Clutch device for watch mechanism

Abstract

The invention relates to a clutch device (1) for a watch mechanism, comprising a first transmission member (2) movable in rotation about an axis of rotation and comprising an opening (21) of polygonal section, coaxial with the axis of rotation, and a second transmission member (3) movable in rotation about the axis of rotation and comprising a coupling piston (31) coaxial with the axis of rotation, comprising a main portion (35) of polygonal section complementary to the polygonal section of the opening (21).The first and / or second transmission member is mobile in translation along the axis of rotation between an engaged position of the clutch device (1) in which the main portion (35) of the coupling piston (31) is housed in the opening (21), the first and second transmission members being then rotationally fixed, and a disengaged position of the clutch device (1) in which the main portion (35) is out of the opening (21), the first and second transmission members being then rotationally unfixed.The clutch device (1) is characterized in that the coupling piston (31) comprises edge teeth on a bearing surface facing the opening (21), the apex of each tooth of the edge teeth being in the same radial longitudinal plane as a vertex of the polygonal section of the main portion (35), each gap between two teeth of the edge teeth being substantially in the same radial longitudinal plane as the middle of a side of the polygonal section of the main portion (35), the proximal edge of the wall of the opening (21) of the first transmission member (2) intended to come into contact with the coupling piston (31) during the engagement of the clutch device (1) being structured to cooperate with the edge teeth (39) in order to facilitate the automatic alignment of the coupling piston (31) and the opening (21) during the engagement.