Method for producing at least one mainspring, and mainspring
Patent Information
- Application Number
- EP2023764657
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-09-07
- Filing Date
- 2023-09-04
- Publication Date
- 2025-07-16
AI Technical Summary
Existing manufacturing processes for watch barrel springs are complex and do not effectively achieve low roughness on the edges of the turns, which can lead to cracking and reduced fatigue resistance, and friction-related energy dissipation.
A method involving a semi-finished barrel spring assembly is polished on both main faces using a felt polishing disk with diamond abrasive to achieve edges with roughness Ra less than or equal to 2 nm, improving tribological properties and reducing fracture risk.
The method results in a barrel spring with enhanced fatigue resistance and increased power reserve due to reduced friction, while being simpler to implement than existing methods.
Smart Images
Figure 1.1
Abstract
Description
[0001] METHOD FOR MANUFACTURING AT LEAST ONE BARREL SPRING AND SAID BARREL SPRING
[0002] Technical field
[0003] The present invention relates to a method of manufacturing at least one barrel spring.
[0004] The present invention also relates to said barrel spring, a method of manufacturing a watch barrel and said watch barrel comprising such a barrel spring.
[0005] State of the art
[0006] A barrel spring is the mainspring of a timepiece that stores energy when it is stretched, and releases it when it is released. Most often, it is a metal blade or ribbon wound into a spiral formed of a certain number of turns. The barrel spring is housed in the barrel drum. It is attached to the barrel drum by its outer turn and to the barrel arbor by its inner turn.
[0007] Once the ribbon is wound into turns, the lower and upper edges of the turns form the two main faces of the barrel spring, parallel to each other, one of the main faces coming into contact with the bottom of the barrel drum, the other of the main faces coming into contact with the cover which closes the barrel.
[0008] Various manufacturing processes for such a barrel spring have been developed to improve the properties of the barrel and its spring.
[0009] For example, various documents, such as patents DE 1020110014784, US 3346938, FR 1138087, propose producing the barrel spring in the form of a ribbon, polishing the edges of the ribbon, and then winding the ribbon into a wound barrel spring. When polishing the edges of the ribbon, defects, such as microcracks or other structural defects, which appear in particular locally on the edges of the ribbon and which can constitute breaking points in the wound and tensioned spring, are removed. Polishing the edges of the ribbon therefore makes it possible to reduce the risk of cracking, improve fatigue resistance, reduce friction forces between the edges of the coils and the drum and / or the cover, increase the power reserve, etc.
[0010] However, polishing the edges of the ribbon as described in these documents is complex to implement.
[0011] Other solutions for improving the properties of a watch barrel have also been proposed. For example, patent JP6876559 describes a method for manufacturing a barrel in which the bottom of the drum and / or the inner face of the cover are polished to have a low roughness to reduce friction with the edges of the barrel spring. Patent EP322608 describes a barrel in which the contacting surfaces comprise an amorphous carbon coating to reduce friction between them. Patent application JP H0913136 describes a barrel spring made of a Cobalt / Nickel alloy whose edges can be polished, said barrel spring being coated with Teflon. However, patent application JP H0913136 does not describe any polishing method and does not give any information on the roughness of the edges of the coils of the resulting barrel spring.
[0012] Documents JP 2015 125031 and FR 1 114 327 describe springs that are balance springs. Such springs cannot be used as barrel springs, as their functions are incompatible and their dimensions are too different.
[0013] However, as part of the continuous improvement process in the field of watchmaking, it is necessary to propose other solutions to continue improving the properties of the watch barrel and its barrel spring, essential elements for the operation of mechanical watches, by means of a manufacturing process that is simple to implement.
