Torsion Springs and Wire Forms
The body of torsion springs offer rotational resistance when force is applied at either end. Because the mechanism where the torsion spring is placed, and the spring itself, rotate around the same axis, this forces the mechanism to return to its original position.
Wire forms are designed to have a similar behaviour as torsion springs, either to be used as clips, restrain systems, etc. When they are designed to behave in the same manner as torsion springs, the intent is that they fulfil the same objective of returning the mechanism to its original position, since, as it works with different axes, the use of torsion springs is not possible here.