Method for producing a timepiece trim

Abstract

A strip is uniformly made of a material of an ornament to be manufactured, a plurality of rows of guide holes are formed along the longitudinal edge of the strip, and at least one group of openings are formed among the plurality of rows of guide holes. The set of openings encircles a central portion of the strip material such that the central portion remains attached to the strip by an attachment formed by a narrow area on the strip between two adjacent openings. A stamping process is then performed on the central portion to form the trim. The size and shape of the opening are configured such that the stamping tool can creep the material of the central portion without causing deformation of the guide hole, resulting in a deformed portion that remains attached to the strip by the attachment portion. At the same time, on one of the faces of the deformed portion, a trim is formed in an embossed form with respect to the face, and preferably, an attachment foot is formed concomitantly on the opposite face. The strip is then fed into a blanking tool to blank the trim part, thereby separating the trim part from the deformed portion. The undeformed guide hole enables the deformed part to be accurately positioned relative to the blanking tool.

Description

Technical Field

[0001] This invention relates to the field of watchmaking, and more particularly to the manufacture of appliques attached to the surface of a watch dial for marking hours or for arranging other marks or symbols. Background Technology

[0002] There are many methods for making ornaments. In terms of production speed, continuous production methods have proven effective. These methods involve processing strips through a series of steps, culminating in the blanking of multiple ornaments.

[0003] One current method uses a steel strip with guide holes along its edge and openings arranged in series between multiple rows of guide holes. A workpiece made of ornament material (typically gold or brass) is pressed into these openings. The strip containing the workpiece is then guided through the guide holes relative to a stamping tool, which deforms the workpiece to the desired shape. The strip is then fed into a blanking tool, which blanks the ornament. Finally, the workpiece is peeled off the steel strip, which can then be reused in the same process.

[0004] Because the steel strip is stronger than the workpiece material, this process avoids guide hole deformation during stamping and blanking. However, this method also has some drawbacks. The steel strip is very hard and difficult to machine. Machining guide holes and openings requires powerful machinery, and the tools used to machine the steel strip may break quickly and cannot withstand the forces applied during blanking and piercing. Due to stamping deformation, the workpiece is subjected to considerable strain, which can cause the steel strip to crack. Ultimately, after repeated use of the steel strip, the openings for the workpiece will deform, thus limiting the service life of such strips. Summary of the Invention

[0005] The present invention aims to provide a method that does not have the defects described above. This objective is achieved by the method according to the appended claims.

[0006] According to the invention, a strip uniformly made from the material of the ornament to be manufactured is used. The strip has multiple rows of guide holes / positioning holes along its longitudinal edge, and at least one set of openings is arranged between the rows of guide holes. In practice, several identical sets of openings are equidistantly arranged in the longitudinal direction of the strip. One set of openings surrounds a central portion of the strip material, such that the central portion is held attached to the strip by an attachment portion formed by a narrow region in the strip between two adjacent openings. A stamping process is then performed on the central portion to form the ornament. The size and shape of the openings are configured such that the stamping tool causes the material of the central portion to creep without deforming the guide holes, thereby creating a deformed portion held attached to the strip by the attachment portion. Simultaneously, on one face of the deformed portion, the ornament is formed in a raised form relative to said face, preferably accompanied by an attachment foot on the opposite face. The strip is then fed into a blanking tool (e.g., by stamping or using a laser), which blanks the ornament, thereby separating the ornament from the deformed portion. Undeformed guide holes allow the workpiece / deformed portion to be precisely positioned relative to the blanking tool.

[0007] This method enables a continuous production line operation from raw materials to finished decorative parts, thereby avoiding the use of steel strips. Because the shape of the central portion defined by the opening absorbs deformation during the stamping process, the guide holes on the strip do not deform, ensuring optimal positioning. Furthermore, the deformed portion remains attached to the strip after the stamping operation, also ensuring optimal positioning. These differences allow the method of this invention to reduce manufacturing costs and time compared to existing technologies. Attached Figure Description

[0008] The invention will now be described in more detail with reference to the accompanying drawings, which are given by way of non-limiting example, wherein:

[0009] Figure 1 A front view of a strip made of watchmaking material, having holes and openings, is shown according to an embodiment of the present invention.

[0010] Figure 2 It shows the result of Figure 1 An example of a decorative piece made of stripes is shown.

[0011] Figures 3a to 3c A magnified view of a portion of the strip is shown, in which... Figure 3a This shows the state of the strip before it is deformed by stamping. Figure 3b and 3c The two sides of the strip after it has been deformed by stamping are shown respectively.

[0012] Figure 4 A 3D view of the strip is shown after multiple trim pieces have been formed by stamping, but before the blanking process.

[0013] Figure 5 This shows what happens after the ornament has been cut out. Figures 3a-3b The strip portion shown.

[0014] Figure 6 This demonstrates the use of a blanking punch configuration for production. Figure 1 The process shown is for a strip with guide holes and openings. Detailed Implementation

[0015] Figure 1 A strap 1 is shown, made of a material suitable for watch ornaments, such as brass or other copper-based alloys. Any other suitable material for making ornaments can be used, such as gold, silver, or their alloys.

