EP3176650B1 - Protection of a timepiece component with micro-machinable material - Google Patents

Description

Field of the invention

The invention relates to a watchmaking subassembly comprising, on the one hand, at least one watchmaking component made of micro-machinable material comprising at least one attachment zone, and on the other hand a shell arranged to surround said zone of fixing, said fixing zone comprising at least one peripheral contact surface, and said shell being deformable with variable geometry between a narrowed shape and at least one expanded shape, and arranged to maintain said fixing zone in a housing that includes said shell, and said shell having at least one complementary contact surface arranged for, in said narrowed shape of said shell, to exert a clamping support on said at least one peripheral contact surface and to firmly immobilize said fixing zone in said shell in all directions .

The invention also relates to a watch assembly, comprising at least one receiving component and at least one such subassembly.

The invention relates to a watch movement comprising at least one such set.

The invention relates to a watch comprising at least one such assembly.

The invention relates to the field of watch mechanisms comprising components made of micro-machinable materials.

Background of the invention

The assembly of micro-machinable components with traditional mechanical components, in clockwork mechanisms, is always delicate, because of the sensitivity to shear stresses.

The document EP2755093 in the name of MASTER DYNAMIC describes a watchmaking subassembly according to the preamble of claim 1 with a spiral shroud for a tight fit with a clock balance bearing, this ferrule comprising elastically deformable arms, forming an annular space and defining together an aperture, each arm comprising a curved concave engagement portion for engaging with such a range, all of the same radius of curvature and equidistant from the central axis, in the free state of a first distance, less than the radius of the litter. These engaging portions have a radius of curvature such that, during the deformation of the arm portions, and engaged with the outer surface of the span, the engagement portions conform to substantially to the outer surface of the span, and the stresses induced by a tight fit are transferred and distributed in the arms, so as to prevent any relative movement between the shell and the bearing when applying a biasing force of spiral.

The document EP 2743 782 A1 in the name of NIVAROX-FAR SA describes, for clockwork components, a system for assembling an element made of a first material in the opening of a workpiece made of a second material that does not include a plastics domain at the same time. using an intermediate portion in a third material mounted between said member and said piece. This piece is received against a first level of the intermediate portion and is resiliently locked on a second level of the intermediate portion by the member to make integral the body - intermediate part - piece.

Summary of the invention

The invention proposes to ensure a correct assembly of micro-machinable components with traditional mechanical components.

For this purpose, the invention relates to a timepiece subassembly according to claim 1.

The invention also relates to a watch assembly, comprising at least one receiving component and at least one such subassembly.

The invention relates to a watch movement comprising at least one such set.

The invention relates to a watch comprising at least one such assembly.

Brief description of the drawings

• la figure 1 représente, de façon schématisée, et en éclaté, un sous-ensemble selon une variante préférée de l'invention, comportant une coque en deux parties agencée pour envelopper un composant en matériau micro-usinable, au niveau d'une zone locale agencée à cet effet;
• la figure 2 représente, de façon similaire à la figure 1, le même sous-ensemble sous une forme rétreinte assemblée de la coque autour de ce composant ;
• la figure 3 est un détail central de la figure 2, montrant la coopération de moyens de positionnement du composant et de la coque ;
• la figure 4 représente, de façon schématisée et en coupe transversale selon un plan sensiblement médian, le même sous-ensemble, dans une position d'approche d'une des deux parties de la coque vers l'autre pour emprisonner la partie centrale du composant ;
• la figure 5 représente, de façon similaire à la figure 4, une autre variante de coque, en un seul morceau avec deux parties articulées l'une à l'autre ;
• la figure 6 représente un ensemble comportant un composant récepteur constitué par un balancier, dans lequel est logé le sous-ensemble des figures 1 à 4 ;
• la figure 7 représente, de façon schématisée et en vue de dessus, un détail d'un autre ensemble comportant un composant récepteur similaire, dans lequel est logé un autre sous-ensemble comportant une coque faisant pince annulaire autour du composant en matériau micro-usinable, cette pince étant représentée à l'état libre en trait interrompu, et à l'état contraint dans un alésage du composant récepteur en trait plein ;
• la figure 8 représente, de façon schématisée et en vue de côté, un autre sous-ensemble à positionnement simplifié entre la coque et le composant en matériau micro-usinable ;
• la figure 9 représente, de façon schématisée et en vue de dessus, encore un autre sous-ensemble où la coque comporte trois parties articulées les unes aux autres ;
• la figure 10 est un schéma-blocs représentant une montre comportant un mouvement d'horlogerie comportant un tel ensemble comportant lui-même un tel sous-ensemble.

