METHOD FOR MANUFACTURING A MECHANISM
20200192299 ยท 2020-06-18
Assignee
Inventors
- Thomas Mercier (La Chaux-de-Fonds, CH)
- Christian Guichard (Passonfontaine, FR)
- Guy Semon (Evette-Salbert, FR)
Cpc classification
International classification
Abstract
A method for manufacturing a mechanism comprises the steps of: i) assembling flat layers together to form a substantially flat multilayer structure; ii) deploying the multilayer structure in a direction substantially normal to the flat layers. At least a first layer of said layers forms a flexible blade in the mechanism. The blade is fixed, in the mechanism, to a mass. The mass is more rigid than the blade. The blade is fixed to the mass in a step subsequent to step ii). This method can in particular be used to manufacture all or part of a mechanism such as a timepiece movement.
Claims
1. A method for manufacturing a mechanism comprising the steps of: i. assembling flat layers together to form a substantially flat multilayer structure; ii. deploying the multilayer structure in a direction substantially normal to the flat layers; wherein at least a first layer of said layers forms at least one flexible blade in the mechanism, the blade or blades being fixed, in the mechanism, to at least one mass, the or each mass being more rigid than the blade or blades, the blade or blades being fixed to the or to each mass in a step subsequent to step ii).
2. The method according to claim 1, wherein each blade has, in the mechanism, a free length greater than one third of the width of the blade in question, the free length being defined as being: the length of the blade which is not in contact with the mass, in the case where the blade is fixed to a mass, or the length of the blade extending between the two masses without being in contact with one of the masses, in the case where the blade is fixed to two masses.
3. The method according to claim 1, comprising a step iii) subsequent to step ii), consisting of locking the multilayer structure in the deployed position.
4. The method according to claim 3, wherein, in step iii), the structure is locked in the deployed position by at least one among: an overmolding, brazing, clipping, gluing, welding, particularly spot welding, more particularly laser spot welding, and clamping, of at least a part of the mechanism.
5. The method according to claim 1, wherein the or each mass is attached to an end of one of said at least one blade.
6. The method according to claim 1, wherein the or each mass is fixed to the blade or to each blade by: overmolding; brazing; clipping; gluing; welding; or clamping.
7. The method according to claim 1, wherein the mass or masses are created by at least one of the flat layers assembled in step i).
8. The method according to claim 1, wherein the mass or masses are of one among: tungsten, molybdenum, gold, silver, tantalum, platinum, alloys comprising these elements and a polymer material loaded with particles of a density greater than ten.
9. The method according to claim 1, wherein the blade or blades are of one among: silicon, glass, sapphire, diamond and an alloy of the elinvar family.
10. The method according to claim 1, wherein, in step i), ten to fifty flat layers are assembled together.
11. The method according to claim 1, wherein the blade or blades have a width, a thickness, and an aspect ratio defined as being equal to the ratio of the width of the blade to the thickness of the blade, the aspect ratio of each blade being greater than 10.
12. Method according to claim 1, wherein the blade or blades have a thickness greater than or equal to 1 m and less than or equal to 30 m.
13. The method according to claim 1, wherein the blade or blades have a width greater than or equal to 0.1 mm and less than or equal to 2 mm.
14. The method according to claim 1, wherein the substantially flat multilayer structure forms at least one mounting scaffold (86), the method comprising a step iv) consisting of detaching the structure in the deployed position, from the at least one mounting scaffold.
15. The method according to claim 1, wherein each layer undergoes a machining step.
16. The method according to claim 1, wherein a plurality of substantially flat multilayer structures, respectively structures in the deployed position.sub.(88), are obtained in step ii), respectively in step iii), from a single assembling of layers in step i).
17. The method according to claim 1, wherein the or each blade is of a more flexible material than the or each mass which is fixed to said blade.
18. Use of a method according to claim 1, for manufacturing all or part of a timepiece.
19. A mechanism, made at least in part by implementing a method according to claim 1.
20. A timepiece movement for a timepiece, made at least in part by implementing a method according to claim 1.
Description
[0049] The invention will be better understood from the description which follows, given with reference to the accompanying drawings. In these drawings:
[0050]
[0051]
[0052]
[0053] In the remainder of the description, elements of the various layers described that are identical or of identical function bear the same reference followed by an index indicating the number of the layer of which this element is a part. The assembly formed by the superposition of identical elements of different layers again bears the same reference, but with no index. In order to provide a more concise description, the elements that are identical or of identical function are not described for each figure.
