Patent ID: 7967385

Claim:
A hinge mechanism comprising: first and second frames mounted rotatably in relation to each other about an axis of rotation, a geared adjustment device connecting the first and second frames to each other, making it possible to adjust a relative angular position of said first and second frames, said adjustment device comprising: at least one first set of gear teeth integral with the second frame, and forming at least one arc of a circle centered on the axis of rotation, at least one first toothed component capable of engaging with said first set of gear teeth and mobile in relation to said first frame, between a locking position in which said first toothed component cooperates with the first set of gear teeth of the second frame in order to immobilize the first and second frames in relation to each other, and a retracted position in which said first toothed component does not interfere with the gear teeth of the second frame, and an actuation device capable of controlling the adjustment device, characterized in that the second frame comprises moreover at least one second set of gear teeth forming at least one arc of a circle centered on the axis of rotation and capable of interfering with the first frame, when the torque applied between the first and second frames exceeds a predetermined threshold in which the second set of gear teeth comprises several arc-shaped sections angularly separated by smooth arc-shaped bearing surfaces, said bearing surfaces resting slidably on a cylindrical bearing of the first frame and being capable of preventing the second set of gear teeth from interfering with the first frame, as long as the torque applied between the first and second frames is below said predetermined threshold.