[0014] Disclosure of the invention
[0015] To this end, the invention relates to a method for manufacturing at least one barrel spring comprising the following steps: a) providing at least one semi-finished barrel spring ring assembly in which a semi-finished barrel spring is wound in turns in the center of a conditioning ring so as to have two accessible parallel main faces, formed respectively by the edges of the wound turns; b) temporarily fixing the barrel spring ring assembly provided in step a) on a support so as to expose one of the main faces of the semi-finished barrel spring; c) polishing the main face of the semi-finished barrel spring exposed according to step b); d) separating the barrel spring ring assembly obtained in step c) from the support; e) provisionally fixing the barrel spring-ring assembly obtained in step d) on the support so as to expose the other main face of the semi-finished barrel spring;f) polishing the main face of the semi-finished barrel spring exposed according to step e); g) separating the barrel spring-ring assembly obtained in step f) from the holder; h) removing the barrel spring obtained in step g) from its conditioning ring; i) lubricating the barrel spring obtained in step h); j) replacing the barrel spring lubricated according to step i) in its conditioning ring to recondition it into a finished barrel spring-ring assembly, steps h) to j) being optional.;
[0016] Unexpectedly and surprisingly, the method for manufacturing a barrel spring according to the present invention makes it possible in particular to obtain, after at least one of steps c) and f), a finished barrel spring for which the edges of the turns have a roughness Ra less than or equal to 60 nm, and preferably less than or equal to 50 nm, preferably less than or equal to 25 nm, preferably less than or equal to 10 nm, preferably less than or equal to 5 nm, and preferably less than or equal to 2 nm. This very low roughness Ra of the edges of the turns of the barrel spring makes it possible to obtain a barrel spring having in particular improved tribological properties, according to a manufacturing method that is easy to implement.Furthermore, the roughness obtained makes it possible to reduce the incipient fractures due to higher roughness values (fractures that begin in very small cavities and / or crevices found in rougher surface conditions). One of the benefits lies in the increase in fatigue resistance and the lifetime of the component. Another benefit is the potential increase in the power reserve since the dissipation of energy due to friction between the edges of the spring and the other components is greatly reduced.
[0017] Advantageously, the barrel ring-spring assembly is temporarily fixed to the support according to at least one of steps b) and e) by gluing.
[0018] Preferably, at least one of steps c) and f) of polishing the main faces of the barrel spring is carried out by means of at least one polishing disc, said at least one disc preferably being made of felt.
[0019] Advantageously, the barrel ring-spring assembly is temporarily fixed to the support according to at least one of steps b) and e) by means of an adhesive, the respective step d) and g) of separating the barrel ring-spring assembly from the support being carried out by dissolving said adhesive.
[0020] In a preferred embodiment, in step a), several semi-finished barrel spring ring assemblies are provided, at least in one of steps b) and e), said several barrel spring ring assemblies are fixed on the same support, at least in one of steps c) and f), the exposed main faces of the barrel springs of all the barrel spring ring assemblies fixed on the support are polished before separating the barrel spring ring assemblies from the support according to at least one of steps d) and g).
[0021] This embodiment makes it possible to process a large number of ring-spring assemblies at the same time. The present invention also relates to a method of manufacturing a watch barrel comprising the manufacture of a barrel spring according to the method as defined above.
[0022] The present invention also relates to a barrel spring obtained by the method of manufacturing a barrel spring as defined above.
[0023] The present invention also relates to a watch barrel comprising such a barrel spring.
[0024] Brief description of the drawings
[0025] Other characteristics and advantages of the present invention will appear on reading the following detailed description of an embodiment of the invention, given by way of non-limiting example, and made with reference to the appended drawings in which:
[0026] - Figure 1 is an exploded view showing a barrel;
[0027] - figure 2 represents an isometric view of a barrel spring;
[0028] - Figure 3 is an isometric view of a barrel ring-spring assembly; and
[0029] - Figure 4 is a schematic representation of the steps of a method according to the invention.
[0030] Embodiments of the invention
[0031] The present invention relates in particular to a method of manufacturing at least one barrel spring intended to be used in a watch barrel.
[0032] With reference to Figure 1, there is shown such a watch barrel 1 comprising a barrel drum 2, a barrel spring 4 manufactured according to the method of the invention, a barrel arbor 6 and a barrel cover 8, with rotation axis A. With the exception of the treatment of the barrel spring specific to the invention, the construction of each of these elements, their functions and their assembly to form a watch barrel 1 are well known to those skilled in the art and do not require a detailed description here.
