Abstract:
A hitch coupling assembly attaching a trailer to a towing vehicle. The towing vehicle including a hitch plate that has an upper surface and an open end for receiving a king pin. The coupling assembly has an arm with opposite ends. A skid plate is attached to one end of the arm and the skid plate has a perimeter defined by sides. The king pin extends from a surface of the skid plate. A journal pin is attached to the opposite end of the arm and is rotatable relative to the arm. The journal pin is optionally lockable or the arm relative to the hitch is optionally lockable.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application No. 60/867,534, filed Nov. 28, 2006, the disclosure of which is hereby incorporated by reference. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a trailer hitch coupling assembly, and more particularly, to a pin box assembly using a combination pin box and extension assembly with locking features to facilitate a change in the axis of rotation of a fifth wheel trailer when attached to a towing vehicle. 
   2. Description of the Background of the Invention 
   Fifth wheel trailers have customarily been adapted with a coupling apparatus which facilitates attachment to a towing vehicle. Typically, a standard fifth wheel hitch is mounted on the towing vehicle, where a standard pin box on the fifth wheel trailer is adapted with a king pin to fit the hitch and properly support the weight of the trailer. 
   The towing vehicle, equipped with the hitch, and with the trailer secured, can then be driven supporting the trailer, which rotates securely around an axis created by the interconnect between the trailer king pin and the adaptive mount on the hitch. 
   Numerous advancements in the art have been shown. For example, as disclosed in U.S. Pat. No. 6,986,524, a fifth wheel pin box assembly with a rubber shear spring to accomplish appreciable cushioned movement in the connection between the towing vehicle and the trailer. 
   Another example includes an extension coupling for use with trailers, as described in U.S. Pat. No. 5,890,728, in which a retainer assembly engages the trailer hitch to resist rotation around the king pin axis and force rotation of the trailer back to a separate axis. This coupling was developed to accommodate use on only short-bed towing vehicles where a more forward axis of rotation of the trailer could cause impact between the trailer and the cab of the towing vehicle. Additionally, by design, this coupling introduces uneven stress on a trailer hitch in its engagement when turning maneuvers are instituted. 
   Many consumers of fifth wheel trailers may own different towing vehicles, including those of the short-bed and long-bed varieties. It would be desirable to have a hitch coupling assembly available for use with a variety of towing vehicles, in which the axis of rotation is easily moved forward or backward based on towing-vehicle bed length through use of a locking mechanism. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide an improved hitch coupling assembly used to couple a trailer and its towing vehicle. 
   It is another object of the present invention to provide a hitch coupling assembly that can be used for both short-bed and long-bed towing vehicles. 
   Another object of the present invention is to provide a hitch coupling assembly for changing the axis of rotation of a fifth wheel trailer around a towing vehicle by providing a removable locking mechanism and an additional pin for a separate rotational axis. 
   According to one aspect of the present invention, there is provided a hitch coupling assembly including a pin box and an attached arm. The pin box includes a pin passing therethrough with attached brackets for connection to a trailer chassis. The arm includes a skid pad assembly to which a pin is attached for connection to a trailer hitch. A lock-out stop is included which allows for rotation of the hitch coupling assembly to be alternately moved from an axis around the pin attached to the skid pad assembly to an axis around the pin inside the pin box. 
   According to another aspect of the present invention, there is also provided a hitch coupling assembly including a pin box and an attached arm. The pin box includes a pin passing therethrough with attached brackets for connection to a trailer chassis. The arm includes a skid pad assembly to which a pin is attached for connection to a trailer hitch. A set of lock-out stops is included which allows for rotation of the hitch coupling assembly to be alternately moved from an axis around the pin attached to the skid pad assembly to an axis around the pin inside the pin box. 
   In another aspect, the present invention provides a hitch coupling assembly including a pin box and an attached arm. The pin box includes a pin passing therethrough with attached brackets for connection to a trailer chassis. The arm includes a skid pad assembly to which a pin is attached for connection to a trailer hitch. A lock-out stop and a hitch plate lock-out stop are included which allow for rotation of the hitch coupling assembly to be alternately moved from an axis around the pin attached to the skid pad assembly to an axis around the pin inside the pin box. 
