Abstract:
A trailer floor assembly includes a pair of longitudinally extending side rails supporting a plurality of self-mating transverse panels. The plurality of transverse panels includes extruded aluminum panels interspersed with roll-formed steel panels at locations where extra strength is desired (e.g., king pin, landing dollies, and rear door). The extruded panels include T-shaped slots in a bottom wall thereof to allow the extruded panels to be fastened to the side rails by fasteners engaging the bottom wall of the panel but not the top wall the panel. The assembly eliminates transverse cross-beams used to support longitudinal panels in the prior art, and thereby provides improved aerodynamics.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates generally to truck trailer bodies, and more particularly to an improved construction for the floor of a trailer utilizing extruded panels that may be extruded from aluminum. 
       BACKGROUND OF THE INVENTION 
       [0002]    In conventional trailer floor assemblies, cross-members arranged transverse to the longitudinal axis of the trailer at spaced intervals along the length of the trailer support a plurality of overlaid plates or sheets typically fabricated of steel or aluminum. The cross-members, usually embodied as structural steel I-beams, are exposed on the underside of the trailer so as to create an undulating exterior surface with troughs between the cross-members. This increases wind drag and acts to collect dirt, ice and snow, road salt, asphalt and other materials, some of which are corrosive. The collected matter increases weight, further increases wind drag, and is a danger to trailing drivers when it dislodges. 
         [0003]    To address this problem, U.S. Pat. No. 7,152,909 discloses a trailer floor constructed of a series of extruded aluminum panels arranged to extend transversely between left and right rails running along the length of the trailer. The rails are also extruded aluminum, and each rail defines a U-shaped channel that is open toward the center of the trailer for receiving left or right ends of the floor panels, as the case may be. As may be seen at FIGS. 6, and 7 of the &#39;909 patent, the floor panels have top and bottom walls connected by a pair opposing side walls and by at least one vertical I-beam member located between the side walls. The floor panels include a rib projecting outward from one side wall and a groove along the out surface of the opposite side wall, whereby adjacent floor panels may be mated with one another as shown in FIG. 6A. Each corner of the floor panel extrusion includes a step or half-groove that cooperates with the step or half-groove on an adjacent floor panel to form a grove to receive welding material or an adhesive. 
         [0004]    In the solution offered by the &#39;909 patent, the floor panels are supported by a bottom horizontal leg portion of the U-shaped channel, which is a relatively thin aluminum wall projecting from the rest of the rail extrusion. This support arrangement may be too weak and not suitable in areas of high stress (e.g., king pin, landing dollies, and rear door), or in situations where the cargo load carried by the trailer is heavy and/or concentrated away from supported regions of the trailer floor. 
         [0005]    What is needed is an improved trailer floor assembly that is stronger, particularly in areas of high stress (e.g., king pin, landing dollies, and rear door), and does not require welding or application of adhesive to join adjacent panels together during assembly. The trailer floor assembly should exhibit better aerodynamics and have a long useful life even when used on snowy and salt-covered roadways. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention meets the above described needs, and furnishes other improvements. The invention provides a trailer floor assembly comprising a left side rail and a right side rail extending parallel to a longitudinal axis of the trailer floor assembly, and a plurality of extruded metal panels supported by and extending transversely between the left and right side rails. The extruded metal panels may be formed of aluminum for a combination of light weight combined and strength. 
         [0007]    The left and right side rails may include a generally rectangular tube member and a right-angle member fixed to an inner vertical wall of the tube member. Each tube member may be roll-formed from metal to include an outer vertical wall greater in height than the inner vertical wall. 
         [0008]    Each of the plurality of extruded metal panels has a top wall and a bottom wall connected by a front wall and a rear wall, and is attached to the left and right side rails by fasteners engaging the bottom wall of the panel but not the top wall of the panel. In an embodiment of the invention, the bottom wall of each extruded metal panel includes at least one T-shaped slot for receiving the fasteners. Each T-shaped slot defines a pair of upwardly facing shoulder surfaces engaged by fasteners. The fasteners may also engage a horizontal leg of the right angle member of each side rail. 
         [0009]    The trailer floor assembly may further comprise at least one roll-formed steel panel interspersed with the plurality of extruded aluminum panels. For example, a roll-formed steel panel may be provided at a rear end of the trailer floor assembly, a plurality of adjacent roll-formed steel panels may be provided at a front end of the trailer floor assembly, and roll-formed steel panels situated between extruded aluminum panels along the length of the trailer floor assembly. In this regard, the word “interspersed” is used in a broad sense and does not require that a roll-formed panel be directly adjacent to an extruded panel or between two extruded panels, but merely that the trailer floor assembly includes both types of panels. 
