Abstract:
A modified seat frame incorporates a wall riser having an integrated mounting flange to reduce welding operations and to reduce the number of parts required to build and install a modular school bus seat.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to school bus seats and more particularly to a flange for mounting a seat riser along a chair support rail of a school bus interior wall. 
         [0003]    2. Description of the Problem 
         [0004]    School bus seats are built to meet many differing customer specifications. For example, some bus seats must accommodate three point safety belts by providing a compatible upper back rest, other specifications call for a universal child restraint attachment equipped lower frame, while still others provide standard DOT (United States Department of Transportation) seat backs. At the same time customers can specify seats in different widths or heights and can demand various strength requirements. 
         [0005]    Differing customers&#39; specifications have required substantially or entirely different component sets from which to assemble the seats. The need to supply such component sets has even occurred with respect to completed vehicles where the vehicle has been moved from one state or municipality to another, based on differing requirements of the new jurisdiction. 
         [0006]    Modular construction of bus seat frames is known, one example being taught in U.S. Pat. No. 6,886,889 to Vits et al. FIGS. 18-20 of the Vits &#39;889 patent teach a modular seat based on four major sub-assemblies. The sub-assemblies include a frame assembly, a floor mount assembly, a passive restraint panel and a seat member. The frame assembly in turn comprises a pair of opposed side forms of generally elbow shaped and concave construction, two upright members or posts which support the passive restraint panel, longitudinal front and rear members for mounting between the opposed side forms and cross members between the front and rear members. The frame assembly is supported by a pair of identical pedestals (collectively the floor mount assembly) disposed under the respective side forms. In some embodiments one of the pedestals is replaced by a wall mount bracket best shown in  FIG. 27  of the patent. 
         [0007]    Current seat designs include numerous fabricated parts and require welds to form joints between frame components and sub-assemblies. The process is labor intensive, adding to the overall seat cost. Frame assemblies must be painted after welds are complete because the welding process would burn off the paint. This process constraint along with the inherent difficulty shipping large seat frames limits sourcing opportunities and necessitates a paint operation in the plant. The prior art design shown in  FIG. 2  had a stamped wall-side riser with separate L-section mounting flange. This construction added to the part count and required its own welding operations. 
         [0008]    Prior art designs have been complicated and have required frequent tests of production material to ensure that components and welds have not drifted outside of compliance, a particularly important step where substantial heat processing, such as welding, is involved in the seat assembly process. It would be advantageous to eliminate metal to metal welding steps wherever possible. 
       SUMMARY OF THE INVENTION 
       [0009]    The invention provides a mounting flange integrated with the wall riser for a modular seat frame. The mounting flange is integrated into the stamped wall-side riser, thus eliminating extra components and welds, by providing a turned out lower strip along the bottom edge of the wall riser. 
         [0010]    Additional effects, features and advantages will be apparent in the written description that follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
           [0012]      FIG. 1  is a perspective view of a school bus. 
           [0013]      FIG. 2  is a perspective view of a prior art school bus seat frame. 
           [0014]      FIG. 3  is a perspective view of a modular school bus seat frame incorporating a wall riser in accordance with a preferred embodiment of the invention. 
           [0015]      FIG. 4  is an exploded view of the school bus seat frame illustrated in  FIG. 3  better illustrating the wall riser with integrated mounting flange. 
           [0016]      FIG. 5  is a perspective view of a wall riser showing the integrated mounting flange. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    Referring now to the drawings and in particular to  FIG. 1 , a school bus  10  with which the present invention is advantageously used is illustrated. Seat frames incorporating wall risers with integrated mounting flanges may be installed with one side nestled against an interior wall of the interior  18  of the bus. 
         [0018]      FIG. 2  illustrates a seat frame  20  according to the prior art. A closed loop, multi-piece full perimeter tube  26  outlines the seating area. The full perimeter tube  26  is supported by an aisle riser  22  and a wall riser  24 . Wall riser  24  is constructed by welding together at least two plates. An internal frame  28  and a back seat support  30  are nestled within the closed perimeter tube  26 . Excluding the risers  22 ,  24 , virtually none of the components are reusable should seat specifications, such as width, or height of the seat back be changed. Internal frame  28  parallels portions of the perimeter tube  26 , reinforcing the sides of the perimeter tube and adding a seat back bottom brace  34  and a cross member  32  to give the frame  20  rigidity. 
