US 12,481,246 B2
Barrel for timepiece
Gerard Vorpe, Le Locle (CH); Laurent Jeanneret, Villers-le-lac (FR); and Pierre Cusin, Villars-Burquin (CH)
Assigned to NIVAROX-FAR S.A., Le Locle (CH)
Filed by Nivarox-FAR S.A., Le Locle (CH)
Filed on Oct. 20, 2022, as Appl. No. 17/970,193.
Claims priority of application No. 21218134.1 (EP), filed on Dec. 29, 2021.
Prior Publication US 2023/0205135 A1, Jun. 29, 2023
Int. Cl. G04B 5/24 (2006.01); G04B 1/16 (2006.01)
CPC G04B 5/24 (2013.01) [G04B 1/16 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A barrel for self-winding timepiece, comprising:
a drum provided with an inner lateral wall, and
a mainspring forming a winding including an outer coil the end of which is friction coupled with said inner lateral wall and free to slip against the inner lateral wall in the event of overtension of the mainspring,
wherein the end of said outer coil comprises an external face having two friction surfaces 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 a central portion between the friction surfaces is not in contact with the inner lateral wall, said central portion forming a reservoir for a lubricant between the two friction surfaces.