Other features and advantages of the invention will appear on reading the detailed description which follows, with reference to the appended drawings, in which:

• the figure 1 schematically represents, and exploded, a subset according to a preferred variant of the invention, comprising a shell in two parts arranged to envelop a component of micro-machinable material, at a local area arranged to this effect;
• the figure 2 represents, similarly to the figure 1 , the same subassembly in an assembled necking of the shell around this component;
• the figure 3 is a central detail of the figure 2 , showing the cooperation of positioning means of the component and the shell;
• the figure 4 represents, in a schematic manner and in cross section along a substantially median plane, the same subset, in a position of approach of one of the two parts of the shell towards the other to imprison the central part of the component;
• the figure 5 represents, similarly to the figure 4 another hull variant, in one piece with two parts hinged to each other;
• the figure 6 represents an assembly comprising a receiver component constituted by a pendulum, in which is housed the subset of the Figures 1 to 4 ;
• the figure 7 represents schematically and in plan view, a detail of another assembly comprising a similar receiving component, in which is housed another subassembly comprising a shell annular clamp around the component of micro-machinable material, this clamp being represented in the free state in broken lines, and in the state constrained in a bore of the receiving component in solid lines;
• the figure 8 is schematically shown in side view, another subassembly with simplified positioning between the shell and the component of micro-machinable material;
• the figure 9 represents, schematically and in plan view, yet another subset where the shell has three parts hinged to each other;
• the figure 10 is a block diagram representing a watch comprising a watch movement comprising such a set including itself such a subset.

Detailed Description of the Preferred Embodiments

The invention relates to a watchmaking subassembly 10 which comprises, on the one hand, at least one watchmaking component 1 made of micro-machinable material, and on the other hand a protective shell 20 arranged to surround a part of this component 1.

Micro-machinable material is broadly understood to mean any material making it possible to obtain watch components made of silicon, silicon oxide, DLC, amorphous material, ceramic, or the like, and in particular by the implementation of processes such as "MEMS Or "LIGA" now well known to those skilled in the art. Considerable progress has been made in watchmaking, because of the particularly advantageous characteristics of the components made with such processes in these materials: perfect reproducibility, high geometric accuracy, good durable elastic characteristics over time, and the realization of very small components is now possible in a repetitive manner. Especially the production of springs-springs, anchors, escape wheels, jumpers, rockers, is well dominated. These technologies also make it possible to reduce the number of components of a set, since they lend themselves well to the production of monolithic components comprising flexible links, articulations, suspended elements, or the like. The realization of entirely new-type components has also been made possible: this is the case of the very particular application, illustrated by the figures, and in no way limiting, to a torsion wire of rectangular section, used as a return element in a pendulum oscillator. However, there are limitations of implementation, in particular the difficulty or the impossibility of producing undercut shapes, and the low shear strength, which limits the application of such components to functions where they are subjected to constraints in compression, elongation, or torsion. Maintaining these components can, therefore, be difficult in some configurations.

The invention proposes in particular to prevent damage to the micro-machinable components during their assembly in a subassembly.

This is why the invention associates such a component 1 with a shell 20, at least partially enveloping, which aims to protect this component 1, and to collect in its place the forces with a risk of destruction of the component 1. Such a shell 20 is similar to a clamp, which submits component 1 only to compression forces, which is no problem.

Preferably, the component 1 comprises an area more widely dimensioned than the others, which is provided for its assembly, and which is called fixing zone 2. If no zone fulfills this condition, the fixing zone 2 is simply the section component 1 which is located in the planned assembly area. The same component 1 can of course have several such attachment zones 2, which can take the form of cores.

