EP0948758B1 - Watch crystal and method of fabricating the same - Google Patents

Watch crystal and method of fabricating the same Download PDF

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Publication number
EP0948758B1
EP0948758B1 EP97938739A EP97938739A EP0948758B1 EP 0948758 B1 EP0948758 B1 EP 0948758B1 EP 97938739 A EP97938739 A EP 97938739A EP 97938739 A EP97938739 A EP 97938739A EP 0948758 B1 EP0948758 B1 EP 0948758B1
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EP
European Patent Office
Prior art keywords
axis
circle
glass according
glass
lateral faces
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EP97938739A
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German (de)
French (fr)
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EP0948758A1 (en
Inventor
Hansruedi Sägesser
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Hans Stettler AG
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Hans Stettler AG
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    • G—PHYSICS
    • G04—HOROLOGY
    • G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
    • G04B39/00—Watch crystals; Fastening or sealing of crystals; Clock glasses
    • G04B39/004—Watch crystals; Fastening or sealing of crystals; Clock glasses from a material other than glass
    • G04B39/006—Watch crystals; Fastening or sealing of crystals; Clock glasses from a material other than glass out of wear resistant material, e.g. sapphire
    • G—PHYSICS
    • G04—HOROLOGY
    • G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
    • G04B39/00—Watch crystals; Fastening or sealing of crystals; Clock glasses

Definitions

  • the present invention relates to a watch crystal, one of the main faces of which is curved, as described in document FR 2 386 851, the glass being formed from a cut stone in the shape of a cabochon.
  • Such glasses are used to give a particular cachet to a watch.
  • the curved face is a surface of revolution, for example spherical.
  • the edge of the glass has, under these conditions, a constant thickness.
  • the face curved is generally a cylindrical surface.
  • the generator of the cylindrical part is oriented perpendicular to the long side of the ice. If the thickness of the edges of the short sides is then constant, on the other hand that of the long sides varies all the more as the ice is long. This drawback is mitigated if the curved face is a spherical shape. It may even be completely eliminated by giving the ice the desired shape by hot molding a plate of constant thickness. Or, if the part of the watch case on which the ice also has a cylindrical shape, the two faces of the ice are then two surfaces parallel cylindrical, and the thickness everywhere constant.
  • the first solution leads however on faces which are not perfectly regular, defect sufficiently visible to keep these watches out of neat quality watches.
  • the second solution has the disadvantage of increasing the manufacturing price of the box and ice.
  • the purpose of the present invention is to provide a corundum ice cream, of elongated shape, in particular rectangular, in which the curved face is a surface which makes it possible to obtain an edge whose thickness is significantly smaller and more constant than in the case windows whose curved face is cylindrical or spherical, for the same thickness of the ice in its center.
  • the watch crystal according to the invention comprising a domed upper surface and a lower surface, is mainly remarkable for its characteristics appearing in the characterizing part of claim 1.
  • a surface toroidal Such a surface is generated, as shown in Figure 1, by a circle 1 of radius R1, the center C1 of which describes a circle 2 of center C2 and of radius r2.
  • the plane of circle 1 is perpendicular to the plane of circle 2, and it passes through its center C2.
