Clutch means for multiple turn variable resistor

Claim 1

A VARIABLE RESISTOR COMPRISING: A HOUSING; A BASE OF NONCONDUCTIVE MATERIAL SUPPORTED BY THE HOUSING; A RESISTIVE PATH AND A CONDUCTIVE PATH SUPPORTED BY THE BASE; A LEADSCREW ROTATABLY MOUNTED IN THE HOUSING AND EQUIPPED WITH A SCREWTHREAD; A BRIDGING CONTACT ELECTRICALLY CONNECTING THE RESISTIVE PATH TO THE CONDUCTIVE PATH; AND CONTACT DRIVING MEANS FO CAUSING THE CONTACT TO MOVE ALONG THE RESISTIVE PATH COMPRISING: A CONTACT SUPPORTING MEMBER ROTATABLY MOUNTED IN THE HOUSING AND PROVIDED WITH TEETH AND WITH A TOOTHLESS SECTION ON ITS PERIPHERY, A U-SHAPED SLOT PROVIDED IN ONE SIDE OF THE TOOTHLESS SECTION, THE LEGS OF THE SLOT BEING WIDER THAN THE BASE OF THE SLOT, SAID TEETH BEING ARRANGED TO ENGAGE THE SCREWTHREAD ON THE LEADSCREW SO THAT ROTATION OF THE LEADSCREW WILL ROTATE THE CONTACT SUPPORTING MEMBER; RESILIENT MEANS DISPOSED IN SAID U-SHAPED SLOT OF THE TOOTHLESS SECTION, SAID RESILIENT MEANS COMPRISING A USHAPED SPRING HAVING TWO LEGS AND A BIGHT SECTION WITH THE LEGS EXTENDING OUTWARDLY FROM THE MEMBER AND IN POSITION TO ENGAGE THE THREAD ON THE LEADSCREW AS THE MEMBER IS ROTATED; STOP MEANS ARRANGED TO LIMIT THE ROTATION OF THE MEMBER IN EITHER DIRECTION WHEN ONE OF THE LEGS OF THE U-SHAPED SPRING ENGAGES THE THREAD OF THE LEADSCREW; AND THE PORTION INTERMEDIATE THE LEGS OF THE U-SHAPED SLOT FORMING A STOP MEMBER FOR LIMITING FLEXURE OF THE LEGS OF THE SPRING TOWARD EACH OTHER FROM THE UNFLEXED POSITION.