Patent ID: 8181550

Claim:
A rotary actuator incorporating a force relationship comprising: a twistably-deformable structure having a first and a second end plate and a helical spring with a first and a second terminal end secured on the first and the second end plate, respectively, and wherein the first and the second end plate have a first and a second notch, respectively, and wherein the first and the second notch have a first and a second contact zone, respectively; an outlet shaft; a motor assembly having an outlet gear configured to drive the twistably-deformable structure so as to drive the outlet shaft in rotation, wherein the motor assembly, the twistably-deformable structure and the outlet shaft are disposed in succession; a first finger constrained to rotate with the outlet gear and extending longitudinally parallel to a twist axis of the twistably-deformable structure so as to cooperate with the first end plate by passing through the twistably-deformable structure; and a second finger constrained to rotate with the outlet shaft and extending longitudinally parallel to the twist axis so as to cooperate with the second end plate by passing through the twistably-deformable structure, wherein at least one of the first and the second finger is an adjustable finger and includes an adjustment device configured to press the adjustable finger against the first contact zone and the second contact zone.