WO2014173974A2

WO2014173974A2 - Mother-of-pearl component and method for producing such a component

Info

Publication number: WO2014173974A2
Application number: PCT/EP2014/058275
Authority: WO
Inventors: Etienne Lebreton; Mathieu Ferrand; Vincent Lepoultier
Original assignee: Les Ateliers Horlogers Dior Sa
Priority date: 2013-04-23
Filing date: 2014-04-23
Publication date: 2014-10-30
Also published as: CH707940A1; WO2014173974A3; CH707940B1

Abstract

A unitary mother-of-pearl component (1) forming a piece of imitation marquetry made from mother-of-pearl, comprising a face milled using a milling tool to create a series of slots (10) defined by surfaces (102, 104) in such a way as to give the visual impression of a piece of marquetry. The mother-of-pearl component according to the invention can advantageously be used in a timepiece component, such as an oscillating mass or a dial, for example.

Description

Mother-of-pearl piece and method of making such a piece

Technical area

The present invention relates to a mother-of-pearl piece and a method of manufacturing such a piece.

State of the art

Mother-of-pearl is the lining of some mollusc shells, composed of crystals of aragonite and conchyoline, with iridescent reflections. Mother-of-pearl is a product that has been used for a long time for decoration, marquetry, jewelery making, buttons and many other decorative products.

Mother-of-pearl has many species of which the principal ones used are mother-of-pearl of the South Seas, mother-of-pearl of Tahiti, black mother-of-pearl or purple or brown or pink or gold, mother-of-pearl Abalon, etc.

Mother-of-pearl is suitable for carving, drilling, engraving, polishing, polishing and many manual or automated machining processes. However, its limited thickness, generally less than 2 millimeters, mainly reduces its use in bas-reliefs or platelets rather than in volume sculpture.

In this context the word "wafer" indicates a thin piece, for example less than 2 millimeters, and having at least one flat face. The mother-of-pearl platelets have thus long been used as marquetry elements, either exclusively or in combination with other materials. In this context the word "marquetry" means a decoration made with small pieces shaped platelets, cut in a drawing and glued on a support. In other words, a marquetry is achieved by gluing or juxtaposing small separate plates on a surface. The work is often manual and a sign of luxury or high value products.

Mother-of-pearl is a partially transparent and milky material, and its iridescence is stronger if mother-of-pearl is thick. Typically, a white mother-of-pearl plate of a tenth of a millimeter thick will be slightly iridescent and more transparent than a plate of more than one millimeter. The iridescence of a mother-of-pearl piece varies according to the position of the piece considered but also according to the level of its depth relative to the mother shell.

We observe the iridescence, that is to say, a gradual color variation of mother-of-pearl as well as a variation of reflected light intensity, by looking at a small surface of mother-of-pearl lit and while moving the gaze step by step . The progressivity of these variations in color and reflected light as well as the color dominance makes it possible to identify whether it is a monobloc mother-of-pearl piece or a marquetry formed of juxtaposed plates. The visual impression of a mother-of-pearl marquetry is therefore marked by the discontinuity of iridescence and therefore of color which is due to the presence of different mother-of-pearl pieces, for example from different shells or from distant parts of the same shell. . FIG. 1 illustrates a sectional diagram of two pieces of mother-of-pearl 1 'and 1 "which are

juxtaposed edge to edge, thus a marquetry format. The mother-of-pearl pieces 1 'and 1 "can also be separated by metal elements.

FIG. 2 illustrates a sectional diagram of a mother-of-pearl piece 1 in the form of a plate with a notch 2. The mother-of-pearl piece 1 is therefore monobloc and engraved. The etched parts keep a matte surface to allow contrast with the rest of the glossy wafer.

In the case of a known one-piece engraved piece, like that of FIG. 2, there is no effect of marquetry because the piece has a continuity of iridescence and therefore of color which is due to the fact that only mother-of-pearl piece was used. Indeed the set of non-engraved parts, even if they are separated by etching lines 2, always belong to the same plate. So there is no effect of marquetry.

On the contrary, the discontinuity of the iridescence of the parts 1 'and 1 "of Figure 1 easily shows that it is a marquetry.

The marquetry effect can also be obtained by a depth play of the mother-of-pearl piece. Indeed, as discussed, the iridescence also varies according to the depth at which the mother-of-pearl piece is cut.

