Back-hitch gaintry

Claim 1

A CRANE COMPRISING A SUPPORTING FRAME STRUCTURE, AN OPERATING CAB IN SAID SUPPORTING FRAME STRUCTURE, A BOOM PIVOTALLY SECURED AT ONE END OF SAID FRAME STRUCTURE, A BACK-HITCH GANTRY AT THE OPPOSITE END OF SAID FRAME STRUCTURE, SAID BACK-HITCH GANTRY COMPRISING A HINGE PIN, A RIGID FRAME PIVOTALLY INTERCONNECTING SAID HINGE PIN AND SAID FRAME STRUCTURE, A PAIR OF TELESCOPING STRUT MEMBERS CONNECTED TO SAID HINGE PIN AND SAID FRAME STRUCTURE, EACH OF SAID PAIR OF TELESCOPING STRUT MEMBERS COMPRISING UPPER AND LOWER MEMBERS ADAPTED LONGITUDINALLY TO TELESCOPE ONE WITHIN THE OTHER, MEANS TO MAINTAIN SAID MEMBERS PARALLEL TO EACH OTHER AT ALL POSITIONS OF TELESCOPIC ADJUSTMENT; AND MEANS TO LOCK SAID MEMBERS IN EXTENDED AND RETRACTED POSITION THUS TO LOCK SAID HINGE PIN IN A RAISED AND LOWERED POSITION COMPRISING LOCKING PINS FOR EACH OF SAID PAIR OF TELESCOPING STRUT MEMBERS, AN OPERATING ROD INTERCONNECTING SAID LOCKING PINS FOR CONJOINT MOVEMENT, CABLE MEANS EXTENDING FROM SAID OPERATING ROD TO SAID OPERATING CAB, MEANS WITHIN SAID CAB TO EXERT A PULL ON SAID CABLE TO RELEASE SAID LOCKING PINS, AND SPRING MEANS ACTING ON SAID ROD AUTOMATICALLY TO URGE SAID ROD AND THUS SAID PINS TO RETURN UPON RELEASE OF SAID CABLE.