Abstract: The water-resistant watch case includes at least one crystal mounted on an upper side of a middle, a fastening gasket being disposed between an upper annular inner wall of the middle and an upper annular outer wall of the crystal. The crystal includes an annular peripheral surface below the upper annular outer wall inclined at a defined angle smaller than 90° in relation to an axis perpendicular to a plane of the watch case to come into direct contact against an annular inner surface of the middle inclined at an angle similar to the inclination of the annular peripheral surface and below the upper annular inner wall of the middle. The annular peripheral surface and/or the annular inner surface of the middle comprise a domed contact portion for a contact on an annular contact line between the two surfaces.

Abstract: A transparent substrate made of a transparent material resistant to temperatures higher than 500° C., such as sapphire, includes recesses in at least one of its faces and/or a groove machined into its thickness, that are covered with opaque, translucent or transparent enamel depositions that may or may not be colored, depending upon the pigments used in the enamel composition.

Abstract: A system of polishing a concave surface of an external piece for a timepiece, including a securing device including a support that carries the piece, and a grinding device including an abrasive mechanism rotatably mounted along a first axis and configured to polish the piece along a first curvature. The securing device further includes a moving mechanism of the support so that the support imparts a back-and-forth motion along a second axis and a contact surface of the abrasive mechanism is curved to polish the piece along a second curvature in addition to the first curvature. The system can be applied to the field of crystals for a timepiece.

Abstract: An external piece for a time piece and a method of manufacturing the same, including a top surface and a bottom surface. At least one of the faces includes a longitudinal curvature and a transverse curvature that are different.

Abstract: A transparent substrate (10) made of a transparent material resistant to temperatures higher than 500° C., such as sapphire, includes recesses (13, 14) in at least one of its faces (11, 12) and/or a groove (15) machined into its thickness, that are covered with opaque, translucent or transparent enamel depositions (23 to 30) that may or may not be coloured, depending upon the pigments used in the enamel composition.

Abstract: A transparent substrate (10) made of a transparent material resistant to temperatures higher than 500° C., such as sapphire, includes recesses (13, 14) in at least one of its faces (11, 12) and/or a groove (15) machined into its thickness, that are covered with opaque, translucent or transparent enamel depositions (23 to 30) that may or may not be colored, depending upon the pigments used in the enamel composition. The invention is applicable to a dial of a timepiece.

Abstract: A system of polishing a concave surface of an external piece for a timepiece, including a securing device including a support that carries the piece, and a grinding device including an abrasive mechanism rotatably mounted along a first axis and configured to polish the piece along a first curvature. The securing device further includes a moving mechanism of the support so that the support imparts a back-and-forth motion along a second axis and a contact surface of the abrasive mechanism is curved to polish the piece along a second curvature in addition to the first curvature. The system can be applied to the field of crystals for a timepiece.

Abstract: An external piece for a time piece and a method of manufacturing the same, including a top surface and a bottom surface. At least one of the faces includes a longitudinal curvature and a transverse curvature that are different.

Abstract: The case includes a middle part (3) and a back cover (5) delimiting a compartment (7) closed by a glass (10), made of a transparent material resistant to temperatures above 500° C., said glass being bonded or welded at joint zones (15) at least partially covering the shoulder (4) of the middle part (3). It is characterized in that the inner face (11) of the glass (10) includes an enamel deposition (20) formed on the zones of the joints (15) with the shoulder (4) of the middle part (3), either in a hollow (14), or on the surface of said inner face (11).

Abstract: The crystal (10), in the inner surface of which contact zones (17) are structured, includes close to its edge a hollow (14) machined in one of its faces (11, 12) or a groove (25) machined in its thickness and provided with an enamel deposition (20) for concealing said contact zones (17) after bonding.

Abstract: A transparent substrate (10) made of a transparent material resistant to temperatures higher than 500° C., such as sapphire, includes recesses (13, 14) in at least one of its faces (11, 12) and/or a groove (15) machined into its thickness, that are covered with opaque, translucent or transparent enamel depositions (23 to 30) that may or may not be coloured, depending upon the pigments used in the enamel composition.

Abstract: The case includes a middle part (3) and a back cover (5) delimiting a compartment (7) closed by a glass (10), made of a transparent material resistant to temperatures above 500° C., said glass being bonded or welded at joint zones (15) at least partially covering the shoulder (4) of the middle part (3). It is characterized in that the inner face (11) of the glass (10) includes an enamel deposition (20) formed on the zones of the joints (15) with the shoulder (4) of the middle part (3), either in a hollow (14), or on the surface of said inner face (11).

Abstract: The crystal (10), in the inner surface of which contact zones (17) are structured, includes close to its edge a hollow (14) machined in one of its faces (11, 12) or a groove (25) machined in its thickness and provided with an enamel deposition (20) for concealing said contact zones (17) after bonding.