Roll-back truck bed

Claim 1

A LOAD-CONVEYING VEHICLE COMPRISING A PAIR OF ELONGATED FRAME MEMBERS HAVING A REAR END MOUNTED UPON GROUND ENGAGING WHEELS, A PLATE PIVOTALLY CONNECTED TO REAR END OF THE FRAME MEMBERS WITH ONE PORTION OF THE PLATE PROJECTING BEYOND THE REAR END OF SAID FRAME MEMBERS AND ANOTHER PORTION ARRANGED TO OVERLIE PART OF SAID FRAME MEMBERS, SAID PLATE BEING MOVABLE FROM A HORIZONTAL POSITION ON SAID FRAME MEMBERS TO A SUBSTANTIALLY VERTICALLY POSITION AT THE END OF SAID FRAME MEMBERS; A PLATFORM SLIDABLY MOUNTED ON SAID PLATE AND FRAME MEMBERS FOR MOVEMENT FROM A POSITION UPON SAID PLATE AND FRAME MEMBERS TO A POSITION UPON THE GROUND REARWARDLY OF SAID VEHICLE, MEANS CARRIED BY SAID FRAME MEMBERS AND ENGAGEABLE WITH SAID PLATFORM FOR SECURING THE PLATFORM UPON SAID PLATE AND FRAME MEMBERS, A PLURALITY OF PULLEYS CARRIED BY SAID PLATE, A WINCH MOUNTED UPON SAID FRAME MEMBERS, SAID WINCH BEING FORMED WITH SPOOL SEGMENTS WITH A CABLE MOUNTED UPON EACH SEGMENT, ONE OF SAID CABLES BEING ENTRAINED ABOUT ONE OF THE PULLEYS ON SAID PLATE AND FASTENED TO THE FORWARD END OF SAID PLATFORM, THE OTHER OF SAID CABLES BEING ENTRAINED OVER ANOTHER OF THE PULLEYS AND FASTENED TO THE REAR END OF THE PLATFORM, AND MEANS TO ACTUATE SAID WINCH TO REEL IN THE CABLE ENTRAINED ABOUT SAID PULLEY AND FASTENED TO THE FORWARD END OF SAID PLATFORM AND PAY OUT THE CABLE ENTRAINED OVER SAID PULLEY AND FASTENED TO THE REAR END OF THE PLATFORM TO MOVE SAID PLATFORM ALONG SAID FRAME MEMBERS AND OVER SAID PLATE TO CAUSE SAID PLATE AND PLATFORM TO PIVOT ABOUT THE REAR END OF SAID FRAME MEMBERS AND DEPOSIT THE REAR END OF SAID PLATFORM UPON THE GROUND, AND CONTINUED ACTUATION OF SAID WINCH WILL CAUSE SAID PLATE TO MOVE INTO A SUBSTANTIALLY VERTICAL POSITION AND THE FORWARD END OF SAID PLATFORM TO SLIDE OVER SAID PLATE AND BE DEPOSITED UPON THE GROUND REARWARDLY OF SAID VEHICLE.