For example, component 1 of the figure 2 comprises in the middle part a first fixing zone 2, illustrated in more detail on the figure 1 , and which is provided for the relative hooking between a beam 110 and the component 1, as visible on the figure 6 and comprises in end portions two cores 2 for hooking and energizing the torsion wire constituted by this particular component 1.

This attachment zone 2 itself comprises at least one peripheral contact surface 3. In a particular embodiment, the fastening zone 2 further comprises at least one positioning surface 4. Among the various surfaces delimiting the fastening zone 2, a peripheral contact surface 3 is a joining surface with the shell 20 which, according to invention, protects the component 1 in particular during its assembly. For example, if the fastening zone 2 is cylindrical, even though this shape is difficult to obtain with the methods mentioned above in the current state of the art, the peripheral contact surface is a single cylindrical surface. If the fixing zone 2 is flat, as visible in the other figures, it comprises two peripheral contact surfaces 3 which are preferably the largest parallel and opposite surfaces, on either side of the zone of smaller thickness. of this fastening zone 2. Other forms of the fastening zone 2 may be feasible, and require support on more than two surfaces: the figure 9 illustrates the theory of an attachment zone 2 having three peripheral contact surfaces 3.

The shell 20 is arranged to maintain this fastening zone 2 in a housing 5 that includes the shell 20, in at least one degree of freedom.

For this purpose, the shell 20 is deformable, with a variable geometry between a so-called shrunken shape and at least one expanded form. By "shrinkage" is meant the contracted shape of the hull 2 resulting from a driving operation or the like. By "deformable" is meant that this shell is sized to withstand without damage relatively small deformations, caused by a driving operation or the like. This shell 2 is designed to allow easy introduction of the component 1 in an inner housing 5, that includes the shell 20, in an open position corresponding to an expanded form, which is generally not unique. The shell 20 is designed to be closed around the attachment zone 2 of the component 1, during the passage from the expanded form to the necking form where the fixing zone 2 is kept under pressure. This passage from one form to another comprises a docking step, which corresponds to a simple support of the shell 20 on the attachment zone 2, without the application of a force.

The shrinkage that follows this berthing may come from an intrinsic effort on the hull 20, as on the figures 5 and 9 where clipping means provide an effort echoed on the fixation zone 2, or on the figure 4 where the elasticity of certain zones of the shell 20 makes it possible both to maintain it in the closed position and to exert a pressure force on the fastening zone 2.

This shrinkage can also be imposed by an interaction with an external component, which compresses the shell 20 around the attachment zone 2. This is the case of the figure 7 where the shell 20 is an expandable clamp, of the type well known in machine tool equipment, held by force in a bore 112. It is the same for the figure 6 , where it is the introduction of the shell 20, containing the component 1, in a bore 112 that comprises a receiving component 110, here a balance, which ensures the application of a centripetal force on the shell 20, which transmits a pressure force to the fastening zone 2 which is thus firmly maintained.

The shell 20 advantageously comprises at least one complementary positioning surface 40, which is arranged to cooperate with at least one positioning surface 4, for the precise positioning of the fixing zone 2 in such a housing 5, according to at least one degree of freedom.

And the shell 20 has at least one complementary contact surface 30, which is arranged for, in the shrunken shape of the shell 20, to exert a clamping support on this at least one peripheral contact surface 3, and to firmly immobilize the fixing 2 in the shell 20 in all directions, by applying a pressure force on the attachment zone 2. To ensure a good positioning of the fastening zone 2 in the housing 5, and then maintain it in the simplest way , the shell 20 comprises at least a first element 21 and a second element 22 movable relative to each other in an expanded form.

This first element 21 and this or these (for example in the example of the figure 9 which comprises two second elements 22) second element 22 each comprise a complementary contact surface: 30, 31, 32.

And the shell 20 comprises clamping means for holding together with each other, with clamping, these first element 21 and second element 22 or second elements 22, in the narrowed shape of the shell 20.

In a particular variant, as illustrated in the figures 5 and 9 , the shell 20 is in one piece. And the first element 21 and second element (s) 22 that the shell 20 comprises are articulated to each other at the joints 23, to allow the opening of the shell 20 for insertion or extraction a component 1, and, in the shrunken shape of the shell 20, to ensure the clamped positioning of all the components 1 which the subassembly 10 comprises in a service position of the subassembly 10.