   The present invention in another aspect also provides a hitch coupling assembly including an integrated arm. The integrated arm includes a pin passing therethrough with attached brackets for connection to a trailer chassis. The integrated arm also includes a skid pad assembly to which a pin is attached for connection to a trailer hitch. A lock-out stop and a hitch plate lock-out stop are included which allow for rotation of the hitch coupling assembly to be alternately moved from an axis around the pin attached to the skid pad assembly to an axis around the pin inside the integrated arm. A collar is provided which allows for multiple vertical positions of the hitch coupling assembly. 
   In another aspect, the present invention provides a hitch coupling assembly including an integrated arm. The integrated arm includes a pin passing therethrough with attached brackets for connection to a trailer chassis. The integrated arm includes an attached pin for connection to a trailer hitch. A lock-out stop and a hitch plate lock-out stop are included which allow for rotation of the hitch coupling assembly to be alternately moved from an axis around the pin attached to the skid pad assembly to an axis around the pin inside the integrated arm. A collar is provided which allows for multiple vertical positions of the hitch coupling assembly. 
   The various objects, features and advantages of the present invention will become more readily apparent from a consideration of the following description of the illustrative embodiments thereof, when read in conjunction with the accompanying drawings, in which like reference numerals represent the same or similar items. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1A  is a top plan view of a towing vehicle and a fifth-wheel travel trailer combination; 
       FIG. 1B  is a side elevational view of the towing vehicle and fifth-wheel travel trailer combination showing use of an embodiment of a rotational pin box assembly according to the present invention; 
       FIG. 2  is an exploded perspective view of an embodiment of the rotational pin box assembly; 
       FIG. 3  is a perspective view thereof; 
       FIG. 4  is a side elevational view thereof; 
       FIG. 5  is a sectional view thereof, taken along line B-B of  FIG. 4 ; 
       FIG. 6  is a front elevational view thereof; 
       FIG. 7  is a sectional view thereof, taken along line A-A of  FIG. 6 ; 
       FIG. 8  is an exploded front elevational view of an embodiment of the rotational pin box only; 
       FIG. 9  is a sectional view thereof, taken along line C-C of  FIG. 8 ; 
       FIG. 10  is a perspective view according to another embodiment of the rotational pin box assembly; 
       FIG. 11  is an exploded perspective view according to further embodiment of the rotational pin box assembly; 
       FIG. 12  is a perspective view thereof, including a stop plate mounted to a hitch; 
       FIG. 13  is a plan view thereof; and 
       FIG. 14  is an exploded perspective view according to another embodiment of the rotational pin box assembly. 
   

   DETAILED DESCRIPTION OF INVENTION 
   A hitch coupling assembly  10  that is useful for connecting a trailer  14  to a towing vehicle  12  according to the present invention is described with reference to  FIGS. 1A and 1B , in which both figures show a trailer axis of rotation X, such as is common for traditional hitch coupling assemblies, and an axis of rotation Y, which is achieved through use of the hitch coupling assemblies further developed below. 
   In  FIGS. 2-9 , one embodiment  10  of a hitch coupling assembly is shown. As shown in  FIG. 2 , this embodiment includes, generally, a pin box  16  for securement to an arm  40 . The pin box encloses a journal pin  22  which passes therethrough around an opening lined with top and bottom bearings  17 . The bearings  17  are preferably fiberglass and Teflon-lined, but may be made of other material designed to allow the pin box  16  to rotate about the journal pin  22 . Secured around the top end of the journal pin  22 , preferably through a weld, are brackets  24  and  26 . A plurality of apertures  70  shown on bracket  26  and apertures  72  shown on bracket  24  allow for connection of the brackets  24 ,  26  to the inner chassis of a fifth wheel trailer  14 . A set of upper washers  18 ,  20  are secured around the journal pin  22  between the top of the pin box  16  and the bottom of the bracket  24 . The first upper washer  18  is preferably made of plastic and used to provide cushioning and ease the rotation of the pin box  16  about the journal pin  22 . The second upper washer  20  is preferably made of metal. A lower set of washers  18 ,  30  are secured around the journal pin  22  between the bottom of the pin box  16  and a lower bolt  32 . The washers  18  are preferably made of plastic and used to provide cushioning and ease the rotation of the pin box  16  about the journal pin  22 . The washer  30  is preferably made of metal. The lower bolt  32  is threaded into a threaded hole located on the bottom of the journal pin  22 , which then secures the above-described components together. It is preferable to include sidewall reinforcements  38  on the pin box  16  to meet current industry ratings standards for strength and rigidity. 
