Method for punching out appliques in the field of watchmaking
By using a hybrid punching method, which utilizes laser beam punching of fragile parts and die punching of complementary parts, the problems of shape limitations and high costs in existing technologies are solved, enabling the manufacture of high-quality, low-cost accessories.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 宇宙股份有限公司
- Filing Date
- 2023-05-16
- Publication Date
- 2026-05-19
AI Technical Summary
Existing technologies for punching dial accessories suffer from shape limitations and high costs, particularly in manufacturing accessories with pointed areas or fine grooves, and laser punching is also expensive.
A hybrid punching method is adopted, which uses a laser beam to punch the fragile parts and fine grooves or pointed areas of the ornament, and uses a die to punch the complementary parts. This method combines the advantages of laser and stamping technologies, avoiding the high cost of laser punching and the shape limitations of stamping.
It enables the manufacture of accessories with pointed areas or fine grooves without increasing costs, combining the advantages of laser and stamping, and reducing production complexity and costs.
Smart Images
Figure CN117075457B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for manufacturing appliques in the field of watchmaking, and more particularly to the découpage of such appliques. Appliques are typically arranged on the surface of a dial (each dial being associated with an analog time display) to provide relief for time markings or time data, such as Roman numerals from I to XII. Background Technology
[0002] Those skilled in the art typically use stamping techniques to cut accessories. The stamping step usually occurs before certain finishing steps of the accessory. A known advantage of stamping is its relatively low cost for mass production of accessories. In fact, once the die has been formed (which can be relatively expensive), the method of using the die to cut accessories is quick and inexpensive. However, stamping has limitations on the shape of the accessory, making it suitable only for relatively simple shapes. In particular, the manufacture of the die and the stamping method do not allow for very narrow recesses or solid portions, or pointed areas that do not have a rounded end profile, the average radius of which technically cannot be less than a certain limit, which is relatively large and depends particularly on the height of the accessory sidewalls in the rounded profile area during the stamping of the accessory.
[0003] Document CH711 256A2 describes a method for manufacturing watch components in a band, particularly for machining and punching inlays with triangular profiles within the band. After machining the inlays to provide some relief on the top surface, especially at small planes, the document proposes partially finishing the inlays with a laser while preserving the band arrangement. Specifically, it provides for laser-cutting the entire profile of the inlay while retaining only one or a few attachment points (very narrow bridges between 0.01 and 0.02 mm wide), which still connect the punched inlays to the band to facilitate transporting these inlays to a location where they are manually separated from the band and arranged on the dial surface. The advantage of laser processing is the ability to punch inlays at the final stage of inlay manufacturing, making it possible to perform finishing steps prior to such laser punching, and thus on all inlays still attached to the band.
[0004] Although the purpose of document CH711256A2 is to propose a method for manufacturing high-quality watch parts more quickly while limiting manual operation, it has been found that, in the case of accessories with relatively long profiles, especially in the case of Arabic or Roman numerals as exemplified in the document, the laser punching step is relatively time-consuming, making the step relatively expensive and thus increasing the manufacturing cost of such accessories.
[0005] Therefore, the choice left to those skilled in the art by the prior art between laser cutting of the ornaments (while advantageously retaining at least one weak attachment point, so that the ornaments can be easily and eventually separated from the strips carrying these ornaments) and die cutting by stamping results in a choice between the following two for the ornaments: relatively high manufacturing costs and relatively simple shapes, in particular, the outline of each ornament does not have at least one recess with a pointed area with a very small end arc (and therefore a very small radius) and / or a fine groove, and does not have a protrusion with a pointed area (with a very small end arc or no end rounded corner) and / or an elongated section. Summary of the Invention
[0006] The purpose of this invention is to provide a method for punching ornaments in the watchmaking field that does not have the aforementioned disadvantages of stamping technology (i.e., the shape limitations of the ornaments) nor the high cost associated with laser punching technology proposed in the prior art.
