Abstract:
An apparatus for loading the bed of a pickup truck comprises a brace for supporting a load from the ground, the brace preventing the load from applying weight to the tail end of the bed with damaging consequences while being drawn into position by a winch and cable system. A pallet is used to stage the load on the ground and to provide a structure with a low angle of attack to the brace, the low angle of attack facilitating the transition of the load to the bed by reducing the tipping moment over the brace.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to loading devices for trucks, and more particularly to winch-driven loading devices for pickup trucks. 
       BACKGROUND OF THE INVENTION 
       [0002]    Loading a truck bed, such as on a pickup truck, sometimes involves heavy or unwieldy lifting in a situation where mechanized equipment is unavailable for the task. Such a situation might occur in a home or field environment. Such a case can be made for snowmobiles, four-wheeled recreational vehicles, boats, game carcasses, or camper-inserts, to name a few objects which are too large or too heavy for manual manipulation. Another case can be made for aggregated loads, such as firewood, shingle bundles, building blocks, or soil, fertilizer, or salt in bags, where lifting individual pieces one-at-a-time would be inefficient. In all cases, it is useful to stage the load at ground level and use a portable device to lift and transfer the load onto the truck bed. 
         [0003]    A winch and cable system powered by a battery comprises an easily portable device to drag a load onto a truck bed. In U.S. Pat. No. 5,232,329 to Livingston, a snowmobile loaded onto a ground-level pallet is lifted by a winch at the end of a boom. The boom doubles as a platform which can be raised to lift the load and then lowered by hydraulic means to receive the load at an appropriate incline. The loaded platform is then further lowered into the truck bed. The platform and associated hydraulics, however, must be installed in the truck, rendering the bed thereby unusable for other purposes. 
         [0004]    In U.S. Pat. No. 3,894,643 to Wilson, a boat is hoisted onto the rear of a pickup truck by means of a winch tugging against a pair of articulating brace members, said members braced against both the rear and the ground to scissor the load thereby upwardly. During the lift, however, the forces of the weight of the boat and the downward pull of the winch cable are collectively applied to the tail, or rearward-most part, of the vehicle. At the tail, in such an extreme position, the forces are applied against the suspension and the frame with damaging leverage. 
         [0005]    In U.S. Pat. No. 5,269,642 to Zoromski, a camper-insert with an integrated structure comprising a winch and cable system is elevated at one end to be partially supported by stiff legs. As the load is winched farther onto the stiff legs, the center of gravity shifts to tilt the structure against the tail of the pickup truck bed. Further movement pivots the load over the tail and into the bed while simultaneously lifting the stiff legs. In spite of the temporary supporting role of the stiff legs, they are ultimately rendered ineffective in preventing weight from being applied to the tail in a potentially damaging way. 
         [0006]    The present invention provides novel solutions for loading a truck bed without the need for installed structure and without using the tail of the bed as a fulcrum edge. 
       SUMMARY OF THE INVENTION 
       [0007]    It is accordingly an object of the present invention to use a structure supported by stiff legs to carry the weight of a load until the load is substantially transferred into the truck bed. It is a further object to use a winch and cable system as a means for transferring the load. It is a further object to minimize the pitch of the load at the point of tipping onto the supporting structure, thereby requiring less winch power. It is a further object to provide a platform for assembling a load on the ground. It is a further object to provide said platform with sufficient rigidity to cantilever weight over the supporting structure. It is a further object to allow the truck bed to move independently from the supporting structure while recoiling from the load burden. It is a further object to provide a loading apparatus which can be disassembled into component parts for portability. 
