HK1243781B - Economical timepiece display component - Google Patents

Description

Economical watch display components

Technical Field

The present invention relates to an economical method for producing a timepiece display component or hand-fitting component, said component comprising at least one aesthetic and/or visible surface.

The invention also relates to a watch comprising at least one display member or hand-engaging member manufactured by this method.

The present invention relates to the field of timepiece display components or hand matching components.

Background Art

In horology, the manufacture of small display components, hand-matching components or external components always presents practical production problems due to their importance in terms of the aesthetics of the watch and how this is valued by the customer or user.

Indeed, the user's eye is drawn to these components, which must therefore have an impeccable appearance, a very fine yet regular surface finish, and brightness and reflectivity properties that are often difficult to achieve in a reproducible manner. Components such as the numeral appliques are, in fact, distributed throughout a watch dial in large numbers and must be identical.

The production costs and weight of these components must also be kept under control, especially when they are movable, such as hands. In luxury watches, a convenient solution is to machine the components in a block of a precious alloy, such as gold, but this solution is not always the most suitable.

It is also known that methods of manufacturing such components by machining first and then surface treating produce relatively high scrap rates because the surface treatment reveals visual and/or surface defects that were not visible at the machining stage and is therefore wasteful when it is expensive due to the desired finish.

Patent application DE 2034006 A1 in the name of MELTER & KUEHN discloses a method for producing markings on a watch dial. The markings are formed in relief from the back of the dial to the front. The hollow portion at the back is filled with a visually contrasting filler material, such as paint, plastic, low-melting metal, or the like. The raised area at the front is then ground down until the contrasting filler material appears.

Summary of the Invention

The present invention proposes to develop an alternative method for manufacturing a timepiece display component or hand-matching component comprising at least one aesthetic and/or visible surface, this method being carried out at controlled costs while guaranteeing a visual and surface repeatability of these visible surfaces, with improved production reliability compared to the prior art.

To this end, the invention relates to an economical method for manufacturing a timepiece display component or a hand-matching component, said component comprising at least one aesthetic and/or visible surface, characterized in that the following steps are carried out in succession:

-AA: the shell material is selected to produce each of said aesthetic and/or visible surfaces, said shell material being an amorphous metal alloy or having a nanocrystalline structure or comprising nickel or a nickel-phosphorus alloy, or said shell material being a pure metal or an alloy of gold and/or silver and/or copper and/or rhodium and/or titanium and/or aluminum;

-BB: manufacturing in a first tool a thick hollow blank with an initial thickness greater than or equal to 20 micrometers from said shell material, said shell material having an initial thickness greater than or equal to 50 micrometers, said blank comprising an excess thickness relative to each of said aesthetic and/or visible surfaces, and said blank comprising a first cavity for receiving a support structure;

CC: selection of an internal material, for manufacturing the support structure, which is easily shaped by deformation, stamping and/or press forming and/or by machining and/or injection molding and/or electrogrowing and/or casting;

DD: producing the support structure in a second tool or directly in the first cavity or in a free manner from the inner material by stamping and/or press forming and/or machining and/or injection molding and/or electrogrowing and/or casting, and joining the support structure to the first cavity of the blank;

- EE: Diamond tool machining of at least one of said aesthetic and/or visible surfaces that is to remain visible, removing all or part of said excess thickness from said blank.

The invention also relates to a watch comprising at least one display member or hand-engaging member manufactured by this method.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent upon reading the following detailed description with reference to the accompanying drawings, in which:

- Figures 1 to 10 show schematic cross-sectional views of different steps for implementing the method according to the invention in different alternatives;

- Figure 1 shows the production of a hollow blank with a specific thickness from a shell material in a first tool.

- FIG. 2 shows a variant in which the first tool comprises an inner peripheral contact layer, for example a metallization layer or the like, allowing the blank to be manufactured by galvanic growth.

- Figure 3 shows the separate production of the support structure by press forming between a punch and a die.

- Figure 4 shows the joining of the support structure to the blank of Figure 1 while it is still held in its first tool.

- Figure 5 shows the free form fabrication of the support structure.

- Figure 6 shows the production of the support structure by stamping.

- Figure 7 shows the joining of the support structure seen in Figures 3 or 5 or 6 to the blank of Figure 1 which has been removed from its first tool.

FIG. 8 shows a variant in which the support structure is produced directly in the cavity contained in the blank of FIG. 1 .

- Figure 9 shows diamond machining of an aesthetic and/or visible surface by removing excess thickness from the blank which has been removed from its first tool and has been joined to a support structure comprising mounting feet.

