Abstract:
A frame and suspension for a high ground clearance truck trailer. Independently moving suspension arms are suspended outboard and rearward on opposing sides of the frame, and wheel spindles are cantilevered outboard and below the frame so as to provide an unobstructed empty volume underneath the frame.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 61/026,303, filed Feb. 5, 2008, titled HIGH GROUND CLEARANCE AXLELESS VEHICLE, all of which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention pertains to vehicle suspension systems that do not have an axle, and in particular, to a suspension system for a truck having high ground clearance between wheels of the payload section. 
       SUMMARY OF THE INVENTION 
       [0003]    Various aspects of some embodiments of the inventions shown and described herein pertain to a ground vehicle with high road clearance. 
         [0004]    Yet other aspects of various embodiments pertain to ground vehicles having independent suspension, with the suspension arms being adapted and configured to support wheels on opposing sides such that the space under the bottom of the frame and between the opposing suspension arms is substantially free of any obstructions. 
         [0005]    Yet other aspects of various embodiments pertain to a substantially flat-bottomed vehicle frame that is suspended from a roadway by suspension arms having spindles that are cantilevered outward. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0006]      FIG. 1-P  is a photographic side view of a tractor trailer of an existing design. 
           [0007]      FIG. 2-P  is a photographic side view of a subchassis according to one embodiment of the present invention. 
           [0008]      FIG. 3-P  is a photographic end view of the apparatus of  FIG. 2 . 
           [0009]      FIG. 4-P  is a photographic view from underneath the apparatus of  FIG. 2 . 
           [0010]      FIG. 5-P  is a photographic side view of a portion of the apparatus of  FIG. 2 . 
           [0011]      FIG. 6-P  is a photographic view of a portion of the apparatus of  FIG. 2 . 
           [0012]      FIG. 7-P  is a rearward, left side photographic view of a suspension arm and frame according to one embodiment of the present invention. 
           [0013]      FIG. 8-P  is a side photographic view of the apparatus of  FIG. 7 . 
           [0014]      FIG. 9-P  is a side photographic view of the apparatus of  FIG. 7 . 
           [0015]      FIG. 1  is a line drawing representation of  FIG. 1-P . 
           [0016]      FIG. 2  is a line drawing representation of  FIG. 2-P . 
           [0017]      FIG. 3  is a line drawing representation of  FIG. 3-P   
           [0018]      FIG. 4  is a line drawing representation of  FIG. 4-P   
           [0019]      FIG. 5  is a line drawing representation of  FIG. 5-P   
           [0020]      FIG. 6  is a line drawing representation of  FIG. 6-P   
           [0021]      FIG. 7  is a line drawing representation of  FIG. 7-P   
           [0022]      FIG. 8  is a line drawing representation of  FIG. 8-P   
           [0023]      FIG. 9  is a line drawing representation of  FIG. 9-P   
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0024]    For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. 
         [0025]    The use of an N-series prefix for an element number (NXX.XX) refers to an element that is the same as the non-prefixed element (XX.XX), except as shown and described thereafter. As an example, an element 1020.1 would be the same as element 20.1, except for those different features of element 1020.1 shown and described. Further, common elements and common features of related elements are drawn in the same manner in different figures, and/or use the same symbology in different figures. As such, it is not necessary to describe the features of 1020.1 and 20.1 that are the same, since these common features are apparent to a person of ordinary skill in the related field of technology. Although various specific quantities (spatial dimensions, temperatures, pressures, times, force, resistance, current, voltage, concentrations, wavelengths, frequencies, etc.) may be stated herein, such specific quantities are presented as examples only. Further, discussion pertaining to a specific composition of matter, that description is by example only, does not limit the applicability of other species of that composition, nor does it limit the applicability of other compositions unrelated to the cited composition. 
         [0026]      FIG. 1  shows a vehicle  20  including a tractor section and a trailer section. Trailer or payload section  22  includes a central container  24  that includes an underneath opening through which the operator of vehicle  20  dumps the contained load. This configuration of vehicle  20  is referred to a “belly dump” or “bottom dump” truck. Container  24  is supported on a frame  26  in the approximate middle of the payload section  22 . The front of the payload section is supported by the rear wheels of the tractor section. The rear of payload section  22  is supported by a subchassis  28  that includes a suspension having a plurality of tires supporting the payload section  22  from the roadway. The tires and wheels are coupled to the subchassis  28  by various suspension components. The subchassis  28  of the vehicle  20  includes numerous components, both static and movable, located between the wheels. The ground clearance of subchassis  28  is largely established by these components, which can include axles, suspension assemblies, springs, brake components, and frame sections. 
         [0027]    Referring to  FIGS. 2-9 , a vehicle  120  according to one embodiment of the present invention includes a subchassis  30  that provides similar support function as subchassis  28 , but accomplishes many of these functions with greater clearance above the roadway. 
         [0028]    Although an inventive subchassis  30  will be shown and described after reference to a particular exiting subchassis  28 , it is understood that various embodiments of the present invention pertain to many other applications, including subchassis mounted forward of the container, and also trucks with a substantially integral frame (in contrast to the tractor trailer shown in  FIG. 1 ) in which the inventive subchassis includes one or more pairs of wheels fore or aft of a bottom dumping container. Further, yet other embodiments of the present invention pertain to road vehicles of any type in which ground clearance is a consideration. 
