Entrepreneurs engaged in a variety of business endeavors have found considerable utility in the use of motor vehicles generally referred to as "pick-up" trucks. These trucks are relatively light as compared to typical heavy haulage vehicles, having capacities ranging from about 1/2 to 3/4 ton. To enhance the appeal of the pick-up trucks, manufacturers have developed pleasing, streamlined body styles, for example, the lines of the bed portion of the trucks generally are integrated in flowing fashion with the lines and design of the cab and hood structure and ornamentation thereupon.
For many uses, the pick-up truck operators have developed a need for power dumping capability. However, while the beds of the trucks are readily removable by unbolting the floor thereof from the truck undercarriage, dump hoist installations heretofore have required the remounting of the dump bed at a higher level above the undercarriage in order to provide hoist access space. For example, the differential gear housing often is found to interfere with hoist installations. In addition to the readily apparent degredation to the design lines and aspects of the vehicle, such elevation of the bed derogates from vehicle stability under load. Vehicle safety further is compromised, inasmuch as the bed is only coupled to the truck body at rearward disposed hinges. In the event of a rearend accident or the like, the hinges tend to be torn from the body frame and the bed is thrust toward the cab. Degredation to body styling additionally is encountered in the repositioning of the rear bumper of the trucks following conversion. As is apparent, the dump bed cannot clear a bumper mounted to the termini of the frame side rail. Consequently, various schemes have been employed for remounting the bumper upon the frame at a lower level to provide dump clearance. Since bumpers are styled and contribute to the overall pleasing appearance of the trucks, this repositioning detracts from the looks of the converted truck.
Conversion heretofore carried out additionally have encountered problems relating to the structural integrity of the hoist equipment. In view of the relatively smaller size of the trucks, the hoist equipment itself remains small and the price of its installation must be low enough as to be commensurate with the lower cost of the trucks themselves. In consequence, the mere scaling down of conventional hoist structures to meet the needs of a smaller vehicle generally has been found to evolve structurally inadequate hoists. For example, extensive stressing has been determined to be present at the coupling between hydraulic motor piston rods and hoist components.