[0033] The finished barrel spring 4 within the meaning of the invention is obtained from a semi-finished barrel spring 4' as will be detailed below. With the exception of the processing of the semi-finished barrel spring 4' to obtain the finished barrel spring 4 specific to the invention, the finished barrel spring 4 is similar to the semi-finished barrel spring 4'. Figure 2 therefore represents both the finished barrel spring 4 and the semi-finished barrel spring 4'.
[0034] With reference to Figure 2, the finished barrel spring 4 or the semi-finished barrel spring 4' is obtained from a metal strip or blade, the blade having an external face 10a and an internal face 10b extending generally along the axis A, with a height h of, for example, between 0.4 mm and 4 mm. The faces 10a, 10b of the blade are connected to each other by two edges, an upper edge 12a and a lower edge 12b in the configuration shown in the drawings, substantially parallel, extending perpendicular to the axis A, and corresponding to the thickness e of the blade, of, for example, between 0.05 mm and 0.3 mm. The blade, seen in section along the axis A, may have a polygonal, for example rectangular, or elliptical section. The unrolled blade can have a length of, for example, between 200 m and 2000 m.The mainspring, when the blade is wound, has for example an outer diameter between 11 mm and 13 mm and an inner diameter between 1.6 mm and 2.2 mm. The mainspring is therefore to be distinguished from a spiral spring associated with a balance wheel which is smaller and which functions differently from a mainspring. The spiral spring expands and contracts more or less concentrically while the mainspring unwinds. Furthermore, the balance spring has for example an outer diameter between 3 mm and 4 mm, an inner diameter between 0.6 mm and 0.9 mm, a thickness between 0.020 mm and 0.030 mm for a height between 0.080 mm and 0.180 mm. The blade can be for example made of stainless steel, Cobalt / Nickel alloy, amorphous metal alloys, or any other suitable material.
[0035] When manufacturing the semi-finished barrel spring 4', the blade is wound according to a standard method around the axis A into a spiral formed of a certain number of turns. Thus, the wound barrel spring 4 or 4' has, in the configuration shown in the drawings, an upper main face 14a in the plane P of which are located all the upper edges 12a of the wound turns and a lower main face 14b in the plane P' of which are located all the lower edges 12b of said turns, the upper 14a and lower 14b main faces being parallel. The upper and lower edges respectively of the wound turns correspond to the upper edge 12a, respectively lower 12b of the unwound blade, as defined above.The upper main face 14a of the barrel spring 4 or 4' is intended to be as close as possible to the inside of the barrel cover 8, to which it is parallel, and the lower main face 14b of the barrel spring 4 or 4' is intended to be as close as possible to the bottom of the barrel drum 2, to which it is parallel.
[0036] For its use in the implementation of step a) of the method of the invention, the semi-finished barrel spring 4' is packaged, in a known manner, wound in turns in a packaging ring 16 to form a semi-finished barrel spring ring assembly 18, shown in Figure 3.
[0037] For use in the manufacture of a barrel, the finished barrel spring 4 is also packaged, in a known manner, wound in turns in a packaging ring 16 to form a finished barrel spring ring assembly 18.
[0038] Except for the processing of the semi-finished barrel spring 4' to obtain the finished barrel spring 4 specific to the invention, the barrel spring ring assembly 18 comprising the finished barrel spring 4 is similar to the semi-finished barrel spring ring assembly 18 comprising the semi-finished barrel spring 4'. Figure 3 therefore represents both the finished barrel spring ring assembly and the semi-finished barrel spring ring assembly. The barrel spring 4 or 4' is positioned wound in the center of the conditioning ring 16 so that its main faces 14a and 14b, formed respectively by the upper 12a and lower 12b edges of the wound turns as defined above, are presented in an accessible manner, in the center of the conditioning ring 16.
[0039] Traditionally, the barrel spring 4 or 4' has a height h greater than the height of its conditioning ring 16 and is positioned in said conditioning ring 16 preferably centered at mid-height, its main faces 14a and 14b protruding from the corresponding side of the ring. The conditioning ring 16 is for example made of aluminum.
[0040] According to the known standard manufacturing process, traditionally used until now, the barrel spring, once packaged in a ring-barrel spring assembly as described above, is ready for use. In general, the barrel spring has been lubricated before being placed in the center of its packaging ring. In particular, its main faces intended to be in contact with the drum and the barrel cover are lubricated.