         [0010]    The front wall and rear wall of the extruded and roll-formed panels may be configured to include complementary curved portions, whereby the front wall of one panel mates with the rear wall of an adjacent panel. One of the complementary curved portions may have a recess for defining a gap between the front and rear walls of adjacent panels so that sealant or epoxy may be injected into the gap. The extruded panels may be provided with partitions connecting the top wall and the bottom wall, wherein a plurality of internal compartments are defined. The internal compartments may be filled with foam insulating material. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING VIEWS 
         [0011]    The invention will be explained further with reference to drawing figures in which: 
           [0012]      FIG. 1  is a top plan view of a trailer floor assembly formed in accordance with an embodiment of the present invention; 
           [0013]      FIG. 2  is a rear end view of the trailer floor assembly shown in  FIG. 1 ; 
           [0014]      FIG. 3  is a cross-sectional view of an extruded metal floor panel used in the trailer floor assembly of  FIG. 1 ; 
           [0015]      FIG. 4  is a cross-sectional view of a roll-formed steel floor panel known from the prior art and incorporated into the trailer floor assembly of  FIG. 1 ; 
           [0016]      FIG. 5  is an enlarged cross-sectional view illustrating how an extruded aluminum floor panel is fastened to a supporting side rail in the trailer floor assembly; and 
           [0017]      FIG. 6  is a cross-sectional view showing mated floor panels of the trailer floor assembly. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]      FIGS. 1 and 2  depict a trailer floor assembly  10  formed in accordance with an embodiment of the present invention. Trailer floor assembly  10  comprises a left side rail  12 L and a right side rail  12 R extending parallel to a longitudinal axis  11  of the trailer floor assembly. The trailer floor assembly  10  also comprises a plurality of extruded metal panels  14  supported by and extending transversely between left side rail  12 L and right side rail  12 R. Assembly  10  may further comprise at least one roll-formed steel panel  16  interspersed with the plurality of extruded metal panels  14 . In the embodiment illustrated in  FIG. 1 , trailer floor assembly  10  has a roll-formed steel panel  16  at a rear end of the trailer floor assembly, a plurality of adjacent roll-formed steel panels  16  at a front end of the trailer floor assembly, and several roll-formed steel panels  16  at intervals between the front and rear ends of the trailer floor. The steel panels  16  provide greater strength over the king pin region at the front of the trailer, at landing dolly positions along the trailer, and at the rear door area of the trailer. 
         [0019]    As best seen in  FIGS. 2 and 5 , each of the left and right side rails  12 L,  12 R may include a generally rectangular tube member  18  and a right-angle member  20  fixed to an inner vertical wall  22  of tube member  18 , for example by welding and/or fasteners. Generally rectangular tube member  18  also includes an outer vertical wall  24  greater in height than inner vertical wall  22 , a horizontal top wall  26 , and a horizontal bottom wall  28 . Tube member  18  may be roll-formed from steel sheet material. Right-angle member  20  may be a standard size structural steel member having a vertical leg  21  arranged in surface-to-surface engagement against vertical wall  22  of tube member  18  and a horizontal leg  23  arranged such that its upwardly facing surface is flush (coplanar) with an upwardly facing surface of top wall  26  of tube member  18 . The height of panels  14  and  16  may be chosen to correspond with the differential height of outer vertical wall  24  above horizontal top wall  26  such that the open side ends of the panels are closed by outer vertical wall  24  in the assembly as depicted in  FIG. 5 . 
         [0020]      FIG. 3  is a cross-sectional view of an extruded metal panel  14  according to an embodiment of the present invention. Metal panel  14  may be extruded from aluminum, which provides good strength yet is lightweight relative to steel. Panel  14  comprises a monolithic body having a top wall  30  and a bottom wall  32  connected by a front wall  34  and a rear wall  36 . While panel  14  is elongated in a direction normal to the drawing sheet of  FIG. 3 , the walls  34  and  36  are referred to herein as front and rear walls, rather than side walls, to indicate the direction that each wall faces with respect to assembly  10  as a whole. It is noted that panel  14  could be reversed such that front wall  34  would become the rear wall (the wall facing the rear of trailer floor assembly  10 ) and rear wall  36  would become the front wall (the wall facing the front of trailer floor assembly  10 ) without straying from the invention. The cross-section of panel  14  is constant along its entire length from the left end of the panel to the right end of the panel. 
