Materials handling apparatus

Claim 1

IN COMBINATION WITH A HIGHWAY TRAVEL TYPE VEHICLE, A MATERIALS HANDLING ELEVATOR APPARATUS COMPRISING: (A) A FRAME STRUCTURE INCLUDING SPACED APART PARALLEL UPRIGHT MEMBERS COUPLED TO THE FRONT END OF SAID VEHICLE, SAID UPRIGHT MEMBERS BEING DISPOSED WITH THEIR UPPER EXTREMITIES BELOW THE LOWER EDGE OF THE FRONTWARD FIELD OF VISION OF THE TRUCK OPERATOR AND WITH THEIR LOWER EXTREMITIES HAVING AT LEAST ROAD TRAVEL CLEARANCE ABOVE THE GROUND SUPPORTING SAID VEHICLE; (B) A MAST STRUCTURE OF LENGTH NOT EXCEEDING THAT OF SAID FRAME STRUCTURE AND TELESCOPIC SAID FRAME STRUCTURE AND MOVABLE LONGITUDINALLY THEREOF, SAID MAST STRUCTURE INCLUDING SPACED APART PARALLEL RAILS DISPOSED ADJACENT THE RESPECTIVE UPRIGHT MEMBERS OF SAID FRAME STRUCTURE AND A CROSS-HEAD MEMBER CONNECTING THE UPPER ENDS OF SAID RAILS; (C) A HYDRAULIC LIFT DEVICE INCLUDING A PLURALITY OF RELATIVELY EXTENSIBLE AND RETRACTILE ELEMENTS; (D) MEANS MOUNTING THE LOWERMOST SAID ELEMENT ADJACENT AND FIXED RELATIVE TO SAID FRAME STRUCTURE; (E) MEANS FIXING THE UPPERMOST ONE OF SAID ELEMENTS TO SAID CROSSHEAD MEMBER; (F) A LOAD RECEIVING STRUCTURE COUPLED TO SAID MAST STRUCTURE AND MOVABLE LONGITUDINALLY THEREOF; (G) AN ELONGATE BAR MEMBER DISPOSED ADJACENT SAID FRAME STRUCTURE AND MOVABLE FROM A FIRST POSITION TO A SECOND POSITION; (H) FLEXIBLE LINKAGE MEANS ANCHORED TO SAID LOAD RECEIVING STRUCTURE AND TO SAID ELONGATE BAR MEMBER; (I) ROTATABLE SHEAVE MEANS CARRIED BY SAID CROSSHEAD OVER WHICH SHEAVE MEANS SAID FLEXIBLE LINKAGE MEANS EXTENDS; (J) MEANS EXTENDING A FIRST ELEMENT OF SAID LIFT DEVICE AND EXTENDING SIMULTANEOUSLY SAID MAST STRUCTURE AND SAID LOAD RECEIVING STRUCTURE EQUALLY A FIRST PREDETERMINED DISTANCE ALONG SAID FRAME STRUCTURE WHILE SAID ELONGATE BAR MEMBERS MOVES FROM SAID FIRST TO SAID SECOND POSITION; (K) MEANS ENGAGING SAID ELONGATE BAR AND MAINTAINING THE SAME AT SAID SECOND POSITION; AND (L) MEANS EXTENDING AT LEAST ONE SAID OTHER ELEMENT OF SAID LIFT DEVICE AND EXTENDING FURTHER SAID MAST STRUCTURE A SECOND PREDETERMINED DISTANCE ALONG SAID FRAME STRUCTURE WHILE SAID SHEAVE MEANS URGES SAID FLEXIBLE LINKAGE MEANS TO MOVE SAID LOAD RECEIVING STRUCTURE RELATIVE TO SAID MAST STRUCTURE.