US Patent 7506608 Hinge mechanism

A hinge mechanism that generates a stress at the start and end points of arbitrary opening and closing range can be constructed by causing one cam set of two cam sets in which a rotating cam and a fixed cam engage only once in 360° rotation to generate a stress at the start point of the rotating range or opening and closing range of the hinge mechanism, and causing the other cam set to generate a stress at the end point of the rotating or opening and closing range. The hinge mechanism of the present invention achieves durability, good feeling, and size and weight reduction.