Abstract: The invention concerns a screw-on crown for a timepiece, including a head, a central portion and a lateral skirt, said head including an end face bearing a design, characterized in that the end face includes a substrate onto one face of which said design is applied, in that said substrate is mounted so as to move in rotation in said head and in that the crown further includes braking means arranged for holding said substrate in different angular orientations with respect to the head about the rotational axis of the crown.

Abstract: The invention concerns a method for assembling a screwed crown on a watch case, characterized in that it includes the following steps: providing a crown with an inner threading the position of which is set with respect to the logo arranged on the front face of the crown; providing an intermediate tube including two threaded sections; mounting said intermediate tube in a smooth through hole passing through the case and wedging it on an assembling jig to arrange the thread start of the tube intended to accommodate the internal screw thread of the crown in an angular position such that when the crown is screwed as far as possible onto the tube said logo or said mark is located in a determined position; providing a nut and immobilizing the tube in said angular position.

Abstract: The invention concerns a method for assembling a screwed crown on a watch case, characterized in that it includes the following steps:

Abstract: The invention concerns a method for assembling a screwed crown on a watch case, characterized in that it includes the following steps:

Abstract: The invention concerns a method for welding hinge pins onto links each formed of one or more elements, the links being connected to each other by means of said hinge pins arranged in passages provided for this purpose in the links, each pin being fixed onto one of the links and hinged onto the next link, characterised in that the connection of the pin to the link is made via an arc welding operation with the aid of an electrode in an inert atmosphere without using a solder.

Abstract: An annular packing (30) has a cross-section in the form of a dumbbell including two enlargements (31, 32) connected by a neck (33). In a preferred embodiment the enlargements exhibit a polygonal cross-section. The packing advantageously replaces an O-ring seal in which the interior diameter of the ring is large relative to the diameter of the cross-section of the ring. The packing is arranged between two parts driven at different speeds, in precision mechanisms or in horology.

Abstract: An annular packing (30) has a cross-section in the form of a dumbbell including two enlargements (31, 32) connected by a neck (33). In a preferred embodiment the enlargements exhibit a polygonal cross-section. The packing advantageously replaces an O-ring seal in which the interior diameter of the ring is large relative to the diameter of the cross-section of the ring. The packing is arranged between two parts driven at different speeds, in precision mechanisms or in horology.