Patent ID: 8845186
Filing Date: 2014-09-30
Classification: F16F,G04B

Abstract:
1. A spiral spring of a watch movement, comprising: a single collet; a rigid frame provided with at least one portion to receive an attachment organ; and a plurality of coplanar leaves wound into one another, wherein inner ends of each leaf are secured to the single collet, wherein the leaves and the collet are made monolithically, wherein outer ends of each leaf are connected to each other by the rigid frame, wherein said frame, the leaves, and the collet being made monolithically and define a single monolithic piece, and wherein the frame includes hollowed-out zones arranged to lighten the spiral spring in an outer zone thereof, and wherein the frame includes wide zones and at least one slim zone, said slim zone being intended to receive a balance-spring stud to attach the spiral spring to the watch movement, wherein the hollowed-out zones are within the wide zones.