RIGID HOROLOGICAL COMPONENT FOR AN OSCILLATOR MECHANISM OR FOR AN ESCAPEMENT MECHANISM AND HOROLOGICAL MOVEMENT INCLUDING SUCH A COMPONENT

Abstract

A rigid horological component (6, 7, 8) for an oscillator mechanism or for an escapement mechanism of a horological movement, the component extending along a principal plane (P) and including at least a part made of a composite material (1), the composite material (1) including a matrix (2) and a multitude of nanotubes or nanowires (3) distributed in the matrix (2), the nanotubes or nanowires (3) being juxtaposed and disposed substantially parallel with an axis (A) substantially perpendicular to the plane (P) of the component, the matrix (2) includes a rigid material (4) to fill the interstices and join the nanotubes or nanowires (3) to one another, the material (4) having rigid mechanical properties to block the elastic deformation of the component, the rigid material (4) comprised in the component having a Young's modulus greater than 2 GPa.

Claims

1. A rigid horological component for an oscillator mechanism or for an escapement mechanism of a horological movement, the component extending along a principal plane and including at least a part made of a composite material, wherein the composite material comprises a matrix and a multitude of nanotubes or nanowires distributed in the matrix, the nanotubes or nanowires being juxtaposed and disposed substantially parallel with an axis substantially perpendicular to the plane of the component, the matrix including a rigid material to fill the interstices and join the nanotubes or nanowires to one another, the material having rigid mechanical properties to block the elastic deformation of the component, the rigid material comprised in the component having a Young's modulus greater than 2 GPa.

2. The component according to claim 1, wherein the nanotubes are made of carbon.

3. The component according to claim 2, wherein the nanotubes are multi-walled.

4. The component according to claim 1, wherein the nanowires are made using an element to be selected from the following list: gold, silicon, boron nitride, gallium nitride, silicon oxide, silicon nitride, zinc oxide, gallium arsenide, tungsten sulphide, silver, copper, manganese arsenide, indium arsenide, carbon, diamond.

5. The component according to claim 1, wherein the nanotubes or nanowires have a diameter within a range ranging from 2 to 50 nm.

6. The component according to claim 1, wherein the nanotubes or nanowires have a length within a range ranging from 100 to 500 microns.

7. The component according to claim 1, wherein the rigid material is made using an element to be selected from the following list: tungsten, organic materials such as parylene, hexagonal boron nitride, Al2O3 type monocrystalline ruby, diamond, tungsten or molybdenum disulphides, graphite, lead, silicon carbide, nickel, indium phosphide, titanium oxide, silicon, silicon oxide, carbon.

8. The component according to claim 1, wherein the component is an escapement mechanism pallet assembly.

9. The component according to claim 1, wherein the component is an escapement mechanism wheel.

10. The component according to claim 1, wherein the component is a horological movement train.

11. The component according to claim 1, wherein the component is an oscillator mechanism balance.

12. A horological movement, wherein it comprises a rigid horological component according to claim 1.

13. The component according to claim 5, wherein the nanotubes or nanowires have a diameter within a range ranging from 3 to 15 nm.

14. The component according to claim 13, wherein the nanotubes or nanowires have a diameter within a range ranging from 5 to 10 nm.

15. The component according to claim 6, wherein the nanotubes or nanowires have a length within a range ranging from 100 to 300 microns.

16. The component according to claim 15, wherein the nanotubes or nanowires have a length within a range ranging from 150 to 200 microns.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Further features and advantages of the present invention will emerge on reading several embodiments given merely by way of non-limiting examples, with reference to the appended drawings wherein:

[0024] FIG. 1 schematically represents a through perspective view of a composite material according to the invention,

[0025] FIG. 2 schematically represents a cross-sectional view of the composite material during the method for manufacturing the first embodiment of the invention,

[0026] FIG. 3 schematically represents a top view of an escapement mechanism pallet assembly,

[0027] FIG. 4 schematically represents a top view of an escapement mechanism wheel according to the invention, and

[0028] FIG. 5 schematically represents a perspective view of an oscillation mechanism balance.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0029] In the description, we describe rigid components for a horological movement. The component is, for example, to be selected from a list comprising an escapement mechanism pallet assembly, an escapement mechanism wheel, a horological movement train, or an oscillator mechanism balance.

[0030] The rigid component is preferably flat and extends along a principal plane P. The component includes at least a part made of a composite material 1, represented in FIG. 1. Preferably, the component is made entirely of this composite material 1. Thus, the components from the preceding list can be made of this composite material 1.

[0031] The composite material 1 comprises a matrix 2 and a multitude of nanotubes or nanowires 3 distributed in said matrix 2. The component has, for example, a generally flat shape extending along a plane P.

[0032] The nanotubes or nanowires 3 form a structure of the composite material 1, wherein they are juxtaposed and disposed substantially parallel with one another. They are substantially perpendicular to the plane P of the component. The term nanotube denotes tubes wherein the inside is generally hollow, whereas nanowires are generally solid tubes.

[0033] The nanotubes or nanowires 3 are disposed substantially parallel with an axis A, perpendicular to the plane P of the component. They are evenly distributed so as to be spaced apart homogeneously in the matrix 2. Advantageously, the composite material is embodied such that nanotubes or nanowires 3 are present in the entire mass of the matrix 2.