[0041] In the method of manufacturing at least one barrel spring according to the present invention, and with reference to Figure 4, step a) consists of providing at least one semi-finished barrel spring ring assembly 18, i.e. a barrel spring ring assembly 18 comprising a semi-finished barrel spring 4' as described above, in which said semi-finished barrel spring 4' has edges for example as rolled or ground before winding, but preferably without prior lubrication.
[0042] Thus, the semi-finished barrel spring ring assembly 18 provided in step a) has been previously prepared according to a known standard manufacturing method, but preferably without lubrication. As described above, the semi-finished barrel spring 4' is wound in turns in the center of its conditioning ring 16 so as to present its two main faces 14a and 14b accessible, according to the configuration shown in the drawings, said main faces 14a and 14b being formed by the set of upper edges 12a, respectively lower edges 12b of the wound turns. The barrel spring 4' used in step a), unlike the known manufacturing method, is semi-finished because it will benefit from other modifications according to the subsequent steps of the method of the invention to result in a finished barrel spring 4, as described below.
[0043] Then, according to step b) of the method of the invention, said at least one semi-finished barrel spring ring assembly 18 provided in step a) is temporarily fixed on a support 20, such as a plate, so as to expose one of the main faces of the semi-finished barrel spring 4', here the upper main face 14a, for the implementation of the following step c).
[0044] Advantageously, the ring-barrel spring assembly 18 is temporarily fixed to the support 20 by gluing, for example by means of a temporary adhesive, of the resin type, which can be easily removed for example by washing, preferably in a bath, with chemicals commonly used in industry. Advantageously, the main face of the semi-finished barrel spring 4' opposite the exposed main face, here the lower main face 14b, is positioned in contact with the support 20, parallel to the latter. Advantageously, the face of the ring 16 and the main face of the spring 4' (here the lower face 14b) opposite the face of the ring 16 and the main face of the barrel spring 4' which are exposed are glued to the support 20.
[0045] Then, according to step c), the main face of the semi-finished barrel spring 4' exposed according to step b), here the upper main face 14a, is polished, in particular to eliminate the sharp edges and to obtain rounded edges.
[0046] Advantageously, step c) is carried out by means of at least one polishing disc 22 positioned above the main face of the semi-finished barrel spring 4' exposed according to step b), here the upper main face 14a. Different discs having different grains can be used. The grains are advantageously the standard grains of watchmaking.
[0047] The polishing disc 22 may be a felt disc. Standard watchmaking felts may advantageously be used. Advantageously, the polishing disc 22 may comprise an active part based on synthetic or natural fibers, such as taffeta, viscose or satin, woven or non-woven or flocked, said active part being configured to be associated with a free abrasive during a polishing operation. Advantageously, the abrasive is an abrasive based on diamond grains, for example with dimensions less than 3 μm. Such polishing discs and such a diamond abrasive are marketed for example by the company LAM PLAN. Such polishing discs and such a diamond abrasive advantageously make it possible to obtain a barrel spring 4 whose edges of the turns wound to form said spring have a very low roughness Ra.
[0048] Polishing is carried out, for example, by means of a flat polishing machine in which the polishing disc is placed, the machine also comprising a device for distributing the abrasive used in liquid form.
[0049] Preferably, the polishing disc 22 is arranged to polish the upper edge 12a of all the turns at the same time. It is also possible to provide polishing means which move relative to the exposed main face in order to polish the edges of the turns in zones.
[0050] Step c) of polishing the exposed main face of the semi-finished barrel spring 4', here the upper main face 14a, is carried out so that the upper edges 12a of the turns of the finished barrel spring 4 have a roughness Ra less than or equal to 60 nm, preferably less than or equal to 50 nm, preferably less than or equal to 25 nm, preferably less than or equal to 10 nm, preferably less than or equal to 5 nm, and preferably less than or equal to 2 nm, or even 1 nm. The roughness Ra is defined according to the ISO 4287 standard. The smallest roughnesses Ra can be obtained for example using polishing discs based on fibers associated with a diamond abrasive as described above.