- Figure 10 shows the component finished and ready for use;

- Figures 11 to 18 show schematic perspective views of non-limiting examples of the invention:

- Figure 11 shows a hollow pointer with a transverse section and a longitudinal section in Figures 11A and 11B.

- Figure 12 shows a lettering block provided with two feet.

- Figure 13 shows a figure provided with two feet.

- Figure 14 shows a symbol provided with two feet.

- Figure 15 shows a monogram provided with a foot.

- Figure 16 shows the indicator.

- Figure 17 shows a marking element provided with two feet.

- Figure 18 shows a window edge provided with four feet.

- Figure 19 is a block diagram illustrating a watch comprising a component manufactured according to the method of the present invention.

- Figure 20 is a block diagram illustrating the steps of the method according to the invention.

DETAILED DESCRIPTION

The present invention proposes to reduce both the cost and the weight of an external component or a hand-matching component, while at the same time ensuring an impeccable appearance of this visible component and minimizing the rate of manufacturing rejects.

The invention proposes to form a preferably hollow housing, the surface portion of which is made of a material compatible with fine machining in order to obtain a regular surface finish with very low roughness.

The thickness of this surface portion is formed to be sufficient to ensure the homogeneity of the material and thus the quality of the final finish after machining.

The preferred finishing is diamond polishing using the tool.

The invention therefore relates to an economical method for manufacturing a timepiece display member or hand-matching member 1 formed by a hand 11 , a letter applique 12 or the like, comprising at least one aesthetic and/or visible surface 2 to be visible to a user of a watch or the like.

According to the present invention, the following steps are performed in succession:

-AA: the shell material chosen for the production of each aesthetic and/or visible surface 2 is an amorphous metal alloy or has a nanocrystalline structure or comprises nickel or a nickel-phosphorus alloy, or is a pure metal or an alloy of gold and/or silver and/or copper and/or rhodium and/or titanium and/or aluminum.

-BB: a hollow blank 4 having an initial thickness greater than or equal to 20 micrometers is formed in a first tool 3 from the shell material, said blank 4 comprising an overthick portion 5 relative to the final height of each aesthetic and/or visible surface 2, and said blank 4 comprising a first cavity 6 for receiving a support structure 7. The term "receiving" is used in this context in a broad sense, since, depending on the embodiment variant, the support structure 7 can be mounted inside the cavity 6 or be attached to it over all or part of its surface.

- CC: An inner material is selected for manufacturing the support structure 7, which is easy to shape by deformation, stamping and/or pressing and/or by machining and/or injection molding and/or electro-growth and/or casting. Since the support structure 7 will not be visible, the inner material can advantageously be an inexpensive material and preferably has a cost lower than or equal to that of the housing material.

-DD: The support structure 7 is produced in the second tool 8 or directly in the first cavity 6 or in a free manner from the internal material by stamping and/or press forming and/or machining and/or injection molding and/or electrogrowing and/or casting and is joined to the first cavity 6 of the blank 4.

EE: diamond tool machining will leave visible at least one such aesthetic and/or visible surface, removing all or part of the excess thickness 5 from the blank 4. More specifically, during this first diamond machining operation, which may also be the only operation, depending on the desired appearance of the finished component 1, the excess thickness 5 is completely removed from the relevant aesthetic and/or visible surface 2.

The method according to the invention can also be implemented using a reusable first tool 3 (e.g. a mold or the like) or using a disposable first tool 3, such as a housing made of a light material, a polymer (e.g. PMMA) or other material, which in turn is manufactured using another tool. Thus, once the blank 4 has been completely formed, it is possible to choose whether to leave it in its first tool 3 for at least part of the subsequent operations or to remove it.

When the first tool 3 comprises a peripheral contact layer 31, for example a metallized layer (formed by PVD or equivalent) to allow electrical growth of the blank 4, this peripheral contact layer 31 can be retained or removed for subsequent operations. In particular, this peripheral contact layer 3 can remain on the surface of the overthickness 5 and be machined together with it during the diamond tool machining operation.

In a preferred embodiment of the invention, the blank 4 is made of a shell material having an initial thickness E greater than or equal to 50 micrometers.

In a particular embodiment of the invention, component 1 is manufactured with at least one aesthetic and/or visible surface 2 bounded by a raised edge 9 and, during diamond tool machining, raised edge 9 is formed and defines aesthetic and/or visible surface 2 .