  • the ice In the raw state, the ice is in the form of a transparent plate, preferably in spinel, in corundum, sapphire or ruby, elongated, by rectangular example, and whose main faces are flat and parallel.
  • the reference 10 designates a circular drum which is fixed on a shaft not shown of the machine so as to be rotated, in the direction of arrow F, around its axis of symmetry xx '.
  • the drum has at its periphery flat areas 11 parallel to the axis xx ', and on each track is glued, equidistant from the faces of the drum, a ice 12.
  • the long side of the ice is oriented perpendicular to the axis xx ', but its orientation might as well be parallel to this axis.
  • a grinding wheel 13 In the extension of the drum 10 is disposed a grinding wheel 13 on a carriage not shown, and it is driven in rotation, in the direction of arrow F ', around its axis yy' by a motor shaft on which it is fixed.
  • the cart is integral with the machine frame while being driven by this in an alternative pivoting movement, in the direction of arrow f, around an axis ZZ 'arranged perpendicular to the axis xx 'and passing through the middle of the drum 10.
  • the grinding wheel 13 is mounted on a slide, integral with the carriage, allowing it to be moved according to the arrow f 'so as to modify its distance to the axis ZZ', manually or by machine, and get it to touch the ice 12 at a point of contact 14.
  • the contact point 14 therefore describes well in relation to the drum 10, when it rotates around the axis xx ', a surface toroidal.
  • the radius of the drum 10 and the thickness of the glass 12 determine the radius R2, and the position of the axis ZZ 'by compared to C2, the radius R1.
  • the drum 10 and grinding wheel 13 are rotated, this causing the pivoting movement of the carriage around the axis ZZ ', along arrow f, the grinding wheel being distant from the glass 12. Then the grinding wheel 13 is approached the axis ZZ ' following the arrow f 'to come into contact with the glass 12 and machine its surface until the nominal values of R1 and R2 are reached. All of these operations can be performed automatically.
  • ice 12 of rectangular shape thus obtained is shown in fig. 3.
  • This ice is bounded by a flat underside 20 coming opposite the dial one when fixed on a watch, a domed upper face 21, and four flat side faces, the faces 22 corresponding to the short sides of the rectangle, and the sides 23 to the long sides.
  • the lower face 20 may advantageously have a recess 24 for the needles, obtained by grinding or by ultrasonic machining and preserving a flat edge 25 on everything around the ice.
  • Lines 26 and 26 give the contour of the upper face 21, and therefore the thickness of the glass with respect to the underside 20 when the glass is cut by planes parallel to the lateral faces and passing through its center
  • line 27 gives the upper outline of small side faces 22, and line 28 that of large lateral faces 23.
  • line 29 indicates the shape, in arc of circle, that would have the upper edge of the small faces side 22, for the same thickness of the glass in the center, if the upper face had a spherical shape
  • the line 30 the shape of the upper edge of the large lateral faces 23.
  • the watch glass which has just been described may undergo other modifications and appear under other variants, obvious to a person skilled in the art, without depart from the scope of the present invention as defined by the revendications.
  • the ice could have a elongated shape different from that of a rectangle, as by example an oval shape, and the underside deviate from the flat shape.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Grinding And Polishing Of Tertiary Curved Surfaces And Surfaces With Complex Shapes (AREA)
  • Surface Treatment Of Glass (AREA)

