BARREL SPRING COMPRISING ENERGY ACCUMULATION CURVES

摘要

#CMT# #/CMT# The barrel (21) has a case (23) receiving an arbor (25) and a spiral-shaped spring (27) that is mounted between an internal wall of the case and an external wall of the arbor. An incrementing device (22) for incrementing torque of the spring comprises additional energy accumulating curvatures (24) formed on the spring, where the curvatures comprise rectangular sections forming alternative parts (26) with respect to a spiral-shaped path on a portion of coils of the spring such that the torque of the barrel is customized according to winding tension of the spring. #CMT# : #/CMT# The spring and the additional energy accumulating curvatures are made of silicon, metal or metal alloys. #CMT#USE : #/CMT# Horology barrel for use as a mechanical energy source in a clock movement of a timepiece (claimed). #CMT#ADVANTAGE : #/CMT# The curvatures comprise the rectangular sections forming the alternative parts with respect to the spiral-shaped path on the portion of the coils of the spring such that the torque of the barrel is customized according to winding tension of the spring, thus permitting the barrel to provide constant torque that is less dependent on winding degree of the spring, and preventing variation in amplitude of oscillation of a balance-wheel of the clock movement, and hence improving precision and isochronism of the timepiece. The barrel is fabricated in an inexpensive manner. The asymmetric spring of the barrel is small in size. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The drawing shows a top view of a torque incrementing device. 21 : Barrel 22 : Incrementing device 23 : Case 24 : Additional energy accumulating curvatures 25 : Arbor 26 : Alternative parts 27 : Spiral-shaped spring.