In a particular embodiment of the invention, during diamond tool machining, the diamond tool machining is performed to maintain all aesthetic and/or visible surfaces 2 visible, remove all or part of the excess thickness 5, and, if the component 1 includes raised edges 9, the diamond tool machining is performed to produce all of the raised edges 9 defining the aesthetic and/or visible surfaces 2. Preferably, during this diamond tool machining operation, the excess thickness 5 is completely removed. In a variant, the removal of the excess thickness 5 is completed during a further diamond tool machining operation, which may be necessary due to the specific geometry of the component 1.

In a particular embodiment of the invention, during this diamond tool machining operation, at least one such aesthetic and/or visible surface 2 to remain visible is machined with a diamond tool, removing all or part of the excess thickness 5, with a surface roughness between 2 nm Ra and 100 nm Ra.

In a particular embodiment of the invention, a residual thickness ER of the blank 4 of at least 5 micrometers remains on each aesthetic and/or visible surface 2 during the diamond tool machining operation.

In a particular embodiment of the invention, at least 50% of the initial thickness E is removed from the blank 4 during the diamond tool machining operation.

In a particular embodiment of the invention, after the diamond tool machining operation, an electro-growth or PVD or CVD or ALD or chemical coloring operation is performed on at least one aesthetic and/or visible surface 2 that will remain visible, to a thickness of less than 5 micrometers. More specifically, this coloring operation is performed on all aesthetic and/or visible surfaces 2.

In a particular embodiment of the invention, the inner material is selected from alloys of copper and/or aluminum and/or zinc.

In a particular embodiment of the invention, brass is chosen as the inner material.

In a specific embodiment of the present invention, an aluminum alloy is selected as the inner material.

In a particular embodiment of the present invention, a zinc alloy is selected as the inner material.

In a specific embodiment of the present invention, POM or PS or PC or polymer is selected as the inner material.

In a particular embodiment of the invention, a charged material is chosen as the inner material so that it is electrically conductive.

In certain embodiments of the present invention, the shell material is selected as the inner material. Thus, component 1, particularly a hollow component 1 having second cavity 70, can be manufactured from a single material. More specifically, blank 4 can be made, for example, of Ni-P by electrogrowth, and support structure 7 can be made by further Ni-P growth; however, the electrical parameters can be modified to save time during the manufacturing cycle, as support structure 7 does not need to be finely grained or defect-free; its sole function is to mechanically retain component 1.

In a particular embodiment of the invention, the shell material is chosen to be different from the interior material.

In a specific embodiment of the present invention, a nickel-phosphorus alloy is selected as the inner material.

In a particular embodiment of the invention, the support structure 7 is bonded within the first cavity 6 of the blank 4 .

In a particular embodiment of the invention, the support structure 7 is inserted and retained by deformation within the first cavity 6 of the blank 4 retained in the first tool 3 .

In a particular embodiment of the invention, the support structure 7 is made by press-forming between a punch 82 and a die 81 which together form the second tool 8 , as seen in FIG. 3 .

In a particular and advantageous embodiment of the invention, the support structure 7 is made hollow, has a second chamber 70 and/or comprises at least one mounting foot 10. Component 1 is thus particularly light, provides an impeccable finishing surface state and is ready for assembly in a watch 100 or the like.

In a particular embodiment of the invention, the component 1 is in the form of a pointer 11 or an inlay 12 or a number 13 or a symbol 14 or a letter combination 15 or an indicator 16 or a logo 17 or a window edge 18 or other similar components.

It is advantageous to make the component 1 hollow, in particular in the case of the pointer 11 , which is shown here with a tube 110 , in order to minimize imbalances.

Of course, for a single component, although a single blank and a single support structure are shown, the invention can also be applied to a single blank and several support structures or several blanks and a single support structure or even several blanks and several support structures.

The invention also relates to a watch 100 comprising at least one display member or hand-engaging member 1 manufactured by the method according to the invention.

The diamond tool machined product of the component is characterized by a good quality of its surface finish (mirror finish) and side intersections defining sharp edges, which cannot be guaranteed by any other manufacturing method.