         [0008]    These objects, and others to become hereinafter apparent, are embodied in an apparatus for loading a load onto a truck with a bed having an open end comprising, in a first part, a brace for supporting the load from the ground, the brace comprised of at least two upright stiff legs joined proximate the top by a crossbar, the crossbar at or above the level of the bed, the brace stabilized by at least one connector bar hingingly attached between the brace and the open end; in a second part, a pallet on which the load is placed while resting on the ground; and, in a third part, a means for drawing the loaded pallet over the crossbar and into the bed. With the apparatus configured in this way and operating in this manner, the weight of the loaded pallet is substantially supported by the brace from the ground to avoid thereby a dynamic weighting of the open end, and the horizontal thrust from pivoting the weight over the brace is transferred to the truck through the at least one connector bar, the bed under loading capable of articulating vertically through the hinged attachment of the at least one connector bar. 
         [0009]    In a preferred embodiment, the means for drawing comprises a first winch and cable system attached between the bed and the pallet. The preferred embodiment further comprises a means for unloading, wherein the means for unloading comprises a second winch and cable system attached between the brace and the front of the pallet. The means for unloading further comprises an at least third stiff leg placed centrally with respect to the crossbar, the at least third stiff leg serving to operationally direct the cable of the second winch and cable system while providing a vertical rail to prevent the pallet from diving beneath the crossbar. The preferred embodiment still further comprises a means for minimizing the tipping moment of the pallet over the crossbar while pivoting there upon, the means for minimizing the tipping moment comprising an extension to the pallet perpendicular to the crossbar, the extension essentially reducing the angle of attack to the crossbar. 
         [0010]    As this is not intended to be an exhaustive recitation, other embodiments may be learned from practicing the invention or may otherwise become apparent to those skilled in the art. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0011]    Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood through the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
           [0012]      FIG. 1  is a perspective view of the apparatus of the present invention with the load staged on the ground; 
           [0013]      FIG. 2  is a perspective view with the load lifted onto the crossbar of the brace during loading; 
           [0014]      FIG. 3  is an elevation view showing the angle of attack; 
           [0015]      FIG. 4  is a perspective view of the brace, in which detail A shows the connector bar; 
           [0016]      FIG. 5  is a partial perspective view of the apparatus showing the second winch and cable system loading; and 
           [0017]      FIG. 6  is a perspective view of the loaded truck bed with the apparatus disassembled for onboard stowage. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0018]    The constituent components of the present invention are best shown in  FIGS. 1 and 2 . An apparatus for loading  1  a load  5  onto a truck  2  having a truck bed  3  with an open end  4  is comprised of a brace  10 , a pallet  20  on which the load  5  is placed, and a means for drawing  30  the loaded pallet  20  over the brace  10  and onto the truck bed  3 . 
         [0019]    In the preferred embodiment, the means for drawing  30  is a first winch and cable system  31 . The winch is typically located at the end of the truck bed opposite the open end  4  to maximize the length of the draw. In the preferred embodiment, the cable is dead-headed at or near the cab bulkhead  8  such that the winch has a two-to-one purchase in drawing the loaded pallet  20 . One or more turning blocks (not shown) may be used on the front end of the pallet to reverse the direction of the cable. 
         [0020]    Referring to  FIGS. 1 and 4 , the brace  10  is comprised of at least two upright stiff legs  11  joined proximate the top ends thereof by a crossbar  12 . The structure thus formed provides a fulcrum resting on a ground surface  6  ( FIG. 3 ), the fulcrum balancing the pallet  20  once the same is lifted thereon. The stiff legs  11  may be comprised of telescoping sections to adjust for height. The preferred height is level with, or higher than, the open end  4  of the truck bed  3 . The preferred height assures that center of gravity of the load  5  will transition the open end  4  prior to any weight being brought to bear on the truck bed  3 , and particularly on the open end  4 . The stiff legs  11  may also be provided with bases  18 , which function to distribute weight and prevent penetration into the ground. 
         [0021]    In the preferred embodiment, the crossbar  12  is provided with a means for reducing frictional drag  34 . In a particular preferred embodiment, the means for reducing frictional drag is rollers  15 , said rollers serving to both guide the pallet  20  and reduce friction as the pallet is drawn over the crossbar. The crossbar  12  may also be provided with sheaves  17  to guide the cable of the first winch and cable system  31 . 