         [0029]      FIGS. 2-9  depict various views of various embodiments of the present invention.  FIGS. 2 ,  3 , and  4  show a subchassis  30  according to one embodiment of the present invention. Subchassis  30  includes a frame  31  comprising right and left side rails  32  interconnected by a plurality of cross members  33 . Subchassis  30  is adapted and configured to integrate into a frame  126  of a vehicle  120 . Subchassis  30  includes a top surface  34  that can support a payload. Subchassis  30  is integrated into vehicle  120  by being combined into frame  126 , or including supporting a payload section  122  on top surface  34 . 
         [0030]    Subchassis  30  includes a plurality of upper spring brackets  36  and pivot support brackets  38  that are adapted and configured to interface with corresponding airbags and pivot couplings, respectively. As shown in  FIGS. 2 ,  3 , and  4 , subchassis  30  provides upper spring brackets  36  and pivot support brackets  38  such that six pairs of tires  41  (not shown) coupled to wheels  40  (not shown) provide support to vehicle  120  from the roadway. Although a subchassis  30  has been shown and described including three pairs of opposing wheels, it is understood that the present invention contemplates single pairs of opposing wheels as well as multiple pairs of opposing wheels. 
         [0031]    During normal operation of vehicle  120 , the rotational axis  77  established by spindle  62  is generally below the pivot axis of the corresponding suspension arm  60 . However, during jounce operation, the rotational axis may be momentarily above the pivot axis. In addition, other embodiments of the present invention contemplate a kneeling arrangement whereby the airbags  44  are deflated to permit the dump opening of container  24  to be located closer to the roadway. 
         [0032]    Referring to  FIGS. 3 and 4 , one embodiment of the present invention provides for support of an opposing pair of wheels (represented by brake drums  46  and  46 ′) that are not interconnected with an axle. Preferably, each wheel of the corresponding opposing pair of wheels can move independently of the other of the pair of opposing wheels, relative to the subchassis frame. The interconnection between opposing wheels is through frame  31 , and not by an axle. 
         [0033]    By not incorporating an axle to interconnect an opposing pair of wheels, it is possible to have a ground clearance volume that extends across the width horizontally underneath the bottom surface  35  of the frame, as represented by arrow  80   w.  Further, the absence of an axle interconnecting opposing wheels also provides a vertical clearance  80   h  from the roadway to the bottom surface  35  of the subchassis frame. Referring to a subchassis such as subchassis  30  incorporating three pairs of axleless opposing wheels, there is a clearance volume underneath subchassis  30  that is generally defined by width  80   w,  height  80   h,  and the length from the forwardmost to the rearward most pair. It is understood that the distance  80   h  from about the bottom surface  35  of the frame to the roadway is greater than the distance shown in  FIGS. 3 and 4  because those photographs lack the corresponding wheels and tires mounted on brake drums  46  and  46 ′. 
         [0034]      FIGS. 5 and 6  show close-ups of a single suspended brake drum  46 . A suspension arm  60  pivotal about a pair of elastomeric bushings  74  rotatable supports a brake drum  46 . Suspension arm  60  is biasingly coupled to upper spring bracket of the frame of subchassis  30  by a spring or airbag  44 . Further, a shock absorber  48  dampingly couples suspension arm  60  to the frame of subchassis  30 . 
         [0035]      FIGS. 7 ,  8 , and  9  depict various viewing angles of a suspension arm  60  coupled to the frame  31  of subchassis  30 . A suspension arm  60  is pivotally coupled to a pivot support bracket  38  by a pair of aligned inboard and outboard elastomeric bushings  74 . Support bracket  38  extends outwardly from frame  26 , such that suspension arm  60  is located outboard of the clearance volume  80 . In one embodiment, suspension arm  60  is cantilevered aft from support bracket  38 . Bushings  74  permit arm  60  to pivot about a pivot axis  72  that is located forward of the rotational centerline  77  of a spindle  62 . Suspension arm  60 , of one embodiment, is of the trailing arm variety. Further information about elastomeric bushings  74  can be found in U.S. Pat. No. 6,398,251, incorporated herein by reference. 
         [0036]    Suspension arm  60  includes a structural peripheral frame  66  to which portions of the bushings  74  are attached. Located within the periphery of frame  66  is a lower spring support  68  that is biasingly coupled by airbag  44  to frame  31 . Bushings  74  are attached to a support bracket  38  that is rigidly attached (such as by welding) to other members of frame  31 . 
         [0037]    Suspension arm  60  further includes a generally vertical plate  64  that extends from an outboard side of frame  66 . A spindle  62  couples to plate  64  and rotatably supports braking equipment, a wheel, and a tire. Spindle  62  is cantilevered outward from plate  64 , as best seen in  FIG. 7 . A plurality of corner stiffening plates  70  are shown in the corners of a generally rectangular frame  66 . Although what is shown in  FIGS. 7 ,  8 , and  9  is an arm  60  that is a weldement, the present invention also contemplates arms fabricated by casting. As one example, suspension arm  60  may include structural features similar to the features shown in the suspension arm of U.S. Pat. No. 6,398,251. 
         [0038]    Referring to  FIG. 9 , it can be seen that the rotational centerline  77  of spindle  62  sweeps a sector of a cylindrical arc as it pivots about pivot axis  72 . It can be seen that this cylindrical sector can be extended into a cylindrical surface underneath bottom surface  35  of frame  31 . This cylindrical surface is largely unobstructed by any static members beneath the frame. 
         [0039]    While the inventions have been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.