Manufacturing method for timekeeping decorations

Abstract

The decorations are manufactured in a continuous manner using strips made from the same material as the decorations. [Solution] A row of pilot holes 5 is formed along a longitudinally extending rim of the strip 1, with a group of openings 6 formed between the rows. The openings in this group surround the central portion of the material of the strip, and the central portion remains attached to the strip by an attachment portion formed by a narrow area between two adjacent openings. Decoration is formed on this central portion through a stamping step. The dimensions and shape of the openings are configured such that the stamping tool creeps the material in the central portion without deforming the pilot holes, creating a deformed portion that remains attached to the strip by the attachment portion. At the same time, decoration is formed on the surface of the deformed portion to create a three-dimensional shape, with attachment feet on the opposite side. The strip is passed through a blanking tool and separated from the deformed portion.

Description

Technical Field

[0001] The present invention relates to the field of timepieces, and more particularly to the manufacture of decorations attached to the face of a portable timepiece (e.g., a wristwatch, a pocket watch) for displaying time or attaching other marks or symbols.

Background Art

[0002] Various methods for making decorations have been developed. In terms of production speed, it has been found that continuous methods are effective. Such continuous methods include methods of machining a strip (elongated material) in a series of steps including a step of finally blanking (punching) a plurality of decorations to form them.

[0003] As one of the currently used methods, there is a method in which a steel strip is used, pilot holes are formed along the rim (edge) of the steel strip, and openings are arranged in series between the rows of pilot holes. A workpiece made of a decorative material, which is often gold or brass, is inserted into the openings. Next, the strip including the workpiece is guided to a stamping tool that deforms the workpiece according to the desired shape of the decoration, using the pilot holes. Then, the strip is passed through a blanking tool that forms the decoration by blanking. Then, the workpiece is peeled off from the steel strip, and this steel strip can be reused in the same process.

[0004] Because the steel strip is stronger than the workpiece material, this process prevents deformation of the pilot hole during the stamping and blanking steps. However, this approach has several challenges: Steel strips are very hard and difficult to process. Also, powerful machinery is required to form pilot holes and openings in the steel strip, and the tools used to process the steel strip break quickly and cannot withstand the forces applied during blanking and drilling. When deformed by stamping, the workpiece is pulled considerably, and the steel strip may crack. Ultimately, after using the steel strip only a few times, the opening formed for the workpiece becomes deformed, shortening the practical life of this type of strip. [Overview of the project] [Problems that the invention aims to solve]

[0005] The present invention aims to provide a method that does not result in the problems described in the preceding paragraph. This objective is achieved by a method according to the claims. [Means for solving the problem]

[0006] According to the present invention, a strip uniformly formed from the material to be manufactured for decoration is used. A row of pilot holes is formed along the longitudinal rim of the strip, and at least one group of openings is formed between these rows. In practice, several identical groups of openings are provided at equal intervals along the longitudinal direction of the strip. Several openings in one group surround one central portion of the strip material, thereby keeping this central portion attached to the strip by an attachment portion formed by a narrow area between two adjacent openings in the strip. Next, a stamping step is performed on this central portion to form the decoration. The dimensions and shape of the openings are configured such that the stamping tool creeps the material in the central portion without deforming the pilot holes, creating a deformed portion that remains attached to the strip by the attachment portion. At the same time, the decoration is formed on one face of the deformed portion in relief with respect to that face, and preferably, an attachment foot is attached to the opposite face. Next, the strip is passed through a blanking tool to form the decoration by blanking, such as by stamping or laser, and separated from the deformed portion. Thanks to the deformation-free pilot hole, the workpiece can be precisely positioned relative to the blanking tool.

[0007] This method enables continuous in-line processing from raw materials to removable decorations, eliminating the need for steel strips. The shape of the central portion formed by the opening absorbs deformation during stamping, ensuring that the pilot holes formed in the strip remain undeformed and optimal positioning is achieved. This is further ensured by the fact that the deformed portion remains attached to the strip after stamping. Thanks to these differences compared to existing technologies, the method according to the present invention makes it possible to reduce manufacturing costs and time.