[0016] According to a non-limiting embodiment of the invention, the strip has a plurality of holes and openings. The ornament to be manufactured in this example is as follows: Figure 2 As shown, this is a rectangular ornament 2 with a central groove 3 and two legs 4 on its lower surface for attaching the ornament to the watch dial. The size of the ornament 2 is adapted to the size of the dial so that the ornament can be presented as a time-grading element or as a decorative element. Therefore, the strip 1 has a similar design, for example, a width between 10 mm and 40 mm. The strip size can be similar to that of a steel strip with a press-fitted workpiece (as described in the introduction). According to a non-limiting embodiment, the thickness of the strip 1 can be between 0.3 mm and 1.5 mm.

[0017] Equidistant guide holes 5 are formed along the edge of the strip 1 by through-cutting or punching. The position and size of these guide holes 5 are designed such that the strip 1 can be guided by the guide teeth of the inserted strip feeder, and the movement of the feeder will convey the strip through various tools.

[0018] Between the two rows of guide holes 5, the strip 1 is provided with multiple sets of openings 6, each set of openings 6 being identical to each other and equidistantly distributed along the longitudinal direction of the strip 1.

[0019] Figure 3aA partial detail view of strip 1 is shown. According to the non-limiting embodiment shown, each set of openings 6 comprises four elliptical openings. The major axes of openings 6a and 6b are oriented perpendicular to the longitudinal direction of strip 1, while the major axes of openings 6c and 6d are oriented parallel to the longitudinal direction. The lengths of openings 6c and 6d are less than the lengths of openings 6a and 6b, and the shorter openings 6c and 6d are located between the ends of the longer openings 6a and 6b, while being spaced apart from the longer openings 6a and 6b by attachment portions 7. The attachment portions 7 are defined by a narrow region on strip 1 located between two adjacent openings (e.g., between 6a and 6c, or between 6b and 6d). Thus, openings 6a-6d surround a central portion 8 of the strip, the edge of which is shaped as a concave curve defined by multiple contour segments of openings 6a-6d.

[0020] The size and position of each set of openings 6a-6d are determined such that the central portion 8 can be plastically deformed in a specific and predetermined manner using a stamping tool used in the existing method described in the introduction. This stamping tool presses the central portion 8 between a die and a punch configured to form the trim 2. The openings 6a-6d are configured such that deformation of the material of the central portion 8 does not cause either separation / breakage of the attachment 7 or deformation of the guide hole 5.

[0021] Figure 3b and 3c This result is shown, illustrating the two faces of the strip 1 after each center portion 8 has been stamped. The stamping deforms the center portion 8, forming the deformed portion 8'. Due to the contours of the die and punch, the trim's legs 4 are formed on the upper surface of this deformed portion. Figure 3b ), which is raised relative to the upper surface, and the decorative piece 2 with the groove 3 is formed on the lower surface ( Figure 3c The deformed portion 8' is raised relative to the lower surface. On the exterior of the trim, stamping has caused material creep, resulting in an enlargement of the surface of the deformed portion 8' relative to the surface of the central portion 8 before deformation. It can be seen that the contour segments of each ellipse 6a-6d surrounding the central portion 8 have been pushed outwards, but the rest of the contour remains essentially intact. In other words, the openings 6a-6d absorb the deformation. Therefore, the guide hole 5 is not deformed. Furthermore, after deformation, the deformed portion 8' remains attached to the strip via the attachment portion 7', which may be slightly deformed relative to the original attachment portion 7, but it still maintains the integrity / consistency of portion 8' with the strip 1. In other words, the attachment portion 7 did not break or fracture due to the force generated by stamping.

[0022] Figure 4A 3D view of a non-limiting embodiment of strip 1 is shown, in which a plurality of central portions 8 have been fed through a stamping tool to form deformed portions 8'. The shape of the deformed portions 8' is similar to... Figure 3b and 3c The flattened portion 8' shown is slightly different. Figure 4 In the image, the end of the deformed portion 8' can be seen to be slightly curved upwards. These deformations are completely equivalent, and in both cases, performing the stamping will not cause deformation of the guide hole 5, nor will it damage the attachment portion 7.

[0023] After stamping, the deformed part 8' undergoes a blanking process, which separates the trim 2 from the deformed part 8'. The undeformed guide hole allows part 8' to be precisely positioned relative to the blanking tool. Figure 5 It shows the process after the material is unloaded. Figures 3a-3c The strip 1 shown is a portion thereof. The tool used can be a laser cutter or a stamping tool similar to the stamping tool described above, but the stamping tool includes a die and a blanking punch. These blanking processes are well known and are also used or can be used in the method described in the introduction. During the stamping process, the punch leaves a gap to allow the legs 4 of the ornament 2 to pass through. The die matches the shape of the ornament and holds the ornament in place during the blanking process. Then, an extractor in the die ejects the blanked ornament.

[0024] In order to obtain an opening configuration that achieves the desired result, i.e., to produce the trim 2 without deformation of the guide hole 5 and without damage or breakage of the attachment 7, those skilled in the art can follow the methods described below.

