CH707940A1 - Coin pearl and such a part manufacturing process. - Google Patents

Abstract

Mother-of-pearl piece (1) constituting an imitation of mother-of-pearl marquetry, comprising a face having a succession of crenellations (10) defined by surfaces (102, 104) so as to give the visual impression of an inlay. The mother-of-pearl piece according to the invention can advantageously be used in a timepiece such as, for example, an oscillating weight or a dial.

Description

Technical area

The present invention relates to a nacre piece and a method of manufacturing such a piece.

State of the art

The mother of pearl is the lining of some mollusk shells, consisting 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.

[0003] The mother-of-pearl contains many species, the main ones of which are mother-of-pearl from the South Seas, mother-of-pearl from Tahiti, mother-of-pearl from black or purple or brown or pink or gold, mother-of-pearl from Abalon, and so on.

The 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 plates have long been used as inlay elements, either exclusively or in combination with other materials. In this context the word "marquetry" refers to a decoration made with small pieces in the form of platelets, cut in a pattern 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.

The nacre is a partially transparent and milky material, and its iridescence is stronger if the nacre 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 piece of mother-of-pearl 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 the mother of pearl and a variation of reflected light intensity, looking at a small surface of mother-of-pearl lit and while moving the eye of close by. 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 pieces of mother-of-pearl, for example from different shells or from parts remote from each other. 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 forming a marquetry. 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 thus one-piece 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 that is due to the fact that only one piece of nacre 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 iridescent parts 1 and 1 of FIG. 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, the machining of a piece of mother-of-pearl staircase, so as to produce several 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.

FIG. 3 illustrates a sectional diagram of a mother-of-pearl piece 1 machined in five different levels of depth eAa in. 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 piece of FIG. 3 is in the form of a staircase, comprising steps 18. In other words, this piece 1 is a succession of substantially horizontal planes (or steps) 18 at heights eA and eEdifferent 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 9 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 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 FIG. 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.

Moreover, the quality of the mother of pearl and its iridescence decreases in depth. Therefore, if the solution of FIG. 3 from a piece of mother-of-pearl of smaller thickness, a piece is obtained with portions of thickness eEtrès fine, so fragile and less iridescent than the thicker portions (eAsur Fig 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. 3.

Brief summary of the invention

An object of the present invention is to provide a mother of pearl component constituting an imitation of marquetry free of the limitations of known parts.

According to the invention, these objects are achieved in particular by means of a mother-of-pearl piece according to claim 1 and by means of a method for manufacturing such a piece according to claim 16.

The mother-of-pearl piece according to the invention comprises a face having a succession of slots defined by surfaces so as to give the visual impression of a marquetry.

In this context the word "crenellations" 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 crenellations is located at a substantially constant depth, like the slots of a castle. Slightly varying depths of depth can, however, also be considered.

The effect obtained by a room according to the invention is the illusion of a work done by machining, carving and successive engravings of several plates and finally their manual collage piece by piece on a support, while he This is actually a piece of mother-of-pearl.

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 embodiment the succession of slots belongs to the opposite face 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 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 x 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.

In a preferred embodiment the first and the second surface were 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 horizontal surface, unlike a mother-of-pearl plate comprising one or more cut-grooves obtained by a metal point engraving the nacre.

The value of the first and second angle is determined so as to obtain the discontinuity of the iridescence between the first and the second surface for printing 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 distance. 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 inclination with respect to the planar base 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 to the base of the room, 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 cone 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 a 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 from 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 nacre piece manufacturing process 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 embodiment, the method also comprises milling the mother-of-pearl piece with a second cutter smaller than the first and / or making engravings between each surface.

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

Brief description of the figures

Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which: <tb> Fig. 1 <SEP> illustrates a sectional diagram of two pieces of mother-of-pearl which are juxtaposed side by side, thus forming an inlay. <tb> Fig. 2 <SEP> illustrates a sectional diagram of a mother-of-pearl piece with a notch. <tb> Fig. 3 <SEP> illustrates a sectional diagram of a mother-of-pearl piece machined in five different depth levels. <tb> Fig. 4 <SEP> illustrates a sectional diagram of an embodiment of a nacre piece according to the invention. <tb> Fig. <SEP> illustrates a sectional diagram of another embodiment of a nacre piece according to the invention. <tb> Fig. 6 <SEP> illustrates a perspective view of an embodiment of a mother-of-pearl piece according to the invention during machining. <tb> Fig. 7 <SEP> illustrates a watch comprising an oscillating weight comprising an embodiment of a mother-of-pearl piece according to the invention.

