Abstract:
A dump trailer coupling apparatus is described. The apparatus is joins a vehicle hitch to the push tongue of a trailer in a way that accounts for and permits all movements of the dump trailer when on a roadway and during the dump process, without translating that stress to the hitch. In one embodiment, the apparatus is a swivel coupler including a pair of swivel structures. The first swivel structure enables lateral movement of the trailer with respect to the vehicle. The second swivel structure enables complete dumping of the trailer without stress on the hitch. In another embodiment, the apparatus is a hinged coupler including a support plate, a ball mount and a ball coupler. The ball coupler retains a roller that moves along on the support plate and addresses lateral movement of the dump trailer. The ball coupler includes a hinge connector attached to the trailer push tongue and enables complete dumping of the trailer without stress on the hitch.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to dump trailer connection devices. More particularly, the present invention relates to devices arranged to enable complete dumping of the trailer while minimizing the stress at the interface between the vehicle hitch and the trailer. 
         [0003]    2. Description of the Prior Art 
         [0004]    Tilting, or dump, trailers are trailers which have a bed or body portion configured for carrying cargo and for tilting in order to offload, or dump the cargo. Dumping trailers are useful in that they offer a cargo-emptying feature without requiring a dedicated vehicle, such as a dump truck. A dump trailer can be used as needed by attaching it to a tow vehicle, such as a conventional truck, tractor, pick-up truck, sport utility vehicle (SUV), automobile, etc. Once the desired cargo has been hauled and dumped using the trailer, the trailer could then be detached from the tow vehicle, and the tow vehicle is then unencumbered and free to be used for other purposes. 
         [0005]    In conventional dump trailers, the dumping mechanism is powered by a separate power source, such as a hydraulic or electric lift mechanism. Such mechanism adds weight and expense to the trailer, and also complexity. However, such a power mechanism is oftentimes required due to the weight of the load in the trailer, the load being prohibitively heavy for allowing the trailer to be tilted upwardly and dumped by hand. 
         [0006]    Modified dump trailers have been described. These modified trailers include supplemental structures for removably connecting the trailer to the hitch of a vehicle. The supplemental structures are supposed to permit upward tilting of the forward end of the trailer so that the trailer contents are dumped from the rearward end. However, the supplemental structure does not permit complete dumping without placing substantial stress on the interface between the structure and the hitch. What is needed is an apparatus to couple a dump trailer to a hitch of a vehicle. In particular, what is needed is an apparatus for coupling a dump trailer to a vehicle in which the apparatus enables complete dumping of the trailer with minimal stress on the connection to the vehicle. Preferably, such an apparatus may be connected to a standard vehicle hitch structure. 
       SUMMARY OF THE INVENTION 
       [0007]    It is an object of the present invention to provide an apparatus to couple a dump trailer to a hitch of a vehicle. It is also an object of the present invention to provide an apparatus for coupling a dump trailer to a vehicle in which the apparatus enables complete dumping of the trailer with minimal stress on the connection to the vehicle. Further, it is an object of the present invention to provide an apparatus for coupling a dump trailer to a vehicle in which the apparatus may be connected to a standard vehicle hitch structure. 
         [0008]    These and other objects are achieved with the present invention, which is a dump trailer coupling apparatus. The coupling apparatus is directed to improving the connection to the vehicle hitch so that the dump trailer can be fully operational for complete dumping. The coupling apparatus further provides a better dump trailer connection by minimizing the stress at the connection under all conditions, including over-the-road operation, vehicle and trailer turning, and complete trailer load dumping, all with a fill trailer load. 
         [0009]    The dump trailer coupling apparatus of the present invention comes in two primary embodiments. In the first embodiment, the coupling apparatus is a swivel coupler. The swivel coupler includes a pair of swivel structures that are arranged to take away from the hitch location the stress associated with movement of the trailer when traveling and when dumping. In particular, a first swivel structure of the swivel coupler is removably connectable to the push tongue of the dump trailer. A second swivel structure of the swivel coupler is removably connectable to the first swivel structure and to a bar mount that is connectable to the vehicle hitch. The first and second swivel structures swivel or rotate with movement of either or both of the trailer push tongue and the bar mount. That swiveling or rotation reorients the two swivel structures with respect to one another in counteracting response to the movement of the trailer and/or the vehicle. That reorientation reconfigures the relationship between the two and in doing so, reduces the stress at the connection interface. 