Claims (22)

1. An economical method for manufacturing a clock display component or a hand-fitting component, said component comprising at least one aesthetic and/or visible surface (2), characterized in that the following steps are performed sequentially: -(AA): Select a housing material to manufacture each of the aesthetic and/or visible surfaces (2), the housing material being an amorphous metal alloy or having a nanocrystalline structure or comprising nickel or nickel-phosphorus alloy, or the housing material being a pure metal or an alloy of gold and/or silver and/or copper and/or rhodium and/or titanium and/or aluminum; -(BB): In the first tool (3), a hollow blank (4) with an initial thickness greater than or equal to 20 micrometers is manufactured using the shell material, the shell material having an initial thickness (E) greater than or equal to 50 micrometers, the blank (4) including an over-thick portion (5) relative to each of the aesthetic and/or visible surfaces (2), and the blank (4) including a first chamber (6) for receiving a support structure (7); -(CC): Select an internal material to manufacture the support structure (7), the internal material being readily shaped by deformation, stamping and/or pressing and/or by machining and/or injection molding and/or electro-growth and/or casting; -(DD): The support structure (7) is manufactured in the second tool (8) or directly in the first chamber (6) or in a free manner using the internal material by stamping and/or pressing and/or machining and/or injection molding and/or electro-growth and/or casting, and the support structure (7) is joined to the first chamber (6) of the blank (4). -(EE): Diamond tool machining will preserve at least one of the aesthetic and/or visible surfaces (2) and remove all or part of the excessively thick portion (5) from the blank (4). 2. The method according to claim 1, wherein the clock display member or the pointer mating member is made to have at least one of the aesthetic and/or visible surfaces (2) defined by a protruding edge (9), the protruding edge (9) defining the aesthetic and/or visible surface (2) being formed during the diamond tool machining. 3. The method according to claim 1, characterized in that, during the diamond tool machining operation, the diamond tool machining will preserve all visible aesthetic and/or visible surfaces (2), remove part of the excessively thick portion (5) from the blank (4), and, if the component (1) includes protruding edges (9), the diamond tool machining defines all protruding edges (9) of the aesthetic and/or visible surfaces (2). 4. The method according to claim 1, characterized in that, during the diamond tool machining operation, the diamond tool machine at least one surface (2) that will remain visible aesthetically pleasing and/or visible, removes a portion of the excessively thick portion (5) from the blank (4), with a surface roughness between 2 nm Ra and 100 nm Ra. 5. The method according to claim 1, characterized in that, during the diamond tool machining operation, a residual thickness (ER) of greater than or equal to 5 micrometers is retained on each of the aesthetic and/or visible surfaces (2) of the blank (4). 6. The method according to claim 1, characterized in that, during the machining operation, at least 50% of the initial thickness (E) is removed from the blank (4). 7. The method according to claim 1, characterized in that, after the diamond tool machining operation, an electrogrowth or PVD or CVD or ALD or chemical coloring operation is performed on at least one of the aesthetic and/or visible surfaces (2) that will remain visible, so as to achieve a small thickness of less than 5 micrometers. 8. The method according to claim 1, wherein the internal material is selected from alloys of copper and/or aluminum and/or zinc. 9. The method according to claim 8, wherein brass is selected as the internal material. 10. The method according to claim 8, wherein an aluminum alloy is selected as the internal material. 11. The method according to claim 8, wherein a zinc alloy is selected as the internal material. 12. The method according to claim 1, wherein POM, PS, PC, or a polymer are selected as the internal material. 13. The method according to claim 12, characterized in that a charged material is selected as the internal material to make it conductive. 14. The method according to claim 1, wherein the shell material is selected as the internal material. 15. The method according to claim 1, wherein the shell material is selected to be different from the internal material. 16. The method according to claim 15, wherein a nickel-phosphorus alloy is selected as the shell material. 17. The method according to claim 1, wherein the support structure (7) is incorporated within the first chamber (6) of the blank (4). 18. The method according to claim 1, wherein the support structure (7) is inserted into and held in the first chamber (6) of the blank (4) by deformation, the blank (4) being held in the first tool (3). 19. The method according to claim 1, wherein the support structure (7) is formed by deformation. 20. The method according to claim 1, wherein the support structure (7) is hollow, has a second chamber (70) and/or includes at least one mounting foot (10). 21. The method according to claim 1, wherein the component (1) is made in the form of a pointer (11) or a letter block (12) or a number (13) or a symbol (14) or a combination of letters (15) or an indicator (16) or a marker (17) or a window edge (18). 22. A watch (100) comprising at least one display element or pointer mating element (1), said element being a pointer (11) or inlay (12) or numeral (13) or symbol (14) or letter combination (15) or indicator (16) or marker (17) or window edge (18), and comprising a thick, hollow blank (4) of a nickel-phosphorus alloy, said blank (4) comprising a first chamber (6) for receiving a support structure (7) made of a conductive internal material selected from: an alloy of copper and/or aluminum and/or zinc, or charged POM, or charged PS, or charged PC, or charged polymer, said support structure (7) being coupled to the first chamber (6), said blank (4) having an aesthetic and/or visible surface (2) machined with a diamond tool, the surface roughness being between 2 nm Ra and 100 nm Ra.