CH704655A2 - System for fabrication of e.g. asymmetrical glass of watch, has machining device including displacing units for displacing rotation axes such that axes are movably mounted in curved directrix for selectively forming curvature to blank - Google Patents

Abstract

The system (21) has a fixing device (25) including a drum (31) rotatingly mounted along first rotation axes (A3). A machining device (27) includes abrasive units (33) rotatingly mounted around second rotation axes (A4), and is utilized for machining a blank (23') of a covering part for forming a first curvature (C3). The machining device comprises displacing units (35) for displacing the second axes such that the second axes are movably mounted in a curved directrix for selectively forming a second curvature (C4) to the blank. The covering part is made of a crystalline alumina e.g. sapphire, corundum or ruby. An independent claim is also included for a covering part.

Description

Field of the invention

The invention relates to a dressing part for a timepiece and its manufacturing system.

Background of the invention

It is known to form sapphire watch windows which are very resistant to scratching. Such ice creams are generally made by contacting a rotating grinding wheel against the surface of a drum supporting a plurality of windows. The resulting grinding makes it possible to form a cylindrical or spherical ice. However, it becomes necessary to form asymmetrical windows to adapt for example to timepiece displays that are not centered relative to its housing which is not possible from the current series of manufacturing techniques. .

Summary of the invention

The object of the present invention is to overcome all or part of the disadvantages mentioned above by proposing a new manufacturing system allowing the mass production of special windows whose longitudinal curvatures are independent of transverse curvatures.

For this purpose, the invention relates to a system for manufacturing a trim piece for a timepiece comprising a fixing device comprising a drum mounted to rotate about a first axis and carrying at least one roughing said part, a machining device comprising abrasive means rotatably mounted along a second axis and intended to machine said at least one blank to form a first curvature characterized in that the machining device further comprises means moving said second axis so that the latter is movably mounted in a curved director to selectively form a second curvature at said at least one blank.

It is therefore understood that at least one of the curvatures of the dressing part is directly formed by the selective displacement, that is to say completely free and controlled, of the axis of rotation of the abrasive means. As a result, it becomes possible to manufacture very complex ice creams in series with an advantageous scrap rate.

According to other advantageous features of the invention: the director of the displacement means is symmetrical to form said second curvature in a single radius; the director of the displacement means is asymmetrical so as to form said second curvature according to several radii; said first axis and said second axis are perpendicular to intersect the machining lines; according to a first embodiment, the drum is a ring against the inner wall of which said at least one blank is fixed and in that the abrasive means are moved in the hollow of said ring to form first and second concave curvatures; according to a second embodiment, the drum is a disk against the outer wall of which said at least one blank is fixed and in that the abrasive means are moved in front of said disk to form first and second convex curvatures; the abrasive means are formed by a grinding wheel; according to a first variant, the displacement means are formed by an actuator moved back and forth against the profile of a fixed cam corresponding to said second curvature; according to a second variant, the displacement means are formed by an automaton programmed to move along said second curvature; said piece is formed from crystallized alumina.

In addition, the invention relates to a trim part comprising an upper surface and a lower surface characterized in that at least one of the faces comprises a longitudinal curvature and a transverse curvature which are different.

It is therefore understood that the dressing part can be complex and allows, for example, to form an asymmetrical ice or whose curve appears visually asymmetrical to adapt for example to timepiece displays that are not not centered with respect to its case.

According to other advantageous features of the invention: the lower and upper faces have a longitudinal curvature and a transverse curvature which are different; at least one of said longitudinal and transverse curvatures is asymmetrical; the dressing part is formed from crystallized alumina.

Finally, the invention relates to a timepiece characterized in that it comprises a dressing part according to one of the previous variants.