[0008] The present invention will be described in detail below with reference to the attached drawings. These are given as examples and are not limited thereto. [Brief explanation of the drawing]

[0009] [Figure 1] This shows a front view of a strip made of decorative material for a timekeeping device, which has holes and openings, according to one embodiment of the present invention. [Figure 2] Figure 1 shows an example of decoration created using the strips shown. [Figure 3] Figures 3a and 3b show enlarged views of a portion of the strip. Figure 3a shows the strip before deformation by stamping. Figures 3B and 3c show two faces of the strip after deformation by stamping, respectively. [Figure 4] This shows a perspective view of the strip after many decorations have been formed by stamping, but before the blanking step is performed. [Figure 5] This shows the strip portion shown in Figures 3a and 3b after the decoration has been blanked out. [Figure 6] This diagram illustrates the process of using a blanking punch configuration to create a strip with pilot holes and openings, as shown in Figure 1. [Modes for carrying out the invention]

[0010] Figure 1 shows a strip 1 made of a material that can be used to decorate a portable watch, such as brass or another copper-based alloy. Any other material suitable for the manufacture of decorations, such as gold, silver, or alloys thereof, can also be used.

[0011] In one embodiment of the present invention, the strip has many holes and openings formed therein. However, it is not limited to this. The ornament to be manufactured in this example is shown in Figure 2. This is a rectangular ornament 2 with a central bed 3 and two legs 4 on the bottom surface, and is used to attach this ornament to the dial of a portable watch. The dimensions of the ornament 2 are compatible with the dimensions of the dial, and the ornament can be seen as a time index or as a decorative element. As a result, the strip 1 has similar dimensions, for example, a width of 10 to 40 mm. The dimensions of the strip are similar to those of a steel strip with an embedded workpiece, as described at the beginning. In one embodiment, the thickness of the strip 1 can be 0.3 to 1.5 mm. However, it is not limited to this.

[0012] Pilot holes 5 are drilled or blanked at equal intervals along the rim of the strip 1. These holes 5 are sized and positioned so that the strip 1 is guided by the insertion of guide teeth of a strip feeder, and so that the strip 1 is transported by the movement of the strip feeder so that it passes through various tools.

[0013] The strip 1 is provided with several groups of openings 6 between two rows of pilot holes 5. These groups of openings 6 are identical to each other and are arranged at equal intervals in the longitudinal direction of the strip 1.

[0014] Figure 3a shows a detailed view of a part of the strip 1. In the illustrated embodiment, each group of openings 6 has four elliptical openings, but is not limited to this. The major axes of openings 6a and 6b are perpendicular to the longitudinal direction of the strip 1, while the major axes of openings 6c and 6d are parallel to the longitudinal direction. The lengths of openings 6c and 6d are shorter than the lengths of openings 6a and 6b, and these shorter openings 6c and 6d are located between the ends of the longer opening 6a and the longer opening 6b, leaving an attachment portion 7 between them. The attachment portion 7 is formed by a narrow area on the strip 1 located between two adjacent openings, for example, between openings 6a and 6c, or between openings 6b and 6d. As a result, openings 6a to 6d surround a central portion 8 of the strip having a concave, curved rim, and the curve is defined by the cross-sectional contour of openings 6a to 6d.

[0015] The dimensional configuration and arrangement of the openings 6a to 6d in each opening group 6 are determined by the stamping tool used in the traditional method described at the beginning, so that the central portion 8 can be deformed by plastic deformation in a specific predetermined manner. This tool is configured to compress the central portion 8 between the die and the punch to form the decoration 2. The openings 6a to 6d are configured so that the material of the central portion 8 deforms without the attachment portion 7 coming off or the pilot hole 5 being deformed.

