Abstract:
A draw bar and universal mount for a trailer hitch comprises a base plate including a first section, a second section and at least two rows of apertures. Furthermore, the draw bar and universal mount includes a shank having a first portion, a second portion and a central portion, the central portion connecting the first portion and the second portion. The shank includes at least one opening and one end disposed on the base plate. The base plate and shank are fabricated from an integral, continuous piece of material.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention generally relates to a trailer hitch mount, and more particularly relates to a pintle hook mount adapted for engagement with a rectangular hitch receiver.  
         [0002]     Conventional pintle hooks are used on various towing vehicles, such as trucks and agricultural equipment for hitching the towing vehicle to a trailer. An example of a conventional pintle hook construction is shown in  FIGS. 1A and 1B . As shown, the pintle hook includes a main body  12  having an integral base plate  14  and an integral lower jaw hook  16 . An upper jaw latch  18  is pivotally attached to body  12  by a pivot pin  20 . As shown in  FIG. 1B , upper jaw latch  18  may be pivoted upward from its resting position (position A) to position B so as to receive the drawbar eye that would be attached to a trailer. The upper jaw latch  18  would then reassume its resting position, position A, and a locking mechanism  22  would lock upper jaw  18  in position A. As best shown in  FIG. 1A , apertures  24  are formed in base plate  14  for attachment to the towing vehicle. Additional details concerning the particular pintle hook shown in  FIGS. 1A and 1B  are disclosed in commonly assigned U.S. Pat. No. 5,332,250.  
         [0003]     While pintle hooks such as those shown in  FIGS. 1A and 1B  have been attached to larger trucks, agricultural equipment, and other specially manufactured vehicles, it has been proposed to attach such pintle hooks to light trucks, vans, and other vehicles that have a conventional rectangular or square receiver of the type which more commonly would receive a ball mount. Accordingly, pintle mounts such as that shown in  FIG. 2  have been constructed to allow pintle hooks to be mounted to vehicles utilizing their conventional receivers. Specifically, the conventional pintle mount includes a shank  30  made of a solid bar having a square or rectangular cross-section with its outer width and height configured to fit within the conventional receiver of smaller vehicles. The shank  30  includes a through-hole  32 , which aligns with similar holes in the receiver for receipt of a pin (not shown), which holds the mount in place within the vehicle&#39;s receiver. The opposite end of shank  30  from the vehicle is welded or otherwise secured to a base plate  34  having a plurality of apertures  36  formed therein. The apertures  36  may thus be aligned with apertures  24  of a pintle hook and bolts may be inserted therethrough so as to secure the pintle hook on the mount at a height selected by selection of the appropriate apertures  36  in the pintle mount. A gusset  38  may also be welded to both base plate  34  and shank  30  for further mechanical support.  
         [0004]     Such pintle mounts as shown, for example, in  FIG. 2  are typically limited to 10,000 pounds gross trailer weight (GTW). When the loads exceed the 10,000-pound GTW limit, the base plate  34  begins to deform and the shank  30  begins to bend. Moreover, welds  40  must be very strong to hold the structure firmly together.  
         [0005]     One approach to address this concern is to form the mount and pintle hook as a single integral structure. Examples of such constructions are disclosed in U.S. Pat. No. 6,139,043. While such a structure may strengthen the pintle hook assembly as a whole, one loses the flexibility of adjusting the height of the pintle hook on the pintle mount. Additionally, the pintle mount cannot then be utilized for attaching other forms of hitches, such as a ball hitch or the like.  
         [0006]     Accordingly, there exists the need for a stronger pintle hook mount that overcomes the problems associated with the prior art pintle mounts while also allowing for the flexibility and variable mounting height provided by such a pintle mount structure.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention provides a draw bar and universal mount for a trailer hitch including, a base plate comprising a first section, a second section and at least two rows of apertures. The draw bar and universal mount also includes a shank having a first portion, a second portion and a central portion, wherein the central portion connects the first portion and the second portion. The shank also includes at least one opening and further includes one end disposed on the base plate. Additionally, the base plate and shank are fabricated from an integral, continuous piece of material.  
         [0008]     In a second embodiment, the draw bar and universal mount includes a base plate further comprising a first section and a second section and at least two rows of apertures. Further, a shank extends from the base plate and includes at least one opening. Additionally, a first strengthening member connects the first section of the base plate to the first portion of the shank and a second strengthening member connects the second section of the base plate with the second portion of the shank.  
         [0009]     A third embodiment includes a base plate further comprising a first section and a second section and at least two rows of apertures. Further, a shank including a first portion, a second portion and a central portion, wherein at least a section of the shank has an I-shaped cross section and the central portion connects the first portion and the second portion in order to form the I-shaped cross section, is provided. Additionally, the shank includes at least one opening and further has one end disposed on the base plate.  
         [0010]     In a fourth embodiment, a draw bar mounting assembly for a trailer hitch includes a base plate comprising a first section and a second section and at least two rows of apertures. A shank including a first portion, second portion, and central portion, wherein the central portion connects the first portion and the second portion, is also provided. Additionally, the shank includes at least one opening and one end disposed on the base plate. Further, the base plate and shank are fabricated from a continuous piece of material. A pintle hook configured to be connected to the base plate is also provided wherein the pintle hook can be connected to the base plate using the two rows of apertures.  