[0051] Then, according to step d), the barrel ring-spring assembly 18 obtained in step c) is separated from the support 20.
[0052] Advantageously, when the barrel spring-ring assembly 18 has been temporarily fixed to the support 20 according to step b) by means of an adhesive, in particular a temporary adhesive, the separation of the barrel spring-ring assembly 18 from the support 20 is carried out by dissolving said adhesive. For example, suitable chemical products (such as solvents) can be used to dissolve the adhesive. These products can be sprayed or preferably used in the form of baths.
[0053] Then, in a step d'), the barrel spring ring assembly 18 obtained in step d) is turned over so that the exposed main face of the barrel spring is now the lower main face 14b. Then steps e) to g) are carried out, which reproduce steps b) to d) but with the other main face of the semi-finished barrel spring 4' now exposed, here the lower main face 14b.
[0054] More particularly, according to step e), at least one barrel spring ring assembly 18 obtained in step d) and returned according to step d') is temporarily fixed on the support 20 so as to expose the other main face of the semi-finished barrel spring 4', here the lower main face 14b, for the implementation of the following step f).
[0055] In a manner similar to step b), the ring-barrel spring assembly 18 is fixed according to step e) provisionally on the support 20, preferably by gluing using, for example, a dissolvable resin. Advantageously, the main face of the semi-finished barrel spring 4' opposite the exposed main face, here the lower main face 14a, is positioned in contact with the support 20, parallel to the latter. Advantageously, the face of the ring 16 and the main face of the spring 4' already polished according to step c) (here the upper face 14a) opposite the face of the ring 16 and the main face of the barrel spring 4' which are exposed are glued to the support 20.
[0056] Then, according to step f), the main face of the semi-finished barrel spring 4' exposed according to step e), here the upper main face 14b, is polished.
[0057] In a similar manner to step c), step f) is carried out by means of at least one polishing disc 22, preferably made of felt, positioned above the main face of the semi-finished barrel spring 4' exposed according to step e), here the lower main face 14b.
[0058] In a manner similar to step c), step f) of polishing the exposed main face of the semi-finished barrel spring 4', here the lower main face 14b, is carried out so that the lower edges 12b of the turns of the finished barrel spring 4 have a roughness Ra less than or equal to 60 nm, preferably less than or equal to 50 nm, preferably less than or equal to 25 nm, preferably less than or equal to 10 nm, preferably less than or equal to 5 nm, and preferably less than or equal to 2 nm, or even 1 nm.
[0059] Then, according to step g), the barrel ring-spring assembly 18 obtained in step f) is separated from the support 20.
[0060] In a similar manner to step d), when the barrel spring-ring assembly 18 has been temporarily fixed to the support 20 according to step e) by means of an adhesive, in particular a temporary adhesive, the separation of the barrel spring-ring assembly 18 from the support 20 according to step g) is carried out by dissolving said adhesive using suitable chemicals.
[0061] A finished barrel spring-ring assembly 18 is thus obtained in which the finished barrel spring 4 is such that the upper 12a and lower 12b edges of the turns have a roughness Ra less than or equal to 60 nm, and preferably less than or equal to 50 nm, preferably less than or equal to 25 nm, preferably less than or equal to 10 nm, preferably less than or equal to 5 nm, and preferably less than or equal to 2 nm, or even 1 nm.
[0062] Except for the upper 12a and lower 12b edges of the coils which have been polished, the finished mainspring 4 is similar to the semi-finished mainspring 4'.
[0063] In a preferred embodiment, the method of the invention is implemented to polish several barrel ring-spring assemblies 18 at the same time, during at least one of steps c) and f).
[0064] For this purpose, in step a), several semi-finished barrel spring ring assemblies 18 are provided as described above. Then, at least in one of steps b) and e), and preferably for each of steps b) and e), said several semi-finished barrel spring ring assemblies 18 are fixed on the same support 20 in order to expose one of the main faces 14a, 14b of the semi-finished barrel springs 4', then at least in one of steps c) and f), and preferably for each of steps c) and f), the exposed main faces 14a and / or 14b of the semi-finished barrel springs 4' of all the barrel spring ring assemblies 18 fixed on the support 20 are polished during the same operation. Then the barrel ring-spring assemblies 18 are separated from the support 20 according to at least one of steps d) and g), and preferably for each of steps d) and g).Between steps d) and e), the barrel spring-ring assemblies 18 are turned over to expose the other main face of the semi-finished barrel springs 4'.
