BARREL FOR SPIRAL SPRING

Japanese Patent JP2015179014

A

PROBLEM TO BE SOLVED: To provide a barrel capable of improving the utilization efficiency of the volumetric capacity for storing energy while reducing variation in the torque generated in the process when a spiral spring is released.SOLUTION: A spiral spring is constituted of a first spiral spring 1 and a second spiral spring 2 each of which has height dimension varying in a longitudinal direction, which are used being wound and overlapped with each other. The two spiral springs may be disposed so that the height of the overlapped spiral springs is constant. The position of the overlapping part of the two spiral springs in height direction of the spiral spring varies in order in a longitudinal direction. The barrel is arranged so that the inner/outer overlapping parts are prevented from overlapping or interfering with each other while preventing useless space from being generated in the spiral springs when the spiral springs are wound to thereby ensure the utilization efficiency of the space in the barrel 5. The width w in the overlapping part 3 gets smaller from the inner end toward the outer end to reduce the rigidity of the spiral spring toward the outer end. With this, uniform torque is obtained as time passes.

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ARAKAWA KOHEI

JP2014056433A

October 08, 2015

March 19, 2014

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CITIZEN HOLDINGS CO LTD

G04B1/12; F16F1/10; F16F3/04

Akira Miyajima

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