Method for producing a clockwork assembly and clockwork assembly thus obtained

Abstract

A method for assembling a watch movement of two components, comprising the following steps: - Supplying a first component (2) being a spring and comprising at least one element made of elastic material having a tab (20); - Supplying a second component (3) having at least one cutout or opening (31, 32); - Permanently assembling the two components. The two components cooperate by means of a barrier to achieve the assembly, in particular the tab is housed in at least one cutout or opening (31, 32).

Description

[0001] The invention relates to a watch barrel spring. The invention also relates to a watch barrel spring clamp. The invention further relates to a spring device comprising such a spring and such a clamp. The invention also relates to a barrel, a movement, or a watch component comprising such a spring, such a clamp, or such a spring device. Finally, the invention relates more generally to a method for manufacturing a watch assembly of two components and a method for manufacturing an elastic watch component. The invention also relates generally to a watch assembly obtained according to the assembly manufacturing method.

[0002] Modern barrel springs are commonly made from Nivaflex®-type spring alloys, and the flange is generally attached with a spot weld. The heat input required at this stage of the process locally alters the material's properties, and depending on the nature of the material used for the barrel spring, particularly in the case of amorphous alloys highly sensitive to high temperatures, this can lead to a loss of spring performance.

[0003] A sliding flange is a well-known feature in watchmaking, used to prevent excessive mechanical stress on the mainspring during over-winding. The flange is traditionally attached to the mainspring by welding or riveting.

[0004] Patent CH346163 describes a brake spring for a barrel spring having a boss intended to serve as a fixing rivet for the main spring.

[0005] Document CH343890 discloses a fastening of the flange to the barrel spring by a spot weld.

[0006] Document GB1386612 discloses a barrel spring attachment using a cut and folded tab, attached to the drum wall, which slides into a slot in the outer end of the spring. This solution does not allow the outer end of the spring to slide within the drum and carries the risk of breaking the spring if it is over-wound.

[0007] The aim of the invention is to provide a method for manufacturing a watch assembly that overcomes the aforementioned drawbacks and improves upon prior art assembly methods. In particular, the invention proposes a method for manufacturing a simple and reliable assembly that is especially applicable to the assembly of a mainspring and a flange.

[0008] A method for producing a watch assembly according to the invention is defined by claim 1.

[0009] Different embodiments of the manufacturing process are defined by claims 2 to 11.

[0010] A spring according to the invention is defined by claim 12.

[0011] A flange according to the invention is defined by claim 14.

[0012] A spring device according to the invention is defined by claim 16.

[0013] Different embodiments of the spring device are defined by claims 17 and 18.

[0014] A barrel according to the invention is defined by claim 19.

[0015] A movement and a timepiece according to the invention are defined by claim 20.

[0016] Different embodiments of the spring and the flange are defined by claims 13 and 15.

[0017] The attached figures represent, by way of example, several embodiments of a timepiece incorporating embodiments of a barrel spring device according to the invention. There figure 1 is a view of a first embodiment of a timepiece according to the invention, comprising a first embodiment of a watch assembly obtained according to the assembly process according to the invention, here a barrel spring device. figure 2 is a detailed view of the functional part of a first variant of a blade or spring from the first embodiment of the barrel spring device. figure 3 This is a detailed view of the functional part of a flange in the first embodiment of the barrel spring device. figure 4 is a view of a blade or barrel spring of the first embodiment of the barrel spring device, the blade being shown in a fixed configuration. figure 5 This is a view of the first embodiment of the barrel spring device during the stretching process. figure 6 is a view of the first embodiment of the barrel spring device during the stretching process, with an operator or actuator acting on a tab of the spring device. figure 7 is a detailed view of the figure 6 at the level of the tongue, part of a strap is also represented. figure 8 is a detailed view of the figure 1 at the spring-flange assembly. The figure 9 is a detailed view of the functional part of a second variant of the blade or spring of the first embodiment of the barrel spring device. figure 10 is a detailed view of the functional part of a third variant of the blade or spring of the first embodiment of the barrel spring device. figure 11 is a view of a second embodiment of a timepiece according to the invention, comprising a second embodiment of a watch assembly obtained according to the assembly process of the invention. figure 12 is a view illustrating a process for making a spring by cutting from a strip of material.