[0007] Therefore, the present invention relates to a method for punching an ornament intended for use on a watch dial, wherein the ornament has a profile at the end of the punching method, the profile defining at least one recess having a pointed region and / or a fine groove, and / or the profile defining at least one protrusion forming a pointed and / or elongated segment. According to the invention, the punching method includes, on the one hand, the step of punching out a first portion of the profile defining at least a first recess in the at least one recess using a laser beam, and / or punching out a first portion of the pointed and / or elongated segment of at least a first protrusion in the at least one protrusion; on the other hand, the step of punching out a second portion of the profile complementary to the first portion by means of a die (i.e., by stamping).
[0008] A “pointed region” refers to a recessed (and therefore empty) region that ends with a pointed tip (and generally has small rounded corners at the ends). A “fine groove” refers to a recessed region in which the distance between the two sidewalls forming the fine groove is relatively small, specifically substantially equal to or less than the average height of these sidewalls in the region under discussion. Similarly, an “elongated segment” of a protrusion refers to a segment of the protrusion that is longer than its width and has a relatively small width, specifically substantially equal to or less than the average thickness of the segment.
[0009] According to a preferred alternative embodiment, the junction between the first and second portions of the accessory outline is located at the apex of the portion of the accessory that forms the outer corner.
[0010] According to the primary embodiment, the contour in the pointed region of the first recess ends with a first joining line connecting two converging line segments of the contour. This first joining line has two endpoints, thereby defining the two endpoints of the two line segments. In a general variation, the two line segments are separated by a distance substantially equal to or less than the height of the accessory sidewall at the two endpoints, particularly the maximum height.
[0011] According to an advantageous variation, the distance separating the two endpoints of the first joining line is less than two-thirds of the aforementioned height. Specifically, the first joining line is a curve defining an average radius that is substantially equal to or less than one-third of the aforementioned height. According to a preferred variation, the distance separating the two endpoints of the first joining line is substantially equal to or less than half of the aforementioned height. Specifically, the first joining line is a curve defining an average radius that is substantially equal to or less than one-quarter of the aforementioned height.
[0012] Therefore, the hybrid punching technique according to the invention makes it possible to obtain an accessory having a profile at the end of the punching method that defines at least one recess having a pointed area and / or a fine groove, and / or / the profile defines at least one protrusion forming a pointed and / or elongated segment, having a structure and specific dimensions that cannot be obtained by punching using only stamping, while limiting the punching cost of the accessory relative to the cost of punching entirely by means of a laser beam, optionally except for attachment points. Attached Figure Description
[0013] The invention will now be described in more detail with reference to the accompanying drawings, which are given by way of example and are by no means limiting, wherein:
[0014] - Figure 1 This illustrates the first step of a first variation of a first embodiment of the method for punching ornaments according to the present invention;
[0015] - Figure 2The second step of the punching method according to the first variation described above is shown;
[0016] - Figure 3 Displaying an accessory produced by the punching method according to the first variation described above;
[0017] - Figure 4 yes Figure 3 A magnified view of a portion of the image;
[0018] - Figure 5 This illustrates the first step of a second variation of a first embodiment of the method for punching ornaments according to the present invention;
[0019] - Figure 6 The second step of the punching method according to the second variation described above is shown;
[0020] - Figure 7 Displaying an accessory produced by the punching method according to the second variation described above;
[0021] - Figure 8 This illustrates the first step of a second embodiment of the method for punching ornaments according to the present invention;
[0022] - Figure 9 This illustrates the second step of the punching method according to the second embodiment;
[0023] - Figure 10 Displays an accessory produced by the punching method according to the second embodiment. Detailed Implementation
[0024] refer to Figures 1 to 7 Two variations of a first embodiment of the method for punching an accessory according to the present invention will be described, the accessory being intended for use on a watch dial.
[0025] Generally, within the scope of a first embodiment of the punching method according to the invention, at the end of the punching method, the ornaments 2 and 4 have a profile 20 (corresponding to 30) defining at least one recess 23 (corresponding to 33a, 33b) having a pointed region 25 (corresponding to 25A, 25B) and / or a fine groove (a variant not shown in the figure). The punching method includes, on the one hand, the step of punching out a first portion 21 (corresponding to 31a and 31b) of the profile defining at least a first recess 23 (corresponding to 33a) in the at least one recess using a laser beam, and on the other hand, the step of punching out a second portion 22 (corresponding to 32) of the profile complementary to the first portion by means of a die (i.e., by stamping).