[0016] The results are shown in Figures 3B and 3c, which show the two faces of strip 1 after stamping on each of the central portions 8. Stamping deforms the central portion 8, forming the deformed portion 8'. Thanks to the die and punch profiles, the legs 4 of the decoration are formed on the upper surface of the deformed portion, creating a three-dimensional shape relative to its upper surface (Figure 3B), while the decoration 2 itself, where the bed 3 is located, is formed on the lower surface, creating a three-dimensional shape relative to its lower surface (Figure 3C). Outside the decoration, the material creeps due to stamping, and the surface of the deformed portion 8' expands relative to the surface of the central portion 8 before deformation. The cross-section of the contours of the elliptical openings 6a-6d surrounding the central portion 8 is pushed outward, but the rest of the contour remains essentially unchanged. That is, the openings 6a-6d absorbed the deformation. Therefore, the pilot hole 5 is not deformed. Furthermore, even after deformation, the deformed portion 8' remains connected to the strip by the attachment portion 7', and although this attachment portion 7' ​​may be slightly deformed compared to the original attachment portion 7, the uniformity between portion 8' and strip 1 is maintained. In other words, the attachment portion 7 is not damaged or ruptured by the force generated by stamping.

[0017] Figure 4 shows a perspective view of one embodiment of strip 1, in which several central portions 8 pass through the stamping tool to form deformed portions 8'. The shape of the deformed portions 8' differs slightly from the flat portions 8' shown in Figures 3B and 3c. In Figure 4, it can be seen that the ends of the deformed portions 8' are slightly curved upward. These variations are completely equivalent, and in both cases, stamping is performed without deforming the pilot holes 5 or damaging the attachment portions 7.

[0018] After stamping, the deformed part 8’ goes through the blanking step to separate the decoration 2 from the deformed part 8’. Thanks to the non-deformed pilot holes, the part 8’ can be accurately positioned relative to the blanking tool. FIG. 5 shows a portion of the strip 1 after blanking, which is also shown in FIGS. 3a - 3c. The tool used can be a laser cutting machine or a stamping tool similar to the stamping tool but with a die and a blanking punch. These blanking processes are well-known and can be used in or for the method described at the beginning. In the stamping process, the punch is provided with a clearance through which the leg 4 of the decoration 2 can pass. The die has a shape matching the shape of the decoration and holds the decoration in place during blanking. Then, the extractor in the die discharges the blanked decoration.

[0019] To reach the configuration of the opening that achieves the desired result, i.e., manufacturing the decoration 2 without deforming the pilot holes 5 and without rupturing or breaking the attachment part 7, a person skilled in the art can follow the method described below.

[0020] First, several parameters are collected as follows. - The material to be used, - The width and thickness of the strip, - The shape and dimensional configuration of the decoration - The diameter and spacing of the pilot holes

[0021] Based on these parameters, simulation software is used to determine the configuration of the opening and calculate the deformation of the parts processed by the stamping tool. Examples of commercially available software that can be used to reach the present invention include Forge (manufactured by Transvalor) and Abaqus (manufactured by Dassault Systemes).

[0022] For example, starting from an initial configuration obtained based on experience or prior calculations, the software simulates the forces exerted by the tools used in this process and derives the deformation of the strip under the influence of this force from the simulation. As a result, by repeating the simulation multiple times and improving the shape and dimensional configuration of the opening each time, the configuration can be optimized to minimize the deformation near the pilot hole and optimize the deformation of the attachment part to prevent breakage. Optimization can be achieved using simulation software or optionally using other calculation software well-known to those skilled in the art.

[0023] Note that the present invention is not limited to a configuration consisting of the four elliptical openings shown. The number of openings surrounding the central portion 8 can be, for example, three, five, or more. The shape of the openings can be other than elliptical, for example, circular or rectangular, and openings of different shapes can also be used in combination. An outline that provides a central portion having a rim recessed with respect to the center of the central portion (e.g., the portion 8 shown) is a preferred embodiment, but this type of outline is not limited to elliptical openings. This recessed rim of the central portion can also be created by applying an opening having another contour such as a circular contour.

