Torsion spring and adjustable mounting for a chair using such a spring

Abstract From the Canadian patent

Straight type torsion spring being clamped together at two ends, which ends being rotatable in relation to each other against the torsion spring force the torsion spring comprising at least four identical torsion rods abutting laterally along their entire extension, thereby utilizing the relatively large twisting angle of the small dimension torsion rods combined with the total torsion force of the torsion spring rods each of, which independently being twisted helically when activating the spring. Adjustable mounting for a chair preferably an, office chair, comprising the torsion spring of the above defined type, a seat frame, a back frame and a mounting bracket, a tilting lever being …