[0026] A first variation of the first embodiment will refer to Figures 1 to 4A detailed description follows. The accessory 2 defines the Roman numeral V. The first portion of the accessory's outline 20 includes a single recess 23 defined by the accessory's inner outline 21. Specifically, this inner outline is formed by two inner straight segments 21a and 21b of the accessory's outline 20 and a joining line 26 connecting these two inner straight segments in the pointed region 25 of the recess 23. Thus, in the pointed region 25 of the recess 23, the outline 20 ends with the joining line 26 connecting the two converging segments 21a and 21b, which has two endpoints 24a and 24b, thereby defining the two endpoints of the two segments. In a general variation, the two endpoints 24a and 24b are separated by a distance D that is substantially equal to or less than the height of the sidewalls of the accessory 2 at these two endpoints. Generally, this distance D is very small, and the height of the sidewalls is substantially the same at the two endpoints 24a and 24b. Otherwise, the maximum height would be considered as the upper limit of the distance D.
[0027] In the field of stamping, general rules for producing accessories state that, whether for fine grooves, the distance between the two endpoints of two converging line segments in the pointed region of a recess, or the width of an elongated segment ending in a pointed or non-pointed section in the case of a protrusion, the minimum ratio between the width of the recess or protrusion and the height of the accessory sidewall at the two points defining the width of the profile is "1". This ratio can be slightly reduced using certain die-making techniques, particularly with a limit of less than or equal to 2 / 3. However, such dies are more difficult to produce and are very fragile, particularly limiting their lifespan. Furthermore, as the lower limit of the aforementioned ratio approaches, the amount of accessory that needs to be removed after stamping due to deformation increases, thus reducing industrial output. The punching method according to the invention effectively solves this technical problem because it limits the additional costs for punching ornaments by proposing a hybrid technique that uses a laser beam to punch a first portion of the contour of each ornament, the first portion of which primarily involves all fragile parts or areas where the width of the provided recesses or protrusions is small or very small. On the other hand, a second portion of the contour, which does not have such fragile parts or areas, is punched by stamping (i.e., by means of a die). Stamping has the advantage of a relatively short punching time because punching the entire contour by the die is performed simultaneously, while the laser punching time depends directly on the length of the contour to be punched.
[0028] The hybrid technique according to the invention makes it possible to combine the advantages of known accessory punching techniques, namely stamping and laser punching. Due to the method for punching accessories according to the invention, it is particularly possible to obtain recesses or protrusions with pointed regions (the pointed regions having end fillets with very small radii), each protrusion forming a very sharp point, which is made possible by laser beam punching. The aim is to limit the length of the accessory profile punched using laser to reduce punching costs. However, as can be seen from the described variation of the punching method according to the invention, the first portion of the profile punched using laser is preferably selected such that the junction point between the first portion and the second complementary portion of the profile punched by stamping corresponds respectively to the vertices of the outer corners of the accessory profile. This makes it possible to avoid tolerance problems, and in particular, the problem of imprecise joining between two line segments of the accessory profile that will be punched successively and separately using laser and by die, without outer corners between them. Inaccurate punching at the junction between the first part of the profile (using laser punching) and the second complementary part of the profile (by stamping) will result in a decrease in the quality of the produced accessory, or require difficult and expensive finishing steps to avoid such a phenomenon.
[0029] Figure 1 A strip 10 with positioning perforations 12 and V-shaped grooves 14 is shown, which is obtained by punching using a laser beam (laser punching), followed by the first step of a punching method, in which these grooves are produced. In production, these grooves 14 define the internal contour 21 of the accessory 2 from the outside. Figure 2 The illustration shows the second step of the punching method, in which the trapezoidal shape defined by the punching line 16 is punched by a relatively simple die, since the trapezoidal shape does not pose a particular challenge to the die. Each accessory 2 is punched sequentially by actuating the die, and the strip 10 is fed in precise steps so that the contour 17 of the male part of the die and, in principle, its female part are correctly positioned relative to the corresponding groove 15 pre-processed using laser technology, to obtain the desired external contour 22 for each accessory 2 being manufactured. After the accessory is punched by stamping, the opening 18 in the strip 10 on the one hand, and on the other hand, as Figure 3 The accessory 2 shown and the triangular scrap piece are retained.