[0054] Firstly, with reference to
[0055]
[0059] Various cuts are made in the first layer 10, in particular in order to create fold starters and/or breakage starters in the first layer 10. These cuts firstly form a cross 12.sub.1 in the central part of the first layer 10. The cross 12.sub.1 has four arms 14a.sub.1, 14b.sub.1 perpendicular to one another. Two arms 14a.sub.1, called longitudinal arms, extending substantially in direction Y, are longer than the other two arms 14b.sub.1, called transverse arms, which extend substantially in direction X.
[0060] The two longitudinal arms 14a.sub.1 are described first. Along each of these longitudinal arms 14a.sub.1, cutouts form, from the center of the first layer 10 to the periphery of the first layer 10: [0061] a first serrated edge 16.sub.1 extending in direction X, [0062] a second serrated edge 18.sub.1 extending in direction X, the serration of the second edge 18.sub.1 being complementary to the serration of the first edge 16.sub.1, and [0063] a third serrated edge 20.sub.1 at the end of the longitudinal arm 14a.sub.1 in question, the third edge 20.sub.1 extending in direction X.
[0064] Complementary serration is understood to mean serration that can be received one within the other, each teeth of one serration being for example received between two adjacent teeth of the other serration.
[0065] Facing the third edge 20.sub.1 of each longitudinal arm 14a.sub.1, the first layer 10 forms a strip 22.sub.1 of material extending substantially in direction X. The strip 22.sub.1 of material extends to each side of the longitudinal arm 14a.sub.1 of the cross 12.sub.1, the length of the strip 22.sub.1 of material being greater than the width of the longitudinal arm 14a.sub.1 of the cross 12.sub.1. The strip 22.sub.1 of material has a fourth serrated edge 24.sub.1, facing the third edge 20.sub.1, the serration of the third and fourth edges 20.sub.1, 24.sub.1 being complementary. The fourth edge 24.sub.1 extends along substantially the entire length of the strip 22.sub.1 of material. The peripheral edge of the strip 22.sub.1, opposite the fourth edge 24.sub.1, is here rectilinear, extending in the direction X.
[0066] The third serrated edge 20.sub.1 extends to each side of the end of the longitudinal arm 14a.sub.1, facing the fourth edge 24.sub.1. This third edge 20, then partially defines the outline of a stirrup 26.sub.1, to which the strip 22.sub.1 of material is connected by tabs 28.sub.1. The outline of the stirrup 26.sub.1 is also partially defined by the extension of the second serrated edge 16.sub.1, in direction X, to each side of the longitudinal arm 14a.sub.1 of the cross 12. The stirrup 26.sub.1 also forms a cross-member 30.sub.1 extending substantially in direction X, two uprights 31.sub.1 extending substantially in direction Y, and two elbows 32.sub.1 at the end of the uprights 31.sub.1. The elbows 32.sub.1 are oriented towards one another. The cross-member 30.sub.1 is arranged between the two elbows 32.sub.1 and the strip of material 22.sub.1, in direction Y. The elbows 32.sub.1 here form a right angle. The free end 33.sub.1 of the elbows 32.sub.1 is connected, via a tab 34.sub.1, to a pallet 36.sub.1. The pallet 36.sub.1 here is of substantially rectangular shape.
[0067] The stirrup 26.sub.1 is connected by its uprights 31.sub.1 to the peripheral edge 38, of the first layer 10.sub.1, by means of tabs 40.sub.1.
[0068] Furthermore, the first serrated edge 16.sub.1 is extended along direction X, to each side of the longitudinal arm 14a.sub.1 of the cross 12.sub.1 on which it is created, facing the extension of the second longitudinal edge 16.sub.1 partially defining the stirrup 26.sub.1.
[0069] Finally, the stirrup 26.sub.1 is connected by tabs 42.sub.1 to the end portion 120.sub.1 of the longitudinal arm 14a.sub.1 of the cross 12.sub.1. The end portion 120.sub.1 of the longitudinal arm 14a.sub.1 extends between the second edge 18.sub.1 and the third edge 20.sub.1.