In a particular variant, the shell 20 constitutes a sheath comprising a housing 5 for each fastening zone 2 of each component 1 that the subassembly 10 comprises, each fastening zone 2 being, in the deployed form, movable in an axial direction in its respective housing 5, and, in the narrowed form, enclosed substantially concentrically in the housing 5.

In a preferred variant, as visible on the Figures 1 to 4 , where they are made in the form of portions of cylinders, the first element 21 and second element (s) 22 that includes the shell 20 are independent of each other to allow the opening of the shell 20 for insertion or the extraction of a component 1, and comprise complementary profiles to ensure their relative retention between them with clamping in the shrunken shape of the shell 20, and to ensure the positioning clamped position of all the components 1 that includes the subassembly 10 in a service position of the subassembly 10.

In the variant of the figure 7 , the clamping means comprise at least one substantially annular peripheral component 29, forming said so-called pliers, and arranged to clamp together the at least one first element 21 and a second element 22 made here in the form of portions of cylinders .

In the variants of figures 5 and 9 , the clamping means comprise clipping means 24, 25, which are arranged to clamp together the at least one first element 21 and a second element 22, at which these clipping means 24, 25 are arranged, for example constituted by nozzles at the ends of resilient tongues cooperating with grooves or notches.

As seen in the variant of the figure 7 at least the first element 21 or the second element 22 comprises at least one element 45, 46, which is more flexible than a more rigid part 47 carrying the complementary contact surface 30. This element 45, 46 constitutes, in cooperation with another similar element 46, 45, or with a rigid part antagonizing the clamping means, and is arranged to elastically tighten the other of the first element 21 or second element 22, at complementary bearing surfaces 43, 44.

In an advantageous embodiment because very simple, each fastening zone 2 is flat and has two parallel and opposite peripheral contact surfaces 3, and each housing 5 is delimited by two parallel and opposite complementary contact surfaces 31 and 32.

In the variant illustrated in Figures 1 to 3 at least one attachment zone 2 comprises at least one elastic arm 6 carrying a positioning surface 4 of each core. This positioning surface 4 is arranged to cooperate in a complementary manner with a complementary positioning surface 40 that comprises a rigid portion of the shell 20. These resilient arms allow better positioning and centering of the silicon part. These resilient arms can be used on the bearing points 61 to 64 (flexible blade positioning in the plane and out of plane).

In the variant of the figure 4 , the shell 20 comprises, at each housing 5, rigid parts 47, 48, here represented on the first element 21 carrying two complementary parallel positioning surfaces 40 and 41, 42, forming a U with the complementary contact surface Respective. And each corresponding attachment zone 2 comprises two symmetrical and opposite elastic arms 6, 61, 62, which are arranged to bear under stress on the parallel and opposite complementary positioning surfaces 40, 41, 42, at least in the hull necking form. 20.

Other embodiments may naturally be selected according to the particular geometrical configuration of the components to be held together.

The invention also relates to a watchmaking assembly 100 comprising at least one receiving component 110 and at least one such subassembly 10.

The receiving component 110 comprises a receiving chamber 111 for each subassembly 10. And the inner surface 112 of each receiving chamber 111 is arranged to receive an outer surface 26 that comprises each corresponding shell 20 of each subassembly 10.

Advantageously, at least one inner surface 112 of a receiving chamber 111 is sized to compress the outer surface 26 of the corresponding shell 20 during insertion of the corresponding subassembly 10 into the receiving chamber 111, to pass the shell 20 from its expanded form to its narrowed shape during this insertion.

