Spring of a barrel including such a spring

摘要

The spring has a set of coplanar strips (10a, 10b) spirally wound on one another. Inner ends of each strip are secured to an attachment device (12) for being fixed on a barrel arbor. Outer ends of each strip are placed symmetrically with respect to center of spiral and arranged so as to cooperate with a barrel drum. The outer ends of each strip are extended by a torque limiting system i.e. flange, cooperating with interior of a wall of the barrel drum. The torque limiting system, strips and the attachment system are formed from a monolithic piece.