Brief description of the drawings

Other features and advantages will clearly be described in the following description, by way of indication and in no way limitative, with reference to the accompanying drawings, in which: fig. 1 is a view of a manufacturing system according to a first embodiment of the invention; figs. 2-4 are views of a manufacturing system according to a second embodiment of the invention; figs. 5-7 are representations of a dressing part according to a first variant of the invention; figs. 8 to 10 are representations of a dressing part according to a second variant of the invention.

Detailed Description of the Preferred Embodiments

The invention relates to a non-symmetrical dressing piece such as an ice, a case or a dial based on crystallized alumina such as sapphire, corundum or ruby. To achieve these new parts, new manufacturing systems have been developed to adapt for example to timepiece displays that are not centered relative to its housing. For example, the housing may be substantially water drop-shaped and / or non-planar requiring for the harmony of the timepiece to be provided with an off-center display.

Of course, even if the present invention has been developed for the field of watchmaking, it can not be limited thereto. Other applications are also conceivable, such as optics, tableware or electronics.

According to a first embodiment illustrated in FIG. 1, a manufacturing system 1 has been developed in order to produce trim parts 3 comprising surfaces whose curvatures C1, C2 are concave. The manufacturing system 1 comprises a fixing device 5 and a machining device 7.

The fixing device 5 comprises a drum 11 rotatably mounted along a first axis Ai and carrying at least one blank 3 of the future part 3. Preferably, as shown in FIG. 1, the drum 11 is a ring having a faceted inner wall, that is to say provided with successive planes Px. As shown in fig. 1, each successive plane Px receives a blank 3 which can be fixed, for example, by gluing.

The machining device 7 comprises abrasive means 13 which are rotatably mounted along a second axis A2 and which are intended to machine each blank 3. Preferably, the abrasive means 13 are moved in the hollow of the drum 11 in the form of a ring. The abrasive means 13 shown in FIG. 1 are formed by a conventional grinding wheel, that is to say without any particular shape of its contact zone. Of course, the abrasive means 13 may be different and, for example, take the form of a curved or conical shoe.

Advantageously according to the invention, the machining device 7 comprises displacement means 15 of the second axis A2afin that the latter is mounted movably along a curved director C2 to selectively form a second curvature at each blank 3. It is therefore clear that the manufacturing system 1 makes it possible to form first and second curvatures C1, C2 concave.

According to the invention, the displacement means 15 may be, without limitation, formed by an actuator moved back and forth against the profile of a fixed cam corresponding to the second curvature C2 or, for example , an automaton programmed to move along said second curvature.

Thus, the first curvature C1 is generated perpendicular to the axis Ai by the radius extending between the axis Ai and the contact zone between the abrasive means 13 and each blank 3. Because the drum 11 is rotated axially each blank 3 is thus transversely excavated along a single radius forming the first concave curvature C1.

In addition, advantageously according to the invention, the second curvature C2 is directly obtained by the selective displacement of the second axis A2. Thus, while the first curvature C1 is generated, the contact zone between the abrasive means 13 and each blank 3 is progressively displaced with respect to the thickness of the ring-shaped drum 11. Therefore, each blank 3 is hollowed longitudinally along a curved director forming the second concave curvature C2.

It is therefore immediately understood that the director curve of the displacement means 15 may be symmetrical or not to form the second curvature C2 in one or more rays.

Finally, preferably according to the invention, the first axis A1 and the second axis A2 are perpendicular to intersect the machining lines. This feature advantageously facilitates the subsequent polishing of the trim pieces 3.

According to a second embodiment illustrated in FIGS. 2 to 4, a manufacturing system 21 has been developed in order to produce trim parts 23 comprising surfaces whose curvatures C3, C4 are convex. The manufacturing system 21 comprises a fixing device 25 and a machining device 27.

The fixing device 25 comprises a drum 31 rotatably mounted along a first axis A3 and carrying at least one blank 23 of the future part 23. Preferably, as shown in FIG. 2, the drum 21 is a disk against the outer wall of which each blank 23 is fixed, for example, by gluing.