         [0022]    The brace  10  is stabilized in an upright position by at least one connector bar  13  hingingly attached between the brace  10  and the open end  4 , as shown in detail A of  FIG. 4 . In the preferred embodiment, there are two connector bars  13  spaced apart and near the sheaves  17  to transmit a horizontal component of the loaded pallet  20  to the truck  2  as the cantilevered weight of the load is drawn over the crossbar  12 . Each connector bar  13  is hinged by hinges  16  at both the point of attachment at the open end  4  and at the brace  10 . The bi-lateral hinging thus allows articulation of the truck bed  3 , weighted by its burden, essentially independent of the brace  10 . 
         [0023]    Referring to  FIGS. 4 and 5 , the apparatus for loading  1  is further comprised of a means for unloading  32 . The means for unloading  32  is comprised of a second winch and cable system  33  attached between the brace  10  and the leading edge of the pallet  20 . In the preferred embodiment, the winch of the second winch and cable system  33  is mounted on or above a third stiff leg  14  placed centrally with respect to the crossbar  12 . The third stiff leg  14  serves to operationally direct the cable through sheaves  17  placed at top and bottom ends of the third stiff leg. The third stiff leg  14  also serves to provide a vertical rail for transitioning the pallet  20  to the ground  6  while preventing the pallet from diving beneath the crossbar during descent there from. During loading, the first winch and cable system  31  is spooling in, as shown by the directional arrows in  FIG. 4 , while the second winch and cable system  33  is free-wheeling and unspooling. During unloading, on the other hand, the second winch and cable system is spooling, as shown in  FIG. 5 , while the first system is either free-wheeling, or otherwise, providing a braking action. 
         [0024]    Referring to  FIGS. 1-3 , the pallet  20  is initially placed on the ground  6  to facilitate loading. Objects comprising a load may be handily placed on the pallet  20  while relying on the first winch and cable system  31  to lift the load by drawing the leading, or front, edge of the pallet  20  to the height of the crossbar  12 . Upon reaching the crossbar, the trailing, or back, edge of the pallet defines the apex of an angle-of-attack  22  with the ground  6 , as shown in  FIG. 3 . The angle-of-attack  22  controls the tipping moment of the pallet as advancement draws the back edge off the ground and balances the weight in a pivot over the crossbar. The shallower the angle, the less the force required to rotate the cantilevered center of gravity of the loaded pallet  20  over the fulcrum of the crossbar  12 ; and, consequently, the smaller the force applied by the winch. 
         [0025]    A means for minimizing the tipping moment  21  comprises an extension  23  to the pallet  20  in a direction perpendicular to the crossbar  12 . The tipping moment is minimized because the angle-of-attack  22  is reduced by this configuration. The angle-of-attack  22  is reduced because the angle rays, namely the extended pallet  20  and the included ground  6 , are lengthened while the triangular side opposite, the brace  10 , is held constant. In the preferred embodiment, the extension  23  is comprised of a light-weight skeleton structure to further reduce the tipping moment. In a particular preferred embodiment, the extension  23  is comprised of frame elements  24 , which may telescope within frame members of the pallet  20 , and may be removed for transport and storage. The frame elements  24  may terminate in rollers  15  to facilitate frictionless ground contact. 
         [0026]    In an alternate embodiment, a unitary load  25  (not shown), such as a camper insert, may substitute for the pallet  20 . The unitary load  25  must have a structure sufficiently rigid to cantilever its weight. The unitary load  25  may also be provided with the means for minimizing the tipping moment  21 . 
         [0027]    The loaded configuration of the truck  2  is shown in  FIG. 6 . The apparatus for loading  1  may be disassembled and rendered portable by detaching the at least one connector bar  13  from the open end  4 . To serve that purpose in the preferred embodiment, the hinges  16  are comprised of a cotter pin to facilitate separation. The frame elements  24  may also be removed and stowed (not shown). 
         [0028]    It is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the preceding description or illustrated in the drawings. For example, rails may be provided in the truck bed  3  to reduce the frictional engagement of the pallet  20  with the bed. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting.