Angular registration assembly and driving apparatus therefor

Claim 1

In a system for positioning a movable object in a preselected translational and rotary orientation with respect to first and second coordinate axes, a rotary drive system comprising: means responsive to the position of the movable object for producing an off-register signal in response to and representative of the angular offset between the object position and the preselected rotary orientation; a first driving means responsive to said off-register signal generating means; a rotatable shaft mechanically coupled to said movable object to rotate the movable object into the preselected rotary orientation; a driven gear mounted for free rotation on said shaft and mechanically coupled to said first driving means to rotate said shaft in response to actuation of said first driving means; a friction member nonrotatively mounted on said shaft having a friction surface disposed toward said driven gear; means for urging said driven gear against said friction surface to create a frictional locking force therebetween greater than the loading torque exerted on said shaft; and, a second driving means for rotating said shaft with a torque greater than the friction locking torque and said loading torque, whereby angular orientation may be accomplished alternately by actuating said second driving means or automatically by coupling said signal generating means and said first driviNg means.