A barrel (1) for self-winding timepiece including a drum (11) provided with an inner lateral wall (12) and a mainspring (2) forming a winding including an outer coil (21) the end (22) of which is friction coupled with the inner lateral wall and free to slip against the inner lateral wall in the event of overtension of the mainspring (2). The end of the outer coil includes an external face (23) having two friction surfaces (24, 25) disposed in the top and bottom portion of the outer coil and arranged to be in contact with the inner lateral wall in such a way that the portion between the friction surfaces, referred to as central portion (26), is not in contact with the inner lateral wall, the central portion forming a reservoir (27) for a lubricant between the two friction surfaces.

A timepiece shaft (1), especially a balance shaft (1), comprising a first functional portion (2a; 2b) including at least one part (221a, 221b) of a pivot-shank (22a; 22b) and/or at least one part (211a, 211b) of a pivot (21a, 21b), the first functional portion being made of ceramic and a first outer diameter (D1) of the first functional portion being less than 0.5 mm, or less than 0.4 mm, or less than 0.2 mm, or less than 0.1 mm

According to a movement of the present disclosure, the prevention of the transmission of torque to a governor when excessive torque is generated and the prevention of the wasteful consumption of energy when the excessive torque is not generated are achieved. The movement includes a main spring which generates torque, a balance wheel, a gear train mechanism for transmitting the torque generated by the main spring to the balance wheel, and a spring seat for moving a second wheel, for example, of the gear train mechanism in a direction to reduce the transmission efficiency of the torque between the wheels of the gear train mechanism when the torque generated by the main spring is higher than a predetermined torque (Tmax).

A timepiece mainspring is accommodated inside a barrel, an inner end thereof is fixed to a barrel arbor included in the barrel, and an outer end thereof engages with an inner wall of the barrel. The timepiece mainspring includes a helical portion wound in a Bernoulli curve shape from the inner end in a free state having no applied load.

A timepiece mainspring is accommodated inside a barrel, an inner end thereof is fixed to a barrel arbor included in the barrel, and an outer end thereof engages with an inner wall of the barrel. The timepiece mainspring includes a helical portion wound in a Bernoulli curve shape from the inner end in a free state having no applied load.

This invention teaches a new class of materials that can be used to manufacture hairsprings and/or other components of mechanical watches, and methods for manufacturing these components. The new class of materials is crystalline compounds, including, but not limited to, gallium arsenide, extrinsically doped gallium arsenide, extrinsically doped silicon, gallium nitride, extrinsically doped gallium nitride, gallium phosphide, extrinsically doped gallium phosphide, and quartz. This invention also teaches laminated/coated crystalline compounds. The lamination/coating may be applied by one of the following methods, including but not limited to: plasma enhanced chemical vapor deposition, atomic layer deposition, sputtering, electron beam evaporation, and thermal evaporation. Using crystalline compounds, in particular extrinsically doping the crystalline compounds, affords the possibility to controllably alter the mechanical, electrical, thermal, magnetic, and/or other properties of the watch components. These properties can be further altered by applying single or multiple laminates/coatings of varying thicknesses and/or geometries.

A timepiece sub-assembly including a mobile timepiece element including first and second annular and opposite peripheral surfaces of revolution about a same pivot axis, and a device for guiding pivoting about a theoretical axis of a timepiece mechanism. The first surface is magnetically or electrically charged, and the device includes at least three first surfaces regularly arranged around the theoretical axis, oppositely magnetically or respectively electrically charged to the first surface to repulse it at a first interface. In a watch, the second surface is magnetically or electrically charged, and the device includes at least three second surfaces regularly arranged around the theoretical axis, oppositely magnetically or electrically charged to the second surface to repulse it at a second interface.

A timepiece sub-assembly including a mobile timepiece element including first and second annular and opposite peripheral surfaces of revolution about a same pivot axis, and a device for guiding pivoting about a theoretical axis of a timepiece mechanism. The first surface is magnetically or electrically charged, and the device includes at least three first surfaces regularly arranged around the theoretical axis, oppositely magnetically or respectively electrically charged to the first surface to repulse it at a first interface. In a watch, the second surface is magnetically or electrically charged, and the device includes at least three second surfaces regularly arranged around the theoretical axis, oppositely magnetically or electrically charged to the second surface to repulse it at a second interface.

A rotary wheel set system of a horological movement with a rotary wheel set a first and a second bearing for a first and a second pivot of the arbor of the rotary wheel set, the wheel set including a mass center in a position of its arbor, the first bearing including an endstone including a main body equipped with a conical cavity configured to receive the first pivot of the arbor of the rotary wheel set, the first pivot being capable of cooperating with the cavity of the endstone to rotate in the cavity, at least one contact zone between the first pivot and the cavity being generated, the normals of the contact zone forming a minimum contact angle relating to the plane perpendicular to the arbor of the pivot, the minimum contact angle being less than or equal to 30°, preferably less than or equal to arctan (½)

A rotary wheel set system of a horological movement with a rotary wheel set a first and a second bearing for a first and a second pivot of the arbor of the rotary wheel set, the wheel set including a mass center in a position of its arbor, the first bearing including an endstone including a main body equipped with a conical cavity configured to receive the first pivot of the arbor of the rotary wheel set, the first pivot being capable of cooperating with the cavity of the endstone to rotate in the cavity, at least one contact zone between the first pivot and the cavity being generated, the normals of the contact zone forming a minimum contact angle relating to the plane perpendicular to the arbor of the pivot, the minimum contact angle being less than or equal to 30°, preferably less than or equal to arctan (½)