Twisted cord actuator

Abstract

This invention relates particularly to a drive mechanism for converting rotary to unidirectional linear movement for use in actuation of hinged members of robotic, prosthetic, and other like devices. The twisted cord actuator includes a motor with an axial shaft to which, by a coupling, the single free end of two or more cords are attached. The opposing ends of the cords are attached to the moveable member. As the shaft rotates the cords are twisted around each other in helical fashion. Thus their combined length is shortened. In this invention the rotating device represents the muscle and the twisting of the cords, the tendons. The twisting pair of cords may then be threaded through a sheath to act as a pull cable for use as a tendon for an artifical finger or robotic arm. The values of this invention are low cost, ease of use and variability of design. In most applications the present invention may be matched to the load by the careful selection of the motor, cord diameter, and cord length without the use of a gear reducer. This combination creates a low inertia resilient actuator.

Dependencies are inferred from the claim text.