| 摘要 |
PURPOSE:To establish an upwardly convex nonlinear characteristic between angle of rotation and torque by fiting a rodlike control member over a coil spring, changing the coil diameter realtive to the member in the axial direction, and providing the other portion with a torsion in advance. CONSTITUTION:With a working end 4 twisted in the winding direction of te coil, only a smaller-diametered portion 6 is twisted, the effective length of the coil spring is equal to the length of the portion 6, and the spring constant increases. When the torque has exceeded that given, in advance, to a larger-diametered portion 5, the portion 5 is twisted together with the portion 6, the coil outside diameter of the portion 5 decreases, so that the outside surface of the portion 5 parts from the internal surface of a control member 7, the effective length of the coil spring is now equal to the whole length thereof, and the spring constant decreases. |