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

FIG. 4 illustrates a sectional diagram of an embodiment of a nacre piece 1 according to the invention.

The mother-of-pearl piece according to the invention 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 in the surface of the mother-of-pearl piece. The slots shown 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 to say regularly spaced, and which may have different shapes, for example and without limitation 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.

In the variant of FIG. Each slot is V-shaped and is 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 direction h. In the variant illustrated, the first angle α has a value different from that of the second β.

The value of the first and 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 α between 10 ° to 20 ° and a second angle value β between 70 and 80 ° provides the desired impression of marquetry.

In the variant illustrated in FIG. 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 surface are parallel to the planar base 16.

In another variant the crenellations 10 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 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 e1of the planar base 16 and all the lower edges 14 being substantially the same. second distance e2 from 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 of the shape of the crenellations, the succession of crenellations 10 forms an angle of inclination 9 with respect to the planar base 16 which is less than 30 °, preferably less than 10 °, for example 0 °. In the variant of FIG. 4 θ = 0 °. 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 to allow movements alternately upwards and downwards. In other words, the angle of inclination 9 is substantially parallel to that of the planar base 16.

The solidity of the piece of mother-of-pearl piece is guaranteed by the minimum value of its thickness e2, chosen during the machining of slots 10 and the size of the mother-of-pearl piece 1. The risks of breakage are thus reduced compared to known solutions.

In the embodiment of FIG. The surfaces 102, 104 defining the crenellations 10 are planar, but they may also be cone portions.

As shown in FIGS. 6 and 7, the surfaces 102, 104 defining the crenellations 10 have a shape defined by a closed line, which in the example illustrated 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 shown, the part according to the invention comprises etchings between the surfaces 102, 104 defining the crenellations 10, so as to add separations between these surfaces 102, 104.

In the example of FIG. 6 the periphery of the piece 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

[0071] <tb> 1 <SEP> Mother of pearl piece <Tb> 2 <September> Slash <tb> 12 <SEP> Upper edge <tb> 14 <SEP> Bottom edge <tb> 16 <SEP> Planar basis <Tb> 18 <September> Marche <tb> 102 <SEP> First surface <tb> 104 <SEP> Second surface <tb> 200 <SEP> Oscillating mass <Tb> 300 <September> Watch <tb> α <SEP> First angle <tb> β <SEP> Second angle <tb> θ <SEP> Slope angle <tb> e1 <SEP> First distance or thickness <tb> e2 <SEP> Second Distance or Thickness <tb> eA to eE <SEP> Distance or thickness <tb> p <SEP> Line passing through equivalent points of each successive step or niche. <tb> h <SEP> Line with a direction parallel to the planar base

Claims (18)

1. Mother-of-pearl piece (1) constituting an imitation of mother-of-pearl marquetry, comprising a face having a succession of crenellations (10) defined by surfaces (102, 104) so as to give the visual impression of a marquetry. 2. Part according to claim 1, comprising a planar base (16), said face being opposite to said planar base (16), 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 (p) having the opposite sign 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 (p) 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 (9) relative to the planar base (16) less than 30 °, preferably less than 10 °, by 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. 11. 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 11, comprising etchings between each first (102) and second surface (104). 13. Timepiece comprising the mother-of-pearl piece according to one of the preceding claims. 14. Part according to claim 13, consisting of an oscillating mass (200). 15. Part according to claim 13, constituted by a dial. 16. Method for manufacturing a 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) to give the impression of an inlay. 17. The method of claim 16, comprising milling the mother-of-pearl piece (1) with a second cutter smaller than the first. 18. Method according to one of claims 16 or 17, comprising performing etchings between each surface (102, 104).