Abstract:
A fifth wheel hitch adapted for receiving a hitch ball. The fifth wheel hitch has a frame that is mountable to a towing vehicle surface. The frame has an outer sleeve that is fixed with respect to the frame and a receiver is telescopingly received inside the outer sleeve. The receiver is moveable longitudinally with respect to the outer sleeve. The receiver has an upper end, a lower end, and a support wall within the receiver that is located between the upper and lower ends. The receiver is selectively lockable with respect to the outer sleeve. The selective locking is done with a combination of a pin driven through aligned holes in the outer sleeve and receiver and threaded fasteners drive through the outer that impinge on the receiver to prevent rattling.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Traditional king pin and fifth wheel hitches used on recreational vehicles are similar to those used on tractor trailer combinations and have the same disadvantages. The king pin must be at a very specific height for its entry into the fifth wheel hitch. The operator of the vehicle must back into the king pin when it is at its proper height. Performing this task can be nearly impossible in locations other than a large, level, and flat surface. 
         [0002]    Another problem with traditional king pin and fifth wheel hitches is the constraint of the trailer to rotate in a single plane. In a traditional fifth wheel hitch, the pin is locked with a jaw that restrictively limits the out of plane movement with respect to the hitch. While this may work for a tractor trailer combination, it is extremely undesirable for smaller vehicles. Traveling over uneven terrain will necessitate out of plane movement. A previous attempt to provide out of plane movement with a fifth wheel hitch has been to provide a pivot pin below the fifth wheel plate. This is done to provide a gimbaled connection and this allows the entire fifth wheel plate to pivot, but adds significant weight and complexity to the hitch. 
         [0003]    An additional problem of traditional fifth wheel hitches and other hitches is difficulty in determining whether a secure connection has been made. The locking parts within a traditional fifth wheel hitch are not visible when the hitch is properly connected. As such, an user of such a hitch is required to test the connection before traveling. If this is not done, the user runs the risk of dropping the trailer. This unsafe situation can damage the towing vehicle as well as other vehicles near the towing vehicle. A more flexible system that provides assurance a proper connection has been made is needed for an ordinary recreational user that may lack the requisite skill to align a king pin in a fifth wheel hitch. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention is for a fifth wheel hitch that is useful for receiving a coupler that may be in the shape of a ball. The fifth wheel hitch has a frame that is mountable to a vehicle surface. The frame includes an outer sleeve that is fixed with respect to the frame. A receiver tube is telescopingly received inside the outer sleeve and moveable longitudinally with respect to the outer sleeve. The receiver tube has an upper end, a lower end, and a support wall within the receiver tube that is located between the upper and lower ends. The receiver tube is selectively lockable with respect to the outer sleeve. 
         [0005]    Additionally, the outer sleeve may include a fastener driven through it that is adapted for impinging on the receiver tube. The receiver tube and outer sleeve may both have apertures through them that are alignable and adapted for receiving a pin to lock the receiver with respect to the outer sleeve. Further, a catch pin may be retractably located in the receiving tube so that in a first position it acts to restrain a hitch ball placed within the receiver, and in a second withdrawn position, the hitch ball is free to be removed from the receiver. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a perspective view of the fifth wheel hitch; 
           [0007]      FIG. 2  is another perspective view of the fifth wheel hitch shown in  FIG. 1 ; 
           [0008]      FIG. 3  is a sectional view of the fifth wheel hitch shown in  FIGS. 1 and 2  taken about the centerline of the hitch ball; 
           [0009]      FIG. 4  is a side view of the fifth wheel hitch shown in  FIGS. 1-3 ; 
           [0010]      FIG. 5  is a perspective view of the fifth wheel hitch taken perpendicularly to that of  FIG. 2  through the center of the hitch ball; 
           [0011]      FIG. 6  is sectional view of the fifth wheel hitch taken through the center of a spring loaded locking pin; 
           [0012]      FIG. 7  is a sectional view of an embodiment of a locking mechanism that uses a non-spring pin for locking; and 
           [0013]      FIG. 8  is a magnified view of the sectional view shown in  FIG. 7 . 
