Abstract:
A truck bed loading platform including a rail mountable on a truck bed. The platform also includes a first and second hingedly connected tray portions. Furthermore, the platform includes means for slidably mounting the first and second tray portions on the rail for sliding movement between first and second positions. The rail includes a plurality of longitudinally spaced rollers. The platform can include an optional handle(s) for facilitating manual sliding of the platform. The platform can also include an optional lock for locking the entire platform in place on a truck bed.

Description:
CROSS REFERENCE TO CO-PENDING APPLICATION 
   This Application claims the benefit of the filing date of U.S. Provisional Patent Application, Ser. No. 60/504,588, filed Sep. 18, 2003, the entire contents of which are incorporated herein. 

   BACKGROUND 
   Truck beds are designed to carry cargo. However, the length of truck beds makes it difficult to access cargo stored at the forward end of the truck bed near the cab unless someone climbs into the truck bed. 
   To address this problem, many cargo trays or extendable frame devices have been designed for mounting in truck beds. Such devices are anchored to the truck bed. A tray is mounted on rails and is slidable relative to the rails from a first position completely overlaying the rails to a second position, usually cantilevered from the tailgate of the truck wherein substantially all of the tray extends from the end of the frame adjacent to the tailgate of the truck. 
   Since the tray usually extends over substantially the full length of the truck bed, it must be fully extended rearward of the tailgate to access cargo at the forward end of the tray. However, even with the tray fully extended, cargo at the forward end of the tray can only be accessed from the side of the tray adjacent to the tailgate. In addition, heavier cargo on pallets cannot be loaded or unloaded to or from the forward end of the tray since the forklift truck typically used to move such pallets cannot ride over the tray to the forward end of the tray. 
   Thus, it would be desirable to provide a truck bed loading platform which allows easy access to the forward end of the platform, particularly for forklift trucks, to load and unload cargo on the forward end of the platform. 
   SUMMARY 
   The present invention is a truck bed loading platform including rail means mountable on a truck bed. The platform includes a first and second hingedly connected tray portions. Furthermore, the platform includes means for slidably mounting the first and second tray portions on the rail means for sliding movement between a first position and a second position. 
   The platform includes a plurality of longitudinally spaced roller assemblies which slidably support the first and second tray portions on the rail for movement between a first and second hinged position. The first position is a generally linear position in which the first and second tray portions are coplanarly aligned on the truck bed. In the second position, the second tray portion extends angularly from the truck bed. 
   An optional feature of the platform encompasses a handle(s) being mounted on one end of the second tray portion. The handle includes a hand grip surface. The handle facilitates manual sliding of the platform between the first and second positions. 
   The platform can include a lock means mounted on at least one of the first and second tray portions for locking the entire platform in one or more longitudinally spaced positions on the truck bed. 
   In conclusion, the present invention allows easy access to the forward end of the platform, particularly for forklift trucks to load and unload cargo on the forward end of the platform. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The various features, advantages and other uses of the present invention will become more apparent by referring to the following detailed description and drawing in which: 
       FIG. 1  is a perspective view of the truck bed loading platform according to the present invention shown in a fully retracted, load carrying position; 
       FIG. 2  is a plan view of a frame of the platform shown in  FIG. 1 ; 
       FIG. 3  is a partial, perspective view of a forward end of the apparatus shown in  FIGS. 1 and 2 ; 
       FIG. 4  is a partial, perspective view of a rear end of the platform shown in  FIGS. 1 and 2 ; 
       FIG. 5  is a partial, end view of a clamp assembly of the frame; 
       FIG. 6  is an end view of one aspect of a roller assembly; 
       FIG. 7  is an end view of another aspect of the roller assembly; 
       FIG. 8  is a partial, perspective view showing the platform in a hinged, unloading position; 
       FIG. 9  is a bottom, perspective view of the platform similar to  FIG. 8 ; 
       FIG. 10  is a partial, plan view showing a modification to the tray handles; 
       FIG. 11  is a perspective view of another aspect of the apparatus with a releasable lock means; and 
       FIG. 12  is a plan view of the lock means shown in  FIG. 11 . 
   

   DETAILED DESCRIPTION 
   Referring now to  FIGS. 1–12  of the drawings, there is depicted a truck bed loading and unloading platform or apparatus  10  according to the present invention. 
   It will be understood that the loading and unloading apparatus  10  of the present invention, while described hereafter as being mounted in an open truck bed, as shown in  FIG. 1 , can also be advantageously mounted in vans, and other vehicles having a closed cargo compartment. 
   As shown in  FIG. 1 , the apparatus  10  includes a tray  12  which is slidably mounted on rail means  14 . The rail means  14  are fixedly mounted to the truck bed by means of rail mounts or clamps  16 . 
   The tray  12  includes a frame structure  20  shown in  FIG. 2  constructed of a first tray portion  22  and at least one second tray portion  24 . The first and second tray portions  22  and  24  are pivotally connected at facing edges by hinge means  26 . 