[0034] The nanotubes or nanowires 3 have, for example, a diameter D within a range ranging from 2 to 50 nm. Preferably, the nanotubes or nanowires 3 have a diameter within a range ranging from 3 to 15 nm, or from 5 to 10 nm.

[0035] The nanotubes or nanowires 3 can have a length L within a range ranging from 100 to 500 microns. Preferably, the nanotubes or nanowires 3 can have a length within a range ranging from 100 to 300 microns, or from 150 to 200 microns.

[0036] In a first embodiment, the composite material includes nanotubes 3 made of carbon. The carbon nanotubes 3 are generally multi-walled, but can also be optionally single-walled.

[0037] According to a second embodiment, the composite material includes nanowires 3 made at least in part using an element to be selected from the following list: gold, silicon, boron nitride, gallium nitride, silicon oxide, silicon nitride, zinc oxide, gallium arsenide, tungsten sulphide, silver, copper, manganese arsenide, indium arsenide, carbon, diamond.

[0038] The matrix 2 includes a material 4 to fill the interstices and join the nanotubes or nanowires 3 to one another. The material 4 can advantageously include the nanotubes or nanowires 3, by being injected into the interstices 5 between the nanotubes or nanowires 3. This material 4 helps provide cohesion between the nanotubes or nanowires 3 and thus modify the mechanical properties of all of the nanotubes or nanowires 3, in particular to render the matrix rigid. In the first embodiment of the nanotubes, the material 4 can also be arranged inside 14 the nanotubes 3.

[0039] According to the invention, the material 4 is rigid, the material 4 having rigid mechanical properties to block an elastic deformation of the component. Thus, thanks to this rigid material 4, specific components of the horological mechanism can be embodied. The rigid material 4 comprised in the component has for example a Young's modulus greater than 2 GPa. The component 4 can also be rigid thanks to the dimensions thereof, for example by selecting a sufficient thickness preventing the deformation thereof.

[0040] For both embodiments, the rigid material 4 forming the matrix 2 is made using an element from the following list: tungsten, organic materials such as parylene, hexagonal boron nitride, Al2O3 type monocrystalline ruby, diamond, tungsten or molybdenum disulphides, graphite, lead, silicon carbide, nickel, indium phosphide, titanium oxide, silicon, silicon oxide, carbon. The rigid materials 4 can advantageously also consist of carbon.

[0041] Thus, the horological components can benefit from the advantages of the composite materials based on nanotubes or nanowires, while retaining a high level of rigidity essential for this type of component. FIG. 3 represents an escapement mechanism pallet assembly 6 made with a composite material according to the invention. FIG. 4 represents an escapement wheel 7 made from such a composite material. Finally, the balance 8 of FIG. 5 is also made from such a composite material.

[0042] To manufacture the components of the first embodiment with the carbon nanotubes, a method comprising the following steps is used, for example: [0043] a first step of preparing a substrate, for example a silicon substrate, preferably by photolithography, so that the nanotube forest growth occurs at a specific location corresponding to the shape of the component sought. Thus, a pallet assembly, wheel or balance shape is designed by photolithography. [0044] a second step of growing the nanotubes or nanowires on the substrate, not shown in the figures, preferably with a catalyst, for example iron, [0045] a third step of infiltrating the rigid constituent material of the matrix in the nanotube or nanowire distribution, and [0046] a fourth step of detaching the component from the substrate.

[0047] An example of the first and second steps is found in the document “Mechanical and electrical properties of carbon-nanotube-templated metallic microstructures” (Richard Scott Hansen June 2012).

[0048] During the second step, the nanotubes 16 or nanowires are grown parallel with an axis substantially perpendicular to the substrate.

[0049] In FIG. 2, the substrate 9 is coated with a layer of silica 10, and a layer of catalyst 11, for example iron. The carbon nanotubes 12 are formed on the layer of catalyst 11 by growth.

[0050] Upstream from the second step, additional nanotubes can be mixed in a solvent and dispersed on the layer of catalyst, for example by ultrasound, to define a top layer of nanotubes. This top layer 13 of nanotubes is porous so that the carbon (or other material) forming the nanotubes 12 can be deposited therethrough, such that the nanotubes 12 grow under the top layer 13. Thus, regular and homogeneous growth of the nanotubes 12 is ensured so that they all have substantially the same length. The third step is also performed through the top layer 13 of nanotubes 12, thanks to the porosity thereof. The detachment is preferably performed by wet or vapour phase etching, for example by means of hydrogen fluoride HF.

[0051] As regards the manufacture of the nanowires of the second embodiment, conventional techniques associated with the material selected in the list are used. Thin layer deposition is preferably used, for example by CVD (Chemical Vapour Deposition) type chemical deposition or by PVD (Physical Vapour Deposition) type physical deposition. As in the first embodiment, photolithography methods are used to select the locations of a substrate, for example made of silicon, where the nanowires are grown. The rigid material is infiltrated between the nanowires. Finally, the component is detached from the substrate once it is complete.

[0052] Naturally, the invention is not limited to the embodiments described with reference to the figures and alternative embodiments could be envisaged without leaving the scope of the invention.