[0024] The optimal configuration is determined according to several parameters such as the shape and dimensional configuration of the decoration, the material of the strip, and the shape and dimensional configuration of the pilot hole. Note that these pilot holes can have a shape that is not circular (e.g., rectangular).

[0025] The present invention is not limited to one or more specific materials in the strip 1. However, preferred materials are those most commonly used in the manufacture of decorations for portable watches, specifically copper and copper alloys such as brass, and further gold, silver, or gold or silver alloys.

[0026] Well-known methods can be used to form the pilot holes 5 and the elliptical or other shaped openings. Taking the specific case of the strip 1 shown in Figure 1, this can be achieved by blanking the strip in three steps and repeating this several times, as shown in Figure 6. A cross-section of the blanking punch group is shown in section P of the drawing. The strip 1, made of brass or the like, is fed under a group of punches of various shapes, which simultaneously blank the material as it appears. This type of tool is known as a progressive stamp. Three blanking steps, A, B, and C, are required to obtain all the pilot holes and elliptical openings, after which the strip is precisely advanced in the direction of the arrow. By repeating these three steps several times, a strip is created with multiple equally spaced holes and openings. [Explanation of symbols]

[0027] 1 strip 2. Decoration 4 pairs 5 pilot holes 6, 6a~6d opening 7, 7' Attachment section 8 Central part 8' Deformed part

Claims

1. A method for manufacturing at least one decoration (2) for a timekeeping device made of a predetermined material, The steps include: preparing a longitudinally extending strip (1) made of the material with two parallel rims as boundaries; The steps include forming rows of equally spaced pilot holes (5) along each of the rims of the strip (1) by blanking or drilling, The steps include: forming a group of at least one opening (6) between the rows of pilot holes by blanking or drilling such that the contour of the opening forms a rim of a central portion (8) made of the material, and leaving the central portion (8) attached to the strip by an attachment portion (7) formed by a narrow region of the strip between two adjacent openings; Subsequently, the step of using the pilot hole (5) to guide the strip through the stamping tool, The steps of simultaneously using the stamping tool to creep the material of the central portion (8) without deforming the pilot hole (5) to create a deformed portion (8') that remains attached to the strip by the attachment portion (7'), and to form the decoration (2) on one surface of the deformed portion (8') in a three-dimensional form relative to that surface, Subsequently, the strip is passed through the blanking tool using the pilot hole (5), The steps include passing the modified portion (8') through the blanking tool to blank out and form the ornament (2), and A method for providing this.

2. The rim on the central portion (8) has a recessed shape relative to the center of the central portion. The method according to claim 1.

3. The openings (6a to 6d) are elliptical in shape. The method according to claim 1.

4. The aforementioned group consists of four elliptical openings (6a to 6d), The contours of the two openings (6a, 6b) of the group have a major axis perpendicular to the longitudinal direction of the strip (1), The contours of the other two openings (6c, 6d) in the aforementioned group have major axes parallel to the longitudinal direction. The method according to claim 3.

5. The strip (1) has multiple groups of openings (6) arranged at equal intervals in the strip, thereby creating multiple central portions (8), and from these central portions (8) multiple decorations (2) are created. The method according to claim 1.

6. Using the stamping tool, simultaneously with the act of creating the deformed portion and the act of creating a decoration that takes on a three-dimensional form on the surface, one or more mounting feet (4) are formed on the surface of the deformed portion (8') opposite to the surface on which the decoration (2) is formed to take on a three-dimensional form. The method according to claim 1.

7. The material of the decoration (2) is copper, gold, silver, or an alloy of copper, gold, or silver. The method according to claim 1.

8. The blanking tool is a laser blanking tool, or a stamping tool that uses a die and a blanking punch. The method according to claim 1.

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