Abstract:
A frame for a vehicle chassis includes C-cross section side rails and interconnecting cross members which extend through the vertical webs of the side rails and are attached with connecting brackets to the outside faces thereof. This construction provides the capability of utilizing extended length cross members to which other vehicle components, such as fuel tanks, suspension members, fenders and the like, may be attached.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims priority to U.S. Provisional Patent Application Ser. No. 60/811,869, filed Jun. 8, 2006. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to frames for heavy trucks and, more particularly, to special multi-function cross members that are used to connect the frame side rails and to provide attachment for other vehicle equipment.  
         [0003]     In order to meet federally mandated vehicle emission requirements, truck manufacturers have had to use larger cooling packages and exhaust systems. In addition to the added cost, these changes also add significantly to the vehicle weight and, as a result, to reduced fuel efficiency. Therefore, there is a great emphasis on weight reduction in all vehicle components.  
       SUMMARY OF THE INVENTION  
       [0004]     Heavy duty truck frames are typically fabricated from steel channel section members that are used for the main side rail pair, as well as for the connecting cross members and connecting brackets (if brackets are used). The channel members may be made of either heat treated steel or high strength low alloy (HSLA) steel. Although side rails may be interconnected by the cross members using welded connections, more typically mounting brackets are used to facilitate bolted connections between side rails and the cross members. It is well known that the side rail flanges provide most of the side rail stiffness in the vertical direction, which stiffness is the primary strength requirement in truck frames. Because the web that connects the flanges has far less effect on vertical stiffness, it has recently been proposed to remove material from the web without significantly decreasing the vertical stiffness of the side rail.  
         [0005]     In accordance with the present invention, heavy truck frame side rails are connected with cross members that extend through the side rail webs and are attached thereto with a mounting bracket that also functions to mount other truck components or equipment. The cross members may utilize conventional channel section members or, preferably, the cross members are square section tubular members. The side rails may be conventional channel sections or may utilize weight saving concepts that remove significant amounts of material from the side rail web. Such side-rail concepts are described in more detail in copending application Ser. No. 11/734,904, filed Apr. 13, 2007, the disclosure of which is incorporated by reference herein. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIGS. 1-4  are perspective views of three different heavy truck frames utilizing multi-function cross bars of the present invention.  
         [0007]      FIGS. 5 and 6  are details of the truck frame of  FIG. 4  showing multi-function mounting brackets of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0008]      FIG. 1  shows a heavy truck frame  9  using conventional C-section channels  10  for the side rails  11 . Each channel section  10  includes horizontal upper and lower flanges  12  connected by a central web  13 . The main cross members  14  connecting the side rails  11  comprise tubular steel members  15  having a square cross section. For each cross member  14 , the webs  13  of the side rails  11  are pierced to form a square hole for receipt of the cross member  14 .  
         [0009]     As is shown in the drawing, each cross member  14  extends a significant distance beyond the outer face of the side rail web  13 . The extended ends  16  of the cross members  14  may be used to support a variety of different truck components. For example, the mid-frame cross members are shown supporting a pair of fuel tanks  17 .  
         [0010]     Each cross member  14  is secured to the web  13  through which it extends with a mounting bracket  18  on the outer face of the web  13 . Each mounting bracket is attached to the web  13  and to the cross member  14 , preferably with bolted connections. The mounting bracket  18  may be fabricated from steel, but preferably comprises a casting made either of iron or steel.  
         [0011]     At the rear end of the frame  9 , cross members  14  having even longer extended ends  20  are used to support the fender and mud flap assemblies  21 . In addition, the rear mounting brackets  22  which secure the cross members to the side rail webs  13  are made to also function to support the rear spring assemblies  23 . This dual function for the mounting brackets  18  eliminates the need for separate rear spring hanger brackets.  
         [0012]     Referring to  FIG. 2 , there is shown a truck frame  24  in which each of the sided rails  25  comprises a pair of upper and lower angle sections  26 , instead of a more conventional channel member. In other words, the space normally occupied by the web of a conventional C-section channel member is eliminated in the side rails  25 . The horizontal flanges of the angle sections  26  provide the side rail flanges which, as indicated previously, are largely responsible for the vertical stiffness of the side rails. The vertical flanges of the angle sections  26  are utilized to connect the cross members  27  which may be identical to the cross members  14  used in the  FIG. 1  frame. Thus, the mid-frame cross members  27  have extended ends  28  which are used to support fuel tanks  30 . The cross members  27  are secured to the side rail angle sections  26  with mounting brackets  29  that can be similar to the mounting brackets  28  of the  FIG. 1  embodiment.  
         [0013]     In a manner similar to the  FIG. 1  embodiment, the cross members have even longer extended ends  32  used to support fender and mud flap assemblies  33 . The rear mounting brackets  31  may be used to help secure the fender assemblies to the frame and may also provide support for the rear spring assemblies  35  or other components.  
         [0014]     The mounting bracket  31 , as also shown in  FIG. 6 , may comprise a unitary casting  60  having a square through hole for receipt of a square section cross member  27 . The bracket includes integral upper and lower plates  61  that attach directly to the vertical flanges of the side rail sections  26 . Each mounting bracket casting  60  includes a central horizontal sleeve  63  sized to receive the end of the tubular cross member  27 , and plates  61  in the form of a peripheral flange  64  that lies against and is attached to a side face of the central web  13 . It may also be desirable to make the side rails more rigid by interconnecting the upper and lower angle members with diagonal struts  62 .  
         [0015]     In  FIG. 3 , there is shown a further embodiment of the invention applied to a truck frame  36  in which the side rails  37  are formed with an expanded metal construction by stretching a pre-slit blank transversely to the slits, resulting in a channel member with an open web construction as shown. The cross members  38  also have a similar expanded web configuration including an open web  40  interconnecting upper and lower flanges  41 .  
         [0016]     Referring to the rearmost cross members  38  in  FIG. 3 , the cross members  38  may be attached to the side rails  37  with mounting brackets  42  and bolted connections in a conventional manner. However, mounting brackets  42  may also be configured to attach to the side rails  37  from the outside and to include an outer mounting structure  43  for direct connection of the rear spring assemblies  44  or other chassis components.  
         [0017]     The frame assembly  45  shown in  FIG. 4  is similar to the  FIG. 1  frame. Frame assembly  45  includes C-section channels  46  for the side rails  47  with square section tubular members  48  as the primary cross members  50  interconnecting the side rails  47 . The side rail webs  51  are pierced to receive the ends of the cross members  50 . Rigid connections between the side rails  47  and the cross members  50  are provided with cast brackets  52  that fit over the outer ends of the cross members  50  and are bolted thereto and to the outside faces of the side rail webs  51 . These brackets  52  are shown in greater detail in  FIG. 6 . Although the cast brackets  52  serve only a frame connecting function,  FIG. 5  shows a modified bracket  53  used at the rear of the frame to provide both the frame connection function and as a mounting bracket for the rear truck suspension. This arrangement provides a weight saving as well as an overall simplification in the assembly of the frame. As indicated previously, because the webs  51  of the side rail channels  46  have negligible effect on vertical frame stiffness, piercing the webs to provide holes for the tubular cross members  50  can be done without significantly decreasing side rail stiffness.