The machining device 27 comprises abrasive means 33 which are rotatably mounted along a second axis A4 and which are intended to machine each blank 23. Preferably, the abrasive means 33 are moved in front of the drum 31. The abrasive means 33 shown in FIG. 2 are formed by a conventional grinding wheel, that is to say without any particular shape of its contact zone. Of course, the abrasive means 33 may be different and, for example, take the form of a curved or conical shoe as will be explained below.

Advantageously according to the invention, the machining device 27 comprises displacement means 35 of the second axis A4afin that the latter is mounted movably in a curved director C4 to selectively form a second curvature to each blank 23. It is therefore clear that the manufacturing system 21 makes it possible to form first and second convex curvatures C3, C4.

According to the invention, the displacement means 35 may be, without limitation, formed by an actuator moved back and forth against the profile of a fixed cam corresponding to the second curvature C4 or, for example , an automaton programmed to move along said second curvature.

Thus, the first curvature C3 is generated perpendicular to the axis A3 by the radius extending between the axis A3 and the contact zone between the abrasive means 33 and each blank 23. Because the drum 31 is rotated along the axis A3, each blank 23 is thus transversely excavated along a single radius forming the first convex curvature C3.

In addition, advantageously according to the invention, the second curvature C4 is directly obtained by the selective displacement of the second axis A4. Thus, while the first curvature C3 is generated, the contact area between the abrasive means 33 and each blank 23 is progressively displaced relative to the thickness of the disk-shaped drum 31. Therefore, each blank 23 is hollowed longitudinally along a curved director forming the second curvature C4 convex.

It is therefore immediately understood that the director curve of the displacement means 35 may be symmetrical or not to form the second curvature C4 in one or more rays.

Finally, preferably according to the invention, the first axis A3 and the second axis A4 are perpendicular to intersect the machining lines. This feature advantageously facilitates the subsequent polishing of the covering parts 23. The polishing may for example be carried out using fastening and machining device close to the fastening devices 25 and machining 27 realizing the outline of the parts 23 explained above. However, a polishing step being less aggressive as to the thickness to be removed, only the abrasive means are mainly modified.

Thus, two examples of polishing are shown in FIGS. 3 and 4. According to a first alternative of the second embodiment illustrated in FIG. 3, a manufacturing system 41 has been developed in order to polish parts 43 of covering comprising surfaces whose curvatures C3, C4 are convex. The manufacturing system 41 comprises a fixing device 45 and a machining device 47.

The fixing device 45 comprises a rotationally mounted drum 51 which carries at least one piece 43 to be polished. The machining device 47 comprises abrasive means 53 rotatably mounted and intended to polish each piece 43. Preferably, the abrasive means 53 are moved in front of the drum 51. The abrasive means 53 shown in FIG. 3 are preferably formed by a conical shoe, for example of metal, regularly coated with a polishing liquid. Of course, other types of abrasive means such as substantially flat shape may also be suitable.

Advantageously according to the invention, the machining device 47 comprises displacement and plating means 55 in order to force the friction of the abrasive means 53 against each piece 43 for the purpose of selectively polishing them according to the second curvature C4. It is therefore clear that the manufacturing system 41 makes it possible to polish first and second curvatures C3, C4 which are convex.

According to the invention, the displacement means 55 may be, without limitation, formed by an actuator moved back and forth against the profile of a fixed cam corresponding to the second curvature C4 or, for example , an automaton programmed to move along said second curvature.

According to a second alternative of the second embodiment illustrated in FIG. 4, a manufacturing system 61 has been developed for polishing trim parts 63 comprising surfaces whose curvatures C3, C4 are convex. The manufacturing system 61 comprises a fixing device 65 and a machining device 67.

The fastening device 65 comprises a drum 71 rotatably mounted which carries at least one part 63 to be polished. The machining device 67 comprises abrasive means 73 for polishing each piece 63. Preferably, the abrasive means 73 are moved in front of the drum 71. The abrasive means 73 shown in FIG. 4 are, preferably, formed by a curved shoe, for example of metal, regularly coated with a polishing liquid.

