Abstract:
A vehicle comprises a passenger cab and a pickup truck cargo bed that extends outward from the passenger cab. The cargo bed comprises two opposing sidewalls, a front wall and a movable rear tailgate. A ramp assembly comprises panels, hinges, retainer brackets, and stiffeners and is stored in the cargo bed. The hinges rotatably interconnect the panels to each other and a single panel to the tailgate. The stiffeners reinforce the panels when in use and are otherwise stowed in the cargo bed. The retainer bracket holds the panels against the tailgate when in the stowed position.

Description:
This application claims priority to and all the benefits of U.S. Provisional Patent Application No. 60/245,434 filed on Nov. 2, 2000 and entitled “Automotive Stowable Ramp Device”. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a multi-panel ramp assembly. In particular, this invention relates to a multi-panel ramp assembly for a pickup truck that is easily stowable on the tailgate when not in use. 
     BACKGROUND OF INVENTION 
     Pickup trucks are known for versatility in cargo carrying capacity. Pickups trucks typically include a cargo bed for receiving and storing cargo and a liftgate allowing access to the cargo bed. It can be very difficult, due to a high floor height of the cargo bed, to load a pickup truck when the cargo is bulky and/or heavy, such as refrigerators, stoves, all terrain vehicles (ATVs), and the like. Ramps extending between the cargo bed and the ground may be utilized to facilitate loading of large items into the cargo bed. A foldable ramp may be integrated into the liftgate and extendable from the liftgate to the ground. An example of such a foldable ramp is disclosed in U.S. Pat. No. 5,597,195 issued on Jan. 28, 1997 to Meek. However, foldable ramps, as disclosed in this patent, are not easily integrated into conventional liftgate designs due to the bulk and weight of such foldable ramps. 
     Therefore, it would be beneficial if a stowable ramp could be integrated into a more conventional liftgate design to be moveable between a folded position for movement with the liftgate and an extended position to facilitate loading of cargo into the cargo bed. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the invention there is provided a stowable ramp assembly for a vehicle having a storage area having spaced apart sidewalls and a liftgate extending therebetween. The stowable ramp assembly includes a plurality of panels extending between the liftgate and the ground. Each of the plurality of panels extends between first and second terminal ends and longitudinal sides. The stowable ramp assembly further includes a plurality of stiffener rails engagable with the first and second terminal ends preventing relative motion between the plurality of panels. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     Advantages of the invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
     FIG. 1 is a partially exploded perspective view of a pickup truck cargo bed with the stowable ramp of the present invention in the extended planar use position; 
     FIG. 2 is a side view of the stowable ramp in the stowed position; 
     FIG. 3 is a side schematic view of the stowable ramp while opening; and 
     FIG. 4 is a cross sectional view of a stiffener for the stowable ramp. 
    
    
     DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, the cargo bed  10  of a pickup truck  12  is generally shown. The cargo bed  10  includes a generally planar floor  14  defined by a perimeter edge  16 . Two opposing, generally parallel sidewalls  18 ,  20  are interconnected to the floor  14  and extend upwardly from the perimeter edge  16 . The sidewalls  18 ,  20  and the floor  14  are further interconnected by a front wall  22  and a movable rear tailgate  24 . The rear tailgate  24  acts as a storage area for a stowable ramp assembly  26  of the invention, when not in use. 
     The ramp assembly  26  includes panels  28 ,  30 ,  32 ,  34 , a plurality of hinges  36 , a retainer bracket  38 , and stiffeners  40 ,  42 . The panels  28 ,  30 ,  32 ,  34  are similar in design and function. Therefore, only panel  28  will be described. The panel  28  is generally planar and rectangular in shape having first  44  and second  46  terminal ends, and longitudinal sides  48 ,  50 . The panels  28 ,  30 ,  32 ,  34  are formed from any suitable material such as glass reinforced polypropylene, glass reinforced urethane, or metal, so long as to withstand required loading characteristics. Furthermore, the panels  28 ,  30 ,  32 ,  34  may have textured surfaces for adding traction while in use. 
     Hinges  36  interconnect panels  28 ,  30 ,  32  and  34 . The hinges  36  can be of any type of hinge mechanism, i.e., multiple hinge, piano hinge, or similar, as known to one of ordinary skill in the art. The hinges  36  include a first attachment bracket  52  and a second attachment bracket  54  which are pivotally connected together. The hinges  36  allow panels  28 ,  30 ,  32 ,  34  to fold on top of one another, as shown in FIG.  2 . The last panel  34  is further connected to the tailgate  24  by way of a stowable hinge  36  having first and second attachment brackets  52 ,  54 . 