         [0010]    The second primary embodiment of the coupling apparatus is a hinged coupler. The hinged coupler also acts to counteract the stress at the connection interface that can occur when the push tongue of the dump trailer changes angles, such as during turns and in the process of dumping the trailer. The hinged coupler includes a support plate removably connectable to the bar mount of the vehicle hitch The support plate includes a ball mount and a modified ball coupler that is arranged to removably capture the ball securely while also permitting axial and circumferential rotation of the coupler about the upper portion of the ball. The modified ball coupler is arranged for removable hinged connection to the push tongue of the dump trailer, allowing complete 90° movement of the push tongue from horizontal to vertical orientation during the dumping process without producing stress at the vehicle hitch. The modified ball coupler further includes a roller frame for retaining therein a roller arranged to enable circumferential movement of the modified ball coupler along the perimeter of the support plate while maintaining load support of the push tongue-modified ball coupler interface during swinging movement of the trailer while the vehicle is swaying or turning The arrangement of the hinged coupler substantially eliminates excessive loading at the trailer hitch while allowing complete use of the dump trailer under any load condition. 
         [0011]    The dump trailer coupling apparatus of the present invention provides full use of a dump trailer, including complete unloading and all movement, while substantially eliminating stress at the vehicle hitch. This and other advantages of the present invention will become apparent upon review of the following detailed description, the accompanying drawings and the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a side view of a swivel coupler embodiment of the dump trailer coupling apparatus of the present invention connected to the push tongue of a dump trailer. 
           [0013]      FIG. 2  is an exploded side view of the swivel coupler. 
           [0014]      FIG. 3  is a top view of the swivel coupler connected to the drop drawbar. 
           [0015]      FIG. 4  is a side view of the swivel coupler connected to a drop drawbar mountable to a vehicle hitch in a first orientation with respect to the drop draw bar. 
           [0016]      FIG. 5  is a side view of the swivel coupler connected to a drop drawbar mountable to a vehicle hitch in a second orientation with respect to the drop draw bar. 
           [0017]      FIG. 6  is a side view of a hinged coupler embodiment of the dump trailer coupling apparatus of the present invention connected to the push tongue of a dump trailer and to a bar mount connectable to a vehicle hitch, with the push tongue horizontally oriented such as when trailering the dump trailer. 
           [0018]      FIG. 7  is a top view of the support plate of the hinged coupler connected to the bar mount. 
           [0019]      FIG. 8  is a side view of the hinged coupler. 
           [0020]      FIG. 9  is a front view of the hinged coupler. 
           [0021]      FIG. 10  is a side view of the hinged coupler connected to the push tongue of a dump trailer and to the bar mount connectable to the vehicle hitch, with the push tongue vertically oriented such as when completely dumping the dump trailer. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0022]    A first embodiment of a dump trailer coupling apparatus of the present invention is a swivel coupler  10  shown in  FIGS. 1-5 , which swivel coupler  10  is arranged for removably connecting a dump trailer to a vehicle, such as a truck, tractor or SUV, for example. The swivel coupler  10  includes a first swivel cylinder  12 , a second swivel cylinder  14 , a cylinder connector  16 , a mount connector  18  and a push tongue connector  20 . The mount connector  18  removably connects the swivel coupler  10  to a hitch mount  22  that is removably connectable to a vehicle hitch (not shown). The hitch mount  22  may be any type of mounting bar including, but not limited to, a drop drawbar of the type shown in  FIGS. 2-5 , for example. The push tongue connector  20  removably connects the swivel coupler  10  to a push tongue  24  that is removably connectable to a dump trailer (not shown). 
         [0023]    The first swivel cylinder  12  is removably connectable to the hitch mount  22  at mount port  26  of the hitch mount  22 . The swivel coupler  10  includes a mount port adapter  28  to establish a portable for passage of first end  30  of the mount connector  18  therein. The first end  30  of the mount connector  18  includes a lock port  32  for removably receiving therein a locking pin  34  that ensures the mounting connector  18  remains retained within the mount port  26  when the swivel coupler  10  is to be retained to the hitch mount  22 . A second end  36  of the mount connector  18  includes attachment means for removable attachment to the first swivel cylinder  12  at transversely oriented first attachment port  38  thereof. The second end  36  may be threaded, as shown, for removable threading engagement with the first attachment port  38 , which may include compatible threading thereof. In this way, the swivel coupler  10  and the hitch mount  22  are removably connected together in a manner that permits the mount connector  18  to rotate in the mount port  26 . 
         [0024]    With specific reference to  FIGS. 1 and 2 , the first swivel cylinder  12  includes an axially oriented second attachment port  40  substantially centered on the first swivel cylinder  12  at its axis and extending completely through from first cylinder first face  42  to first cylinder second face  44 . The cylinder connector  16  is configured for removable insertion into and through the second attachment port  40 . It includes attachment means  46  at a connecting end  48  thereof for removable attachment to second swivel cylinder  14  at transversely oriented first attachment port  50  thereof. The attachment means  46  may be threaded, as shown, for removable threading engagement with the first attachment port  50  of the second swivel cylinder  14 , which may include compatible threading thereof. In this way, the first swivel cylinder  12  and the second swivel cylinder  14  are removably connected together in a manner that causes the second swivel cylinder  14  to move with movement of the first cylinder  12 . 