   The first and second tray portions  22  and  24  are substantially identically constructed and may be the same or different lengths. The first tray portion  22  can be longer than the second tray portion  24 . Thus, the following description of the construction of the frame  20  for the second tray portion  24  will be understood to apply equally to the construction of the frame  20  for the first tray portion  22 . 
   As shown in  FIGS. 2–9 , the frame  20  includes a pair of spaced lateral tubular members  32  and  34  which are joined at opposite ends by means of longitudinal support or angle members  36  and  38 . A plurality, such as three by way of example only, of longitudinally extending lateral members  40 ,  42  and  44  are fixed, such as by welding, at opposite ends to the tubular members  32  and  34 . The laterally outermost longitudinal tubular members  40  and  44  may also be joined by means of fasteners, welds, etc., to the angle members  36  and  38 , respectively. 
   Inverted U-shaped channel members  46  and  48 , each carrying a plurality of linearly aligned rollers or wheels  50 , see  FIG. 9 , are also fixed at opposite ends to the tubular members  32  and  34 , such as by welding. A plurality of cross members, with three cross members  52 ,  54  and  56  being shown by way of example only, are fixed at opposite ends to the angle members  36  and  38  and may optionally be joined, such as by welding, to the tubular members  40 ,  42  and  44 . 
   This arrangement forms a lattice-ike structure for the frame  20  which provides both a lightweight and strong construction. A plate  60  is mounted over the frame  20  and attached to the angle members  36  and  38  and the tubular members  32  and  34  by suitable fastening means, such as mechanical fasteners, welds, etc. By way of example only, the plate  60  is shown as a step-type plate formed with alternating projections for a relatively slip-free surface. 
   As explained above, the same frame structure applies for the frame of the first tray portion  22 . 
   The rail means  14  shown in  FIGS. 1 ,  3 ,  4  and  5  includes a pair of longitudinally extending, laterally spaced angle members  70  and  72 . The angle members  70  and  72  are stationarily mounted on the truck bed  74  by clamp members  78 . A plurality of clamp members  78  are located along each longitudinal edge of the rails  70  and  72 . 
   As shown in  FIGS. 3–5 , each clamp assembly  78  includes a two-part clamp formed of generally inverted L-shaped arms  80  and  82  which have bearing surfaces  84  and  86 , respectively, disposed against opposite sides of an in-turned wall  88  of the truck bed side wall  90 . Plates may be interposed between the bearing surfaces  84  and  86  and the truck bed wall  88  to protect the wall  88  and to more equally distribute clamping forces on the upper wall  88 . 
   The arm  80  includes a depending portion  92  which is adapted to engage an inner surface of a strut  94 , generally in the form of a U-shaped strut, commonly sold under the name Uni-Strut. An end leg portion  96  of the arm  82  extends along an outer surface of the strut  94 . The end leg portion  96  includes an internally threaded bore  98  which receives the threaded shank  100  of a bolt  102  which extends through a similar bore in the arm  80 . Tightening or loosening of the bolt  102  causes the arms  80  and  82  to move toward each other in tightening engagement with the wall of the strut  94  or in an opposite direction separating the depending portions  92  and  96  enabling movement of the strut  94  relative to the truck bed  74 . 
   As shown in  FIGS. 3 and 5 , a short length strut  110  extends from the bottom of the strut  94  and is supported by welds or an angle strap  112  which is bolted to both of the struts  94  and  110 . The opposite end of the short strut  110  is fixed to one leg of the rails  70  or  72  by means of a T-shaped strut  114 , such as a strut sold by Unistrut as product number P2345, for example. The leg  116  or the strut  114  is fastened to the strut  110 . Each of the two arms  118  extending from one end of the leg  116  are fastened to one leg of the angle member  70 . 
   Referring to  FIG. 6 , a channel member  120 , such as a Uni-Strut member is formed with a central wall  122  and opposed side walls  124  and  126 , each terminating in inward turned ends  128  and  130 . The member  120  is fixed to the angle member  70  by suitable means, such as welds or bolts  132 . A plurality of linearly spaced apertures  134  may be formed in one leg of the angle member  70  for receiving the shank and head of each bolt  132 . 
   The channel member  120  defines an interior chamber which receives a plurality of longitudinally spaced roller assemblies  140 , each formed of one or more wheels, with two rollers or wheels  142  and  144  depicted by way of example only. The wheels  142  and  144  are rotatably mounted on an axle  146 . The axle  146  is carried in a bracket  148  in the form of an inverted U-shaped member, by way of example only, which is fixed, such as by mechanical fasteners  150 , at spaced linear locations to one leg of one of the angle members  36  and  38  on the first and second tray portions  22  and  24 . In this manner, the roller assemblies  140 , which are spaced linearly apart to distribute weight on the tray portions  22  and  24 , slidably supports the tray portions  22  and  24  on the rails  70  and  72  for movement between a first, generally linear position in which the first and second tray portions  22  and  24 , as shown in  FIGS. 1 and 2  are coplanarly aligned on the truck bed  74  and a second hinged position shown in  FIGS. 8 and 9  in which the second tray portion  24  extends angularly from the truck bed  74  at an angle approaching perpendicularly from the first tray portion  22  which still has at least a portion overlaying the truck bed  74 . 