To return to the particular case of Figures 1 to 4 the receiving component 110 is a pendulum, and the component 1 is a torsion wire. The invention provides a good solution for assembling a silicon part in a metal part. In this case, the part to be assembled, constituting the attachment zone 2, is a substantially parallelepipedal plate. The shell 20 is here composed of two half-moons, forming the first element 21 and the second element 22, and which encase the silicon wafer of the fixing zone 2. This fixing zone 2 comprises, on the one hand, and on the other another and symmetrically, two flexible elements 6: 61, 62, which allow to precisely position this core 1 in the half-moons 21 and 22. These half-moons 21 and 22 are dimensioned so that they hunt one to the other, and they apply to the fastening zone 2 in silicon only compressive stresses. In this way, once the half-moons 21 and 22 assembled on the wire 1, the whole is maintained by itself and can be handled easily. Once the wire 1 coated with this shell 20 to two half-moons 21 and 22, the whole can be driven into a receiving chamber 111, including a bore of the balance beam 110.

The positioning means 4 represented on the Figures 1 to 4 allow lateral positioning in the flat plane of the attachment zone 2 by the elastic arms 61 and 62, and also axial positioning in the direction of the wire 1, by supports 63 and 64 that includes the fixing zone 2, and are arranged to cooperate with corresponding surfaces 65 and 66 of the first element 21, as visible on the figure 3 . These supports 63 and 64 may comprise flexible elements to ensure accurate positioning.

The figure 8 summarizes another simple positioning, wherein the attachment zone 2 comprises a bore 7, arranged to cooperate with a pin or a pin 33 that comprises the main complementary surface 31. The reverse configuration is naturally achievable.

• le composant 1 en matériau micro-usinable, notamment du silicium, est enveloppé d'un composant intermédiaire constitué par une coque 20, puis le tout est chassé dans un composant récepteur 110. Le composant 1 ne perçoit du chassage qu'une contrainte de compression, mais pas de frottement ou de déplacement ;
• le composant 1 peut comporter des éléments de guidage, permettant d'obtenir un positionnement précis ;
• le ou les composants intermédiaires, ici les deux demi-lunes 21 et 22, peuvent former un sous-ensemble 10 autoporteur, avant d'être chassé dans le composant récepteur 10.

The assembly process can be summarized as follows:

• the component 1 of micro-machinable material, in particular silicon, is wrapped with an intermediate component consisting of a shell 20, then the whole is driven into a receiving component 110. The component 1 perceives hunting only a compressive stress but no friction or displacement;
• the component 1 may comprise guide elements, to obtain a precise positioning;
• the intermediate component or components, here the two half-moons 21 and 22, can form a self-supporting subassembly, before being driven into the receiving component 10.

The invention also relates to a watch movement 200 comprising at least one such assembly 100.

The invention also relates to a watch 300 comprising at least one such assembly 100.

The principle of the invention is applicable to other configurations of components, such as for example the assembly to a structure of a silicon stud, or a fixed rod of silicon, or the like.

In sum, thanks to the invention, a component of micro-machinable material, in particular silicon, can be driven into another element. The invention is also usable for the assembly of certain fragile materials, such as glass, sapphire, or the like, or for the maintenance of micro-components of very small thickness.

Claims (15)

