Patent ID: 8789672

Claim:
A mechanical transmission device for transmitting a threshold force, the device comprising: a first element and a second element rotatably mounted relative to each other about an axis of rotation, and a transmitter member interposed between the first element and the second element to constrain the two elements to rotate together when a torque is imparted to one of the elements for transmitting the torque to the other one of the elements, up to a threshold torque beyond which the two elements become movable in rotation against an opposing torque equal to the threshold torque, the transmitter member comprising: at least a first friction disk constrained to rotate with the first element, and a second friction disk facing the first disk; and a bearing member that is axially movable to press the disks together and against a bearing turntable of the first element under drive from a presser member; wherein the second disk is directly constrained to rotate with the bearing member, while rotary drive means are interposed between the bearing member and the second element and are arranged to cause the bearing member to move axially against the presser member during relative rotation of the bearing member and the second element, and wherein the bearing member is fabricated as a single part.