Abstract: Provided is a device for fastening a back on a middle portion of a watch. The back includes a cover arranged to form a bearing surface with the middle portion and a body arranged to rest in the middle portion. The device includes an indexing ring disposed between the back and the middle portion, and the ring includes at least one lower catch arranged to cooperate with the back and ensure the indexing with the back and an upper catch are arranged to cooperate with the middle portion and ensure the indexing of the back and ring assembly in relation to the middle portion, and the upper catch has a height greater than that of the lower catch, or vice versa.

Abstract: A watch case (10) including a back (30) driven into a middle (20) by a joint (40), and including a body (31) from which radially extends a lip (32), the body (31) including an axial annular shoulder (310) and the lip (32) including a radial annular shoulder (320). The middle (20) has an axial opening (21), an axial annular shoulder (200), and a radial annular shoulder (201) resting against the radial annular shoulder of the lip, the joint being interposed between the axial annular shoulders. The axial annular shoulders have peripheral profiles of complementary shapes, substantially circular, including one and the other, a first circular-arc-shaped portion having a first radius (R1, R2), and a second circular-arc-shaped portion to which is connected the first portion, having a second radius (r1, r2) the value of which is lower than that of the first radius (R1, R2).

Abstract: A device is for fastening a back on a middle of a watch. The back includes a cover arranged to form a bearing surface with the middle and a body arranged to rest in the middle. The device includes a ring disposed between the back and the middle, the ring being arranged to ensure the water resistance and indexing of the back. The ring includes an upper part ensuring the water resistance and a median part including positioning to ensure precise placement of the back.

Abstract: Provided is a device for fastening a back on a middle portion of a watch. The back includes a cover arranged to form a bearing surface with the middle portion and a body arranged to rest in the middle portion. The device includes an indexing ring disposed between the back and the middle portion, and the ring includes at least one lower catch arranged to cooperate with the back and ensure the indexing with the back and an upper catch are arranged to cooperate with the middle portion and ensure the indexing of the back and ring assembly in relation to the middle portion, and the upper catch has a height greater than that of the lower catch, or vice versa.

Abstract: A water-resistant closing device for a watch case, the device including an annular gasket (1) arranged to be placed between a middle (2) and a back (3), a bezel or a crystal (4), or a bezel and a crystal, or a back and a crystal. The gasket (1) has on its middle portion a bulge (10) protruding on its outer lateral face (11), the bulge being arranged to be engaged against the middle (3) and compressed following the installation of the back or of the crystal on the middle, the bulge being delimited by an upper (12) and lower material countersink (13) on either side of the bulge (10) in the non-compressed state of the gasket (1) to facilitate its installation and its deformation.

Abstract: A watch case (10) including a back (30) driven into a middle (20) by a joint (40), and including a body (31) from which radially extends a lip (32), the body (31) including an axial annular shoulder (310) and the lip (32) including a radial annular shoulder (320). The middle (20) has an axial opening (21), an axial annular shoulder (200), and a radial annular shoulder (201) resting against the radial annular shoulder of the lip, the joint being interposed between the axial annular shoulders. The axial annular shoulders have peripheral profiles of complementary shapes, substantially circular, including one and the other, a first circular-arc-shaped portion having a first radius (R1, R2), and a second circular-arc-shaped portion to which is connected the first portion, having a second radius (r1, r2) the value of which is lower than that of the first radius (R1, R2).

Abstract: A device is for fastening a back on a middle of a watch. The back includes a cover arranged to form a bearing surface with the middle and a body arranged to rest in the middle. The device includes a ring disposed between the back and the middle, the ring being arranged to ensure the water resistance and indexing of the back. The ring includes an upper part ensuring the water resistance and a median part including positioning to ensure precise placement of the back.