[0025] First, collect some parameters, including:

[0026] The materials to be used,

[0027] The width and thickness of the strip,

[0028] The shape and size of the ornaments

[0029] Diameter and spacing of the guide holes.

[0030] Based on these parameters, simulation software is used to calculate the deformation of the part machined by the stamping tool, thereby determining the opening configuration. Examples of commercially available software that can be used to implement this invention include... (manufactured by Transvalor) and Abaqus (manufactured by Dassault Systèmes).

[0031] Starting with an initial configuration, such as one obtained based on experience or preliminary calculations, the software can simulate the forces applied by tools used in the process and deduce the deformation of the strip under these forces from the simulation results. By repeating the simulation multiple times, improving the shape and size of the opening each time, the configuration can eventually be optimized to minimize deformation near the guide hole and optimize the deformation of the attachment to prevent attachment breakage. Optimization can be achieved using the simulation software described above, or other computational software well known to those skilled in the art can be used.

[0032] It should be noted that the present invention is not limited to the configuration shown, which consists of four elliptical openings. The number of openings surrounding the central portion 8 can vary, for example, three, five, or more. The shape of the openings can be other than elliptical, such as circular or rectangular, or a combination of openings of different shapes can be used. In a preferred embodiment providing the outline of the central portion, the central portion has a recessed edge relative to its center (e.g., portion 8 shown in the figure), but this type of outline is not limited to elliptical openings. The recessed edge of the central portion can also be achieved by using openings with other outlines (e.g., circular outlines).

[0033] Determining the optimal configuration depends on many parameters, including the shape and size of the trim, the strip material, and the shape and size of the guide holes. It should be noted that these guide holes can be any shape other than circular (e.g., rectangular or other shapes).

[0034] For strip 1, the invention is not limited to one or more specific materials. However, preferred materials are those most commonly used in the manufacture of watch ornaments, particularly copper and copper alloys, such as brass, as well as gold or silver, or alloys of gold or silver.

[0035] The guide hole 5 and the elliptical opening or other opening configurations can be manufactured using known methods. For example... Figure 6 As shown, the strip blanking process can be repeated multiple times to obtain the desired result. Figure 1 The specific state of strip 1 is shown. The cross-section of a set of blanking punches is shown in part P of the figure. For example, strip 1 made of brass is fed under a set of punches with different shapes, which can simultaneously blank any material present. This type of tool is called a progressive stamping press. To obtain all the guide holes and elliptical openings, three blanking processes A, B, and C are required, after which the strip is precisely advanced in the direction of the arrow. By repeating these three processes multiple times, a strip with multiple equidistant guide holes and openings can be produced.

Claims

1. A method for manufacturing at least one ornament (2) for a watch, said ornament being made of a predetermined material, said method comprising: Provides a longitudinal strip (1) made of the material, the strip being defined by two parallel edges. Multiple rows of equidistant guide holes (5) are punched or drilled along each edge of the strip (1). At least one set of openings (6) is punched or punched at the center position between multiple rows of guide holes, such that the outline section of the opening defines the edge of a central portion (8) made of the material, the central portion being held attached to the strip by an attachment portion (7) defined by a narrow region on the strip located between two adjacent openings. Then, the strip is guided through the punching tool using the guide hole (5). At least the following operations are performed simultaneously using the stamping tool: The material of the central portion (8) is creeped without causing deformation of the guide hole (5) to create a deformed portion (8'), which is held attached to the strip by the attachment portion (7'). A decorative element (2) is formed on one of the surfaces of the deformed portion (8') in a raised form relative to the surface. Then, the guide hole (5) is used to guide the strip through the blanking tool. The deformed portion (8') is fed through the blanking tool to blank the ornament (2).

2. The method according to claim 1, wherein, The edge portion on the central portion (8) has a concave shape relative to the center of the central portion.

3. The method according to claim 1 or 2, wherein, The openings (6a-6d) are elliptical.

4. The method according to claim 3, wherein, The set of openings includes four elliptical openings (6a-6d), namely, two openings (6a, 6b) whose major axis of the profile is oriented perpendicular to the longitudinal direction of the strip (1), and two openings (6c, 6d) whose major axis of the profile is oriented parallel to the longitudinal direction.

5. The method according to any one of the preceding claims, wherein, The strip (1) includes multiple sets of openings (6) arranged equidistantly on the strip to generate multiple central portions (8), and multiple ornaments (2) are made from these central portions (8).

6. The method according to any one of the preceding claims, wherein, While creating the deformed portion and forming a raised ornament relative to the surface, one or more attachment feet (4) are formed using the stamping tool, the attachment feet (4) being located on the surface of the deformed portion (8') opposite to the surface of the raised ornament (2).

7. The method according to any one of the preceding claims, wherein, The material of the ornament (2) is copper, gold, silver, or copper alloy, gold alloy, silver alloy.

8. The method according to any one of the preceding claims, wherein, The blanking tool is either a laser blanking tool or a stamping tool using a die and a blanking punch.

Images