) between the stressed elastic devices (5, 15, 25, 35, 65) having passages (8, 68) with shapes corresponding to the tool. 2. The method according to claim 1, characterized in that the elastic device (5, 15, 25, 35, 65) forms at least two deformable strips (L1, L2, _L3 , L' ₁ , L' ₂ , L” ₁ , L” ₂ ) integrally connected to the wall of the opening ( ₄ , 14, 24, 34) in the element (3, ₁₃ , 23, 33). 3. The method according to claim 2, characterized in that at least one end of one of the at least two deformable strips ( _L1 , _L2 , _L3 , L' ₁ , L' ₂ , L” ₁ , L” ₂ ) is integrally connected to at least one end of the other deformable strip ( _L1 , _L2 , _L3 , L' ₁ , L' ₂ , L” ₁ , L” ₂ ). 4. The method according to claim 3, wherein the at least two deformable strips ( _L1 , _L2 , _L3 , L' ₁ , L' ₂ , L” ₁ , L” ₂ ) that are interconnected form a V-shaped structure. 5. The method according to claim 3, wherein the at least two deformable strips ( _L1 , _L2 , _L3 , L' ₁ , L' ₂ , L” ₁ , L” ₂ ) that are interconnected form a polygonal structure. 6. The method according to claim 3, wherein the at least two deformable strips ( _L1 , _L2 , _L3 , L' ₁ , L' ₂ , L” ₁ , L” ₂ ) that are interconnected form a Y-shaped structure. 7. The method according to claim 1, characterized in that, in step c), at least a portion of the amorphous metal alloy billet is heated to a temperature between its glass transition temperature (Tg) and its crystallization temperature (Tx) in order to cover the elastic device. 8. The method according to claim 1, characterized in that, in step c), at least a portion of the amorphous metal alloy cladding layer forms the protrusion (9) of the element (3, 13, 23, 33) to provide the composite member (1, 61) to be entirely formed of at least a portion of the amorphous metal alloy thickness (E). 9. The method according to claim 1, wherein in step c), a mold is placed on the element (3, 13, 23, 33) to define an area of the element (3, 13, 23, 33) that can be covered by the at least partially amorphous metal alloy. 10. A composite member (1, 61) comprising elements (3, 13, 23, 33) having openings (4, 14, 24, 34), a force-bearing elastic device (5, 15, 25, 35, 65) confined within a volume of at least a portion of an amorphous metal alloy (7, 67) extending into said opening, said composite member comprising a passageway (8, 68) centered relative to said force-bearing elastic device. 11. The composite component (1, 61) according to claim 10, characterized in that the elastic device (5, 15, 25, 35, 65) forms at least two deformable strips ( _L1 , _L2 , _L3 , L' ₁ , L'2, L” ₁ , L” ₂ ) integrally connected to the wall of the opening (4, 14, 24, 34) in the element ( ₃ , 13, 23, 33). 12. The composite component (1, 61) according to claim 11, characterized in that at least one end of one of the at least two deformable strips ( _L1 , _L2 , _L3 , L' ₁ , L' ₂ , L” ₁ , L” ₂ ) is integrally connected to at least one end of the other deformable strip ( _L1 , _L2 , _L3 , L' ₁ , L' ₂ , L” ₁ , L” ₂ ). 13. The composite component (1, 61) according to claim 12, characterized in that the at least two deformable strips ( _L1 , _L2 , _L3 , L' ₁ , L' ₂ , L” ₁ , L” ₂ ) that are interconnected form a V-shaped structure. 14. The composite component (1, 61) according to claim 12, characterized in that the at least two deformable strips ( _L1 , _L2 , _L3 , L' ₁ , L' ₂ , L” ₁ , L” ₂ ) that are interconnected form a polygonal structure. 15. The composite component (1, 61) according to claim 12, characterized in that the at least two deformable strips ( _L1 , _L2 , _L3 , L' ₁ , L' ₂ , L” ₁ , L” ₂ ) connected to each other form a Y-shaped structure. 16. The composite component (1, 61) according to claim 10, characterized in that the at least partially amorphous metal alloy (7, 67) of a certain volume forms the protrusion (9) of the element (3, 13, 23, 33) to provide the thickness (E) of the composite component (1, 61) which is entirely formed of at least partially amorphous metal alloy. 17. The composite component (1, 61) according to claim 10, wherein the element (3, 13, 23, 33) comprises doped or undoped monocrystalline silicon, doped or undoped polycrystalline silicon, silicon dioxide, quartz, silica, monocrystalline corundum, polycrystalline corundum, silicon nitride or silicon carbide. 18. The composite component (1, 61) according to claim 17, wherein the element (3, 13, 23, 33) comprises at least a partial coating of silicon oxide, silicon nitride, silicon carbide or an allotrope of carbon. 19. The composite component (1, 61) according to claim 10, characterized in that the at least part of the amorphous metal alloy (7, 67) of a certain volume is formed of magnesium-based alloy, titanium-based alloy, zirconium-based alloy, iron-based alloy, cobalt-based alloy, gold-based alloy, palladium-based alloy or platinum-based alloy. 20. The composite component (1, 61) according to claim 19, characterized in that the at least part of the amorphous metal alloy (7, 67) of a certain volume is formed of a ZrTiCuNiBe, PdCuNiP or PtCuNiP type alloy. 21. The composite component (1, 61) according to claim 10, wherein the element (3, 13, 23, 33) comprises alumina or ruby. 22. An integrated component (10, 50, 60, 70) comprising a mandrel (2, 42, 52, 62) pressed into a passage (8, 68) of the composite component (1, 61) according to claim 10. 23. The integrated component (10, 50, 60, 70) according to claim 22, characterized in that the mandrel (2, 42, 52, 62) is arranged to press against only a certain volume of the amorphous metal alloy (7, 67) of the composite component (1, 61). 24. The integrated component (10, 50, 60, 70) according to claim 22, characterized in that the passage (8, 68) is arranged such that the mandrel (2, 42, 52, 62) presses only against at least a portion of the amorphous metal alloy (7, 67) of the defined volume of the composite component (1, 61). 25. The integrated component (10, 50, 60, 70) according to claim 22, characterized in that the composite component (1, 61) is locked against the shoulder of the mandrel (2, 42, 52, 62). 26. The integrated component (10, 50, 60, 70) according to claim 22, characterized in that the integrated component forms all or part of the gear train (101) of a clock. 27. The integrated component (10, 50, 60, 70) according to claim 22, characterized in that the integrated component forms all or part of the escapement system (103) of a clock. 28. The integrated component (10, 50, 60, 70) according to claim 22, wherein the integrated component forms all or part of the resonator (105).