Abstract:
A pickup bed support structure that includes longitudinally extending frame rails to which transversely extending beams used to support the truck bed box are assembled. The beams are received below a top surface of the frame rails by forming notches or holes in the frame rails into which the beams are inserted. Alternatively, notches or holes may be provided in the transversely extending beams that receive the longitudinal extending frame rails. One method of manufacturing a pickup truck bed support structure is disclosed in which holes are provided in the longitudinally extending frame rail that receive the transversely extending beam that support the pickup truck bed. An alternative method is also disclosed in which notches are formed in the frame rails that receive the beams that are welded to the frame rails prior to assembling the pickup truck bed to the beams.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to a reduced height pickup truck bed support structure and method of manufacturing a pickup truck bed structure. 
         [0003]    2. Background Art 
         [0004]    Pickup trucks are popular vehicles for work and personal use that have a cargo box including a truck bed that is assembled to the vehicle behind a passenger compartment. Pickup trucks are popular because they can be used to haul cargo conveniently while also offering a comfortable passenger compartment, or pickup truck cab. 
         [0005]    Pickup trucks have a cargo box and floor that are closed by a tailgate that is folded down to provide access to the pickup truck box. At times it is preferred to load the pickup truck bed box from the side. One problem associated with loading a pickup truck bed from the side is that the height of the side wall of the cargo box makes it difficult for persons to lift cargo into the box from the side. One way of reducing the height of the side wall of the cargo box is to reduce the height of the side wall. However, reducing the height of the side wall may also reduce the cargo carrying capacity of the cargo box. 
         [0006]    The height of the load floor of the cargo box raises the height of the load carried in the cargo box which raises the center of gravity of the truck. The center of gravity of a vehicle affects handling and vehicle suspension performance. Generally, it is preferred to reduce the center of gravity of a truck to improve ride and handling. 
         [0007]    These and other problems are addressed by Applicants&#39; invention as summarized below. 
       SUMMARY 
       [0008]    A pickup truck having an improved cargo box or truck bed support structure reduces the height required for a customer to lift cargo into the pickup truck bed. A reduced height offers advantages for loading the pickup truck from the side or from the rear. In addition, the improved pickup truck bed support structure will lower the center of gravity for the cargo box and its contents while maintaining the same volume of cargo carrying space. 
         [0009]    Some of the benefits of the improved pickup truck bed support structure is that a lower bed floor may be provided and the step up height required for customers to access the cargo box is reduced. Another benefit associated with the improved pickup truck bed support structure is that the center of gravity of the truck may be lowered that in turn improves the static stability factor. 
         [0010]    According to one aspect of the present invention, an improved pickup truck bed support structure is provided in which a pair of frame rails extend longitudinally and inboard of the sides of the bed. The truck bed box is supported by a plurality of transversely extending beams that are assembled to a bottom side of the bed. The frame rails define a plurality of openings that receive the transverse beams below the top surface of the frame rails. 
         [0011]    According to another aspect of the present invention, an alternative embodiment of a pickup bed support structure is disclosed wherein a pair of longitudinally extending frame rails receive a plurality of transverse beams that are assembled to the bottom side of the pickup truck bed. The beams each define a plurality of openings that receive the frame rails with the beams being partially disposed below a top surface of the frame rails. 
         [0012]    According to yet another aspect of the present invention, a method of manufacturing a pickup truck support structure is provided that is supported by two longitudinally extending frame rails. The method comprises forming a hole in an outer side wall of an outer C-channel of an outer rail of each frame rail. A notch is formed through an upper wall and partially through an inner side wall of an inner C-channel of an inner rail of each of the frame rails. The inner rail is assembled to the outer rail with the hole aligned with the notch of the C-channel of each of the frame rails. A beam is inserted in the transverse direction through the hole and notch of each of the frame rails. The beam or beams are then welded to each of the frame rails adjacent to the hole and the notch. A pickup truck bed is then assembled to the beams after the beams are inserted in and welded to the frame rails. 
         [0013]    According to another method of manufacturing a pickup truck support structure is supported by two longitudinally extending frame rails comprising forming a first notch extending through an upper wall and partially through an inner side wall and an outer C-channel of an outer rail of each of the frame rails. A second notch is formed to extend through an inner upper wall and partially through an inner side wall of an inner C-channel of an inner rail of each of the frame rails. The inner rail is assembled to the outer rail with the notches of each of the frame rails in alignment. A beam is inserted into the notches of the frame rails and welded to the frame rails where the beam is disposed adjacent to the notch. The pickup truck bed is then assembled to the beam or beams. 
         [0014]    These and other aspects of the present invention will be better understood in view of the attached drawings and the following detailed description of the illustrated embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a side elevation view of a pickup truck. 