[0018] A first embodiment of a 300 timepiece is described below with reference to figures 1 à 10 A timepiece is, for example, a watch, in particular a wristwatch. A timepiece includes a watch movement, specifically a mechanical movement.

[0019] The movement can be automatic or manual winding. The movement includes a 100-barrel barrel.

[0020] The barrel itself includes an assembled barrel spring device 1.

[0021] The assembled barrel spring device 1 comprises: a barrel spring 2, a flange 3, a first conformation 20 on the spring, and a second conformation 30 on the flange, the first conformation and the second conformation being arranged so as to cooperate to assemble by obstacle, the spring and the flange.

[0022] The barrel spring - flange assembly is advantageously made without any other third-party connecting element to link the barrel spring and the flange, in particular without welding, brazing, riveting or glue.

[0023] Assembling a barrel spring onto a flange is not possible using conventional welding techniques when at least one of the components is made of an amorphous alloy. The heat required to create the bond between the two elements (spring and flange) deteriorates the mechanical properties of the amorphous metal part, making it brittle and causing it to break when the spring is subjected to mechanical stress.

[0024] Riveting is not optimal and is therefore only suitable for small production runs. The required assembly precision is particularly difficult to achieve. Furthermore, the rivet head adds bulk, which is detrimental to maintaining the power reserve.

[0025] Bonding the spring and flange is unsuitable because it is not possible to achieve the necessary adhesion to withstand the stretching operation, nor to guarantee the required reliability during operation, particularly during winding and unwinding cycles and spring sliding on the barrel wall. Furthermore, most high-strength adhesives require heat curing, which is difficult to implement and detrimental to amorphous metal alloy components.

[0026] In the first embodiment, the first conformation includes a tab 20, and the second conformation 30 includes at least one cutout or opening 31, preferably two cutouts or openings 31 and 32. The use of two cutouts or openings 31 and 32 is particularly advantageous. Indeed, it allows for a precise and reliable assembly. This can be ensured because the tab fits into both cutouts as described below.

[0027] The tongue may include a rounded free end 21. Alternatively or additionally, the tongue may include parallel or substantially parallel sides 22, 23, or sides forming an angle α between 0° and 40°, preferably between 1° and 20°, or even between 2° and 5°. Preferably, the two sides of the tongue are not parallel to facilitate assembly and to maintain optimal alignment of the assembly along the transverse axis. The tongue may have a generally rectangular or trapezoidal shape, optionally with a rounded free end.

[0028] The length Lo of the tongue can be between 1mm and 3mm, preferably between 1mm and 2mm, or between 0.5 times and 2 times the width La of the spring, preferably between 0.6 times and 1 times the width of the spring.

[0029] The width La of the tongue can be between 0.2mm and 1.2mm, preferably between 0.3mm and 0.8mm or between 0.1 times and 0.8 times the width of the spring, preferably between 0.2 times and 0.5 times the width of the spring.

[0030] The ratio of the length Lo of the tongue to the width La of the tongue can be between 2 and 5, preferably between 2.5 and 4.

[0031] A first variant of the tongue design is shown on the figure 2 The tongue generally has an elongated shape. Preferably, its free end is rounded.

[0032] A second variant of the tongue design is shown on the figure 9 It differs from the first variant in that holes 201 are provided at the ends of the cut defining the tongue. These holes are designed to limit stress concentration zones at the cut ends and thus prevent material failure initiation.

[0033] A third variant of the tongue design is shown on the figure 10 This version differs from the first variant in that the width La of the tongue varies, forming a shoulder 202. This shoulder is located, for example, approximately in the middle of the tongue and allows the tongue's blocking and deformation functions to be separated. Indeed, only the narrow portion 203 will cooperate with at least one of the flange cutouts by penetrating it. The other portion 204 of the tongue will allow for greater deformation of the tongue to facilitate its insertion into the flange while limiting the concentration of stress at the bending point located at the end of the cutout.

[0034] In a fourth embodiment of the tongue (not shown), the characteristics of the second and third embodiments are combined.

[0035] Any other tongue geometry aimed at limiting stress concentrations can of course be used, the examples described above are not limiting.

