To provide a device for storing energy in a spring by a motor, and taking the energy as needed.

A pinion gear 7 mounted to a motor output shaft 8a is meshed with a camed gear 6. A swing plate 9 is attached below the camed gear 6, so as to hold a connection pin 18. A drive plate 10 fixed to a main spindle 5 is mounted below the swing plate 9. A drive plate stopper pin 21, and positioning L/R bushes 25/26 are mounted to the drive plate 10, and a drive plate arc-like groove 10a is installed at a same phase as the connection pin 18. The connection pin 18 is pulled in a direction of a spring post 19 by a rotation spring 31. A motor 8 so constituted is sequentially rotated, so as to take a swing motion of a large torque from the main spindle 5 at high speed.