Advantageously according to the invention, the machining device 67 comprises displacement and plating means 75 to force the friction of the abrasive means 73 against each piece 63 for the purpose of selectively polishing them according to the second curvature C4. It is therefore clear that the manufacturing system 61 makes it possible to polish first and second curvatures C3, C4 which are convex.

According to the invention, the displacement means 75 may be, without limitation, formed by an actuator moved back and forth against the profile of a fixed cam corresponding to the second curvature C4 or, for example , an automaton programmed to move according to said twelfth curvature.

These first and second embodiments and their variants can be used alone or in combination. Therefore, a wide variety of dressing part can be obtained in particular that its upper surface and / or lower surface are machined. It is therefore understood that advantageously according to the invention, at least one of the upper and lower faces may comprise a longitudinal curvature and a transverse curvature which are different.

In addition, according to the orientation of each piece 3, 23, 43, 63 relative to the fasteners 5, 25, 45, 65, at least one of said longitudinal and transverse curvatures may be symmetrical or asymmetric. It is therefore understood that such a non-symmetrical cladding piece can perfectly form an ice, a case or a dial based on crystallized alumina such as sapphire, corundum or ruby for, for example, a timepiece.

Two variants of parts 83, 103 forming realizable timepiece glasses according to the invention are shown in FIGS. 5-7 and 8-10. According to the first variant, the covering part 83 has an upper surface 82 and a lower surface 84 which are machined in order to obtain a substantially constant thickness e1 despite the complex shape of the part 83.

Thus, FIG. 5 is a representation, seen from above, of the piece 83 substantially ovoid. The longitudinal curvature C4 intersects the transverse curvature C3 at the point O1. Note that the point O1 is not centered with respect to the substantially ovoid shape but is closer to the flared portion than the tip. This configuration of the piece 83 when it is attached to a timepiece case makes it possible to visually accentuate the remote integration of the display of the timepiece.

As shown in FIG. 7presentant the section A-A of FIG. 5, that is to say a longitudinal section, it can be seen that the curvatures C2 and C4 are parallel. In the example of fig. 5 to 7, it will be noted that in fact the curvatures C2 and C4 respectively form a single radius R2 and R4 so that R4 = R2 + e1.

Similarly, as shown in FIG. 6 representing the section B-B of FIG. 5, i.e. a cross-section, it can be seen that the curvatures C1 and C3 are parallel. In the example of fig. 5 to 7, we note that in fact the curvatures C1 and C3 respectively form a single radius R1 and R3 so that R3 = R1 + e1.

Therefore, the piece 83 is very curved and allows, for example, to form a glass that appears visually asymmetrical to adapt for example to timepiece displays that are not centered with respect to its housing .

According to the second variant, the covering part 103 comprises an upper surface 102 and a lower surface 104, of which only the upper face is machined in order to obtain a substantially constant thickness e2 on its edges despite the complex shape of the part. 103.

Thus, FIG. 9 is a perspective representation of the substantially ovoid piece 103. The longitudinal curvature C4 intersects the transverse curvature C3 at the point O2. Note that the point O2 is not centered with respect to the substantially ovoid shape but is closer to the flared portion than the tip. This configuration of the piece 103 when it is reported on a timepiece case makes it possible to visually accentuate the remote integration of the display of the timepiece.

As shown in FIG. 10presenting the section C-C of FIG. 9, i.e. a longitudinal section, it can be seen that the curvature C4 is asymmetrical. In the example of fig. 8 to 10, it is noted that in fact the curvature C3 forms a single radius R3 and that the curvature C4 forms two adjacent radii R4 and R4. Thus, the radius R4 between the edge of the flared portion and the point O2 is greater than the radius R4 between the edge of the tip and the point O2.