Therefore, machining a step-length mother-of-pearl piece to produce multiple polished surfaces at different depths produces a discontinuity effect of the iridescence. In front view, the illusion is given that it is two or more pieces of mother-of-pearl different.

Figure 3 illustrates a sectional diagram of a mother-of-pearl piece 1 machined in five levels of different depths ΘΑ to ΘΕ. This machining causes a discontinuity of the iridescence and gives the visual impression that it is a marquetry. The piece includes a planar base 16.

The part of FIG. 3 is in the form of a staircase, comprising steps 18. In other words, this part 1 is a succession of substantially horizontal planes (or steps) 18 at heights ΘΑ and ΘΕ that are different from each other . The line p is an imaginary line that passes through equivalent points of each step 18, for example a line that passes through the edge of each step. The angle of the slope of the staircase Θ is defined as illustrated in FIG. 3 as the angle between this line p and a direction h parallel to that of the planar base 16 and the steps 18. In the illustrated example, this angle has a value equal to or greater than 30 °, for example 45 ° or more.

The disadvantage of the solution illustrated in Figure 3 is that to obtain a discontinuity effect giving the visual impression of a marquetry, it is necessary to have a sufficient depth offset between two consecutive levels. In addition, a large number of levels makes it possible to create more complex marquetry decorations. A complex marquetry therefore requires a piece of mother-of-pearl too thick to be used in a fine device such as a dial or an oscillating weight of a watch.

In addition, the quality of the mother of pearl and its iridescence decreases in depth. Consequently, if the solution of FIG. 3 is made from a mother-of-pearl piece of smaller thickness, a piece having portions of thickness ΘΕ that is very thin, thus fragile and less iridescent, is obtained than the portions more thick (ΘΑ in Figure 3).

There is therefore a need for a machined mother-of-pearl piece so as to give the visual impression of an inlay, but which does not have the disadvantages discussed in relation to FIG.

KR201 10030776 describes a method in which a mother-of-pearl piece is adhered to a paper sheet by means of an adhesive, a roll then passes over the mother-of-pearl piece, the mother-of-pearl piece is after finely cracked in order to create a piece of nacre. pattern-mosaic and then the sheet of paper is separated from the mother-of-pearl piece using water. US5091 136 discloses a method for making embossed prints on a mother-of-pearl piece. The piece is placed in a negative mold containing a relief shape, a modeling material is placed on the mother-of-pearl piece, and this modeling material is pressed, thus pressing the mother-of-pearl piece so as to make embossed prints on the mother-of-pearl piece.

JP2005331346 discloses a watch face, in which a mother-of-pearl piece is divided into twelve parts having an angular amplitude of 30 °. These parts are arranged so as to form a rectangular dial by arranging the different pieces one on the other like layers ("layers").

JP61270200 discloses a method of working mother-of-pearl.

JP2003194966 discloses a watch face, comprising a resin layer, a smooth layer and colored shapes that give the impression that the dial is made of stone, mother-of-pearl, etc.

Brief summary of the invention

An object of the present invention is to provide a mother-of-pearl piece constituting an imitation of marquetry free from the limitations of known pieces.

According to the invention, these objects are attained in particular by means of a mother-of-pearl piece according to claim 1 and by means of a manufacturing method of such piece according to claim 18.

The mother-of-pearl piece according to the invention is monobloc and comprises a countersunk face using a milling cutter to create a succession of slots defined by surfaces. Advantageously, these slots make it possible to give

the visual impression of a marquetry, because they allow to have an iris discontinuity similar to that obtained by a machining, carving and successive engraving of several plates and finally their manual bonding piece by piece on a support.

Advantageously these slots allow to give the visual impression of a marquetry, because they allow to have a game of depth of the mother-of-pearl piece allowing the iridescence to vary depending on this depth. In this context the word "slots" indicates openings, for example grooves, made in the surface of the mother-of-pearl piece. The slots are not necessarily periodic, that is to say regularly spaced, and may have different shapes, for example and without limitation, V-shaped, U-shaped, etc. A succession of slots may include slots of different shapes.

The bottom of the battlements is located at a substantially constant depth, like the battlements of a castle. Slightly varying depths of depth can, however, also be considered.