         [0025]    The second swivel cylinder  14  includes an axially oriented second attachment port  52  substantially centered on the second swivel cylinder  14  at its axis and extending completely through from second cylinder first face  54  to second cylinder second face  56 . The push tongue connector  20 , which may be a connection bolt, is configured for removable insertion into and through the second attachment port  52  for rotatable motion therein. The push tongue connector  20  includes attachment means  58  at a connecting end  60  thereof for removable attachment to push tongue  24 . The attachment means  58  may be threaded for removable threading engagement with the push tongue  24 , which may include compatible threading thereof In this way, the swivel coupler  10  and the push tongue  24  are removably connected together in a manner that permits the push tongue connector  20  in the second attachment port  52 . 
         [0026]    In operation, the swivel coupler  10  enables complete functional operation of the dump trailer, including permitting its tipping to maximum position for complete dumping, without undue stress on the connection of the dump trailer to the vehicle hitch. The swivel coupler  10  also accommodates variable movement of the dump trailer in relation to the vehicle, such as under high speed conditions and through turns, without undue stress on the connection of the dump trailer to the vehicle hitch. When the dump trailer is connected to the vehicle via the swivel coupler  10 , lateral movement of one with respect to the other, such as during a turn, causes the mount connector  18  to rotate in the mount port  26 . The resultant lateral stress is not absorbed by the mount  24  or by a corresponding conventional ball mount if that is used to connect the dump trailer to the vehicle. Instead, the lateral stress is relieved by the rotation of the swivel coupler I  0  at the first swivel cylinder  12  when the vehicle and dump trailer move in relation to one another. This can be seen when viewing the change of position of the swivel coupler  10  from that seen in  FIG. 4  to that seen in  FIG. 5 . 
         [0027]    When the dump trailer has been moved to a desired location for the purpose of unloading its load, the swivel coupler  10  is configured to permit its complete unloading without generating any excess stress at the connection between the vehicle and the dump trailer. When the vehicle is backed up and the dump trailer prevented from making any rearward movement, such as by blocking its rear wheels, for example, the swivel coupler  10  is arranged to permit the push tongue  24  to rotate from a horizontal orientation to a vertical orientation. As the vehicle backs up, it forces the push tongue  24  to pivot at its connection to the dump trailer. This pivoting is enabled by the swivel coupler  10  because the push tongue connector  20  is free to rotate in the second attachment port  52  of the second swivel cylinder  14  so that the vehicle may continue to back up as the push tongue  24  moves to the vertical orientation, including substantially perpendicular to its horizontal orientation.  FIG. 1  illustrates an interim position of the push tongue  24  as it moves to or from the vertical orientation. Complete trailer dump occurs when the push tongue  24  is substantially vertically oriented. The rotation of the push tongue connector  20  in the second swivel cylinder  14  relieves any stress at the vehicle to trailer connection that would otherwise occur during the process of dumping the trailer. 
         [0028]    A second embodiment of a dump trailer coupling apparatus of the present invention is a hinged coupler  100  shown in  FIGS. 6-10 , which hinged coupler  100  is also arranged for removably connecting a dump trailer to a vehicle, such as a truck, tractor or SUV, for example. The hinged coupler  100  includes a support plate  102 , a hitch ball  104 , a ball coupler  106  and a roller  108 . The support plate  102  removably connects the hinged coupler  100  to a hitch mount  110  that is removably connectable to a vehicle hitch (not shown). The hitch mount  110  may be any type of mounting bar, such as the extension bar shown in  FIG. 6 . The ball coupler  106  removably connects the hitch ball  104  to a push tongue  112  that is removably connectable to a dump trailer (not shown). 
         [0029]    The support plate  102  includes a plate flange  114  for fitting to end  116  of the hitch mount  110 . The support plate  102  further includes a ball attachment means, such as nut  118 . The nut  118  is arranged for removable engagement with attachment end  120  of hitch ball  104 , which attachment end  120  may be threaded for threading engagement with the nut  118 , for example. The attachment end  120  of the hitch ball  104  is arranged to pass through plate port  122  of the support plate  102  and be removably retained therein by the nut  118  or other suitable attachment arrangement. When the nut  118  is substantially completely engaged with the attachment end  120 , the hitch ball  104  is joined to the support plate  102  over end  116  of the hitch mount  110 . 
