Spectacles e.g. sun spectacles, temples extending device, has torsion spring made from single piece of wire such that arm presents at rest, closure angle between when it is at rest position and in temple position, after angular extension

摘要

The device has a cylindrical torsion spring (R) made from a single piece of round wire such that an arm (B2) of the spring presents a closure angle of about 45 degrees between when it is at rest position and when it is in temple position, after angular extension. The arm is extended by an operational temple (W). Parallelism is present between another arm (B1) and the arm (B2) by external angular movement of the temple (W).