[0070] Furthermore, each transverse arm 14b.sub.1 has a substantially equivalent configuration. Identical elements of the longitudinal 14a.sub.1 and transverse 14b.sub.1 arms bear the same reference.
[0071] Thus, along each of the transverse arms 14b.sub.1, cutouts form, from the center of the first layer 10 to the periphery of the first layer 10: [0072] a first serrated edge 16.sub.1 extending in direction Y [0073] a second serrated edge 18.sub.1 extending in direction Y, the serration of the second edge 20.sub.1 being complementary to the serration of the first edge 18.sub.1, and [0074] a third serrated edge 20.sub.1 forming the end of the transverse arm 14b.sub.1 in question, the third edge 20.sub.1 extending in direction Y.
[0075] Facing the third edge 20.sub.1 of each transverse arm, the first layer 10 forms a strip 22.sub.1 of material extending substantially in direction Y. The strip 22.sub.1 of material extends to each side of the transverse arm 14b.sub.1 of the cross 12.sub.1, the length of the strip 22.sub.1 of material being greater than the width of the transverse arm 14b.sub.1 of the cross 12.sub.1. The strip 22.sub.1 of material has a fourth serrated edge 24.sub.1, facing the third edge 20.sub.1, the serration of the third and fourth edges 20.sub.1, 24.sub.1 being complementary. The fourth edge 24.sub.1 extends along substantially the entire length of the strip 22.sub.1 of material.
[0076] The third serrated edge 20.sub.1 extends to each side of the end of the transverse arm 14b.sub.1, facing the fourth edge 24.sub.1. This third edge 20.sub.1 then partially defines the outline of a square 44.sub.1 of material. The outline of the square 44.sub.1 is also partially defined by the extension of the second serrated edge 16.sub.1, in direction Y, to each side of the transverse arm 14b.sub.1 of the cross 12.sub.1.
[0077] The square 44.sub.1 is connected to the peripheral edge 38.sub.1 of the layer 10 by tabs 461. Furthermore, the first serrated edge 16.sub.1 extends in direction Y, to each side of the transverse arm 14b.sub.1 of the cross 12.sub.1 on which it is created, facing the extension of the second edge 16.sub.1 partially defining the square 44.sub.1.
[0078] The square 44.sub.1 is also connected to the end portion 120, of the transverse arm 14b.sub.1 of the cross 12.sub.1 by tabs 48.sub.1. The end portion 120.sub.1 of the transverse arm 14b.sub.1 extends between the second edge 18.sub.1 and the third edge 20.sub.1.
[0079] Finally, the strips 22.sub.1 facing the transverse arms 14b.sub.1 are directly connected to the peripheral edge 38, of the layer 10 by tabs 501.
[0080] It should be noted that the distance d1 between the second edge 18.sub.1 and the third edge 20.sub.1 is identical on each arm 14a.sub.1, 14b.sub.1 of the cross 12.sub.1. Furthermore, the width of the strips 22.sub.1 is identical, the width being measured between the fourth edge 24.sub.1 and the side of the strip 22.sub.1 opposite this fourth edge 24.sub.1. Here, the distances d1 and d2 are substantially equal.
[0081] The first layer 10 is also provided with four holes 52.sub.1 distributed at the corners of the first layer 10, allowing the passage of a pin to align the first layer with other layers superimposed on this first layer. Two holes 54.sub.1 are also made in the center of the first layer 10. The function of these two holes 54.sub.1 will be described below.
[0082] The first layer 10 as described above is for example created from a monolithic layer by cutting and/or shaping. The cuts can be made by any method suitable for the material of the first layer. The cuts can in particular be made by laser cutting, chemical cutting, stamping. The shaping may consist of adding material, in particular by a LIGA process (from the German Rntgenlithographie, Galvanoformung, Abformung which means X-ray lithography, electroplating, and molding). The cutting and/or shaping steps are preferably carried out before assembling the first layer 10 with other layers, in order to facilitate the implementation. The same is true for the other layers described below.