         [0030]    The ball coupler  106  includes ball cap  124  sized to fit loosely enough on the hitch ball  106  to allow the swivel about on the hitch ball when placed thereon. The ball coupler  106  includes a releasable safety lock  126  of the type those of ordinary skill in the art will recognize to be suitable for releasably retaining the ball cap  124  engaged with the hitch ball  104 . The ball coupler  106  further includes first coupler port  128  and second coupler port  130  for removably retaining therein push tongue hinge  132 . The push tongue hinge  132  may be a bolt that is removably affixed to attachment means such as nut  134  or other suitable means arranged to enable rotatable movement of the push tongue hinge  132  while retained in the first coupler port  128  and the second coupler port  130 . The push tongue hinge  132  is also arranged for rotatable engagement through first tongue port  136  and second tongue port  138 . When the first tongue port  136  is positioned adjacent to the first coupler port  128 , the second tongue port  138  is positioned adjacent to the second coupler port  130  and the push tongue hinge  132  is passed through and retained in all four such ports, the push tongue  112  is removably and hingedly joined to the ball coupler  106 . 
         [0031]    The ball coupler  106  further includes a roller frame  140  that provides a guide for the roller  108 . A frame plate  142  includes a first frame plate port  144  and a second frame plate port  146 , each arranged to permit passage therethrough of respective attachment means. A frame plate attachment means, such as removable frame bolt  148  connects the frame plate  142  to the roller frame  140  of the ball coupler  106 . Additionally, a roller attachment means, such as roller bolt  150 , also connects the frame plate  142  to the roller frame  140 . The roller bolt releasably retains the roller  108  in the roller frame  140  of the ball coupler  106  such that when the ball coupler  106  is engaged with the ball  104  on the support plate  102 , the roller  108  contacts an upper surface  152  of the support plate  102 . The frame plate  142  includes a safety flange  154  arranged to extend under the support plate adjacent to a lower surface  156  thereof when the ball coupler  106  is engaged with the ball  104 . The safety flange  154  aids in maintaining the orientation of the frame plate with the support plate  102 . 
         [0032]    In operation, the hinged coupler  100  enables complete functional operation of the dump trailer, including permitting its tipping to maximum position for complete dumping, without undue stress on the connection of the dump trailer to the vehicle hitch. The hinged coupler  100  also accommodates variable movement of the dump trailer in relation to the vehicle, such as under high speed conditions and through turns, without undue stress on the connection of the dump trailer to the vehicle hitch. When the dump trailer is connected to the vehicle via the hinged coupler  100 , lateral movement of one with respect to the other, such as during a turn, causes the ball coupler  106  to rotate about laterally on the ball  104 , with the roller  108  rolling along on the support plate  102  to maintain uniform loading on the connection between the ball coupler  106  and the hitch ball  104  during such lateral rotation. The resultant lateral stress is not absorbed by the hitch mount  110  or by a corresponding conventional ball mount if that is used to connect the dump trailer to the vehicle. Instead, the lateral stress is relieved by the rotation of the ball coupler  106  on the hitch ball  104  when the vehicle and dump trailer move in relation to one another. 
         [0033]    When the dump trailer has been moved to a desired location for the purpose of unloading its load, the hinged coupler  100  is configured to permit its complete unloading without generating any excess stress at the connection between the vehicle and the dump trailer. When the vehicle is backed up and the dump trailer prevented from making any rearward movement such as by blocking its rear wheels, for example, the hinged coupler  100  is arranged to permit the push tongue  112  to rotate from a horizontal orientation, as shown in  FIG. 6 , to a vertical orientation, as shown in  FIG. 10 . As the vehicle backs up, it forces the push tongue  112  to pivot at its connection to the dump trailer. This pivoting is enabled by the hinged coupler  100  because the push tongue hinge  132  is free to rotate in the first coupler port  128 , the second coupler port  130 , the first tongue port  136  and the second tongue port  138  so that the vehicle may continue to back up as the push tongue  112  moves to the vertical orientation, including substantially perpendicular to its horizontal orientation.  FIG. 6  shows the push tongue  112  in a horizontal orientation and  FIG. 10  shows the push tongue in a vertical position, wherein each position is enabled without stress at the ball coupler  106  to ball  104  interface. Complete trailer dump occurs when the push tongue  112  is substantially vertically oriented as in  FIG. 10 . 
         [0034]    The coupling apparatus of the presented invention represented by the swivel coupler  10  and the hinged coupler  100 , is directed to improving the connection to the vehicle hitch so that the dump trailer can be fully operational for complete dumping. The coupling apparatus further provides a better dump trailer connection by minimizing the stress at the connection under all conditions, including over-the-road operation, vehicle and trailer turning, and complete trailer load dumping, all with a full trailer load. The present invention has been described with respect to various combinations of specified components in two example embodiments. Nevertheless, it is to be understood that various modifications may be made without departing from the spirit and scope of the invention as described by the following claims.