Self-unloading truck body

Claim 1

IN COMBINATION WITH A VEHICLE, COMPRISING, A BODY MOUNTED ON SAID VEHICLE HAVING A FLOOR, SIDES AND FORWARD END, A MOVABLE END GATE IN SAID BODY HAVING REARWARD AND FORWARD SIDES, A FIRST CABLE HAVING ITS ENDS SECURED TO THE REARWARD SIDE OF SAID END GATE ADJACENT ONE END THEREOF, A SECOND CABLE HAVING ITS ENDS SECURED TO THE REARWARD SIDE OF SID END GATE ADJACENT THE OTHER END THEREOF, A THIRD CABLE HAVING ITS ENDS SECURED TO THE FORWARD SIDE OF SAID END GATE ADJACENT ONE END THEREOF, A FOURTH CABLE HAVING ITS ENDS SECURED TOTHE FORWARD SIDE OF SAID END GATE ADJACENT THE OTHER END THEREOF, A HYDRAULIC CYLINDR SECURED TO SAID VEHICLE AND HAVING AN EXTENDABLE PISTON ROD, A CROSS-HEAD SECURED TO THE OUTER END OF SAID PISTON ROD, SAID CROSS-HEAD HAVING A PLURALITY OF PULLEYS ROTATABLY MOUNTED THEREON, SAID PULLEYS ON SAID CROSS-HEAD ENGAGING SAID FIRST, SECOND, THIRD AND FOURTH CABLES TO MOVE SAID END GATE IN ONE DIRECTION WHEN SAID PISTON ROD IS WITHDRAWN INTO SAID HYDRAULIC CYLINDER AND TO MOVE SAID END GATE IN AN OPPOSITE DIRECTION WHEN SAID PISTON ROD IS EXTENDED, AND MEANS FOR EXTENDING AND WITHDRAWING SAID PISTON ROD WITH RESPECT TO SAID HYDRAULIC CYLINDER, SAID BODY HAVING A PLURALITY OF DOUBLE PULLEYS ROTATABLY SECURED THERETO ADJACENT ITS REARWARD AND FORWARD ENDS AT EACH SIDE THEREOF BELOW SAID FLOOR AND A SINGLE PULLEY ROTATBLE SECURED TO EACH SIDE OF SAID BODY ADJACENT ITS REARWARD AND FORWARD END ABOVE SAID FLOOR, SAID FIRST, SECOND, THIRD AND FOURTH CABLES ENGAGING SAID DOUBLE PULLEYS AND SAID SINGLE PULLEY ADJACENT THERETO AT A POINT BETWEEN SAID ENG GATE AND SAID CROSSHEAD.