[0036] The barrel spring 2 is preferably made of an amorphous alloy, a CoNiCr-based alloy, or an electroformed nickel-based alloy. As previously mentioned, the barrel spring has a first tongue-shaped conformation 20 designed to cooperate with at least one cutout 30 on the flange 3 to assemble the spring and the flange by means of a stop.

[0037] The barrel spring flange 3 is preferably made of an amorphous alloy. As seen previously, the flange has a second conformation 30 in the form of at least one cutout 31, 32 provided so as to cooperate with the tab 20 on the spring 2 to assemble, by means of a stop, the spring and the flange.

[0038] In a variant of the first embodiment (not shown), the spring device is such that the first conformation includes at least one cutout, preferably two cutouts, and the second conformation includes a tab. The barrel spring thus has a first conformation in the form of at least one cutout designed to cooperate with a tab on the flange to interlock the spring and the flange, and the flange has a second conformation in the form of a tab designed to cooperate with at least one cutout on the spring to interlock the spring and the flange. Preferably, in this variant of the first embodiment, a groove is formed in the barrel drum to prevent the tab (formed on the flange) from rubbing against the drum and to prevent wear on the tab that protrudes outside the spring device.

[0039] A second embodiment of a 300' timepiece is described below with reference to the figure 11 A timepiece is, for example, a watch, specifically a wristwatch. A timepiece includes a watch movement, specifically a mechanical movement. The movement can be automatic or manual-winding. The movement includes a mainspring barrel.

[0040] The barrel itself comprises a 2' barrel spring assembled to a 9' barrel shaft. The barrel comprises a first 20' conformation on the spring and a second 30' conformation on the shaft.

[0041] The first conformation and the second conformation are arranged so as to cooperate to assemble, in particular to assemble by obstacle, the spring and the shaft.

[0042] The barrel spring - shaft assembly is advantageously made without any other third-party connecting element to link the barrel spring and the shaft, in particular without welding, brazing, riveting or glue.

[0043] In the second embodiment, the first configuration includes a tongue 20' and the second configuration includes a cutout 30'. The tongue has, for example, a substantially trapezoidal terminal portion designed to cooperate with complementaryly shaped openings formed in a groove 31' on the barrel shaft. The openings are, for example, cut into the sides 32' of the groove 31'.

[0044] The 2' barrel spring is preferably made of an amorphous alloy or a CoNiCr-based alloy or an electroformed nickel-based alloy.

[0045] An embodiment of a method for making a watch assembly of two components according to the invention is described below, considering the spring 2 and the flange 3 previously described as respectively the first and second components.

[0046] The process includes the following steps: Supply of the spring 2 comprising at least one element of elastic material, in particular an element of elastic metallic material, having the tab, the spring being here entirely formed of elastic material; Supply of the flange having at least one cutout, here two cutouts 31, 32; Permanent assembly of the spring and the flange.

[0047] The assembly is achieved through the interlocking action of the spring and the flange, specifically the tab and the two cutouts. In particular, the assembly is achieved by the tab being housed within the cutouts.

[0048] The term "permanent assembly" means that during operation or normal operation of the assembly, the two components remain permanently joined. However, this does not preclude the assembly from being disassembled without altering or damaging either component.

[0049] Advantageously, the watch assembly does not include any other elements for connecting the two components, in particular no rivets, glue, welding or brazing.

[0050] The assembly stage of the two components includes the following steps: A mechanical force is applied to the tongue to elastically deform it as shown in the diagram. figures 6 And 7 This mechanical action is, for example, performed by a watchmaker using a tool 50. Then, the tab 20 is put in place, in particular, it is threaded into the cutout 31 as shown in the diagram. figure 7 by bringing the spring and the tab closer together while maintaining the mechanical action on the tab. Then, the mechanical action on the tab is removed, and it tends to return to its shape and rest position by curling so that its free end fits into the cutout 32 as shown in the diagram. figure 8 .

[0051] The spring and the flange are thus assembled together. The assembly remains removable for servicing by applying a force to displace the spring relative to the flange in the direction of arrow F shown on the diagram. figure 8 This allows for easy replacement of the spring or the clamp of a lock cylinder.