[0083] In
[0084] It should be noted that cuts are made in the second layer 56 so that the second layer 56 has a shape substantially identical to the first layer 10. The second layer 56 forms for example a cross 12.sub.2 of identical shape to the cross 12.sub.1 of the first layer 10. However, the cross 12.sub.2 on the second layer 56 is solid, with the exception here of two holes 54.sub.2. In particular, the cross 12.sub.2 on the second layer 56 is without serrated edges. More generally, the second layer 56 as a whole is without serrated edges.
[0085] Furthermore, the arms 14a.sub.2, 14b.sub.2 of cross 12.sub.2 are not connected to the peripheral edge 38.sub.2 of the second layer 56 by tabs extending in direction X. Conversely, the arms 14a.sub.2, 14b.sub.2 are connected here to the peripheral edge 38.sub.2 of the second layer solely by their ends. In other words, the cross 12.sub.2 on the second layer 56 is without tabs connecting it to the edge 38.sub.2 of the second layer 56.
[0086] In
[0087] The third layer 58 is here of identical shape to the first layer 10. Thus, in
[0088] In
[0089] The fourth layer 60 is of substantially identical shape to the third layer 58.
[0090] The fourth layer 60 differs from the first 10 and third 58 layers essentially in that the free ends 33.sub.4 of the elbows 32.sub.4 are connected, each via a respective tab 34.sub.4, to a same blade 62.
[0091] The fourth layer 60 is preferably made of a material different from the constituent materials of the first and third layers 10, 58, which may be of the same material if appropriate. In particular, the fourth layer 60 may be of a more flexible material than the first and third layers 10, 58. Additionally or alternatively, the fourth layer 60 may be thinner than the first and third layers 10, 58, particularly in the case where all these layers are of the same material.
[0092] In the example, the fourth layer 60 is then covered with a fifth layer 64 as illustrated in
[0093] This fifth layer 64 is also fixed to the fourth layer 60, for example by gluing. To achieve this, a layer of glue or adhesive material, for example of similar shape to the fifth layer 64, is interposed between the fourth 60 and fifth 64 layers.
[0094] The fifth layer 64 is of identical shape to the first and third layers 10, 58. This fifth layer 64 is for example of a material that can be brazed or welded, unlike the fourth layer 60. This fifth layer 64 does not form a blade superimposed on the blade 62 formed by the fourth layer 60.
[0095] This gives a substantially flat multilayer structure 68, visible in particular in
[0096] Finally, in the example method described with reference to the figures, a base 66 is arranged on the fifth layer 64, as shown in
[0097] The method for manufacturing a mechanism then continues with a step of cutting out tabs 28, 40, 42, 46, 48, 50. This step results in the substantially flat multilayer structure 68 of
[0101] The manufacturing method then continues with a step of deployment along an axis Z substantially normal to the plane of the multilayer structure 68, this step being illustrated in
[0102]
[0103] Here, because of the pulling in the Z direction, and as shown in
[0104]
[0105] Together with the second layer 56, the serrated edges previously mentioned thus form the following hinges: [0106] a first hinge 70 of axis X between the base of each longitudinal arm 14a and the corresponding end portion; [0107] a second hinge 72 of axis X between the end portion 120 of each longitudinal arm 14a and the facing strip 22; [0108] two third hinges 74 of axis X between each strip 22 of material facing a longitudinal arm 14a and the associated stirrup 26; [0109] two fourth hinges 76 of axis X between each stirrup 26 and the edge 38 of the different layers; [0110] a fifth hinge 78 of axis Y between the base of each transverse arm 14b and the corresponding end portion; [0111] a sixth hinge 80 of axis Y between the end portion of each transverse arm 14b and the facing strip 22; [0112] two seventh hinges 82 of axis Y between each strip 22 of material facing a transverse arm 14b and the two associated squares 44; [0113] an eighth hinge 84 of axis Y between each square 44 and the edge 38 of the different layers.
[0114] Thus, by choosing perpendicular orientations of the hinges, a Sarrus linkage 86 is formed here. This Sarrus linkage is a particular example of a mounting scaffold that can be used in the method.
[0115] Such a mounting scaffold is created by the multilayer structure, in addition to the structure that we wish to create. This mounting scaffold makes it possible to connect the various movements required for the deployment of the multilayer structure, so that this deployment can be achieved by acting on the multilayer structure along a single degree of freedom. This mounting scaffold thus facilitates the deployment step.