[0030] According to the specific features of the accessory 2 obtained by the first embodiment of the punching method according to the invention, the two inner straight segments 21a and 21b have an angular offset α, i.e. an angular opening, the value of which is substantially equal to or less than 20°, and less than 15° in a certain variant.
[0031] In an advantageous variation, the distance D separating the two endpoints 24a and 24b of the joining line 26 is less than two-thirds of the height of the sidewall of the accessory 2 at these two endpoints. In a particular variation, the joining line 26 is a curve defining an average radius that is substantially equal to or less than one-third of the height, particularly less than 0.06 mm. In a particular variation, the curve is an arc with a given radius.
[0032] In a preferred variant, the distance D separating the two endpoints 24a and 24b of the joining line 26 is substantially equal to or less than half the height of the sidewall of the accessory 2 at these two endpoints. In a particular variant, the joining line 26 is a curve defining an average radius that is substantially equal to or less than one-quarter of the height, particularly less than 0.04 mm. In a particular variant, the curve is an arc with a constant radius, particularly less than 0.04 mm. As an example, after the outline 20 of the accessory is punched, the height of the accessory sidewall is between 0.25 and 0.35 mm, while the radius of the arc forming the joining line 26 is between 0.025 and 0.035 mm. Therefore, the ratio between the radius of the joining line 26 and the height of the accessory sidewall in the pointed region 25 of the recess 23 is 1 / 10, particularly at the two endpoints 24a and 24b of the joining line. This can be achieved by laser punching in a metal strip 10, which has a thickness provided for the ornament after punching, and this thickness is typically reduced slightly by subsequent finishing steps, particularly by producing a polished top surface or a bright top facet obtained by a tool equipped with diamond.
[0033] A second variation of the first embodiment will be referred to below. Figures 5 to 7 The description is as follows. In this second variation, the ornament 4 defines the Roman numeral X. The first part of the outline 30 of the ornament includes two recesses, namely a lower recess 33a and an upper recess 33b, which are defined by the inner outlines 31a and 31b of the ornament 4, respectively. In particular, as in the first variation involving a V-shaped ornament, the inner outline 31a of the lower recess 33a is formed by two straight line segments 31c and 31d and a joining line, which is similar to... Figure 4 The connecting line 26 shown connects these two straight line segments in the pointed region 25A of the recess 33a. This also applies to the upper recess 33b, which is similar to the lower recess 33a. Therefore, the disclosure associated with the first variant regarding the lower recess 33a and the upper recess 33b also applies to the second variant associated with the X-shaped accessory.
[0034] More specifically, the accessory 4 defines four recesses. The first portion of the accessory's outline 30 includes two recesses with defined pointed areas: a lower recess 33a defining the first recess and an upper recess 33b defining a second recess, also with a pointed area. Regarding the first recess, the outline in the pointed area 25B of the second recess 33b ends with a second joining line connecting two straight line segments that converge and define the second recess. This second joining line has two endpoints separated by a distance substantially equal to or less than the height of the accessory's sidewall at these two endpoints of the second joining line. The second portion 32 of the outline 30 is formed by a portion complementary to the first portion. This second portion of the outline includes: line segments defining two lateral recesses of the outline 30, each lateral recess having an obtuse angle at its bottom; and four lines defining the outline by the ends of the four arms of the X-shaped accessory.