[0052] Advantageously, before the mechanical action step, an elastic deformation is implemented on at least one elastic material element in the vicinity of the tongue, without deforming the tongue itself. Specifically, this involves extending at least one elastic material element between two tenons 40, 41 to bring the tongue out onto a face B of the spring. This step is, for example, shown in the figure 5 One of the tenons 40 is rotated to wind the spring into an open ring 60. Due to the deformation in the vicinity of the tab (without deformation of the tab itself, which remains in its rest state), the tab has a shape, specifically a curvature, different from that of its surroundings. This allows the tab to be highlighted on the spring. Preferably, the elastic deformation of at least one element made of elastic material in the vicinity of the tab is maintained at least as long as the tab is deformed by a mechanical action, that is, at least until after the mechanical action on the tab has ceased. Thus, due to the preload that gives the spring its free shape, when the part of the spring including the tab is deformed into a straight configuration, the tab becomes taut, detaches, and points freely on the face B of the spring opposite the face A against which the flange will be brought.

[0053] To exert mechanical action on the tongue to elastically deform the tongue as shown in the figures 6 And 7 The watchmaker pushes back the tab, notably using a tool 50, to make it protrude from face A of the spring.

[0054] Thus, the flange can be presented to the tab. To position the tab 20 in the cutout 31, the watchmaker can indeed bring the flange against the spring by threading or sliding the tab into the cutout 31.

[0055] Due to the constraints in the tongue, when it is released, it presses against the flange to lock it in place. Advantageously, the end of the tongue then sits in cutout 32 of the flange, as shown in the figure 8 .

[0056] Preferably, the implementation of the elastic deformation of at least one element made of elastic material is carried out during a spring stretching operation, in particular at the end of the stretching operation.

[0057] As a consequence of what has been described previously, the assembly of the flange is carried out during the swaging operation, aimed at winding the pre-stressed spring in the open ring 60, the winding of the spring starting from the inner end (shell) and ending at the outer end presenting the tongue.

[0058] Another embodiment of a method for making a watch assembly of two components according to the invention is described below, considering the spring 2' and the barrel arbor 30' previously described as respectively the first and second components.

[0059] The process includes the following steps: Supply of the spring 2' comprising at least one element of elastic material having the tab, the spring being here entirely formed of elastic material; Supply of the barrel shaft 9 having at least one cutout, here two cutouts 32'; Permanent assembly of the spring and the barrel shaft.

[0060] The assembly is achieved through the interaction of the spring and the barrel arbor, specifically the tab and the two cutouts. In particular, the assembly is accomplished by the tab being housed within the cutouts.

[0061] An execution method of a process for making a spring 2 or 2', in particular a spring used in the process for making a watch assembly mentioned above, is described below.

[0062] The spring manufacturing process includes: a step of trimming the spring 2; 2' in a strip 19 of elastic material as shown on the figure 12 or an electroforming step of the spring, and a cutting step of the 20; 20' tab in the spring.

[0063] Advantageously, the cutting stage includes laser cutting, particularly femtosecond laser cutting, and / or electrical discharge machining (EDM), particularly wire EDM, and / or machining, and / or stamping. Given the dimensions and the need to maintain the mechanical properties of the alloy used, femtosecond laser cutting is the preferred solution. However, other techniques remain feasible. Laser cutting, particularly femtosecond laser cutting, offers the following advantages: It allows for precise cutting without altering the mechanical properties of the spring; it offers great freedom in cutting geometry and therefore in cutting design, including rounded edges at the start of the tongue; it is implemented by an industrial process that eliminates wear as it occurs in a cutting tool.

[0064] Advantageously, when the spring manufacturing process includes a spring electroforming step, this step incorporates the creation of the tab in the spring.

[0065] Advantageously, the spring manufacturing process includes a shaping and fixing step for the elastic material element. This fixing step is crucial for proper spring function, regardless of the material used. For an amorphous alloy, an example of a fixing process is described in application WO2011069273. For spring alloy elements such as Nivaflex®, fixing can be carried out conventionally, using heat in a vacuum furnace.

[0066] Preferably, the spring manufacturing process described above is implemented in the spring supply step comprising at least one element in elastic material having the tab of the watch assembly manufacturing process described above.

[0067] An execution method of a process for making an elastic watch component, in particular a barrel spring blade or flange, is described below.

