Abstract:
A vehicle trailer hitch including an aluminum tubular U-shaped strut and a cast aluminum receiver mounted thereto. Ends of the strut tube are flatted to form integral planar mounting flanges for mounting the hitch to a vehicle.

Description:
RELATED APPLICATIONS  
       [0001]    This application is a continuation of U.S. Ser. No. 10/269,483 entitled “Trailer Hitch” filed Oct. 11, 2002, which is a divisional of U.S. Ser. No. 09/694,590, filed Oct. 23, 2000, now U.S. Pat. No. 6,464,240, entitled “Trailer Hitch”. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to vehicle trailer hitches, more particularly to a two component trailer hitch manufactured from aluminum.  
         BACKGROUND OF THE INVENTION  
         [0003]    Many passenger vehicles, particularly trucks, vans and sport utility vehicles are used to tow a trailer. The trailer is attached to a towing vehicle via a trailer hitch. One common type of trailer hitch is a receiver trailer hitch which includes a generally rectangular shaped tubular receiver in an assembly fixed to the vehicle frame structure. A generally rectangular shaped tongue extending from the trailer is mounted inside the receiver. The trailer hitch communicates the pulling, turning and braking forces from the towing vehicle to the trailer. Trailer hitches must bear a significant load and are designed for both functionality and aesthetics. In view of the strength and safety requirements of trailer hitches, a conventional 10,000-pound capacity trailer hitch typically weighs about of 35 pounds.  
           [0004]    These conventional devices are typically formed from steel and include assembly of numerous components which may number as high as eight or more and which are joined together via arc welding. These heavy trailer hitches are often difficult to manipulate when installing or removing from a vehicle. Moreover, the weight of the trailer hitch adds significantly to the vehicle weight, thus reducing the fuel efficiency of the towing vehicle.  
           [0005]    Typical trailer hitches formed from steel and having multiple components are disclosed in U.S. Pat. Nos. 3,578,358; 4,032,170; 5,102,156; 5,511,813; 5,620,198 and 5,277,448. Common to the trailer hitches disclosed in each of these patents is a multi-piece structure having an overall U-shaped configuration which is bolted at least at the ends of the U-shaped structure to the towing vehicle. U.S. Pat. No. 5,489,111 discloses a hidden trailer hitch having a curved strut member with mounting flanges attached to the end of the curved structure. U.S. Pat. No. Des. 427,118 discloses a design of elliptical tubes for use in a trailer hitch.  
           [0006]    A significant drawback to conventional trailer hitches is the sheer number of components of the trailer hitches. The number of components adds to the complexity in manufacturing and installing the trailer hitch as well as the overall weight of the trailer hitch.  
           [0007]    Accordingly, a need remains for a simple, lightweight vehicle trailer hitch having a minimum number of components.  
         SUMMARY OF THE INVENTION  
         [0008]    This need is met by the vehicle trailer hitch of the present invention which includes 1) a unitary strut having a pair of integrally formed mounting members positioned at the ends of the strut and 2) a unitary receiver fixed to the strut at a position between the ends of the strut. Preferably, the strut is a U-shaped tubular member manufactured from extruded aluminum alloy having a cross-sectional configuration of an oval or a football-shape, with the mounting members formed at the ends of the tube. The ends of the tube are flattened to provide substantially planar portions. One or more openings are defined in the planar portions for receiving a fastener therethrough to fix the tube to a vehicle. The receiver includes a cast aluminum body preferably welded to the strut. An opening defined in the receiver is configured to receive one end of a trailer. The internal surfaces of the opening may be coated with a protective material such as stainless steel.  
           [0009]    The receiver further includes a bracket extending from the top of the receiver body. The bracket includes an arcuately shaped attachment surface which abuts the exterior surface of the tube. A support member extends from the bottom of the receiver body and includes an elongated support surface is disposed on an opposing side of the tube from the arcuately shaped attachment surface. A hanger may be fixed to the tube for supporting and mounting electrical cables thereto.  
           [0010]    The present invention further includes a method of manufacturing a vehicle trailer hitch having the steps of providing a tube having a pair of ends, bending the tube into a U-shape, flattening the ends of the tube to form a pair of substantially planar portions, reforming a portion of the tube between the ends to mate with a trailer receiver and mounting a trailer receiver on the tube at a position between the ends. The step of providing a tube preferably includes extruding an aluminum alloy tube having an oval or football-shaped cross-sectional configuration. A portion of tube is reformed to achieve a cross-sectional configuration which mates with a surface of the receiver. The receiver preferably is manufactured from cast aluminum and is welded to the tube. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    A complete understanding of the invention will be obtained from the following description when taken in connection with the accompanying drawing figures wherein like reference characters identify like parts throughout.  
         [0012]    [0012]FIG. 1 is a perspective view of a vehicle trailer hitch made in accordance with the present invention including a tube, a receiver and a bracket;  
         [0013]    [0013]FIG. 2 is a cross-sectional view of the tube shown in FIG. 1 taken along line  2 - 2 ;  
         [0014]    [0014]FIG. 3 is a cross-sectional view of the tube shown in FIG. 1 taken along line  3 - 3 ;  
         [0015]    [0015]FIG. 4 is a cross-sectional view of the vehicle trailer hitch shown in FIG. 1 taken along line  4 - 4 ;  
         [0016]    [0016]FIG. 5 is a perspective view of the receiver shown in FIG. 1;  
         [0017]    [0017]FIG. 6 is a front elevation view of the receiver shown in FIG. 5;  
         [0018]    [0018]FIG. 7 is a top view of the receiver shown in FIG. 5;  
         [0019]    [0019]FIG. 8 is a front elevation of the bracket shown in FIG. 1; and  
         [0020]    [0020]FIG. 9 is a top view of the bracket shown in FIG. 8. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0021]    For purposes of the description hereinafter, the terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom” and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting.  