[0035] Figure 5 A strip 10 with positioning perforations 12 and V-shaped grooves 15a and 15b is shown, which are obtained by laser punching followed by a first step of a punching method, in which these grooves are produced. In production, these grooves 15a and 15b define the internal contours 31a and 31b of the accessory 4, respectively. Figure 6 The illustration shows the second punching step, in which the outer frame defined by the punching line 16A is punched by a die having such a shape. Each accessory 4 is punched sequentially by actuating the die, and the strip 10 is fed in precise steps so that the contours 17A of the male and female portions of the die are correctly positioned relative to two corresponding grooves 15a and 15b pre-processed using laser technology, to obtain the desired outer contour 32 for each accessory 4 being manufactured. After the accessory 4 is punched by stamping, the opening 18A in the strip 10 on the one hand, and on the other hand, as Figure 7 Accessory 4 shown, the two triangular parts (which are production waste) have been preserved.
[0036] According to the specific characteristics of the accessory 4 obtained by the first embodiment of the punching method of the present invention, the two inner straight segments 31c and 31d have an angular offset α, the value of which is less than 30°, and in a certain variant, it is substantially equal to or less than 20°.
[0037] As disclosed above, in an advantageous variation, the distance separating the two endpoints of the second joining line is less than two-thirds of the height of the accessory sidewall at those two endpoints. According to a specific feature, the second joining line is a curve defining an average radius that is substantially equal to or less than one-third of the height of the accessory sidewall at the two endpoints of the second joining line. In particular, the average radius of the second joining line is less than 0.06 mm.
[0038] In a preferred variation, the distance separating the two endpoints of the second joining line is substantially equal to or less than half the height of the accessory sidewall at those endpoints. Specifically, the second joining line is a curve defining an average radius that is substantially equal to or less than one-quarter of the height of the accessory sidewall at the two endpoints of the second joining line. In a particular variation, the second joining line is an arc with a radius equal to or less than 0.04 mm.
[0039] A second embodiment of the method for punching an ornament according to the present invention will be further described below. At the end of the punching method according to this second embodiment, the ornament has a profile defining at least one protruding portion forming a pointed or / and elongated segment. Generally, the punching method includes the steps of punching out a first portion of the profile defining at least a first protruding portion, the pointed or / and elongated segment, using a laser beam, and punching out a second portion of the profile complementary to the first portion by means of a die.
[0040] exist Figures 8 to 10 In the variant shown, at the end of the punching process, the accessory 6 has a profile 37 that defines at least one protruding portion 40 forming a pointed tip. The first portion 38 of the laser-cut profile 37 includes two straight line segments 42a and 42b defining the pointed tip 40, and two additional straight line segments located on either side of the tip's base, forming two interior angles with the two straight line segments 42a and 42b respectively. The two straight line segments 42a and 42b of the pointed tip's profile have an angular offset / angle opening β. In a particular variant, the value of angle β is substantially equal to or less than 20°, and in another variant, less than 15°. The second portion 39 of the profile 37 is complementary to the first portion 38; that is, the first and second portions 38 and 39 together form the entire profile 37 of the accessory 6.
[0041] Figure 8 A strip 10 with positioning perforations 12 and grooves 36 is shown, which is obtained by punching using a laser beam (laser punching), followed by the first step of a punching method, in which these grooves are produced. In production, these grooves 36 define the first portion 38 of the outline 37 of the accessory 6. Figure 9 The illustration shows the second step of the punching method, where the shape defined by the punching line 16B corresponds at the top to the shape defined by the second portion 39 of the outline 37 of each accessory 6. The punching line 16B forms a relatively wide arm at the bottom, positioned such that the arm overlaps and completely covers the tip 40 obtained by laser punching. The workpiece defined by the punching line 16B is punched using a relatively simple die, as its shape is relatively simple and does not pose a particular challenge to the die. (As shown in...) Figure 2 and 6In the first embodiment described herein, the ends of the laser-processed groove 36 slightly extend beyond the first portion 38 of the contour 37 provided for the accessory 6. The additional portions of the groove 36 at its ends relative to the first portion 38 of the contour 37 are provided on the outside of the accessory during production, and thus remain in the strip 10 once the accessory is completely punched. Specifically, for this reason, like the two straight segments of the tip 40, the two straight segments extending transversely to the longitudinal direction of the tip on both sides of the tip base are laser-cut, forming two interior angles with the two straight segments of the tip 40.