   An alternate roller means  160 , shown in  FIG. 7  may also be employed in the platform  10 . In this aspect of the invention, a strut  162 , similar shaped as strut  120 , but disposed in a generally C-orientation is secured to the angle member  70  by welds, fasteners, etc., in the same manner as the strut  120  is secured to the angle member  70 . 
   A plurality of individual track rollers  164  carried on axles  166  are fixed to the angle member  36  of the second tray portion  24 , as well as at spaced locations to the first tray  22 , not shown, by means of a threaded shank  168  extending from the axle  166 . The threaded shank  168  engages a threaded bore in the angle member  36 . 
   The hinge means  26  shown generally in  FIG. 2 , and in greater detail in  FIGS. 2 ,  8  and  9 , allows pivotal movement of the second tray portion  24  relative to the first tray portion  22  during repositioning of the entire platform  10  relative to the rails  70  and  72 . As shown in  FIG. 9 , each of the hinge means  26  includes a bar  170  that is fixedly secured at one end to one of the tubular members  40  and one of the angle members, such as angle member  36  of the first or second tray portions  22  and  24 . As shown in  FIG. 9 , one of the laterally outermost bars  170  is fixed by means of bolts  172  which extend through one leg of the angle member  36  and into bores in the tubular member  40  of the frame  20  through bores formed in one end of the bar  170 . The other end of the bar  170  is rotatably fixed by means of a pivot shaft  174  to the adjacent angle member of the first tray portion  22 . This same hinge  26  is repeated at a plurality of laterally spaced locations across the width of the first and second tray portions  22  and  24  as shown in  FIGS. 2 and 9 . 
   An additional feature of the present invention is shown in  FIGS. 2 ,  4  and  10 . At least one and preferably a pair of handles  180  are fixedly mounted by welds, fasteners, etc., to the tubular member  32  on one end of the second tray portion  24 . Each handle  180  has a hand grip surface or bar  182  which is spaced from the tubular member  32  by side legs  184 . The handles  180  facilitate manual sliding of the platform  10  between the first and second positions. 
   An optional feature of the handle  180  is shown in  FIG. 10 . At least one and preferably a plurality of rollers or castors  190 , with two being shown by way of example only, are mounted on opposite ends of the hand grip bar  182 . The casters or rollers  190  are positioned to engage the ground surface when the second tray portion is in the hinged, depending position shown in  FIG. 8 . The casters  190  facilitate movement of the end of the second tray portion  24  along the ground surface during extension of the platform  10  relative to the truck bed  74 . 
   The rollers or castors  190  could also be mounted on the tubular member  32  to extend outward beyond the outer extent of the hand grip  182  of the handles  180 . 
   Referring now to  FIGS. 11 and 12 , there is depicted a lock means  210  which can be mounted in the first and second tray portions  22  and  24  for locking the entire platform  10  in one or more longitudinally spaced positions on the truck bed  74 . By way of example only, a housing or block  212  is fixedly mounted at one end of the first tray portion  22 , adjacent to the side angle member  36 . The block  212  contains a through bore  214  through which extends a rod  216 . A stop  218  is formed on the rod  216  to limit axial movement of the rod  216  relative to the block  212 . A biasing means  220 , such as a coil spring, is disposed within an enlarged bore  222  in the block  212 . The biasing means or spring  220  seats at one end against a shoulder formed at one end of the bore  222  and normally biases a pin or dowel  224  outward through one end  226  of the block  212 . The pin  224  extends through an aperture formed in one leg of the angle member  36  and is engagable with one or more apertures, not shown, spaced along the one leg of the rail  70 . 
   The rod  214  is connected to a push/pull cable  230  which extends through a stationary sheath  232  to a push/pull knob  234 . The cable  230  and sheath  232  can extend through apertures formed in the tubular members  32  and  34  at facing edges of the first and second tray portions  22  and  24  and an aperture in a tubular member  32  at the outer end of the second tray portion  24 . The knob  234  may take any suitable hand grip shape. 
   In operation, the spring  220  will normally bias the pin  224  outward through an aperture in the angle member  36  into one aperture in the rail  70 . This aperture may be longitudinally positioned to lock the entire platform  10  in the first position wherein the entire platform  10  overlays the truck bed  74  with the first and second tray portions  22  and  24  in a coplanar arrangement. 
   When it is necessary to extend the platform  10 , the user pulls on the knob  234 . This causes the cable  230  to retract the pin  224  from the aperture in one end of the rail  70 . The entire platform  10  can be extended to the desired position for loading or unloading operations. In the second position, a similar aperture may be formed in the rail  70  at an intermediate position between the cab and the tailgate of the truck bed. This could coincide with the downward hinged position of the second tray portion  24  shown in  FIG. 8 . 
   In either position, and any other intermediate positions that may also be employed, the platform  10  is locked from longitudinal sliding movement. This is particularly advantageous during movement of the vehicle. 
   As described in the specification and shown in the drawings, the present invention allows easy access to the forward end of the platform by forklift trucks for loading and unloading cargo on the forward end of the platform.