           [0016]      FIG. 2  is a right rear upper perspective view of the frame rails and bed support beams shown assembled together. 
           [0017]      FIG. 3  is a right rear lower perspective view of a pickup truck bed box, frame rails and bed support beams shown assembled together. 
           [0018]      FIG. 4  is a fragmentary side elevation view of a frame rail and bed support beams. 
           [0019]      FIG. 5  is a transverse cross-sectional view of a pickup truck bed, frame rails and a transverse bed support beam. 
           [0020]      FIG. 6  is an exploded perspective view for a pickup truck bed, transverse bed support beams and a pair of frame rails. 
           [0021]      FIG. 7  is a fragmentary exploded perspective view of a two-part frame rail. 
           [0022]      FIG. 8  is a fragmentary perspective view of a frame rail with a bed support beam shown ready for insertion into an opening in the frame rail. 
           [0023]      FIG. 9  is a fragmentary perspective view of a frame rail and bed support rail assembled together. 
           [0024]      FIG. 10  is an exploded fragmentary perspective view of an alternative embodiment of a frame rail. 
           [0025]      FIG. 11  is a fragmentary perspective view of a frame rail made according to the embodiment of  FIG. 10  with a bed support beam ready for assembly to a slot in the frame rail. 
           [0026]      FIG. 12  is a fragmentary perspective view of a bed support beam shown attached to a frame rail. 
           [0027]      FIG. 13  is a fragmentary exploded perspective view of an alternative bed support structure in which the bed support beam is notched to receive a frame rail. 
           [0028]      FIG. 14  is a fragmentary perspective view of the bed support structure shown in  FIG. 13  after assembly and welding. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    Referring to  FIG. 1 , a truck  10 , for example a pickup truck, is shown that includes a cargo box  12 . The cargo box  12  has a side wall  16  that has a top edge  18 . The top edge  18  of the side wall  16  is shown with a lower top edge as compared to the higher top edge  18  shown in phantom lines. The depth of the box indicated by D is measured from the bottom of the chassis  20  to the top edge  18 . The depth D′ of a higher profile cargo box  12  is also indicated. 
         [0030]    Referring to  FIG. 2 , a right frame rail  22  and a left frame rail  24  extend in a longitudinal vehicle direction. Bed frame beams  28  extend in a transverse vehicle direction through the right and left frame rails  22  and  24 . One of the frame rails has an additional section and may be referred to as a shock support rail  30 . 
         [0031]    Referring to  FIG. 3 , a cargo box  12  is shown assembled to the frame rails  22  and  24  and bed frame beams  28 . The truck bed  32  in the bottom of the cargo box  12  is provided with a plurality of stiffening ribs  36  that extend in the longitudinal vehicle direction. A wheel housing  38  forms part of an inner side wall  40  of the cargo box  12 . 
         [0032]    Referring to  FIG. 4 , a plurality of bed frame rails  28  are inserted transversely through the right frame rail  22 . 
         [0033]    Referring to  FIG. 5 , a truck bed  32  is shown assembled to a top wall  42  of the left and right frame rails  22  and  24 . The frame rails also have a bottom wall  43 . The frame rails each include an outer C-channel  44  and an inner C-channel  46  that are assembled and welded together to form the right and left frame rails  22  and  24 . A strap  48  may be provided between truck bed  32  and the right and left frame rails  22  and  24 . The strap  48  provides additional support across the truck bed  32 . 
         [0034]    Referring to  FIG. 6 , a cargo box  12  is shown separated from the bed frame beams  28  that extend in a transverse vehicle direction and the right and left frame rails  22  and  24  that extend in the longitudinal vehicle direction. The side wall  16  has a top edge  18 . The portion of the cargo box  12  shown in  FIG. 6  is the inner side wall  40  of the truck bed  32 . It should be understood that outer side walls and a front and a rear tailgate are to be provided to complete the structure of the cargo box  12 . The truck bed  32  is reinforced by the straps  48  that extend in the transverse vehicle direction across the bottom of the truck bed  32 . The bed frame beams  28  are inserted through the right and left frame rails  22  and  24 , as will be described more specifically with reference to  FIGS. 7-9  below. 
         [0035]    Referring to  FIG. 7 , left frame rail  24  is shown split into an outer C-channel  44  and an inner C-channel  46 . An opening  50  is formed in the outer C-channel  44  through a side wall  52  of the outer C-channel  44 . A top corner  54  of the outer C-channel  44  is removed and forms part of the opening  50  that extends into the top wall  42 . The opening  50  may be formed in a flat blank that is formed by a press or roll former to have a bottom wall  43  and a top wall  42 . A slot  56  is formed in the inner C-channel  46 . Slot  56  extends through the top wall  58  and side wall  60  of the inner C-channel  46 . The inner C-channel  46  also has a bottom wall  59 . The inner and outer C-channels  44  and  46  are assembled together and welded at the top walls  42 ,  58  and bottom walls  43 ,  59  to form the left frame rail  24 . 
