Counterbalancing torsion spring mechanism for devices which move up and down and method of setting the torsion springs thereof

Abstract From the Canadian patent

Counterbalancing mechanism for a garage door or other device in which a torsion spring end member is fastened to a second member to which it is connected during normal operation of the counterbalance by cooperating interfitting elements on the members which allow longitudinal movement of the end of the spring during a spring adjusting operation. The counterbalance hardware includes a self-locking winding mechanism for winding or unwinding one or more torsion springs which operates to fix one end of the spring connected thereto against movement during normal operation of the counterbalance. The structure connecting the ends of each torsion spring into the hardware is such that each end of …