Double Tursion Spring

The defining feature of double torsion springs, as the name suggests, is that they are comprised of two torsion spring coils which are connected in the centre to form a single spring. The two coils are wound from a single piece of wire in opposite directions, with one wound counter clockwise and the other clockwise.

Although the name implies otherwise, torsion springs are subjected to bending stress rather than torsional stress. They can store and release angular energy or statically hold a mechanism in place by deflecting the legs about the body centerline axis.
This type of spring is normally close wound but can have pitch to reduce friction between the coils. They offer resistance to twist or rotationally applied force.
Depending on the application, torsion springs can be designed to work in a clockwise or counter-clockwise rotation, thus determining the direction of the wind.