         [0036]    The bed frame beam  28  is inserted through the left frame rail  24 , as shown in  FIG. 8 . The bed frame beam  28  is inserted in the transverse vehicle direction as shown by the arrow on the side of the bed frame beam  28  in  FIG. 8 . The bed frame beam  28  is inserted either from the inside or through the outside of the frame rail  24 . The bed frame beam  28  is located below the top wall  42  of the outer C-channel  44 . The strap  48  may be secured to the top walls  42  of the outer C-channels  44 ,  46 . A flange  49  may be provided or formed on one of the lateral edges of the straps  48 . 
         [0037]    Referring to  FIG. 9 , the left frame rail  24  and a bed frame beam  28  are shown assembled together and welded in place. The bed frame beam  28  extends completely through the left frame rail  24 . The outer C-channel  44  and inner C-channel  46  are welded together as shown by the X marks as identified by letter W in  FIG. 9 . The top walls  42  and  58  of the outer C-channel  44  and inner C-channel  46  may be welded together by a laser weld penetrating the top surfaces or may be welded together by a MIG welding operation with the top wall  42  of the outer C-channel  44  being welded at its end to the top wall  58  of the inner C-channel  46 . The bottom walls  43 ,  59  are welded in a similar manner. The bed frame beam  28  is welded about its periphery where it contacts the edges of the slot  56  in the inner C-channel  46  and also is preferably welded to the opening  50  in the outer C-channel  44 . By welding the bed frame beams  28  on both sides to the frame rail  24 , the structural integrity of the frame rails is maintained and no substantially weakening of the frame rail is caused by the formation of the opening  50  and slot  56  in respective C-channels  44  and  46 . 
         [0038]    Referring to  FIG. 10 , an alternative embodiment is shown. The same reference numerals are used to refer to the same parts of frame rail  24 . As shown in  FIG. 10 , an outer C-channel  44  is shown next to inner C-channel  46 . A slot  62  is formed in the outer C-channel  44  that extends through the top wall  42 . Another slot  64  is formed in the inner C-channel  46  and is in alignment with the slot  62  in the outer C-channel  44 . The slot  62  extends through the top wall  42  and partially through the side wall  52  of the outer C-channel  44 . The slot  64  is formed in the top wall  58  and partially through the side wall  60  of the inner C-channel  46 . 
         [0039]    Referring to  FIG. 11 , the outer C-channel  44  and inner C-channel  46  are shown assembled together with the slots  62  and  64  in alignment. The bed frame beam  28  is shown just prior to assembly into the slots  62  and  64 . In this embodiment, the bed frame beam  28  may be attached to the truck bed  32  and then simply dropped into the slots  62  and  64  with the full height of the bed frame beams  28  being disposed fully or substantially below the top wall  42 . 
         [0040]    Referring to  FIG. 12 , the bed frame beam  28  is shown assembled to and welded in place on the left frame rail  24 . The inner and outer C-channels  44  and  46  are welded together in a MIG welding operation as indicated by the X marks identified by reference letter W. The welds W that secure the inner C-channel  46  to the outer C-channel  44  are formed on the top wall  58  o the inner C-channel  46  and at the end of the top wall  42  of the outer C-channel  44 . While only one set of welds is shown, it should be understood that a similar weld construction is provided to join the bottom walls  43  and  59  of the inner and outer C-channels together. Additional welds W are formed between the left frame rail  24  and the bed frame beam  28  around the edges of the slots  62  and  64  in which the bed frame beams  28  are received. By welding substantially completely around the slots  62  and  64  to the bed frame beams  28 , the strength of the frame rail  28  is not compromised and a robust cargo box  12  may be provided at a lower height due to the fact that the bed frame beams  28  are received below the top wall  42  of the outer C-channel  44 . 
         [0041]    Referring to  FIGS. 13 and 14 , another alternative embodiment is illustrated that could be used with the bed structure shown in  FIGS. 1-6 . The beam  28  has a slot  68  formed in a bottom wall  70  and side walls  72  of the beam  28 . The left frame rail  46  as shown and right frame rail  44  need not have an opening or slot, but may be received in the slot  68 . As another alternative, mating slots (not shown) could be provided in both the beams  28  and frame rails  22  and  24 . With either alternative, a lower height truck bed could be provided. 
         [0042]    While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.