The effect obtained by a part according to the invention is the illusion of a work done by machining, carving and successive engravings of several wafers and finally their manual gluing piece by piece on a support, while it is a question of in fact a piece of mother-of-pearl, that is to say made of a single block.

The mother-of-pearl part is advantageously a wafer, that is to say comprising at least one flat surface or planar base and having a small thickness, for example less than 2 millimeters. In a preferred variant the succession of slots belongs to the face opposite to the planar base.

In a preferred embodiment each slot is V-shaped and is defined by a first surface and a second surface. The first surface forms a first angle with a direction parallel to that of the planar base, the second surface forms a second angle with the direction parallel to that of the base, the second angle having the opposite sign to that of the first angle. In a preferred embodiment, the first angle has a value different from that of the second. Advantageously, these surfaces are not parallel to the planar base, so they are not horizontal. In other words, in a preferred embodiment of the invention the first and second angles have a value that is different from n × 180 °, where n = 0, 1, 2, 3, and so on.

Thus, in a variant, the succession of crenellations comprises only surfaces that are not parallel to the planar base.

Advantageously, the first and second surfaces have been obtained by milling, and therefore they are milled. The milling process is performed with a tool, the cutter, which allows to create a continuous succession of first and second inclined surfaces, that is to say non-horizontal. This succession advantageously does not include any surface

horizontal, unlike a mother-of-pearl plate comprising one or more notches or grooves obtained by a metal point engraving mother-of-pearl.

The value of the first and the second angle is determined so as to obtain the discontinuity of the iridescence between the first and the second surface allowing the printing of marquetry. Tests of the applicant have shown that a value of the first angle between 10 ° and 20 ° and a second angle value of between 70 ° and 80 ° provides the desired impression of marquetry. In a preferred embodiment the area of the first surface is substantially larger than that of the second surface, for example it is at least twice the area of the second surface.

In a variant, neither the first nor the second surface are parallel to the planar base.

In another variant the slots have a U-shape and are also defined by a third surface between the first and the second, this third surface being able to be parallel to the planar base. In yet another variant between the first and second surfaces there are two or more other surfaces.

Advantageously, the part according to the invention comprises an alternating succession of upper edges and lower edges, all the upper edges being substantially at the same first distance from the planar base and / or all the lower edges being substantially at the same second distance. from the planar base.

In all the cases mentioned and independently of the shape of the crenellations, the succession of crenellations forms an angle of slope with respect to the planar base of less than 30 °, preferably less than 10 °, for example 0 °. In other words, the angle of inclination is substantially parallel to that of the planar base.

The slots are defined by surfaces that are inclined alternately towards the base of the room and then to an opposite direction.

It is thus possible to make imitations of inlaid large area, without reducing the minimum thickness of the room. The risks of breakage are thus reduced compared to known solutions. In a variant, the surfaces defining the crenellations are planar and / or conical portions.

In one embodiment, the surface of the mother-of-pearl is crenellated in two orthogonal directions, and thus formed in each direction of surfaces oriented alternately towards the base and then towards a direction opposite to the base. In one embodiment, the surface of the nacre is formed of surfaces arranged relative to each other in the manner of fish scales.

In one variant, the part according to the invention comprises etchings between the surfaces defining the slots, so as to add separations between these surfaces.

The invention also relates to a timepiece covered at least partially with the described mother-of-pearl piece. This timepiece can be for example an oscillating mass, a dial, a needle, a watchmaking element or any other moving or immobile timepiece. The mother-of-pearl piece can be glued to the timepiece support.

The environment of the watch is very constrained in thickness by the superposition of the dial, needles or other mobile elements. The mother-of-pearl piece according to the invention makes it possible to control its thickness while guaranteeing the desired marquetry impression.

The invention also relates to a method for manufacturing a monobloc mother-of-pearl piece comprising the following step:

- Milling the mother of pearl piece with a first bur to create a series of slots defined by surfaces to give the impression of an inlay. In a preferred variant, the method also comprises milling the mother-of-pearl piece with a second cutter smaller than the first and / or making etchings between each surface.

The limit to the complexity of the design of each surface depends only on the diameter of the cutter used during the machining.