         [0019]    Referring to  FIG. 3 , an assembled modular school bus seat frame  40  is illustrated disposed on the floor  42  (shown in phantom). Modular frame  40  is supported on its inside end by attachment of wall riser  48  which is mounted to a chair rail  62  of a school bus interior wall  44  (shown in phantom). Modular school bus seat frame  40  thus is supported both from the floor  42  and from the wall  44 . Support from the floor  42  is provided by an aisle riser  46 . Support from the wall  44  is provided by a wall riser  48 . Aisle riser  46  and wall riser  48  differ from the aisle risers and floor risers known from the art in that they form part of what would traditionally be considered the frame itself. Both the aisle riser  46  and the wall riser  48  are modified to function as frame elements, in part by inclusion of necks  50  which provide bases of support for an open, partial perimeter tube  52  used to define the top and sides of a seat back portion of frame  40 . In addition, wall riser  48  is formed  72  from a one piece stamping which provides a riser integrated mounting flange for attachment to the chair rail  62 . Extending between and fitted into the aisle riser  46  and the wall riser  48  are front and back latitudinal supports  60  and  56 . Supports  56  and  60  come in varying lengths to support seats of varying widths. Risers  46  and  48  are stamped elements with interior (i.e. facing) sides which are contoured to reinforce the riser and to provide convenient points of attachment for the front and rear cross member supports  60 ,  56 . 
         [0020]      FIG. 4  illustrates the modular seat frame  40  in an exploded view which better illustrates the contours of risers  46 ,  48  and cross supports  56 ,  60 , which meet to provide the joints. Necks  50  are formed from C-channel sections extending upwardly from the upper rearward areas of aisle riser  46  and wall riser  48 . The channels are open one with respect to the other. Open perimeter tube  52  fits into the necks  50  at its opposite ends. The joint formed by joining the ends of the perimeter tube  52  to the necks  50  is reinforced by addition of an U-reinforcement member  64  which fits into the neck  50  between the tube  52  and the interior of the necks  50 . Bolts  66  are inserted through the walls of the necks  50 , U-reinforcement members  64  and the ends of perimeter tube  52 . 
         [0021]    In one embodiment, back panel  54  includes a partial perimeter flange  74  by which the panel is attached to tube  52 . Risers  46 ,  48  include inner face contours  76  which position the ends of rear and front supports  56 ,  60 . Risers  46 ,  48  have integral inwardly turned flanges  78  along their top and front edges. In addition, risers  46 ,  48  have a back edge flange  71 , which are also inwardly turned. Flanges  71  and  78  provide surfaces against which opposite surfaces of the front and rear cross members  60 ,  56  may be placed to be secured by self pierce rivets (not shown), or other methods such as low temperature welding. Front cross member  60  is substantially formed in three panels, front panel  61 , intermediate panel  63 , and top panel  65  with panel  63  being intermediate to panels  61  and  65 . Cross members with alternative cross sectional profiles are possible. The angle between panels  61  and  65  corresponds to the angle between the front and top edge sections of flange  78 , allowing the cross member to be brought into contact with both portions of the flange concurrently. Panel  63  intersects both panels  61  and  65  obliquely along the respective interior side (i.e. the underside of the member relative to the risers) and positioned between the two panels functions as a cross brace between the flange  78  portions. 
         [0022]    Rear cross member  56  incorporates two major sections, a top section  57  and a back section  59 . The ends of top section  57  and back section are angled (essentially a right angle) to allow them flush mating of the sections to the under surface of the top portion of flange  78  and the forward surface of flange  71 . Self pierce rivets (not shown), adhesives or welds are used to attach either member  60 ,  56  to the riser. 
         [0023]    Aisle riser  46  includes legs which support the structure from the floor. A plate  68  is provided for securing fasteners between the riser  46  and a vehicle floor. Wall riser  48  includes an integrated mounting flange  72  allowing securing of the wall riser  48  to a wall support. Attachment plate  68  and washer  70  are used in mounting the riser to the wall support. 
         [0024]      FIG. 5  is a perspective view of the wall riser  48  of the preferred embodiment where a mounting flange  72  has been formed in a one piece stamping joined at a right angle to adjacent portions of the main body  82  of the wall riser. Mounting flange  72  is located along a lower edge of the main body  82  of the wall riser  48 , connected along a right angle bend  84  which is interrupted only by three reinforcement darts  80 , which resist changes in the overall shape of the riser. The mounting flange  72  is flat and orients the riser  50  on the chair rail upon positioning of the riser. The flat upper  81  and lower (not shown) major surfaces are horizontal and parallel to the floor of the vehicle after installation. Three holes  86  are located in flange  72 , connecting the upper and lower major surfaces of the flange. The holes  86  provide points for the insertion of conventional fasteners/darts for connecting the flange  72  to the chair rail  62 . Flange  72  is positioned on the major body  82  to be horizontal upon positioning of a completed seat frame in a bus for installation. 
         [0025]    While the invention is shown in only a few of its forms, it is not thus limited but is susceptible to various changes and modifications without departing from the spirit and scope of the invention.