   The arm  40  includes on a distal end  46 , on which is attached a skid pad assembly  48 , described generally in U.S. Pat. No. 6,986,524, and incorporated herein by reference, for mounting the hitch coupling assembly  10  to a trailer hitch  74 . The skid pad assembly  48  includes a skid pad  50  having sides  51 . A back end portion  62  supports a rubber shear spring  66  and accompanying bolts  60  that restrain shafts  58  and channel members  68 . A king pin  42  may be secured to the skid pad  50  by welding and is of a standard conventional construction known in the art. As is well-known, the king pin  42  has a reduced section which receives lever-operated jaws in the receiving mechanism on the towing vehicle to lock the king pin  42  therein. The straight end  54  contains holes for removably securing lock-out stop  34  to the bottom of skid pad  50 . In operation, lock-out stop  34  will rest against a trailer hitch plate  76  and prevent movement of the king pin  42  within the hitch plate  76 . 
   A plurality of holes  45  on the arm  40  are aligned with a plurality of holes  35  on the pin box  16 , and the arm  40  is secured to the pin box  16  with a plurality of fasteners  37  passing through holes  35  and  45 . As shown in  FIGS. 2-7 , the arm  40  is shown at its upmost position secured to the pin box  16 . As all fifth wheel trailers do not maintain an exact height in relation to a towing vehicle hitch, additional holes  35  are provided to be able to secure the arm  40  in at least two positions within the pin box  16 . It can be appreciated that the pin box  16  may be designed with additional vertical adjustments to allow for additional rows of holes  35  for different vertical positions of the arm  40 . 
   As shown in  FIGS. 3-7 , the lock-out stop  34  may be moved from its position on the bottom of skid pad  50  to a position on the bottom and back of the bracket  24  which extends laterally beyond the pin box  16 , being secured by fasteners  33  and attached nuts  36 . 
   To use the hitch coupling assembly  10  as a standard hitch coupling assembly, it should be configured as shown in  FIG. 3 , the brackets  24  and  26  are used to secure the hitch coupling assembly  10  within the chassis of a standard fifth wheel trailer  14 . The pin box  16  and arm  40  may be attached either before or after the assembly  10  is secured to the trailer  14 . The lock-out stop  34  is secured to the bottom and back of the bracket  24  through use of the fasteners  33  and attached nuts  36 . As the back end of the bracket  24  extends laterally beyond the pin box  16 , the lock-out stop is maintained adjacently abutted to the pin box  16 . When the towing vehicle  12  is engaged in a turning maneuver, rotation of the pin box  16  and attached arm  40  will not be allowed around the journal pin  22 , as the abutment of the lock-out stop  34  will force rotation of the trailer  14  forward to the axis formed around the king pin  42  within the hitch plate  76 . 
   Alternatively, the hitch coupling assembly  10  may be for short-bed towing vehicles, as shown in  FIGS. 2 ,  10 , and  12 . The brackets  24  and  26  are again used to secure the hitch coupling assembly  10  within the chassis of a standard fifth wheel trailer  14 . The pin box  16  and arm  40  may be attached either before or after the assembly  10  is secured to the trailer  14 . The lock-out stop  34  is secured to the bottom of skid pad  50  through use of the fasteners  33  and nuts. As the hitch coupling assembly  10  is moved into position to engage the hitch plate  76  through the king pin  42 , the lock-out stop  34  is maintained adjacently abutted to the hitch plate  76 . When the towing vehicle  12  is engaged in a turning maneuver, rotation of the king pin  42  within the hitch plate  76  will be prevented by the abutment of the lock-out stop  34  to the hitch plate  76 , and rotation of the trailer will be forced backward to an axis of rotation around the journal pin  22 . In this configuration, the pin box  16  and attached arm  40  move with the towing vehicle  12 , as the journal pin  22  with attached brackets  24 ,  26 , rotate within the pin box  16 . As shown in  FIGS. 8 and 9 , the washers  18 ,  20  and  18 ,  30  and bearings  17  provide ease of rotation as the pin box  16  rotates around the journal pin  22 . 
