Patent ID: 8460222

Claim:
Rotation mechanism for a forearm which includes a moving stay ( 2 ) designed to support a wrist, where the moving stay ( 2 ) includes at least one guide track in the form of an arc of a circle, a fixed stay ( 4 ) designed to support the rear end of a forearm, rods ( 12 ) that are rigid lengthwise which link the moving stay ( 2 ) and the fixed stay ( 4 ) and which allow the moving stay ( 2 ) to rotate relative to the fixed stay ( 4 ) around a longitudinal axis (Z) by articulated links which can rotate ( 14 , 32 ), and a strut ( 6 , 6 ′) rigidly linked at one of its ends to the fixed stay ( 4 ), and linked at its other end to a roller-bearing, whose rollers ( 8 ) are in rolling contact with at least one guide track of the moving stay ( 2 ), where the rollers ( 8 ) cause the moving stay ( 2 ) to pivot around a longitudinal axis (Z), where the direction of said longitudinal axis (Z) passes through a centre of the arc of the circle of the guide track and through a centre of a circle defined by ends of rods linked to the fixed stay.