[0042] Similar to the first embodiment of the punching method, each accessory 6 is punched sequentially by actuating the die. The strip 10 is fed in precise steps, ensuring that the contours 17B of the male and female portions of the die are correctly positioned relative to the corresponding grooves 36 pre-processed using laser technology, thereby obtaining the desired external contour 32 for each accessory 6 being manufactured. After punching the accessory, on the one hand, the opening 18B in the strip 10, and on the other hand... Figure 10 The accessory 6 shown and the U-shaped scrap piece were preserved.
Claims
1. A method for punching an accessory (2, 4, 6) intended for use on a dial, the accessory having a profile (20, 30, 37) at the end of the method, the profile defining at least one recess (23, 33a, 33b) having a pointed region (25, 25A, 25B) and / or a fine groove, and / or / the profile defining at least one protrusion forming a pointed (40) and / or an elongated segment; characterized in that, The method includes the step of punching out a first portion (21, 31a, 31b, 38) of the contour using a laser beam, wherein the first portion defines the pointed region of at least a first recess (23, 33a) of the at least one recess and / or the fine groove, and / or the pointed (40) of at least a first protrusion of the at least one protrusion and / or the elongated segment, and the step of punching out a second portion (22, 32, 39) of the contour by means of a die after the punching step using the laser beam.
2. The method according to claim 1, characterized in that, The contour in the pointed region of the first recess ends with a first joining line (26) that connects two converging line segments (21a, 21b; 31c, 31d) of the contour. The first joining line has two endpoints (24a, 24b) that define the two endpoints of the two line segments, which are separated by a distance (D) that is substantially equal to or less than the height of the sidewall of the ornament at the two endpoints.
3. The method according to claim 2, characterized in that, The distance separating the two endpoints of the first junction line is less than two-thirds of the height.
4. The method according to claim 3, characterized in that, The first junction line (26) is a curve defining an average radius (R) that is less than one-third of the height.
5. The method according to claim 4, characterized in that, The average radius is less than 0.06 mm.
6. The method according to claim 2, characterized in that, The distance separating the two endpoints of the first joining line (26) is less than half the height.
7. The method according to claim 6, characterized in that, The first junction line is a curve that defines an average radius that is substantially equal to or less than one-quarter of the height.
8. The method according to claim 7, characterized in that, The average radius is equal to or less than 0.04 mm.
9. The method according to any one of claims 2 to 8, characterized in that, The junction between the first and second portions of the outline of the accessory is located at the apex of the portion of the accessory that forms the outer corner.
10. The method according to claim 9, characterized in that, The accessory (2) defines the Roman numeral V, and the first portion of the outline of the accessory includes a first recess defined by an inner outline of the accessory, the inner outline being formed by two inner line segments of the outline of the accessory and a first junction line connecting the two inner line segments.
11. The method according to claim 10, characterized in that, The two inner straight line segments have an angular offset, the value of which is less than 20°.
12. The method according to claim 9, characterized in that, The accessory (4) defines the Roman numeral X, and thus the outline of the accessory defines four recesses. The first part of the outline of the accessory includes a lower recess defining the first recess and an upper recess defining a second recess from the at least one recess. The outline in the pointed region of the second recess ends with a second joining line connecting two straight line segments of the outline, which converge and define the second recess. The second joining line has two endpoints separated by a distance that is substantially equal to or less than the height of the sidewall of the accessory at the two endpoints of the second joining line.
13. The method according to claim 12, characterized in that, The two inner straight segments of the second recess are defined to have an angular offset, the value of which is less than 30°.
14. The method according to claim 12 or 13, characterized in that, The distance separating the two endpoints of the second joining line is less than two-thirds of the height of the sidewall of the ornament at those two endpoints.
15. The method according to claim 14, characterized in that, The second joining line is a curve that defines an average radius less than one-third of the height of the sidewall of the ornament at both ends of the second joining line.
16. The method according to claim 12 or 13, characterized in that, The distance separating the two endpoints of the second joining line is substantially equal to or less than half the height of the sidewall of the accessory at those two endpoints.
17. The method according to claim 16, characterized in that, The second joining line is a curve that defines an average radius that is substantially equal to or less than one-quarter of the height of the sidewall of the ornament at both ends of the second joining line.