Lead screw compensator

Claim 1

IN A COMPUTER CONTROLLED MACHINE HAVING A LEAD SCREW AND A NUT DRIVEN THEREBY AND A FEED BACK UNIT DRIVEN BY THE LEAD SCREW TO FEED POSITIONAL INFORMATION BACK TO THE CONTROL UNIT TO THE MACHINE, SAID UNIT COMPRISING A ROTOR CONNECTED TO THE LEAD SCREW AND A STATOR, MEANS ROTATABLY SUPPORTING SAID STATOR, AND MEANS FOR ADJUSTING SAID STATOR ANGULARLY TO COMPENSATE FOR ERRORS IN THE LEAD SCREW COMPRISING CAM MEANS HAVING A CAM SURFACE AND CONNECTED TO THE LEAD SCREW AND DRIVEN THEREBY, A FOLLOWER BEARING ON THE CAM SURFACE AND CONNECTED TO SAID STATOR TO MOVE THE STATOR ANGULARLY IN CONFORMITY WITH THE CONTOUR OF SAID SAME SURFACE, SAID CAM SURFACE HAVING A LENGTH SUCH THAT THE NUT ON THE LEAD SCREW WILL MAKE A SINGLE TRANSVERSE THEREOF WHILE THE FOLLOWER MAKES A SINGLE TRAVERSE OF THE CAM SURFACE, SAID CAM SURFACE BEING SHAPED TO DEFLECT SUCH FOLLOWER FROM A NORMAL POSITION IN CONFORMITY WITH THE LEAD SCREW ERROR AT THE POINT THEREOF CORRESPONDING TO THE POINT ON THE CAM SURFACE ENGAGED BY THE FOLLOWER, SAID CAM MEANS COMPRISING A CYLINDRICAL MEMBER HAVING A SPIRAL RIB THEREOF FORMING THE SAID CAM SURFACE, SAID FOLLOWER COMPRISING A GROOVED ROLLER ENGAGING SAID RIB AND SUPPORTED TO FOLLOW THE RIB AS THE MEMBER ROTATES, AND MEANS FOR EFFECTING RELATIVE ADJUSTMENT BETWEEN SAID CAM MEANS AND SAID FOLLOWER IN CONFORMITY WITH THE TEMPERATURE OF THE LEAD SCREW SO AS TO EFFECT A STRAIGHT LINE ADJUSTMENT OF THE ANGULAR POSITION OF SAID STATOR AS THE FOLLOWER MOVES ALONG SAID CAM MEANS.