     A ramp retainer bracket  38  is generally S-shaped and includes first and second generally horizontal planar shelves  56 ,  58  interconnected by a generally vertical planar member  60 . Further, the ramp retainer bracket  38  has a hole  62  that accepts a threaded retainer  64  for holding the ramp retainer bracket  38  against the tailgate  24 . The threaded retainer  64  may be any removable hold down device such as, a bolt or a quick release mechanism for holding the ramp retainer bracket  38  to the tailgate  24 . It should be noted that more than one ramp retainer bracket  38  may be used in this invention. 
     The stiffeners  40 ,  42  are generally C-shaped in cross section, as shown in FIG. 4, and are of a length to cover and surpass the interconnection of the hinges  36  to each panel  28 ,  30 ,  32 ,  34  for reinforcement of the hinges  36 . The stiffeners  40 ,  42  have a hooked or J-shaped flange  76  extending out therefrom. The stiffeners  40 ,  42  include a generally vertical wall  66  extending from a first end  68  to a distal second end  70 . The first end  68  of the wall  66  has a generally perpendicular flange  72  that protrudes therefrom. A similar flange  74  extends perpendicular from the wall  66  intermediate of the first and second ends  68 ,  70 . The second end  70  includes the J-shaped flange  76  that extends in the same direction as the flanges  72 ,  74 . 
     Further, in the preferred embodiment, sidewall brackets  78 ,  80  are secured to the sidewalls  18 ,  20 , respectively, of the cargo bed  10  as shown in FIG.  1 . As shown in FIG. 4, each of the sidewall brackets  78 ,  80  includes two generally vertical walls  82 ,  84  interconnected by a generally horizontal wall  86  creating a generally J-shaped bracket. The larger of the walls  84  is positioned on the inside of the cargo bed  10 , i.e., between the sidewalls  18 ,  20 . Furthermore, the wall  84  has an L-shaped flange  88  which is further extending toward the inside of the cargo bed  10  and is upwardly facing for receiving the J-shaped flange  76  of the stiffeners  40 ,  42 , thus storing on either sidewall  18 , 20 . 
     In operation, referring to FIG. 2, the tailgate  24  is shown in the closed position between the sidewalls  18 ,  20  of the cargo bed  10 . The ramp assembly  26  is shown in a stowed position retained against the tailgate  24  within the cargo bed  10 . To deploy the ramp assembly  26 , the tailgate  24  is pivoted from the closed position, FIG. 2, to an open position, as shown in FIGS. 1 and 3, extending generally planar from the cargo bed floor  14 . The retainer bracket  38  retains the ramp assembly  26  in the stowed position. That is, with the ramp assembly  26  folded in the stowed position against the tailgate  24 , the bracket  38  retains the ramp assembly  26  between the shelf  56  and the tailgate  24 . The threaded retainer  64  may be removed from the bracket  38  to disconnect the bracket  38  from the tailgate  24  and release the ramp assembly  26 . The panels  28 ,  30 ,  32 ,  34  may now be unfolded or pivoted by the hinges  36  as shown in FIG. 3 from the stowed position against the tailgate  24  to the deployed or extended planar use position as shown in FIG.  1 . 
     Finally, the stiffeners  40 ,  42  may be removed from the sidewall brackets  78 ,  80  and engaged along the opposing side edges  48 ,  50  of the panels  28 ,  30 ,  32 ,  34 . Specifically, the flanges  72 ,  74  of the stiffeners  40 ,  42  are placed over the side edges  48 ,  50  of the panels  28 ,  30 ,  32 ,  34  and across each hinge  36  interconnecting the panels  28 ,  30 ,  32 ,  34  to form a single rigid panel for use as a ramp between the tailgate  74  and the ground or other surface adjacent the tailgate  24 . When the ramp assembly  26  is in the stowed position, the stiffeners  40 ,  42  may be stowed within the truck bed  12  by the sidewall brackets  78 ,  80 . Specifically, the J-shaped flange  76  of the stiffeners  40 ,  42  is hooked over the L-shaped flange  88  of the respective sidewall bracket  78 ,  80  for support thereon along the sidewalls  18 ,  20  of the bed  12 . 
     The invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation. 
     Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.