Therefore, the piece 103 is complex and allows, for example, to form an asymmetrical ice to adapt for example to timepiece displays that are not centered relative to its housing. As such, the maximum thickness e3 of the piece 103 is located vertically above the imaginary point O2 and the minimum thickness e2 all around the edge of the piece 103.

Of course, the present invention is not limited to the illustrated example but is susceptible to various variations and modifications that will occur to those skilled in the art. In particular, other variations of parts are possible depending on whether the upper face and / or the lower face are machined with one or more spokes both transversely and longitudinally.

Claims (15)

1. Manufacturing system (1, 21, 41, 61) of a cladding piece (3, 23, 43, 63, 83, 103) for a timepiece comprising a fixing device (5, 25, 45, 65) comprising a drum (11, 31, 51, 71) rotatably mounted along a first axis (A1, A3) and carrying at least one blank (3, 23) of said workpiece, a machining device (7, 27, 47, 67) having abrasive means (13, 33, 53, 73) rotatably mounted along a second axis (A2, A4) and for machining said at least one blank to form a first curvature ( C1, C3) characterized in that the machining device (7, 27, 47, 67) further comprises displacement means (15, 35, 55, 75) of said second axis (A2, A4) so that the latter is movably mounted in a curved director to selectively form a second curvature (C2, C4) to said at least one blank. 2. System (1, 21, 41, 61) according to the preceding claim, characterized in that the director of the displacement means is symmetrical to form said second curvature in a single radius. 3. System (1, 21, 41, 61) according to claim 1, characterized in that the director of the displacement means is asymmetrical in order to form said second curvature along several radii. 4. System (1, 21, 41, 61) according to one of the preceding claims, characterized in that said first axis (A1, A3) and said second axis (A2, A4) are perpendicular in order to cross the lines of machining. 5. System (1) according to one of the preceding claims, characterized in that the drum (11) is a ring against the inner wall of which said at least one blank (3) is fixed and in that the abrasive means (13) ) are moved in the hollow of said ring to form first and second concave curvatures (C1, C2). 6. System (21, 41, 61) according to one of claims 1 to 4 characterized in that the drum (31, 51, 71) is a disc against the outer wall of which said at least one blank (23, 43 63) is fixed and that the abrasive means (33, 53, 73) is moved in front of said disk to form first and second convex curvatures (C3, C4). 7. System (1, 21, 41, 61) according to one of the preceding claims, characterized in that the abrasive means (13, 33, 53, 73) are formed by a grinding wheel. 8. System (1, 21, 41, 61) according to one of the preceding claims, characterized in that the displacement means (15, 35, 55, 75) are formed by an actuator moved back and forth against the profile of a fixed cam corresponding to said second curvature. 9. System (1, 21, 41, 61) according to one of claims 1 to 7, characterized in that the displacement means (15, 35, 55, 75) are formed by an automaton programmed to move according to said second curvature. 10. System (1, 21, 41, 61) according to one of claims, characterized in that said part is formed from crystallized alumina. 11. A trim piece (3, 23, 43, 63, 83, 103) having an upper surface (82, 102) and a lower surface (84, 104) characterized in that at least one of the faces (82, 84, 102, 104) has a longitudinal curvature (C2, C4) and a transverse curvature (C1, C3) which are different. 12. Part (3, 23, 43, 63, 83, 103) according to the preceding claim, characterized in that the lower and upper faces (82, 84, 102, 104) comprise a longitudinal curvature (C2, C4) and a transverse curvature (C1, C3) which are different. 13. Part (3, 23, 43, 63, 83, 103) according to claim 11 or 12, characterized in that at least one of said longitudinal and transverse curvatures (C1, C2, C3, C4) is asymmetrical. 14. Part (3, 23, 43, 63, 83, 103) according to one of claims 11 to 13, characterized in that it is formed from crystallized alumina. 15. Timepiece characterized in that it comprises a trim piece (3, 23, 43, 63, 83, 103) according to one of claims 11 to 14.