         [0022]    The vehicle trailer hitch  2  of the present invention shown in FIG. 1 includes, in its most basic form, a U-shaped strut  10  and a receiver  30  mounted to the strut  10  with an optional hanger  70 .  
         [0023]    The strut  10  is preferably in the form of a tube having a cross-sectional configuration which varies long its length. The strut  10  preferably is extruded aluminum alloy of the Aluminum Association 6000 series, more preferably alloys 6082, 6063 or 6061, most preferably alloy 6082. The ends of the strut  10  are flattened, e.g. in a press, to form the cross-sectional configuration shown in FIG. 2, thereby creating integrally formed mounting members  12 . The mounting members  12  may have other configurations yet be integrally formed with the strut  10 . The mounting members  12  each define at least one, preferably two, holes  14  in an underside  16  thereof and a corresponding number of holes  18  in an upper side  20 . Preferably, the holes  14  and  18  have the same or similar dimensions, although one set of holes  14  and  18  may have different dimensions from another set of holes  14  and  18 . Each set of one hole  14  and one hole  18  is aligned to receive a fastener (not shown) therethrough. Preferably, a headed bolt or the like seats on the underside  16  of the mounting members  12  and the shank of the bolt extends through the holes  14  and  18  and into the underside of a vehicle (not shown) to mount the hitch  2  to the vehicle.  
         [0024]    An intermediate portion  22  of the strut  10  has a generally oval or football-shaped cross-sectional configuration as shown in FIG. 3, and a central portion  24  of the strut  10  has an irregular cross-sectional configuration as shown in FIG. 4 in the location of the receiver  30 . Preferably, the strut  10  is extruded as a straight tube having a wall  25  and a football-shaped cross-sectional configuration. The ends are flattened to form the mounting members  12 , and the tube is bent into a U-shape forming curved portions  26 .  
         [0025]    Referring to FIG. 1, the wall  25  of the strut  10  may further define one or more openings  28  through a single thickness of the wall  25 . The openings  28  are positioned and sized to accommodate downwardly extending structures on the underside of a vehicle which would otherwise interfere with the positioning of the strut  10  against the under side of the vehicle.  
         [0026]    The wall  25  of the strut  10  is deformed from the extruded cross-sectional configuration as shown in FIG. 4 to permit mounting of the receiver  30  to the central portion  24  of the strut  10 . The receiver  30  is preferably fixed to the central portion  24  of the strut  10  via welding as shown at reference numerals  31 . The cross-sectional configuration of the central portion  24  of the strut  10  achieves an acceptable mating relationship between the strut  10  and the receiver  30 .  
         [0027]    The receiver  30  includes a unitary body  32  which defines a socket opening  34  for receiving the tongue member of a trailer (not shown). The receiver preferably is manufactured from cast aluminum of the Aluminum Association 3xx series, more preferably alloy A356. An inner surface of the socket opening  34  is preferably lined with a plasma sprayed composition such as stainless steel to provide wear resistance and corrosion resistance to the aluminum receiver  30 . An arm  36  extends from the body  32  on an opposite side thereof from the socket opening  34 . An elongated flange  38  extends from the arm  36  and includes a strut support surface  40 . Preferably, the central portion  24  is welded to the strut support surface  40  of the receiver  30 . One or more brackets  42  extend from an upper side of the receiver  30  and include a wall  44 . A sloped ledge  46  extends from one side of the wall  44 , a generally horizontal ledge  48  extends from a topside of the wall  44 , and a generally vertical ledge  50  extends from a rear side of the wall  44 . An arcuately shaped flange  52  extends from the vertical ledge  50  and includes a strut receiving surface  54  on an underside of the ledge  50  and at least one, preferably two, ribs  56  formed in an upper surface thereof. Each sloped ledge  46  defines an opening  58  for receiving safety chains and the like of a trailer (not shown), and each wall  44  defines an opening  60  for receiving a trailer hitch pin (not shown). A mounting hole  62  is defined in the horizontal ledge  48 . A bolt (not shown) may extend from an underside of the ledge  48 , through the hole  62  and into the underside of a vehicle (not shown) to further secure the hitch  2  to the vehicle.  
         [0028]    Referring to FIGS. 1, 8 and  9 , the trailer hitch  2  may include a hanger  70  fixed to the intermediate portion  22  of the strut  10 . The hanger  70  includes a planar member  72  defining one or more first openings  74  for providing access to weld the hanger  70  to the strut  10 . A second opening  76  and third openings  78  defined in the planar member  72  are sized and configured to receive electrical connections and/or cables between the vehicle and the trailer. A pair of side support members  78  is integrally formed with the planar member  72  and has curved surfaces  80  which mate with the strut  10 .  
         [0029]    Having described the presently preferred embodiments, it is to be understood that the invention may be otherwise embodied within the scope of the appended claims.