1. Timepiece sub-assembly (10) comprising, on the one hand, at least one timepiece component (1) made of micromachinable material comprising at least one attachment area (2), and on the other hand, a shell element (20) arranged to surround said attachment area (2), said attachment area (2) comprising at least one peripheral contact surface (3), and said shell element (20) being deformable with a geometry varying between a contracted shape and at least one expanded shape, and arranged to hold said attachment area (2) inside a housing (5) contained in said shell element (20), and said shell element (20) comprising at least one complementary contact surface (30) arranged, in said contracted shape of said shell element (20), to exert a clamping force on said at least one peripheral contact surface (3) and to firmly immobilise said attachment area (2) inside said shell element (20) in all directions, characterized in that said shell element (20) comprises at least a first element (21) and a second element (22), movable with respect to each other in a said expanded shape, each comprising a said complementary contact surface (30, 31, 32), and in that said shell element (20) comprises clamping means for holding said at least a first element (21) and second element (22) clamped to each other in said contracted shape of said shell element (20).
2. Sub-assembly (10) according to claim 1, characterized in that said attachment area (2) comprises at least one positioning surface (4), and in that said shell element (20) comprises at least one complementary positioning surface (40) arranged to cooperate with said at least one positioning surface (4) for the precise positioning of said attachment area (2) inside said housing (5) contained in said shell element (20) with at least one degree of freedom.
3. Sub-assembly (10) according to claim 1 or 2, characterized in that said shell element (20) is in one-piece, and in that said at least a first element (21) and a second element (22) comprised in said shell element (20) are articulated to each other to allow the opening of said shell element (20) for the insertion or the removal of a said component (1), and, in said contracted shape of said shell element (20), to ensure that all said components (1) comprised in said sub-assembly (10) are held clamped in position in an operating position of said sub-assembly (10).
4. Sub-assembly (10) according to claim 3, characterized in that said shell element (20) forms a sheath comprising a said housing (5) for each said attachment area (2) of each said component (1) comprised in said sub-assembly (10), each said attachment area (2) being, in said deployed shape, movable in an axial direction inside said respective housing (5) thereof, and, in said contracted shape, enclosed in a substantially concentric manner inside said housing (5).
5. Sub-assembly (10) according to one of claims 1 to 4, characterized in that said at least a first element (21) and a second element (22) comprised in said shell element (20) are independent of each other to allow the opening of said shell element (20) for the insertion or the removal of a said component (1), and have complementary profiles to ensure the relative clamping together thereof in said contracted shape of the shell element (20), and to ensure that all said components (1) comprised in said sub-assembly (10) remain clamped in position in an operating position of said sub-assembly (10).
6. Sub-assembly (10) according to one of claims 1 to 5, characterized in that said clamping means comprise at least one substantially annular peripheral component (29) arranged to clamp together said at least a first element (21) and a second element (22).
7. Sub-assembly (10) according to one of claims 1 to 5, characterized in that said clamping means comprise snap-fit means (24, 25) arranged to clamp together said at least a first element (21) and a second element (22), on which are disposed said snap-fit means (24, 25).
8. Sub-assembly (10) according to one of claims 1 to 5, characterized in that at least said first element (21) or said second element (22) comprises at least one element (45, 46) that is more flexible than a stiffer portion (47) carrying said complementary contact surface (30), forming said clamping means and arranged to elastically clamp the other of said first element (21) or second element (22).
9. Sub-assembly (10) according to one of claims 1 to 8, characterized in that each said attachment area (2) is plane and comprises two said peripheral contact surfaces (3) which are parallel and opposite, and in that said shell element (20) comprises a said housing (5) for receiving each said attachment area (2), each said housing (5) being delimited by two said complementary contact surfaces (30) which are parallel and opposite (31, 32).
10. Sub-assembly (10) according to claim 2 and one of claims 1 to 9, characterized in that at least one said attachment area (2) comprises at least one elastic arm (6) carrying a said positioning surface (4) for each said core, arranged to cooperate in a complementary manner with a said complementary positioning surface (40) comprised in a stiff portion of said shell element (20).
11. Sub-assembly (10) according to claim 10, characterized in that said shell element (20) comprises, in each said housing (5), stiff portions carrying two said complementary positioning surfaces (40) which are parallel and opposite (41, 42), forming a U-shape with said respective complementary contact surface (30), and in that each said corresponding attachment area (2) comprises two said elastic arms (6) which are symmetrical and opposite (61, 62) arranged to bear under stress on said complementary positioning surfaces (40) which are parallel and opposite (41, 42) at least in said contracted shape of said shell element (20).
12. Timepiece assembly (100) comprising at least one receiving component (110) and at least one sub-assembly (10) according to one of claims 1 to 11, characterized in that said receiving component (110) comprises a receiving chamber (111) for each said sub-assembly (10), and in that the inner surface (112) of each said receiving chamber is arranged to receive an outer surface (26) comprised in each said shell element (20) of each said sub-assembly (10).
13. Assembly (100) according to claim 12, characterized in that at least one said inner surface (112) of a said receiving chamber (111) is dimensioned to compress said outer surface (26) of said corresponding shell element (20) upon the insertion of said corresponding sub-assembly (10) into said receiving chamber (111), to cause said shell element (20) to change from said expanded shape to said contracted shape thereof upon said insertion.
14. Timepiece movement (200) including at least one assembly (100) according to claim 12 or 13.
15. Watch (300) including at least one assembly (100) according to claim 12 or 13.

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