Abstract:
A motor vehicle frame having parallel frame rails and at least one cross member constructed from a tube. The tube is sealed at its opposite ends by first and second mounting plates to provide a sealed, closed space for the storage of fluids. The mounting plates directly abut the frame rails for attachment of the cross member to the vehicle frame.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    The disclosure relates to frames for motor vehicles and in particular to an improved frame incorporating one or more air tanks disposed as structural cross members between long axis frame rails. 
         [0003]    2. Description of the Problem 
         [0004]    The fundamental structural members in frames for heavy duty motor vehicles, such as trucks, are a pair of elongated, longitudinally-extending main frame rails. The frame rails lie in parallel to the long or longitudinal axis of the vehicle. The two frame rails are spaced from one another and secured to one another using cross members. These cross members are usually, but not always, perpendicular to the frame rails and lie in the plane of the frame rails. 
         [0005]    It has been common to hang various components, such as fuel tanks, battery packs and compressed air tanks for heavy duty vehicles from the frame. These components may be bolted to the frame rails or cross members, or supported on subassemblies which in turn are hung from or otherwise supported from the frame. These components and their support arrangements add weight to the vehicle, and in some applications take up valuable space or require compensating actions to off set balance issues raised by the components. 
         [0006]    Ramsey, United States Published Patent Application 2005/0062251 recognized that it has been generally desirable to reduce the weight of heavy duty vehicles and to simplify their construction. Ramsey proposed utilizing air tank(s) to double as vehicle frame cross member(s), replacing existing cross members and thereby saving some weight while concurrently simplifying vehicle construction and maintaining, or even increasing, the structural integrity of the frame. Ramsey taught securing air tanks between frame main members and wheel suspension system hangers so that the frame reacts loads imposed on the frame during vehicle operation. 
       SUMMARY 
       [0007]    A motor vehicle is provided with a frame having parallel frame rails and at least one cross member constructed from a tube sealed at its opposite ends by first and second mounting plates. The cross member directly abuts the frame rails along the mounting plates which close the opposite ends of the tube. 
         [0008]    Additional effects, features and advantages will be apparent in the written description that follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The contribution to the art believed novel is set forth in the appended claims. The preferred mode of use will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
           [0010]      FIG. 1  is a plan view of a vehicle chassis or frame. 
           [0011]      FIG. 2  is a plan view of a vehicle frame incorporating the present invention. 
           [0012]      FIG. 3  is a perspective view of an air tank cross member. 
           [0013]      FIG. 4  is a perspective view of end mounting plates for the air tank cross member of  FIG. 3 . 
           [0014]      FIG. 5  is a cross sectional view of an air tank cross member taken along section lines  5 - 5  in  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    Referring now to the drawings and in particular to  FIG. 1 , a plan view of a vehicle chassis/frame  80  illustrates a conventionally constructed chassis. Chassis  80  comprises a pair of parallel, longitudinally extending frame rails  10  and  12  which extend from the front end  82  of the vehicle to the rear end  84 . Frame rails  10  and  12  are connected to one another by a plurality of cross members  83 . The cross members  83  are mounted perpendicular to the frame rails in the plane of the frame/chassis  80 . Chassis designs employing other configurations for cross members, such as an X-member frame where cross members also cross one another, are known but less usual. Front steerable wheels  86  are carried on a front axle  88  while rear drive wheels  90  are carried on a rear axle  92 . An accessory support platform  20  hangs from side rails  10  and  12  between the front axle  88  and rear axle  92 . A tank  25  is illustrated supported on the rails  22 ,  24 ,  26  along the driver&#39;s (left hand) side of the chassis/frame  80 . The support rails  22 ,  24 ,  26  illustrate a conventional application of supporting an accessory such as a tank from a vehicle frame. The use of such support rails, and alternative techniques for supporting accessories from the frame such as hanger brackets, etc., adds weight to the final vehicle and occupies space. Accessory support platform  20  comprises three support rails  22 ,  24  and  26 , which are mounted hung from the frame rails  10  and  12 . Support rails  22 ,  24  and  26  are parallel to one another and perpendicular to the frame rails. Support rails  22 ,  24  and  26  are substantially longer than the spacing between frame rails  10  and  12 , with the result that the support rails extend out from the frame rails toward the sides of the vehicle and can be used to provide a substantial area of support between the frame rails and the outside edges of the vehicle. 
         [0016]    Referring now to  FIG. 2 , a combined structural member/air tank  30  has been substituted for one of the cross members  30  between frame rail  10  and frame rail  12 . This structural air tank cross member  30  is disposed perpendicular to the frame rails  10  and  12  in the plain of the frame  80  and is mounted directly against the inside faces of the frame rails along its ends. 
         [0017]    Referring to  FIG. 3 , structural air tank cross member  30  is illustrated in greater detail. Structural air tank cross member  30  combines reinforced flat mounting plates  41 , which function both as cross member mounting elements and to close the ends of the cross member  30 , with a section  31  of tube/pipe to form a volume  60  (shown in  FIG. 5 ) for the storage of compressed air. Tube section  31  is closed at its opposite ends using the reinforced flat mounting plates  41  to form the tank. Since essentially any thickness of tube may be used for tube section  31 , provided it meets the structural requirements of the vehicle, the cross member  30  can be built to meet any strength requirement. Tube section  31  conventionally has a circular cross section for greater strength and reduced material usage for a given volume, but could have other cross sectional shapes including rectangular. Inlet and outlet check valves  45  and  47  provide for the introduction and release of air from air tank cross member  30  as required. 
         [0018]      FIG. 4  shows a reinforced flat mounting plate  41  used to close either end of a tube section  31 . Mounting plate  41  comprises three major pieces, a back plate  42  and two front collar plates  43 ,  44 , which incorporate collars  45 ,  46 , respectively. The front collar plates  43 ,  44  bracket one end of a tube section  31 . An open end of a tube section  31  fits against the back plate  42  and may be welded to the back plate to seal the end of the structure and provide the volume for storage for compressed air. Front plates  43  and  44  are mounted with the collars  45 ,  46  fit snugly around the end of the tube section  31  to seat the tube section and protect the welds. Plates  43  and  44  are welded to back plate  42 . Apertures  51  are located through the front plates  44 ,  43  and the back plate  42  allowing the member to be secured by bolts to a vehicle frame rail. 
         [0019]      FIG. 5  is a cross section of one end of member  30 , illustrating the juncture of tube  31  with back plate  42 , and the use of front plates  43  and  44  to collar an end of the tube. Back plates  42  close the ends of tube  31  complete enclosure of volume  60 . Tube  31  may be conventionally attached to the back plate  42  using welding. 
         [0020]    Conflating air tank and cross member allows better packaging of multiple air tanks, lower vehicle weight, and eliminates air tank hanger brackets on a bus chassis. The lower cost and weight of vehicles afforded by using the air tanks as the center portion of the cross members allows for better packaging on short wheel base vehicles. The mounting arrangement simplifies the assembly of the vehicle. 
         [0021]    While only a preferred embodiment is described here in detail, the claims are not limited thereto, but are intended to extend to various changes and modifications thereof.