Description

La présente invention concerne une glace de montre dont l'une des faces principales est bombée, comme cela est décrit dans le document FR 2 386 851, la glace étant formée d'une pierre taillée en forme de cabochon.The present invention relates to a watch crystal, one of the main faces of which is curved, as described in document FR 2 386 851, the glass being formed from a cut stone in the shape of a cabochon.

De telles glaces sont utilisées pour donner un cachet particulier à une montre. Lorsque la glace est ronde et l'une des faces principales plane, la face bombée est une surface de révolution, par exemple sphérique. Le bord de la glace présente, dans ces conditions, une épaisseur constante. Such glasses are used to give a particular cachet to a watch. When the glass is round and one of the main faces planar, the curved face is a surface of revolution, for example spherical. The edge of the glass has, under these conditions, a constant thickness.

Si la glace s'écarte de la forme circulaire, en particulier lorsqu'elle est rectangulaire, la face bombée est généralement une surface cylindrique.If the glass deviates from the circular shape, especially when it is rectangular, the face curved is generally a cylindrical surface.

Pour des raisons d'esthétique, la génératrice de la partie cylindrique est orientée perpendiculairement au grand côté de la glace. Si l'épaisseur des bords des petits côtés est alors constante, par contre celle des grands côtés varie d'autant plus que la glace est longue. Cet inconvénient est atténué si la face bombée est une forme sphérique. Il peut même être complètement éliminé en donnant à la glace la forme voulue en moulant à chaud une plaque d'épaisseur constante. Ou bien, si la partie de la boíte de montre sur laquelle est appliquée la glace a également une forme cylindrique, les deux faces de la glace sont alors deux surfaces cylindriques parallèles, et l'épaisseur partout constante. La première solution conduit cependant à des faces qui ne sont pas parfaitement régulières, défaut suffisamment visible pour écarter ces glaces des montres de qualité soignée. La deuxième solution a l'inconvénient de renchérir le prix de fabrication de la boíte et de la glace.For aesthetic reasons, the generator of the cylindrical part is oriented perpendicular to the long side of the ice. If the thickness of the edges of the short sides is then constant, on the other hand that of the long sides varies all the more as the ice is long. This drawback is mitigated if the curved face is a spherical shape. It may even be completely eliminated by giving the ice the desired shape by hot molding a plate of constant thickness. Or, if the part of the watch case on which the ice also has a cylindrical shape, the two faces of the ice are then two surfaces parallel cylindrical, and the thickness everywhere constant. The first solution leads however on faces which are not perfectly regular, defect sufficiently visible to keep these watches out of neat quality watches. The second solution has the disadvantage of increasing the manufacturing price of the box and ice.

Le but de la présente invention est de proposer une glace en corindon, de forme allongée, notamment rectangulaire, dans laquelle la face bombée est une surface qui permet d'obtenir un bord dont l'épaisseur est sensiblement plus faible et plus constante que dans le cas desglaces dont la face bombée est cylindrique ou sphérique, pour une même épaisseur de la glace en son centre.The purpose of the present invention is to provide a corundum ice cream, of elongated shape, in particular rectangular, in which the curved face is a surface which makes it possible to obtain an edge whose thickness is significantly smaller and more constant than in the case windows whose curved face is cylindrical or spherical, for the same thickness of the ice in its center.

Pour atteindre cet objectif, la glace de montre selon l'invention, comportant une surface supérieure bombée et une surface inférieure, est principalement remarquable de par ses caractéristiques figurant dans la partie caractérisante de la revendication 1.To achieve this objective, the watch crystal according to the invention, comprising a domed upper surface and a lower surface, is mainly remarkable for its characteristics appearing in the characterizing part of claim 1.

Il est certes connu de réaliser des surfaces toroïdales sur des pièces en matériau transparent. C'est le cas, par exemple, dans le document US 4 585 296, qui se rapporte à un système optique dans lequel certaines lentilles présentent une surface toroïdale. De telles lentilles permettent de corriger certains défauts dans un système de balayage d'un rayon lumineux. It is certainly known to produce toroidal surfaces on parts made of transparent material. This is the case, for example, in document US 4,585,296, which relates to a system optics in which certain lenses have a toroidal surface. Such lenses allow to correct certain faults in a scanning system of a light ray.

D'autres caractéristiques et avantages de la glace selon la présente invention ressortiront de la description qui va suivre, faite en regard du dessin annexé et donnant, à titre explicatif mais nullement limitatif, un exemple de réalisation d'une telle glace. Sur ce dessin, où les mêmes références se rapportent à des éléments analogues :

  • la figure 1 est une construction géométrique montrant comment est définie une surface toroïdale ;
  • la figure 2 est une vue schématique d'une machine permettant de meuler une surface toroïdale ; et
  • la figure 3 représente dans des vues en plan, de face et de profil, une glace de forme rectangulaire selon l'invention.
Other characteristics and advantages of the glass according to the present invention will emerge from the description which follows, given with reference to the appended drawing and giving, by way of explanation but in no way limiting, an example of embodiment of such a glass. In this drawing, where the same references relate to similar elements:
  • Figure 1 is a geometric construction showing how a toroidal surface is defined;
  • Figure 2 is a schematic view of a machine for grinding a toroidal surface; and
  • FIG. 3 shows in plan, front and side views, a rectangular glass according to the invention.