Brief description of the figures

Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which:

Figure 1 illustrates a sectional diagram of two pieces of mother-of-pearl which are juxtaposed edge to edge, thus format a marquetry. Figure 2 illustrates a sectional diagram of a mother-of-pearl piece with a notch.

Figure 3 illustrates a sectional diagram of a mother-of-pearl piece machined in five different depth levels.

Figure 4 illustrates a sectional diagram of an embodiment of a piece of mother-of-pearl according to the invention.

Figure 5 illustrates a sectional diagram of another embodiment of a mother-of-pearl piece according to the invention.

FIG. 6 illustrates a perspective view of an embodiment of a monobloc mother-of-pearl piece according to the invention during machining. FIG. 7 illustrates a watch comprising an oscillating weight comprising an embodiment of a one-piece mother-of-pearl piece according to the invention.

Example (s) of embodiment (s) of the invention

Figure 4 illustrates a sectional diagram of an embodiment of a mother-of-pearl piece 1 according to the invention.

The mother-of-pearl piece according to the invention is one-piece and comprises a face having a succession of slots 10 defined by surfaces 102, 104 so as to give the visual impression of a marquetry.

In this context the word "slots" indicates openings, for example grooves, interstices, a-dishes, etc., milled into the surface of the mother-of-pearl piece. The slots illustrated in FIG. 1 are periodic and all V-shaped. However, the invention is not limited to this embodiment and can be implemented with slots which are not necessarily periodic, that is, that is to say, regularly spaced, and which may have different shapes, for example and in a non-limiting manner U-shaped shapes. A succession of slots may comprise slots of different shapes.

The mother-of-pearl piece of FIG. 4 is a wafer, that is to say it comprises at least one flat surface or planar base 16 and has a small thickness, for example less than 2 millimeters, for example less than 0.50. mm, for example in the range 0.25 mm - 0.30 mm.

In a preferred variant the difference between the thickness e1 and the thickness e2, visible in FIG. 4, is less than 0.15 mm, for example in the range 0.05 mm - 0.10 mm. In the variant of FIG. 4, each slot is V-shaped and defined by a first surface 102 and a second surface 104. The first surface 102 forms a first angle α with a direction h parallel to that of the planar base 16, the second surface 104 forms a second angle β with the direction h. In the variant illustrated, the first angle aa has a value different from that of the second angle β.

The value of the first and the second angle is determined so as to obtain a discontinuity of the iridescence between the first and the second surface 102 respectively 104 allowing the printing of marquetry. Tests of the applicant have shown that a value of the first angle has between 10 ° to 20 ° and a second angle value β between 70 and 80 ° to obtain the desired impression of marquetry.

In the variant illustrated in FIGS. 4 and 6, the area of the first surface 102 is substantially greater than that of the second surface 104, for example at least twice the area of the second surface 104.

In the variant of FIG. 4, neither the first nor the second are parallel to the planar base 16.

In another variant not illustrated, the slots 10 have a shape of U and are also defined by a third surface between the first and the second, this third surface being able to be parallel to the planar base 16. In another variant still between the first and second and second surface there are two or more other surfaces.

Advantageously, the part 1 comprises an alternating succession of upper edges 12 and lower edges 14, all the upper edges being substantially at the same first distance e1 of the planar base 16 and all the lower edges 14 being substantially at the same second distance e2 of the planar base 16. However, other embodiments are also possible, such as that illustrated in FIG. 5, where the upper edges 12 and / or lower 14 are placed at different distances from the planar base 16. In all the cases mentioned and independently In the shape of the crenellations, the succession of crenellations 10 forms an angle of slope Θ with respect to the planar base 16 which is less than 30 °, preferably less than 10 °, for example 0 °. In the variant of Figure 4 9 = 0 °

(as illustrated by the line p which is parallel to the planar base 16).

The slope angle is defined as the angle of a straight line passing through an equivalent point of each successive slot, for example by the upper edge of each slot.

Indeed the slots are defined by surfaces 102, 104 which are inclined so as to allow movements alternately upwards and downwards. In other words, the slope angle Θ is

substantially parallel to that of the planar base 16.

The solidity of the piece of the mother-of-pearl piece is guaranteed by the minimum value of its thickness e2, chosen during the machining of the crenellations 10 and by the size of the mother-of-pearl piece 1.

The risk of breakage is thus reduced compared with known solutions.