[0065] It is possible to provide several barrel spring ring assemblies 18 positioned on the same support 20, but also several supports 20 comprising several barrel spring ring assemblies 18. The configuration of the polishing machine is adapted accordingly. For example, each support 20 can be arranged on a revolving wheel above which one or more polishing means, such as polishing discs 22, is or are positioned. The polishing means can be arranged to polish the upper edge 12a or the lower edge 12b of all the turns of all or some of the barrel spring ring assemblies 18 at the same time, the barrel spring ring assemblies 18 being on the same support 20 or on different supports 20.It is also possible to provide polishing means which move relative to the exposed main faces of the barrel springs in order to polish the edges of the coils of the barrel spring-ring assemblies 18 distributed by zones on the same support.
[0066] Optionally, but preferably, the barrel spring 4 is lubricated so that it is fully finished, ready for use.
[0067] For this purpose, according to step h) of the method of the invention, the barrel spring 4 obtained in step g) is removed by the watchmaker from its conditioning ring 16.
[0068] Then, according to step i) the barrel spring 4 obtained in step h) is lubricated by any lubricating agent known to those skilled in the art.
[0069] Then, according to step j), the barrel spring 4 lubricated according to step i) is replaced by the watchmaker in its conditioning ring 16 to recondition it into a finished barrel spring-ring assembly 18.
[0070] The finished barrel spring-ring assembly 18 obtained after step g), and preferably after step j), is ready for use and can be used in a similar manner to known barrel spring-ring assemblies for the manufacture of a watch barrel 1.
[0071] More particularly, the method of manufacturing such a timepiece barrel comprises manufacturing a barrel spring according to the method described above, said method of manufacturing the timepiece barrel 1 comprising the following steps: k) positioning the finished barrel spring-ring assembly 18 obtained in step g) or j) on the barrel drum 2; l) introducing the finished barrel spring 4 into the barrel drum 2 by removing it from its conditioning ring 16; m) releasing the conditioning ring 16 from the barrel drum 2; n) completing the assembly of the barrel 1, in particular by mounting the barrel arbor 6 and fitting the barrel cover 8 to close the barrel 1.
[0072] A barrel 1 is thus obtained in which the barrel spring 4 is such that the edges of the turns wound to form said spring have a roughness Ra less than or equal to 60 nm, and preferably less than or equal to 50 nm, preferably less than or equal to 25 nm, preferably less than or equal to 10 nm, preferably less than or equal to 5 nm, and preferably less than or equal to 2 nm, or even 1 nm.
[0073] The method for manufacturing at least one barrel spring according to the invention is simple to implement, and makes it possible to obtain a barrel spring whose edges likely to be in contact with the barrel drum or the barrel cover have a very low roughness Ra. This very low roughness Ra makes it possible to obtain barrel springs which have in particular a reduction in the risks of cracking, an improvement in fatigue resistance, a reduction in the friction forces between the edges of the coils and the drum and / or the barrel cover, and a potential increase in the power reserve, improved compared to barrel springs manufactured by a standard method.
Claims
Claims 1. A method of manufacturing at least one barrel spring (4) comprising the following steps: a) providing at least one semi-finished barrel spring ring assembly (18) in which a semi-finished barrel spring (4') is wound in turns in the center of a conditioning ring (16) so as to have two accessible parallel main faces (14a, 14b), formed respectively by the edges (12a, 12b) of the wound turns; b) temporarily fixing the barrel spring ring assembly (18) provided in step a) on a support (20) so as to expose one of the main faces (14a, 14b) of the semi-finished barrel spring (4'); c) polishing the main face (14a, 14b) of the semi-finished barrel spring (4') exposed according to step b); d) separating the barrel ring-spring assembly (18) obtained in step c) from the support (20);e) provisionally fixing the barrel spring ring assembly (18) obtained in step d) on the support (20) so as to expose the other main face (14a, 14b) of the semi-finished barrel spring (4'); f) polishing the main face (14a, 14b) of the semi-finished barrel spring (4') exposed according to step e); g) separating the barrel spring ring assembly (18) obtained in step f) from the support (20); h) removing the barrel spring (4) obtained in step g) from its conditioning ring (16); i) lubricating the barrel spring (4) obtained in step h); j) replacing the barrel spring (4) lubricated according to step i) in its conditioning ring (16) to recondition it into a finished barrel spring ring assembly (18), steps h) to j) being optional.; 2. Method for manufacturing at least one barrel spring (4) according to claim 1, in which the barrel spring-ring assembly (18) is temporarily fixed to the support (20) according to at least one of steps b) and e) by gluing.