Une des faces principales de la glace selon l'invention est délimitée par une surface toroïdale. Une telle surface est engendrée, comme cela est représenté sur la figure 1, par un cercle 1 de rayon R1 dont le centre C1 décrit un cercle 2 de centre C2 et de rayon r2. Le plan du cercle 1 est perpendiculaire au plan du cercle 2, et il passe par son centre C2. Une surface toroïdale est donc définie par deux paramètres, les rayons R1 et r2 ou, de façon équivalente, par R1 et R2 = R1 + r2.One of the main faces of the glass according to the invention is delimited by a surface toroidal. Such a surface is generated, as shown in Figure 1, by a circle 1 of radius R1, the center C1 of which describes a circle 2 of center C2 and of radius r2. The plane of circle 1 is perpendicular to the plane of circle 2, and it passes through its center C2. A toroidal surface is therefore defined by two parameters, the radii R1 and r2 or, so equivalent, by R1 and R2 = R1 + r2.

La face bombée de la glace correspond plus précisément à une portion 3 de la surface toroïdale obtenue en coupant cette dernière par un plan perpendiculaire au plan contenant le cercle 2, et dont la distance au centre C2 est comprise entre r2 et R2 = R1 + r2.The curved face of the ice corresponds more precisely to a portion 3 of the surface toroidal obtained by cutting the latter by a plane perpendicular to the plane containing the circle 2, and whose distance to the center C2 is between r2 and R2 = R1 + r2.

A l'état brut, la glace se présente sous la forme d'une plaquette transparente, préférentiellement en spinelle, en corindon, en saphir ou en rubis, de forme allongée, par exemple rectangulaire, et dont les faces principales sont planes et parallèles.In the raw state, the ice is in the form of a transparent plate, preferably in spinel, in corundum, sapphire or ruby, elongated, by rectangular example, and whose main faces are flat and parallel.

Pour donner à la face bombée la forme voulue, celle-ci est usinée par une machine à meuler. De telles machines sont connues en soi, et les aménagements nécessaires pour obtenir une surface toroïdale sont à la portée de l'homme du métier. La machine sera donc décrite sommairement en se référant à la fig. 2.To give the curved face the desired shape, this is machined by a grinding machine. Such machines are known per se, and the arrangements necessary to obtain a toroidal surface are within the reach of those skilled in the art. The machine will therefore be briefly described with reference to the Fig. 2.

La référence 10 désigne un tambour circulaire qui est fixé sur un arbre non représenté de la machine de manière à être entraíné en rotation, dans le sens de la flèche F, autour de son axe de symétrie xx'. Le tambour comporte à sa périphérie des plages planes 11 parallèles à l'axe xx', et sur chaque plage est collée, à égale distance des faces du tambour, une glace 12. Dans le cas présent le grand côté de la glace est orienté perpendiculairement à l'axe xx', mais son orientation pourrait tout aussi bien être parallèle à cet axe.The reference 10 designates a circular drum which is fixed on a shaft not shown of the machine so as to be rotated, in the direction of arrow F, around its axis of symmetry xx '. The drum has at its periphery flat areas 11 parallel to the axis xx ', and on each track is glued, equidistant from the faces of the drum, a ice 12. In this case the long side of the ice is oriented perpendicular to the axis xx ', but its orientation might as well be parallel to this axis.

