Bi-directional spring clutch for reducing worm gear drive

Claim 1

A bi-directional spring clutch apparatus, comprising: an output shaft rotatably mounted in a housing and adapted at one end for coupling to an external device to which said output shaft may impart rotational force; a secondary drive member rotatably mounted coaxially about said output shaft intermediate the ends thereof and having a pair of coaxial extensions, one on each side, which rotate coaxially about said output shaft and which are rotatably fixed relative to said secondary drive member; a primary drive member rotatably mounted in said housing so that it is rotationally coupled to said secondary drive member and adapted at one end for coupling to an external power device for imparting rotational force to said primary drive member; a pair of torque transfer bushings mounted coaxially about said output shaft and rotatably fixed thereto, one torque transfer bushing being located adjacent one of said coaxial extensions and the other torque transfer bushing being located adjacent to the other coaxial extension and dimensioned to have the same outside diameter as said coaxial extensions; a pair of wound springs, each of the same hand of winding, one of which is stretched over one torque transfer bushing and one coaxial extension located adjacent thereto, the other stretched over the other torque transfer bushing and other coaxial extension located adjacent thereto, and each of which is bent radially outward at both ends thereof to form tangs; a pair of cylindrical control sleeves, one of which is rotatably mounted coaxially about one of said wound springs, the other is rotatably mounted coaxially about the other wound spring, each control sleeve including a pair of notches through which said tangs of the corresponding wound springs projects; and stop means for controlling the rotation of said control sleeves.