[0116] The Sarrus linkage 86 so produced causes, by pulling on a portion of the multilayer structure 68 in direction Z, a raising of the stirrups 26. The raising of the stirrups 26 is accompanied by the blades 62 of the support 66 moving closer together. The raising of the stirrups 26 also causes the blades 62 to pivot, so that their width extends in a direction normal to the plane of the flat multilayer structure 68, the length and thickness of the blades extending substantially in a plane parallel to the plane of the flat multilayer structure 68. Thus, from a blade initially adapted to oscillate in a plane normal to the plane of the flat multilayer structure 68, a blade is obtained that is adapted to oscillate in a plane parallel to the plane of the multilayer structure 68.
[0117] A deployed multilayer structure 88 is thus obtained, as shown in
[0118] In addition, in this step or after the locking step, the pallets 36 fixed to the ends of the blades 62 can be fixed to masses 92, here in the form of rails. This can be achieved by brazing. In this case, a metal plate can be glued to each end of the masses 92, thus allowing a brazing attachment.
[0119]
[0120] Finally,
[0121] In the illustrated example, the blades 62 are more flexible than the masses 92 and pallets 36. In particular the blades 62 are made of a more flexible material than the masses 92 and possibly the pallets 36. The flexible mechanism 100 can thus form an oscillator.
[0122] It should be noted here that the blades 62 are oriented so that they allow the flexible mechanism 100 to oscillate in a plane extending substantially in directions X and Y. In contrast, in the flat multilayer structure 68, the blades 62 were oriented so that they tended to oscillate in a plane normal to this plane.
[0123] The blades 62 are for example made of one among: silicon, glass, sapphire or alumina, diamond, in particular synthetic diamond, more particularly synthetic diamond obtained by a chemical vapor deposition process, titanium, a titanium alloy, particularly an alloy of the Gum Metal family and an alloy of the elinvar family, more particularly Elinvar, Nivarox, Thermelast, NI-Span-C, and Precision C.
[0124] These materials have the advantage that their Young's modulus is very insensitive to temperature variations. This is particularly advantageous in the field of making timepieces, for example, where the mechanism, in particular the regulating member, must maintain its precision, even during temperature variations.
[0125] Gum Metals are materials comprising: 23% niobium; 0.7% tantalum; 2% zirconium; 1% oxygen; optionally vanadium; and optionally hafnium.
[0126] Elinvar alloys are nickel-iron alloys comprising nickel and chromium which are very insensitive to temperature. Elinvar, in particular, is a nickel-iron alloy comprising 59% iron, 36% nickel, and 5% chromium.
[0127] NI-Span-C comprises between 41.0 and 43.5% nickel and cobalt; between 4.9 and 5.75% chromium; between 2.20 and 2.75% titanium; between 0.30 and 0.80% aluminum; not more than 0.06% carbon; not more than 0.80% manganese; not more than 1% silicon; not more than 0.04% sulfur; not more than 0.04% phosphorus; and the supplemental iron needed to reach 100%.
[0128] Precision C comprises: 42% nickel; 5.3% chromium; 2.4% titanium; 0.55% aluminum; 0.50% silicon; 0.40% manganese; 0.02% carbon; and the supplemental iron needed to reach 100%.
[0129] Nivarox comprises: between 30 and 40% nickel; between 0.7 and 1.0% beryllium; between 6 and 9% molybdenum and/or 8% chromium; optionally, 1% titanium; between 0.7 and 0.8% manganese; between 0.1 and 0.2% silicon; carbon, up to 0.2%; and the supplemental iron.
[0130] Thermelast comprises: 42.5% nickel; less than 1% silicon; 5.3% chromium; less than 1% aluminum; less than 1% manganese; 2.5% titanium; and 48% iron.
[0131] All the above compositions are indicated in percents by weight.
[0132] The blade or blades advantageously have a thickness greater than or equal to 1 m, preferably greater than or equal to 5 m, and/or less than or equal to 30 m, preferably less than or equal to 20 m, more preferably less than or equal to 15 m.
