Mechanism for adjusting the angular position of an arm hinged on a support

An angular position arm adjusting mechanism comprising:

• an arm hinged on a support around a hinge shaft of the type including a toothed circular segment attached to the said arm and meshing with one pinion installed so as to rotate on the said support, the arm formed of two elements connected by at least a pivot with axis parallel to a hinge axis and with at least one connecting member with a predetermined strength so that the connection assured by the said connecting member is broken when the pivoting torque of one of the said elements in relation to the other, around the said pivot, exceeds a predetermined threshold, and in that at least one of the said elements includes a main set of teeth in the form of an arc of a circle with its center of curvature located at the hinge shaft and at least another element includes a second set of teeth in the form of an arc of a circle with same center, the pinion being located between the two sets of teeth, the radial distance between the said sets of teeth being determined so that the pinion meshes only with the main set of teeth when the two elements of the arm are securely connected, and that the second set of teeth meshes with the pinion subsequent to relative pivoting of the two said elements when the connection ensured by the connecting member is broken.