Automatic backlash eliminator

Claim 1

IN A MECHANISM FOR ELIMINATING BACKLASH IN A DRIVE ASSEMBLY WHICH IS CONNECTED TO EFFECT RELATIVE MOVEMENT BETWEEN TWO MEMBERS OF A MACHINE; AN ABUTMENT FIXED TO THE FIRST OF THE MACHINE MEMBERS, A SCREW ROTATABLY SUPPORTED BY THE SECOND MACHINE MEMBER, MEANS OPERATIVELY CONNECTED TO ROTATE SAID SCREW FOR EFFECTING RELATIVE MOVEMENT BETWEEN SAID MACHINE MEMBERS, A PAIR OF NUT ELEMENTS IN THREADED ENGAGEMENT WITH SAID SCREW, MEANS INTERCONNECTING SAID NUT ELEMENTS FOR SIMULTANEOUS ROTATION IN OPPOSITE DIRECTIONS RELATIVE TO SAID SCREW TO EFFECT THEIR SIMULTANEOUS AXIAL MOVEMENT TOWARD AND AWAY FROM SAID ABUTMENT, A PAIR OF THRUST BEARINGS EACH OF WHICH IS SUPPORTED FOR AXIAL MOVEMENT WITH ONE OF SAID NUT ELEMENTS IN POSITION TO BE MOVED INTO TIGHT ENGAGEMENT WITH SAID ABUTMENT TO PLACE THE PORTION OF THE SCREW BETWEEN SAID NUT ELEMENTS IN TENSION FOR ELIMINATING THE BACKLASH BETWEEN THE THREADS OF SAID SCREW AND SAID NUT ELEMENTS, AND CLUTCH MEANS CONNECTING SAID THRUST BEARINGS FOR ROTATION WITH THEIR ASSOCIATED NUT ELEMENTS WHEN THE LATTER ARE ROTATED IN DIRECTIONS TO EFFECT THEIR MOVEMENT TOWARD SAID ABUTMENT, SAID CLUTCH MEANS OPERATING TO RELEASE SAID NUT ELEMENTS FOR ROTATION INDEPENDENT OF SAID THRUST BEARINGS WHEN SAID NUT ELEMENTS ARE ROTATED IN DIRECTIONS TO EFFECT THEIR MOVEMENT AWAY FROM SAID ABUTMENT TO THEREBY FACILITATE THE RELEASE OF SAID THRUST BEARINGS FROM TIGHT ENGAGEMENT WITH SAID ABUTMENT.