Patent ID: 8693822
Filing Date: 2014-04-08
Classification: G02B

Abstract:
1. A single channel limited rotation rotary joint comprising: a rotor; a stator; one or more bearings; one or more optical fiber(s); a fiber spool; a shaft; and a wound spring; wherein said optical fiber(s) are mechanically attached to said rotor and said stator and said optical fiber(s) are attached to and wound around said fiber spool such that when said fiber spool is rotated in one direction said optical fiber(s) are released to said stator side, said rotor or both said stator and said rotor sides and when said fiber spool is rotated in the other direction said optical fiber(s) are re-wound onto said fiber spool from the location to which it was previously dispensed; wherein said fiber spool is mechanically attached to said wound spring which is also attached to said shaft and said shaft is either free floating within the rotary joint, mechanically attached to said stator or is mechanically attached to said rotor; wherein said rotor is rotated it twists said optical fiber(s) which creates tension applying a tangential force component onto said fiber spool causing said fiber spool to rotate relative to said shaft releasing more said optical fiber and the relative rotation of said fiber spool to said shaft moves said wound spring out of its equilibrium position balancing the tangential force applied onto said fiber spool by said twisted optical fiber; and rotating said rotor in the opposite direction untwists said optical fiber(s) reducing the tangential force on said fiber spool allowing said wound spring to move back towards its equilibrium position causing said fiber spool to rotate in the opposite direction relative to said shaft resulting in said optical fiber(s) being re-wound onto said fiber spool.