3. Method for manufacturing at least one barrel spring (4) according to one of claims 1 and 2, in which at least one of the steps c) and f) of polishing the main faces (14a, 14b) of the semi-finished barrel spring (4') is carried out by means of at least one polishing disc (22).
4. Method for manufacturing at least one barrel spring (4) according to claim 3, wherein the polishing disc (22) is a felt disc.
5. Method for manufacturing at least one barrel spring (4) according to claim 3, in which the polishing disc (22) comprises an active part based on fibers configured to be associated with an abrasive.
6. Method for manufacturing at least one barrel spring (4) according to claim 5, in which the abrasive is based on diamond grains.
7. Method for manufacturing at least one barrel spring (4) according to one of claims 1 to 6, wherein at least one of the steps c) and f) of polishing the main faces (14a, 14b) of the semi-finished barrel spring (4') is carried out so that the edges (12a, 12b) of the turns of the finished barrel spring (4) have a roughness Ra less than or equal to 60 nm, and preferably less than or equal to 50 nm, preferably less than or equal to 25 nm, preferably less than or equal to 10 nm, preferably less than or equal to 5 nm, and preferably less than or equal to 2 nm.
8. Method for manufacturing at least one barrel spring (4) according to one of claims 1 to 7, in which the barrel ring-spring assembly (18) is temporarily fixed to the support (20) according to at least one of steps b) and e) by means of an adhesive, the respective step d) and g) of separating the barrel ring-spring assembly (18) from the support (20) being carried out by dissolving said adhesive.
9. A method of manufacturing at least one barrel spring (4) according to one of claims 1 to 8, wherein, in step a), several semi-finished barrel spring ring assemblies (18) are provided, at least in one of steps b) and e), said several barrel spring ring assemblies (18) are fixed on the same support (20), at least in one of steps c) and f), the exposed main faces (14a, 14b) of the semi-finished barrel springs (4') of all the barrel spring ring assemblies (18) fixed on the support (20) are polished before separating the barrel spring ring assemblies (18) from the support (20) according to at least one of steps d) and g).
10. Method for manufacturing at least one barrel spring (4) according to one of claims 1 to 9, characterized in that said barrel spring (4) is made of a material chosen from the group consisting of a stainless steel, a Cobalt / Nickel alloy, and an amorphous metal alloy.
11. A method of manufacturing a timepiece barrel (1) comprising manufacturing a barrel spring (4) according to a method defined by one of claims 1 to 10, comprising the following steps: k) positioning the finished barrel spring-ring assembly (18) obtained in step g) or j) on the barrel drum (2); l) introducing the finished barrel spring (4) into the barrel drum (2) by removing it from its conditioning ring (16); m) releasing the conditioning ring (16) from the barrel drum (2); n) completing the assembly of the timepiece barrel (1).
12. Barrel spring (4) obtained according to a method defined by one of claims 1 to 10, characterized in that the edges (12a, 12b) of the wound turns have a roughness Ra less than or equal to 60 nm, and preferably less than or equal to 50 nm, preferably less than or equal to 25 nm, preferably less than or equal to 10 nm, preferably less than or equal to 5 nm, and preferably less than or equal to 2 nm. Barrel spring (4) according to claim 12, characterized in that it is made of a material chosen from the group consisting of a stainless steel, a Cobalt / Nickel alloy, and an amorphous metal alloy. Watch barrel (1) comprising a finished barrel spring (4) according to one of claims 12 and 13.