       
    
    
     DETAILED DESCRIPTION OF INVENTION 
       [0014]      FIG. 1  shows a view of the fifth wheel hitch  10  of the present invention as it is used with a pin box  12  of a mating trailer. The trailer is not shown but may be a recreational vehicle or other trailer that would be towed using a fifth wheel in a pickup truck or other towing vehicle capable of supporting a fifth wheel hitch. For the purposes of this description hereinafter, a pickup truck will be considered the towing vehicle. 
         [0015]    The fifth wheel hitch  10  of the present invention is used with a hitch ball  16  that extends downwardly from the pin box  12 . A hitch ball  16  is shown, but it is not absolutely necessary that the hitch ball  16  that acts as a coupling member be a complete ball. Production of a ball is a simple way to achieve the goals of this invention and provides rounded contact surfaces that assist the function of the invention. It is possible that the coupling member, which is shown as a hitch ball  16  in the figures, be a non-spherical shape or a partially spherical shape. Having the lowermost portion of the hitch ball  16  as a spherical shape is generally advantageous to facilitate smooth movement. The hitch ball  16 , or more generally hitch  16 , is best seen in  FIG. 3 . The hitch  16  provides multiple degrees of freedom for rotation when it is connected to the fifth wheel hitch  10 . The fifth wheel hitch  10  has a frame  18  that is adapted to be mounted into the bed of a pickup truck. The frame  18  shown in  FIGS. 1-3  has horizontal bed rails  20  that are mounted to the bed. However, the frame  18  may be of the type that has downwardly extending mounting lugs that are adapted to mate with the pickup manufacturers&#39; sockets that may be provided as original equipment or as aftermarket accessories. The frame  18  shown in  FIGS. 1-3  or one using lugs will work well with the concept of the present invention. 
         [0016]    The frame  18  includes an outer sleeve  26  that is welded within the frame  18 . The outer sleeve  26  includes an upper end  28  and a lower end  30 . The outer sleeve  26  also includes threaded holes  32  that are best shown in  FIG. 5 . The threaded holes  32  include bolts  34  that extend into the outer sleeve  26 . The outer sleeve  26  includes a series of transverse holes  36  at various vertical heights that are perpendicular to the threaded holes  32 . These transverse holes  36  are adapted to receive a pin  38  that extends through the outer sleeve  26 . The pin  38  is bent downwardly at one end and cannot be passed through its corresponding hole  36 . The opposite end of the pin  38  receives a cotter pin  40  that holds the pin in the transverse holes  36  on an opposite side of the outer sleeve  26 . It is contemplated that the cotter pin  40  could be replaced an E-clip, snap ring, or other mechanical fastening device. A receiver tube  46  is slidingly and telescopically received in the outer sleeve  26 . The outer sleeve  26  is coaxially aligned with receiver tube  46  shown in  FIG. 3 . The receiver tube  46  has an upper end  48  and a lower end  50 . The receiver tube  46  is defined by a continuous sidewall  47  having an outer surface  49  and an inner surface  51 . The receiver tube  46  is shown as a cylindrical cross section, but it is contemplated that the receiver tube  46  could be a rectangular or other enclosed polygon shape. A support wall  52  is located near the upper end  48  of the receiver tube  46 . The support wall  52  is welded into the receiver tube  46  and is adapted for supporting the weight of the hitch ball  16 . A receiver pocket  53  is defined by the inner surface  51  of the receiver tube  46 , the upper end  48  and the support wall  52 . The support wall  52  is adjustable with respect to the outer sleeve  26  and may be adjusted to a height that locates the support wall  52  within the outer sleeve  26 . The receiver tube  46  has a funnel  54  located at its upper end  48 . The funnel  54  has an upper edge  56  that defines its outer diameter and the funnel  54  has an inner diameter  58  that is concentrically aligned with the receiver tube  46  inner surface  51  that defines the inner diameter of the receiver tube  46 . The funnel  54  extends well outwardly of the outer surface  49  of the receiver tube  46 . As such, the funnel  54  is cantilevered with respect to the receiver tube  46 . It is possible that gussets may be added to support the funnel  54 , but is generally not necessary if a thick enough material is chosen to make the funnel  54 . The funnel  54  is adapted to guide the hitch ball  16  into the receiver tube  46 . The receiver tube  46  has a series of transverse holes  61  that are selectively alignable with the holes  36  in the outer sleeve  26 . When the holes  61  in the receiver tube  46  are aligned with the holes  36  in the outer sleeve  26 , pin  38  may be inserted through the aligned holes  61 ,  36  to selectively lock the vertical position of the receiver tube  46  with respect to the outer sleeve  26  and frame  18 . 
