Tortion springs are helical springs that store mechanical energy to exert a torque or rotary force. Compression springs and extension springs work with pulling and pushing forces, but tortion springs work with twisting forces. After being twisted a porportional force to the applied force is exerted in the opposite direction.
The ends of the spring are attached to other components and rotated around the spring center as the spring pushes back to its origional position.
Tags: Equations for Spring