Lifter mechanism with horizontally extensible jaw-supporting arms

Claim 1

IN A LIFTER OF THE CHARACTER DESCRIBED AND HAVING A PAIR OF JAW-SUPPORTING ARMS WHICH ARE EXTENSIBLE FOR JAW-OPENING MOVEMENTS AND COLLAPSIBLE FOR JAW-CLOSING MOVEMENTS, IN COMBINATION, A LIFTER FRAMEWORK INCLUDING MEANS WHEREBY THE SAME MAY BE OPERATIVELY ENGAGED BY A CRANE LIFTING HOOK OR THE LIKE, SAID FRAMEWORK PROVIDING A PAIR OF ADJACENT PARALLEL LONGITUDINALLY EXTENDING GUIDEWAYS, ONE FOR EACH ARM, EACH ARM BEING SLIDABLY DISPOSED IN A RESPECTIVE GUIDEWAY AND MOVABLE BETWEEN A RETRACTED POSITION WHEREIN A MAJOR PORTION THEREOF IS DISPOSED WITHIN THE LINEAR CONFINES OF THE GUIDEWAY AND AN EXTENDED POSITION WHEREIN A MAJOR PORTION THEREOF IS PROJECTED OUTWARDLY BEYOND THE LINEAR CONFINES OF THE GUIDEWAY, A JAW CARRIED AT THE DISTAL END OF EACH ARM, A DRIVEN TRACTION WHEEL ROTATABLY MOUNTED ON SAID FRAMEWORK ADJACENT ONE END THEREOF, AN IDLER TRACTION WHEEL ROTATABLY MOUNTED ON SAID FRAMEWORK ADJACENT THE OTHER END THEREOF, A FIRST FLEXIBLE CONNECTOR HAVING ITS OPPOSITE ENDS SECURED TO SAID ARMS, RESPECTIVELY, AND TRACTIONALLY ENGAGING SAID DRIVEN TRACTION WHEEL, A SECOND FLEXIBLE CONNECTOR HAVING ITS OPPOSITE ENDS SECURED TO SAID ARMS, RESPECTIVELY, AND TRACTIONALLY ENGAGING SAID IDLER TRACTION WHEEL, AND MEANS FOR ROTATING SAID DRIVEN TRACTION WHEEL SELECTIVELY IN OPPOSITE DIRECTIONS.