[0068] The process includes the following steps: Supply of a strip of amorphous material; Cutting of the component from the strip, the cutting being carried out using a femtosecond laser.

[0069] Such a process allows for the precise cutting of the tab before the spring is shaped, for example using the process described in application WO2011 / 069273. Thus, a pre-stressed tab can then be obtained, which will be released from the spring during the stretching step as described above with reference to the figure 5 .

[0070] Thus, the invention makes it possible to form, within the mainspring, a tab intended to act as a pin that fits into cutouts made in the flange during the barrel spring assembly stage. This allows the flange to be attached to the spring in a non-permanent manner (i.e., the assembly can be disassembled) without compromising the mechanical properties of the spring and flange materials, and more generally, without compromising the mechanical properties of the materials of the two assembled watch components. As long as the spring and flange are held within a ring or drum, the assembly is very strong. The fact that the two parts are assembled freely with a slight play, i.e., without the constraints associated with welding or riveting, reduces the internal stresses in both components. This is beneficial to the properties of the final assembled component.

[0071] Unlike welding the flange and spring, this invention allows the flange to be separated from the spring once the spring assembly is removed from the barrel. Furthermore, as previously mentioned, the assembly is performed without overheating and with reduced internal stresses at the joint. Indeed, welding requires the two parts to be pressed firmly together before proceeding, which can induce significant local stresses.

[0072] Thus, according to the invention, it is possible to mechanically assemble the barrel spring to a flange without resorting to thermal means (welding or brazing) or an assembly part (rivet). The connection between the two components is elastic, reversible, and does not impair the properties of the assembled components.

[0073] Throughout this document, the term "tab" refers to any portion of a strip of material delimited by an open cut curve in the strip along the strip's thickness and by a segment connecting the two ends of the open curve. Advantageously, the tab is completely enclosed by the remaining material of the strip. Thus, the tab is formed by cutting the spring or flange without any material waste (other than the material on the cut curve). In other words, the width of the spring or flange at the tab is not reduced to the width of the tab, but is greater than the width of the tab. This is because material forming the spring or flange is present on both sides of the tab relative to the longitudinal direction of the spring or flange. Furthermore, the tab does not form the end of the spring or flange.

[0074] In the various embodiments and variants, the bridle is a sliding bridle.

[0075] Throughout this document, the terms "barrel spring assembly" or "assembled barrel spring" refer to a unit comprising a barrel spring and a flange. The barrel may be part of a finishing gear train or integrated, for example, into an additional module such as a striking mechanism. Furthermore, throughout this document, preferably when the spring is made of an amorphous alloy, "spring" or "barrel spring" refers to a leaf spring that has undergone a fixing treatment.

Claims

1. Method for producing a horology assembly of two components, comprising the following steps: - supply of a first component (2; 2') being a spring, and comprising at least one element made of elastic material, in particular of an amorphous metal alloy or an alloy based on CoNiCr, or an electro-formed alloy based on nickel, provided with a tongue (20; 20'); - supply of a second slipping-flange component (3; 9) provided with at least one cut-out or opening (31, 32); - permanent assembly of the two components; characterized in that the two components cooperate by means of an obstacle such as to create the assembly, the tongue being accommodated in the at least one cut-out or opening (31, 32), the tongue being a part of a strip of material delimited by a curve opened by cutting the strip through the thickness of the strip and by a segment which connects the two ends of the open curve, the tongue being formed by cutting the spring without discarded material other than the material which is on the cutting curve.

2. Method according to the preceding claim, characterized in that the tongue is completely surrounded by material.

3. Method according to Claim 1 or 2, characterized in that the horology assembly does not comprise other connection elements of the riveting, gluing or welding type.

4. Method according to one of the preceding claims, characterized in that the step of supplying the first component comprises: - a step of routing the first component in a strip (19) of elastic material, or a step of electro-forming the first component; and - a step of cutting the tongue (20) in the first component.

5. Method according to one of the preceding claims, characterized in that the cutting step comprises laser cutting, in particular femtosecond laser cutting, and / or cutting by electro-erosion, in particular by electro-erosion wire, and / or cutting by machining, and / or cutting by stamping.