Dans le prolongement du tambour 10 est disposée une meule 13 sur un chariot non représenté, et elle est entraínée en rotation, dans le sens de la flèche F', autour de son axe yy' par un arbre moteur sur lequel elle est fixée. Le chariot est solidaire du bâti de la machine tout en étant entraíné par celle-ci dans un mouvement de pivotement alternatif, dans le sens de la fléche f, autour d'un axe ZZ' disposé perpendiculairement à l'axe xx' et passant par le milieu du tambour 10. Enfin la meule 13 est montée sur une coulisse, solidaire du chariot, permettant de la déplacer suivant la flèche f' de manière à modifier sa distance à l'axe ZZ', manuellement ou par la machine, et l'amener à toucher la glace 12 en un point de contact 14.In the extension of the drum 10 is disposed a grinding wheel 13 on a carriage not shown, and it is driven in rotation, in the direction of arrow F ', around its axis yy' by a motor shaft on which it is fixed. The cart is integral with the machine frame while being driven by this in an alternative pivoting movement, in the direction of arrow f, around an axis ZZ 'arranged perpendicular to the axis xx 'and passing through the middle of the drum 10. Finally the grinding wheel 13 is mounted on a slide, integral with the carriage, allowing it to be moved according to the arrow f 'so as to modify its distance to the axis ZZ', manually or by machine, and get it to touch the ice 12 at a point of contact 14.

En se référant à la fig. 1, on peut constater que tous les paramètres géométriques nécessaires pour définir une surface toroïdale se retrouvent sur la fig. 2. En effet, le point milieu du tambour 10 se trouvant sur l'axe xx' correspond au centre C2 du cercle 2, et l'axe de pivotement ZZ' du chariot, donc de la meule 13, est situé dans le plan du cercle 2, auquel il est tangent. En outre le déplacement de la meule suivant la flèche f entraíne le déplacement du point de contact 14 suivant un cercle, contenu dans un plan passant par l'axe xx', qui correspond au cercle 1 de centre C1 et de rayon R1.Referring to fig. 1, we can see that all geometric parameters necessary to define a surface toroidal are found in fig. 2. Indeed, the point middle of the drum 10 located on the axis xx 'corresponds to the center C2 of circle 2, and the pivot axis ZZ 'of the carriage, so of the grinding wheel 13, is located in the plane of the circle 2, to which it is tangent. Additionally moving the grinding wheel following the arrow f causes the displacement of the point of contact 14 following a circle, contained in a plane passing through axis xx ', which corresponds to circle 1 with center C1 and radius R1.

Le point de contact 14 décrit donc bien par rapport au tambour 10, lorsqu'il tourne autour de l'axe xx', une surface toroidale.The contact point 14 therefore describes well in relation to the drum 10, when it rotates around the axis xx ', a surface toroidal.

Le rayon du tambour 10 et l'épaisseur de la glace 12 déterminent le rayon R2, et la position de l'axe ZZ' par rapport à C2, le rayon R1. Ces paramètres étant choisis, le tambour 10 et la meule 13 sont mis en rotation, ceci entraínant le mouvement de pivotement du chariot autour de l'axe ZZ', suivant la flèche f, la meule étant éloignée de la glace 12. Ensuite la meule 13 est approchée de l'axe ZZ' suivant le flèche f' pour entrer en contact de la glace 12 et usiner sa surface jusqu'à ce que les valeurs nominales de R1 et de R2 soient atteintes. Toutes ces opérations peuvent être effectuées automatiquement.The radius of the drum 10 and the thickness of the glass 12 determine the radius R2, and the position of the axis ZZ 'by compared to C2, the radius R1. These parameters being chosen, the drum 10 and grinding wheel 13 are rotated, this causing the pivoting movement of the carriage around the axis ZZ ', along arrow f, the grinding wheel being distant from the glass 12. Then the grinding wheel 13 is approached the axis ZZ ' following the arrow f 'to come into contact with the glass 12 and machine its surface until the nominal values of R1 and R2 are reached. All of these operations can be performed automatically.