In the embodiment of FIG. 4, the surfaces 102, 104 defining the slots 10 are planar, but they can be

also cone portions.

As can be seen in FIGS. 6 and 7, the surfaces 102, 104 defining the slots 10 have a shape defined by a closed line, which in the illustrated example is a circumference or a line comprising arcs of circumference. In addition these surfaces 102, 104 are arranged relative to each other in the manner of flaking fish. In a variant not illustrated, the part according to the invention comprises engravings between the surfaces 102, 104 defining the crenellations 10, so as to add separations between these surfaces 102, 104.

In the example of Figure 6 the periphery of the part 1 comprises a succession of arcs of the circles, each corresponding to a slot.

The invention also relates to a timepiece decorated and at least partially covered with the nacre piece 1 described. This timepiece can be for example an oscillating mass, a dial, a needle, a watchmaking element or any other moving or immobile timepiece. In general, the mother-of-pearl piece is glued to the timepiece.

FIG. 7 illustrates a watch 300 comprising an oscillating mass 200 on which the mother-of-pearl piece 1 according to the invention has been fixed, for example glued.

Reference numbers used in the figures

1 mother of pearl

2 Notch

12 Upper edge

14 Lower edge

1 6 Planar base

18 Walking

102 First surface

104 Second surface

200 oscillating weight

300 Watch

at first angle

β Second angle

Θ Slope angle

ei First distance or thickness

e ₂ Second distance or thickness

ΘΑ to ΘΕ Distance or thickness

p Line passing through equivalent points of each successive step or niche.

h Line having a direction parallel to the planar base

Claims

claims

1. Monobloc mother-of-pearl piece (1) comprising a milled face using a milling cutter to create a succession of slots (10) defined by surfaces (102, 104).

2. Part according to claim 1, comprising a planar base (16), said face being opposed to said planar base (1 6), each slot (10) being defined by a first surface (102) forming with a direction (h) parallel to that of the planar base (16) a first angle (a), and a second surface (104) forming with the direction (h) parallel to that of the planar base (16) a second angle (β) having the sign opposite to that of the first angle (a).

3. Part according to the preceding claim, said first angle (a) having a value between 10 ° and 20 °, said second angle (β) having a value between 70 ° and 80 °.

4. Part according to one of claims 2 to 3, the area of said first surface (102) being at least twice the area of said second surface (104).

5. Part according to one of claims 1 to 4, comprising an alternating succession of upper edges (12) and lower edges (14).

6. Part according to the preceding claim, all the upper edges (12) being substantially at the same first distance (e1) of said planar base (16) and / or all the lower edges (14) being substantially at the same second distance ( e2) of said planar base (16).

7. Part according to one of claims 2 to 6, said succession of crenellations (10) forming a slope angle (Θ) relative to the planar base (1 6) less than 30 °, preferably less than 10 °, for example 0 °.

8. Part according to one of claims 1 to 7, each surface (102; 104) defining the slots (10) having a shape defined by a closed line.

9. Part according to one of claims 2 to 8, said first (102) and second (104) surfaces being arranged in the manner of fish scales.

10. Part according to one of claims 2 to 9, said first (102) and second (104) surfaces being obtained by milling.

1 1. Part according to one of claims 2 to 10, said succession of crenellations (10) comprising only surfaces (102, 104) not parallel to the planar base (16).

12. Part according to one of claims 2 to 1 1, comprising etchings between each first (102) and second surface (104).

13. Part according to one of the preceding claims, said slots (10) having a shape defined by a circumference or a line comprising arcs of circumference.

14. Part according to one of the preceding claims, comprising a series of arcs of circles, each corresponding to a slot.

5. Timepiece comprising the mother-of-pearl piece according to one of the preceding claims.

16. Part according to claim 1 5, constituted by an oscillating mass (200).

17. Part according to claim 1 5, constituted by a dial.

18. A method of manufacturing a monobloc mother-of-pearl piece (1) comprising the following step

- Milling the mother-of-pearl piece (1) with a first bur to create a series of slots (10) defined by surfaces (102, 104).

19. The method of claim 18, comprising milling the mother-of-pearl piece (1) with a second cutter smaller than the first.

20. Method according to one of claims 18 or 19, comprising the production of etchings between each surface (102, 104).