         [0017]    A locking mechanism  62  located on the receiver tube  46 . The locking mechanism  62  near the upper end  28  of the receiver tube  46  is adapted to retain the hitch ball  16  within the receiver tube  46 . The pin  66  is chordally located with respect to the center of the diameter of the receiver tube  46 . In other words, the pin  66  is offset from the center of the receiver tube  46 . The side of the pin  66  is adapted to prevent upward movement of the hitch ball  16  from the receiver tube  46  as can be seen in  FIG. 6 . A first position is shown in  FIG. 6  and corresponds to a locking position that acts to retain the hitch ball  16  in the receiver tube. The pin  66  is movable away from the receiver tube  46  so that the pin is retracted from the receiver tube  46 , and this corresponds to a second and unlocked position of the pin  66  that allows removal of the hitch ball  16  from the receiver tube  46 . The pin  66  may be retracted by a pull rod  68  that is inserted into loop  70  of the pin  66  and pulled away from the receiver tube  46 . The pin  66  serves to lock the hitch ball  16  within the receiver tube  46  when the pin  66  is in its first position. 
         [0018]    A user of the fifth wheel hitch  10  will first determine the height above the truck bed that is desired and set the height of the receiver tube  46  with respect to the frame  18 . This is done by removing the pin  38  from the outer sleeve  26  and the receiver tube  46 . Holes in the receiver tube  61  and outer sleeve  36  are aligned at the desired height and the pin  38  is inserted through the aligned holes  61 ,  36 . The cotter pin  40  or other mechanical locking device is then snapped into the pin  38  to prevent it from being dislodged from the holes  61 ,  36 . To further lock the receiver tube  46 , bolts  34  are tightened against the receiver tube  46 . This not only locks the receiver tube  46  with respect to the outer sleeve  26  but serves to prevent rattling of the receiver tube  46 . The rattling would be felt by a driver of the towing vehicle and the bolts  34  provide a more responsive connection during towing. With the receiver tube  46  set at the proper height, the driver of the towing vehicle will back the vehicle, to which the fifth wheel hitch  10  is attached, underneath the hitch ball  16  of the trailer to be towed. It is not critical that the hitch ball  16  on the trailer be in the same plane as the receiver tube  46 . When the receiver tube  46  is near the hitch ball  16  the driver will stop the vehicle and lower the hitch ball  16  into the receiver tube  46 . The funnel  54  assists in this effort because the hitch ball  16  need only be near the receiver tube  46  and the hitch ball  16  will be guided into the receiver tube  46 . The user of the fifth wheel hitch  10  knows with absolute certainty that a secure connection is made to the hitch ball  16  because he can see the receiver tube  46  and the hitch ball  16  as they connect and the receiver tube  46  completely circumscribes the hitch ball  16 . The pin  66  of locking mechanism  62  must be moved into the second position (withdrawn from the receiver tube  46 ), which will allow the hitch ball  16  to rest on the support wall  52 . The pin  66  will be biased into its first, locked position by spring  64 . The biasing spring  64  will serve as an effective mechanism to prevent the pin  66  from retracting. 
         [0019]    The invention is not limited to the description above but may be modified within the scope of the following claims.