A sub-assembly of external parts including, coaxially with a first component and a second component compressing together a sealing and friction joint, and interposed therebetween, a bolt securing them together by axially blocking the first component, and a lower surface of which lies, in the assembled position, in the vicinity of an upper surface of the second component, which bolt includes a lower relief protruding axially from this lower surface towards the second component, arranged to either complementarily cooperate with an oblong groove which is partially of revolution that the upper surface includes, and interrupted by a stopper limiting the angular travel between the second component and the bolt within a turn, or else to constitute an angular stopper to an upper relief protruding from the upper surface of the second component and extending axially towards the bolt.

A case middle/horn connection device for a watch, a method for attaching an attachment piece including at least one horn to a case middle and a case middle/horn assembly. The connection device includes an attachment piece including at least one horn having a first connector and a case middle having a second connector, the first connector being configured to cooperate with the second connector to attach the attachment piece to the case middle. The first connector includes a tongue with a recess. The second connector includes a groove with an undercut portion. The undercut portion is configured to lodge inside the recess of the tongue; and the case middle and the attachment are made integral when the undercut portion of the second connector is lodged in the recess of the tongue of the first connector.

A case including a case body, and an exterior member which is arranged on an outer periphery of the case body in a manner to be deformable in a circumferential direction and which is provided with a separation section for separating at least a part of the case body in the circumferential direction.

A timepiece component is formed of an austenitic-ferritic stainless steel including a base portion formed of a ferrite phase, a surface layer formed of an austenitic phase, and a mixed layer formed between the base portion and the surface layer and obtained by mixing the ferrite phase and the austenitic phase. A recessed portion is formed in the surface layer and a distance from a front surface of the surface layer to a bottom surface of the recessed portion is shorter than a distance from the front surface to the mixed layer.

A modular watch (1) including at least a middle (10), a back (11), a display module (12) having a dial, time display means, a crystal and first magnetic gear means, a horological module (13) including a horological movement with second magnetic gear means arranged to cooperate with the magnetic gear means of the display module (12), and first and second bracelet strands integral with the middle (10) at a pair of horns (20, 30). The display module (12) and the horological module (13) are mounted one on top of the other, said display module (12) being mounted such that it is fixed against the middle (10), and the horological module (13) being mounted such that it can rotate between the back (11) and the display module (12) in order to set the time.

A professionally customizable timepiece includes a primary casing including a movement and configured to operate independently as a timepiece, and a secondary casing having an interior space for receiving the primary casing and further design elements. The secondary casing completely encloses the interior space and can be opened without tool for placement of the primary casing and/or design elements into the interior space or to remove them from there. The secondary casing includes a sight glass and is configured to secure the primary casing at a selectable position in the interior space.

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.

The assembly includes a watch, a watchband, a tracking device and a flexible retaining part formed to engage the watchband and to retain the watch and the tracking device. The part has a cylindrical shape wall with an open top edge spaced from an inwardly extending collar to define a recess to receive the tracking device. Frist and second arcuate wall extensions are connected by a member and define aligned openings through which the tracking device can be inserted into the retaining part, and which are adapted to receive the watchband. When the watch is situated in the top of the part, the tracking device is situated in the collar in the interior surface of the retaining part, and the watchband is inserted through the align openings, the tracking device is securely retained between the watchband and the watch. The watchband may be a slap watchband.

A watch includes a case, and a solar cell disposed inside the case and including a substrate made of resin and having a surface, a power generating unit having, at the surface, a first electrode, a first semiconductor layer, and a second electrode that are stacked in order, a first antenna including a third electrode that is provided at the surface and that is disposed at a position not to overlap the power generating unit in a plan view viewed in a direction orthogonal to the surface, and a protective layer disposed covering the power generating unit and the first antenna.

A timepiece including a device for opening a cover including a fixed pendant mounted inside a middle part and a movable pendant for sliding within the fixed pendant towards the center of the case, the movable pendant having a guide element for moving along an axial guide groove, then in a circumferential guide groove into which the axial guide groove opens out and which is delimited by a boundary, such that, when the movable pendant is pushed, this movable pendant can be firstly displaced axially, then pivoted by an angle defined by the place at which the guide element abuts against the boundary, the movable pendant having a helical groove which comes into contact with at least one pin arranged with a clearance between the movable pendant and the locking spring and which is axially displaced towards the locking spring when the movable pendant is pushed, then pivoted, such that the pin presses against the locking spring and releases the cover.