Un exemple de glace 12 de forme rectangulaire ainsi obtenue est représentée sur la fig. 3. Cette glace est délimitée par une face inférieure plane 20 venant en regard du cadran une fois fixée sur une montre, une face supérieure bombée 21, et quatre faces latérales planes, les faces 22 correspondant aux petits côtés du rectangle, et les faces 23 aux grands côtés. La face inférieure 20 peut avantageusement présenter un évidement 24 pour les aiguilles, obtenu par meulage ou par usinage par ultrasons et préservant un bord plan 25 sur tout le pourtour de la glace. Les lignes 26 et 26' donnent le contour de la face supérieure 21, et donc l'épaisseur de la glace par rapport à la face inférieure 20 lorsque la glace est coupée par des plans parallèles aux faces latérales et passant par son centre, la ligne 27 donne le contour supérieur des petites faces latérales 22, et la ligne 28 celui des grandes faces latérales 23. Enfin la ligne 29 indique la forme, en arc de cercle, qu'aurait le bord supérieur des petites faces latérales 22, pour une même épaisseur de la glace au centre, si la face supérieure avait une forme sphérique, et la ligne 30 la forme du bord supérieur des grandes faces latérales 23. On constate que l'épaisseur des faces latérales de la glace selon l'invention est plus régulière et bien inférieure à celle des glaces bombées connues.An example of ice 12 of rectangular shape thus obtained is shown in fig. 3. This ice is bounded by a flat underside 20 coming opposite the dial one when fixed on a watch, a domed upper face 21, and four flat side faces, the faces 22 corresponding to the short sides of the rectangle, and the sides 23 to the long sides. The lower face 20 may advantageously have a recess 24 for the needles, obtained by grinding or by ultrasonic machining and preserving a flat edge 25 on everything around the ice. Lines 26 and 26 'give the contour of the upper face 21, and therefore the thickness of the glass with respect to the underside 20 when the glass is cut by planes parallel to the lateral faces and passing through its center, line 27 gives the upper outline of small side faces 22, and line 28 that of large lateral faces 23. Finally the line 29 indicates the shape, in arc of circle, that would have the upper edge of the small faces side 22, for the same thickness of the glass in the center, if the upper face had a spherical shape, and the line 30 the shape of the upper edge of the large lateral faces 23. We see that the thickness of the side faces of the glass according to the invention is more regular and much less than that of known domed ice.

Il y a lieu de relever que le meilleur choix pour R1 et R2, dans le cas d'une glace rectangulaire de largeur 11 et de longueur 12, est celui qui satisfait la relation R1/R2 = 11/12. It should be noted that the best choice for R1 and R2, in the case of a rectangular window of width 11 and length 12, is that which satisfies the relationship R1 / R2 = 11/12.

C'est en effet dans ce cas que l'épaisseur au centre de chaque face latérale est en proportion directe de sa longueur.It is indeed in this case that the thickness at the center of each lateral face is in direct proportion to its length.

Il est bien entendu que la glace de montre qui vient d'être décrite peut subir d'autres modifications et se présenter sous d'autres variantes, évidentes pour l'homme du métier, sans sortir du cadre de la présente invention telle que définie par les revendications. En particulier la glace pourrait avoir une forme allongée différente de celle d'un rectangle, comme par exemple une forme ovale, et la face inférieure s'écarter de la forme plane.It is understood that the watch glass which has just been described may undergo other modifications and appear under other variants, obvious to a person skilled in the art, without depart from the scope of the present invention as defined by the revendications. In particular the ice could have a elongated shape different from that of a rectangle, as by example an oval shape, and the underside deviate from the flat shape.

Claims (8)