   In  FIG. 10 , another embodiment of a hitch coupling assembly is shown. This embodiment includes alternative lock-out stop  78  secured to the skid pad  50  for maintaining adjacent abutment of the lock-out stop  78  against the hitch plate  76 , for use with short-bed towing vehicles. Alternatively, when a standard hitch coupling assembly is desired, the lock-out stop  78  is secured to the bottom and back of the bracket  24 . The lock-out stop  78  performs essentially the same function as the lock-out stop  34 . 
   In  FIGS. 11-13 , a further embodiment of a hitch coupling assembly is shown. A skid pad assembly  148  has a skid pad  80  and upturned ends  82 . All other elements of assembly  148  are identical to the elements of assembly  48 . The lock-out stop  34  and a hitch lock-out plate  86  are provided. The lock-out plate  86  has a back wall  88  and side walls  90  and is designed to be rigidly mounted over a hitch plate  76  using a plurality of fasteners  94  driven through holes  92  into the hitch plate  76 . 
   Adjusting the rotational axis of the hitch coupling assembly is accomplished through movement of the hitch lock-out plate  86  and the lock-out stop  34 . In a standard configuration, lock-out stop  34  is connected to the pin box  16  and bracket  24  with fasteners  36 . This is shown in  FIG. 11 . Simultaneously, the lock out-plate  86  is in the stored position on top of the arm  44 . The king pin  42  engages the trailer hitch plate  76  and the trailer  14  rotates about the axis of the king pin  42 . 
   A short-bed towing vehicle configuration is shown in  FIG. 12 . The hitch lock-out plate  86  is removed from its stored position and attached by fasteners  94  to the hitch plate  76 . Such a hitch plate  76  may need modification, through drilling or punching holes, to accommodate fasteners  94 . The lock-out stop  34  is disconnected from the bracket  24  and moved to a stored position near the bottom of the pin box  16  where it is secured through fasteners  33  to supports  15 , as shown in  FIG. 12 . When a towing vehicle engages in a turning maneuver in this configuration, the sides of skid pad  50  and upturned ends  82  are maintained adjacently abutted to the side walls  90  and back wall  88  of the hitch lock-out plate  86 , forcing rotation of the trailer around an axis formed by the journal pin  22 . It is important to remove lock-out stop  34  in this configuration, or an undesirable double lock-out situation would occur in which the trailer  14  would not be allowed any axis of rotation. 
   A modification of the hitch coupling assembly is shown in another embodiment in  FIG. 14 . This configuration includes an integrated arm  140  with attached skid pad  50 . The basic operation of the configuration shown in  FIG. 14  is the same as the configuration shown in  FIGS. 11-13 . A lock-out stop  96  is designed to attach to the bracket  24  with fasteners  33  and maintain an adjacent abutment and attachment to the integrated arm  140  with fasteners  98  in a standard towing vehicle configuration and to be removed entirely for short-bed towing purposes. A plate  130  has holes for securement of fasteners  132  to journal pin  122  for securing the journal pin  122  within the integrated arm  140 . A collar  99  has two sections  100 ,  102  fit between the washer  18  and the top of the integrated arm  140  around the hole for the journal pin  122 . The two sections  100 ,  102  are connected through fasteners  103  and nuts  101 . A plurality of tabs  104  removably secure the collar  99  within a plurality of slots  105  formed in the integrated arm  140 . 
   If the height of the integrated arm  140  is desired to be movable vertically so as to accommodate different heighted trailers and trailer hitches, the collar  99  may be removed through removal of fasteners  103 . The sections  100 ,  102  are pulled away from the journal pin  122  and either placed in a position on the upperside or underside of the integrated arm  140 , where a plurality of slots  106  are located to removably secure the collar in either position. It can be appreciated from this description that a variety of collars  99  may be designed with different vertical extents to accommodate a variety of height configurations for the integrated arm  140  as it is positioned relative to the trailer hitch  74 . 
   From the above description, it will be apparent that the invention disclosed herein provides a novel and advantageous pin box assembly. The foregoing discussion discloses and describes merely exemplary methods and embodiments of the present invention. As will be understood by those familiar with the art, the invention may be embodied in other specific forms and utilize other materials without departing from the spirit or essential characteristics thereof. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.