         [0021]    The bottom wall  32  of each extruded metal panel  14  includes at least one T-shaped slot  38  for receiving fasteners to attach the left and right ends of each panel  14  to the left and right side rails  12 L,  12 R, respectively. In the present embodiment, exactly two T-shaped slots  38  are provided. Each T-shaped slot  38  defines a pair of upwardly facing shoulder surfaces  40 . As may be understood from  FIG. 5 , the fasteners may each be comprised of a bolt  18  and mating nut  19 , wherein the bolt  18  is inserted into the slot from the open left or right end of panel  14  such that the enlarged head of the bolt engages shoulder surfaces  40  when nut  19  is tightened onto a threaded end of the bolt arranged to extend through a hole  25  provided in horizontal leg  23  of right-angle member  20 . In this way, the left and right ends of panel  14  may be attached to side rails  12 L,  12 R by fasteners engaging the bottom wall  32  of panel  14  but not the top wall  30  of panel  14 . 
         [0022]    Front wall  34  and rear wall  36  of each panel  14  may be configured to include complementary curved portions  42  and  44 , whereby the front wall  34  of one panel mates with the rear wall  36  of an adjacent panel as illustrated in  FIG. 6 . One of the complementary curved portions  42 ,  44  may have a recess for defining a gap between the front and rear walls  34 ,  36  of adjacent metal panels  14 . In the embodiment shown in  FIG. 3 , curved portion  42  associated with front wall  34  has such a recess  46 . As shown in  FIG. 6 , the gap between front and rear walls  34 ,  36  of adjacent panels may be injected with sealant or epoxy  48  to keep water out and prevent dissimilar met al corrosion where aluminum and steel panels are arranged adjacent one another as described below. 
         [0023]    Complimentary curved portions  42 ,  44  of front and rear walls  34 ,  36  may be configured to enable extruded panels  14  to mate with adjacent roll-formed steel panels  16  in addition to other extruded panels  14 .  FIG. 4  shows a roll-formed steel panel  16 , which is known in the prior art in connection with railcar flooring as evidenced by U.S. Pat. No. 6,973,881, the entire disclosure of which is incorporated herein by reference. Roll-formed panel  16  is shown as including a top wall  70 , a pair of bottom walls  72 , a front wall  74  connecting one of the pair of bottom walls  72  to the top wall, and a rear wall  76  connecting the other bottom wall  72  to the top wall. Panel  16  further includes a pair of inner support walls  82  extending almost vertically from respective bottom walls  72 . Front wall  74  and rear wall  76  include complementary curved portions  78 ,  80  having the same size and curvature as complimentary curved portions  42 ,  44 . As may be understood from  FIG. 6 , this allows the front wall  34  of an extruded panel  14  to mate with the rear wall  76  of an adjacent roll-formed panel  16 , and the rear wall  36  of an extruded panel  14  to mate with the front wall  74  of an adjacent roll-formed panel  16 . As may be appreciated, it is desirable to configure extruded panels  14  to have the same overall height as roll-formed panels  16 . In order to attach roll-formed steel panel  16  to side rails  12 L and  12 R, it is necessary to drill holes through bottom walls  72  to accommodate the fastener elements, i.e. bolt  18  and nut  19 . 
         [0024]    Extruded panels  14  may further include at least one internal partition connecting top wall  30  and bottom wall  32 , wherein a plurality of internal compartments are defined. In the embodiment of  FIG. 3 , panel  14  has exactly four partitions cooperating with the front and rear walls  34 ,  36  to define exactly five internal compartments. In the exemplary embodiment of  FIG. 3 , panel  14  has a pair of vertical partitions  50  centered one above each T-shaped slot  38 , and another pair of inclined partitions  52  in the region between vertical partitions  50 . Partitions  50  cooperate with front wall  34  and rear wall  36 , respectively, to define internal compartments  54  and  55 . Partitions  50  also cooperate with respective adjacent partitions  52  to define internal compartments  56  and  57 . Partitions  50  cooperate with each other to define a central internal compartment  58 . In an embodiment of the invention, one or more of the internal compartments  54 ,  55 ,  56 ,  57 , and  58  may be filled with foam insulating material  84  as shown in  FIG. 6   
         [0025]    Other features of extruded panels  14  may prove advantageous. For example, top wall  30  of extruded panel  14  may include a plurality of striations  64  on an upper surface thereof to help prevent slipping. For improving strength under loading, reinforced regions  60  may be provided where partitions  50  join with an underside of top wall  30 . Top wall  30  may also include a central reinforced region  62  between partitions  52 . 
         [0026]    As will be appreciated, panels  14  and  16  are self-mating and do not require welding. The T-shaped slots of panel  14  remove the need to drill fastener holes for use in attaching the panel to the side rails  12 L,  12 R. The trailer floor assembly  10  of the present invention decreases wind drag and reduces deposits of dirt, salt and debris by eliminating cross-beams and the undulating undersurface associated with the cross-beam construction of prior art floor assemblies. 
         [0027]    While the invention has been described in connection with exemplary embodiments, the detailed description is not intended to limit the scope of the invention to the particular forms set forth. The invention is intended to cover such alternatives, modifications and equivalents of the described embodiment as may be included within the spirit and scope of the invention.