  1. Watch glass (12), including a convex upper face (21) and a lower face (20), characterized in that it has a generally rectangular shape defined by lateral faces (22, 23), and in that the upper face matches a toroidal-shaped segment defined by a first generator circle (1), of radius R1, rotating about an axis (x-x'), the centre (C1) of the first circle describing a second circle (2) of radius r2, said segment corresponding to a portion (3) of the toroidal surface obtained by cutting the latter through a plane perpendicular to the plane containing the second circle (2) and whose distance to the centre of the second circle (2) is comprised between r2 and R1+r2.
  2. Glass according to claim 1, characterized in that said lateral faces (22, 23) are flat.
  3. Glass according to any of claims 1 and 2, characterized in that the ratio between the length of the large lateral faces (23) and that of the small lateral faces (22) is substantially equal R1/(R1+r2).
  4. Glass according to any of claims 1 to 3, characterized in that said lower face (20) is flat.
  5. Glass according to any of claims 1 to 4, characterized in that said lower face includes a recess (24).
  6. Glass according to any of claims 1 to 5, characterized in that it is made of a hard and optically transparent material such as spinel, corundum, sapphire or ruby.
  7. Method for manufacturing a watch glass according to any of claims 1 to 6, by means of a grinding machine including:
    a frame,
    a drum (10) mounted so as to move in rotation about a first axis (xx'), provided, at its periphery with flat areas (11) parallel to the first axis (xx')
    a grinding wheel (13) arranged in the extension of said drum and driven in rotation about a second axis (yy')
    a carriage carrying the grinding wheel (13) and mounted so as to pivot on said frame about a third axis (ZZ'),
    characterized in that the third axis (ZZ') is perpendicular to the first axis (xx') and at a distance of a value of r2 from the latter, and said glass is arranged on one of said areas, at an equal distant from the faces of said drum (10).
  8. Method according to claim 7, characterized in that said large lateral faces (23) are arranged perpendicularly to the first axis (xx').
EP97938739A 1996-10-04 1997-09-18 Watch crystal and method of fabricating the same Expired - Lifetime EP0948758B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
CH241996 1996-10-04
CH02419/96A CH690873A5 (en) 1996-10-04 1996-10-04 Ice shows.
PCT/CH1997/000352 WO1998015876A1 (en) 1996-10-04 1997-09-18 Watch crystal

Publications (2)

Publication Number Publication Date
EP0948758A1 EP0948758A1 (en) 1999-10-13
EP0948758B1 true EP0948758B1 (en) 2003-12-10

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EP97938739A Expired - Lifetime EP0948758B1 (en) 1996-10-04 1997-09-18 Watch crystal and method of fabricating the same

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EP (1) EP0948758B1 (en)
JP (1) JP3892910B2 (en)
CH (1) CH690873A5 (en)
DE (1) DE69726755T2 (en)
HK (1) HK1019937A1 (en)
WO (1) WO1998015876A1 (en)

Cited By (1)

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Publication number Priority date Publication date Assignee Title
EP2228694A1 (en) 2009-03-12 2010-09-15 Stettler Sapphire AG Method and device for grinding watch glasses

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Publication number Priority date Publication date Assignee Title
EP1645919B1 (en) * 2004-10-11 2007-12-19 Fuji Crystal Manufactory Ltd. Cambered watch crystal
EP2500135A1 (en) * 2011-03-16 2012-09-19 Comadur S.A. System for polishing a cover part for a timepiece
EP2500134A1 (en) * 2011-03-16 2012-09-19 Comadur S.A. Cover part for a timepiece and system for the manufacturing thereof

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DE1498833U (en) * 1940-09-09 1941-03-13
FR2386851A1 (en) * 1977-04-07 1978-11-03 Suchet Edmond PRESENTATION OF TIME INFORMATION BY STATIC OR ELECTRO-OPTICAL INDICATOR SYSTEM THROUGH PRECIOUS, FINE OR DECORATIVE STONE
GB2096789B (en) * 1981-03-03 1985-03-13 Canon Kk Optical mechanical scanning system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2228694A1 (en) 2009-03-12 2010-09-15 Stettler Sapphire AG Method and device for grinding watch glasses
WO2010102909A1 (en) 2009-03-12 2010-09-16 Stettler Sapphire Ag Method and device for grinding watch glasses

Also Published As

Publication number Publication date
JP3892910B2 (en) 2007-03-14
CH690873A5 (en) 2001-02-15
JP2001503139A (en) 2001-03-06
DE69726755D1 (en) 2004-01-22
HK1019937A1 (en) 2000-03-03
WO1998015876A1 (en) 1998-04-16
DE69726755T2 (en) 2004-09-23
EP0948758A1 (en) 1999-10-13

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