6. Method according to one of the preceding claims, characterized in that the step of supplying the first component comprises: - a step of electro-forming of the first component incorporating the creation of the tongue (20) in the first component.

7. Method according to one of the preceding claims, characterized in that it comprises a step of forming and securing of the element made of elastic material.

8. Method according to one of the preceding claims, characterized in that the step of assembly of the two components comprises the following steps: - mechanical action on the tongue in order to deform the tongue elastically; - putting the tongue into the at least one cut-out, in particular by inserting it; - end of the mechanical action on the tongue.

9. Method according to the preceding claim, characterized in that, before the step of mechanical action, it comprises implementation of elastic deformation of the at least one element made of elastic material in the vicinity of the tongue, without deformation of the tongue, in particular extension of the at least one element made of elastic material between two studs, in order to make the tongue come out.

10. Method according to the preceding claim, characterized in that the implementation of the elastic deformation of the at least one element made of elastic material is maintained until after the end of the mechanical action on the tongue.

11. Method according to Claim 9 or 10, characterized in that the implementation of the elastic deformation of the at least one element made of elastic material is carried out during an operation of winding of the spring, in particular at the end of the winding operation.

12. Barrel spring (2; 2'), in particular a barrel spring made of amorphous alloy, characterized in that it comprises a first configuration: - in the form of a tongue (20) which is designed to cooperate with at least one cut-out or opening (31, 32) in a slipping flange (3), in order to assemble the spring and the flange, by means of an obstacle; or - in the form of at least one cut-out which is designed to cooperate with a tongue in a slipping flange, in order to assemble the spring and the flange, by means of an obstacle; the tongue being a part of a strip of material delimited by a curve opened by cutting the strip through the thickness of the strip and by a segment which connects the two ends of the open curve, the tongue being formed by cutting the flange or the spring without discarded material other than the material which is on the cutting curve.

13. Spring according to the preceding claim, characterized in that the tongue is completely surrounded by material.

14. Barrel spring slipping flange (3), in particular a flange made of amorphous alloy, with a second configuration: - in the form of a tongue, which is designed to cooperate with at least one cut-out in the spring, in order to assemble the spring and the flange, by means of an obstacle, the tongue being a part of a strip of material delimited by a curve opened by cutting the strip through the thickness of the strip and by a segment which connects the two ends of the open curve, the tongue being formed by cutting the flange without discarded material other than the material which is on the cutting curve.

15. Flange according to the preceding claim, characterized in that the tongue is completely surrounded by material.

16. Assembled barrel spring device (1) comprising: - a barrel spring (2), - a flange (3), - a first configuration (20) on the spring; and - a second configuration (30) on the flange, the first configuration and the second configuration being arranged such as to cooperate in order to assemble the spring and the flange by means of an obstacle, the barrel spring (2) being a spring according to Claim 12 or 13 and / or the flange (3) being a flange according to Claim 14 or 15.

17. Device according to the preceding claim, characterized in that: - the first configuration comprises a tongue (20), and the second configuration comprises at least one cut-out or opening (31), and preferably two cut-outs or openings (31, 32); or - the first configuration comprises at least one cut-out, and preferably two cut-outs, and the second configuration comprises a tongue.

18. Device according to the preceding claim, characterized in that the tongue comprises a rounded free end (21), and / or the tongue comprises flanks (22, 23) which are parallel or substantially parallel, or form an angle (α) of between 0° and 40°, and preferably between 1° and 20°, preferably between 2° and 5°, and / or the length (Lo) of the tongue is between 1 mm and 3 mm, preferably between 1 mm and 2 mm, or between 0.5 times and 2 times the width of the spring, preferably between 0.6 times and 1 times the width of the spring, and / or the width (La) of the tongue or the at least one cut-out is between 0.2 mm and 1.2 mm, preferably between 0.3 mm and 1.8 mm, or between 0.1 times and 0.8 times the width of the spring, preferably between 0.2 times and 0.5 times the width of the spring.

19. Barrel (100; 100') comprising a device according to one of Claims 12 to 18.

20. Horology piece (300; 300') or horology movement (200; 200'), in particular an automatic movement, comprising a barrel (100; 100') according to the preceding claim, or a device according to one of Claims 12 to 18.

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