Electro-mechanical drive for torsion winders and the like

Abstract

An electro-mechanical drive for use between mechanically independent master and slave rotary elements, as for example the cam shaft and spring winding spindle of a spring winding machine of the type commonly known as a torsion spring winder. A harmonically cut cam on the cam shaft operates a follower which in turn drives adjustably interconnected first and second slides respectively driving a rack and an associated pinion and an oscillable lever. The lever in turn imparts axial movements to the winding spindle as may be required for pitching torsion springs wound thereon. The pinion operated by the rack in turn drives a direct current tachometer generator which provides a variable voltage signal having a cyclically repetitive wave form with sloped leading and trailing edges and, more particularly, a voltage at least approximately in the form of a sine wave. The sine wave is rectified to provide for a half wave form voltage signal to a servo motor and controller in turn connected in driving relationship with the slave rotary element or winding machine spindle. The spindle is thus operated to wind springs thereon and the relative angular velocity of master and slave, or cam shaft and spindle, is controlled by a manually adjustable potentiometer which varies the amplitude of the half wave signal to the servo motor and controller. A desired number of turns of the spindle is thus provided for each cam shaft revolution and the desired characteristics of the spring are obtained.