[0133] The blade or blades may further have a width greater than or equal to 0.1 mm and/or less than or equal to 2 mm, preferably less than or equal to 1 mm.
[0134] The blade or blades may also have a length, for example, between 5 and 13 mm.
[0135] The or each blade 62 may also have an aspect ratio, defined as the ratio between the width and the thickness of the blade, greater than 10, preferably greater than 25.
[0136] The masses 92 are, for example, of one among: tungsten, molybdenum, gold, silver, tantalum, platinum, alloys comprising these elements and a polymer material loaded with particles of a density greater than ten, in particular tungsten particles. These materials are indeed heavy. In the case of a mechanism 100 forming an oscillator, this makes it possible to have masses 92 of reduced dimensions but with a relatively large weight.
[0137] The pallets 36, and therefore the first, third, and fifth layers 10, 58, 64, are for example of polymeric materials. These pallets 36 can improve the impact resistance of the mechanism 100.
[0138] As indicated above, the mechanism 100 may advantageously form an oscillator. In this case, one of the masses 92 may form a frame or be fixed rigidly to a frame, the other mass 92 oscillating relative thereto. In the current case, one of the masses 92 oscillates in a circular translational movement T relative to the other mass 92. In such a case, a high aspect ratio of the blade or of each blade 62 allows limiting the oscillation modes of this or these blades 62 out of plane.
[0139] Advantageously, the or each blade 62 has a free length L greater than or equal to one third of the width of the blade 62. In the case where the blade is fixed to a single mass, the free length is defined as being the length of the blade that is not in contact with the mass. In the case where the blade is fixed to two masses, the free length refers to the length of the blade, between the two masses, which is not in contact with one or the other of the masses. Preferably, over the free length of the blade 62, the latter is not in contact with any other element of the mechanism integrating the blade or blades 62.
[0140] A flexible mechanism of the type in
[0141] In a known manner, a timepiece 200 such as the watch illustrated in
[0148] As is schematically shown in
[0156] The invention is not limited to the single embodiment described above with reference to the figures, but on the contrary is capable of many variants accessible to those skilled in the art.
[0157] Firstly, in the example method described, the masses are fixed to the blades, more specifically at the ends of the blades, after deployment of the multilayer structure. In the example described, this is done using brazing. Alternatively, however, the masses are fixed to the blade or blades, in particular at the ends of these blades, by overmolding, clamping, clipping, gluing, welding, particularly spot welding, more particularly laser spot welding, or any other method accessible to those skilled in the art.
[0158] The masses may be attached on the deployed multilayer structure in the form of a cutout into a layer of additional material that is superimposed on the deployed multilayer structure. The cutout into the layer of additional material may in particular form housings for receiving the ends of the flexible blades, in particular pallets fixed to the ends of the blades, the receiving then preferably being carried out with clamping.
[0159] Also, according to a variant, the masses may be formed by the multilayer structure. The masses are then arranged facing the ends of the blades or the pallets attached to these ends at the time of deployment of the multilayer structure.
[0160] Furthermore, the described example method comprises a step of locking the structure in the deployed position. This step is optional in principle. It is preferred, however, when further manipulations of the deployed structure are required in order to obtain the mechanism. In the case where such locking is to be performed, it can be obtained by any means accessible to those skilled in the art, in particular by gluing, overmolding, brazing, clipping, welding, particularly spot welding, more particularly laser spot welding, or more generally by fastening together elements of the structure in the deployed position.
[0161] In addition, the method for manufacturing a mechanism may include a step of assembling many layers atop one another. Preferably, however, the number of superimposed layers of material is between ten and fifty.
[0162] Finally, in the example described, a single mechanism 100 is obtained by implementing the method. However, advantageously, it may be provided that a same stack of layers enables the formation of a plurality of multilayer structures and/or a plurality of deployed structures. It is thus possible to substantially improve the yield of the method for manufacturing a mechanism.
[0163] Finally, the serrated edges mentioned in the described example may be replaced by fold starters. In particular, the fold starters may be made by partial cuts into the layers. The partial cuts may consist of dotted cuts and/or a cut into only some of the thickness of the layers. In the case of a cut into only some of the thickness of the layers, the partial cut may possibly be continuous. A complete cut through the layers may also be considered.