         [0011]     A fifth embodiment includes a draw bar mounting assembly for a trailer hitch including a base plate comprising a first section and a second section and at least two rows of apertures. A shank is included with at least one opening wherein the shank further includes one end disposed on the base plate. Additionally, a first strengthening member connecting the first section of the base plate to the first portion of the shank and a second strengthening member connecting the second section of the base plate with the second portion of the shank is also provided. Finally, a pintle hook configured to be connected to the base plate is provided, wherein the pintle hook can be connected to the base plate through the two rows of apertures.  
         [0012]     Finally, a sixth embodiment is disclosed and includes a base plate comprising a first section and a second section and at least two rows of apertures. Further, a shank including a first portion, second portion, and central portion, wherein the central portion connects the first portion and the second portion is provided. The first and the second portion is at least partially longer in one direction than the central portion in the one direction. Additionally, the shank includes at least one opening and has one disposed on the base plate. A pintle hook is provided and configured to connect to the base plate wherein the pintle hook can be connected to the base plate through the two rows of apertures. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     In the drawings:  
         [0014]      FIG. 1A  is a perspective view of a conventional pintle hook;  
         [0015]      FIG. 1B  is a side view of the conventional pintle hook shown in  FIG. 1A ;  
         [0016]      FIG. 2  is a perspective view of a conventional pintle mount;  
         [0017]      FIG. 3A  is a plan view showing the top of a pintle hook mount constructed in accordance with a first embodiment of the present invention;  
         [0018]      FIG. 3B  is a side view of the pintle hook mount shown in  FIG. 3A ;  
         [0019]      FIG. 3C  is a front view of the pintle hook mount shown in  FIGS. 3A and 3B ;  
         [0020]      FIG. 3D  is a perspective view showing the pintle hook mount shown in  FIGS. 3A-3C ;  
         [0021]      FIG. 4A  is a perspective view showing the step of securing the inventive pintle hook mount in a vehicle&#39;s receiver;  
         [0022]      FIG. 4B  is a perspective view showing the second step of securing the inventive pintle hook mount in a vehicle&#39;s receiver;  
         [0023]      FIG. 4C  is a perspective view showing the third step of securing the inventive pintle hook mount in a vehicle&#39;s receiver;  
         [0024]      FIG. 5A  is a perspective view of a pintle hook mount constructed in accordance with a second embodiment of the present invention;  
         [0025]      FIG. 5B  is a plan view of the top of the pintle mount shown in  FIG. 5A ;  
         [0026]      FIG. 5C  is a front view of the pintle mount shown in  FIGS. 5A and 5B ;  
         [0027]      FIG. 5D  is a side view of the pintle mount shown in  FIGS. 5A-5C ;  
         [0028]      FIG. 5E  is a cross-sectional view of a portion of the pintle mount shown in  FIG. 5D  taken along line VE-VE;  
         [0029]      FIG. 5F  is a cross-sectional view of a portion of the pintle mount shown in  FIG. 5D  taken along line VF-VF.  
         [0030]      FIG. 6A  is a perspective view of a pintle hook mount constructed in accordance with a third embodiment of the present invention;  
         [0031]      FIG. 6B  is a plan view of the top of the pintle mount shown in  FIG. 6A ;  
         [0032]      FIG. 6C  is a side view of the pintle mount shown in  FIGS. 6A and 6B ; and  
         [0033]      FIG. 6D  is a front view of the pintle mount shown in  FIGS. 6A-6C . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0034]     Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. The dimensions provided in the drawings are included for purposes of example only and are not intended to limit the scope of the present invention.  
         [0035]     The pintle mount of the present invention utilizes a one-piece cast design rather than using multiple separate components to form the shank, strengthening member, and base plate, as commonly employed in the prior art pintle mounts. Thus, the weakness provided by the welds  40  is eliminated. In addition, because of the added strength, the construction is generally more compact, lighter in weight, and less costly than the prior art products.  
         [0036]     As illustrated in  FIGS. 3A-3D , the first embodiment of the pintle mount of the present invention is shown and comprises a shank  130  in the form of an I-beam, a base plate  132 , and a second strengthening member  134  all integrally formed as a one-piece casting. Second strengthening member  134  advantageously is molded in and integrally formed with shank  130  and base plate  132  so as to gently transfer the loads to the shank without causing any stress risers in shank  130 . An optional first strengthening member  136  may also be integrally formed to extend from the top of the I-beam shank  130  to the upper portion of base plate  132 . By providing first strengthening member  136 , the upper portion of base mounting plate  132  is more strongly supported and secured to shank  130 .  
         [0037]     Base plate  132  preferably has a plurality of apertures  138  ( FIG. 3C ) formed therethrough for securing a pintle hook or other form of hitch. Preferably, at least two rows of apertures are disposed longitudinally on base plate  132 . Further, by positioning at least one pair  138 ′ of apertures  138  in base plate  132  so as to straddle opposite sides of I-beam shank  130 , the installation of washers and nuts on the mounting bolts that fit through holes  138 ′ may be improved.  
         [0038]     Shank  130  preferably includes a first portion  160 , a second portion  162 , and a central portion  164  ( FIG. 3C ). The first portion  160  and the second portion  162  are equal in length in a direction which is perpendicular to central portion  164  to form an I-beam-type of construction. By shaping the I-beam shank  130  so as to have the I-beam-type construction, the strength of shank  130  may be maximized while allowing it to be easily manufactured and installed into the receiver by the user. Additionally, the weight of the shank relative to a solid construction is significantly decreased.  
         [0039]     To facilitate the provision of a through-hole  140  in shank  130 , the portion of shank  130  in the vicinity of through-hole  140  is preferably formed to have a rectangular or square cross-section serving as a crossover gusset  142  that provides sufficient strength to that portion of the shank  130 . This crossover gusset  142  additionally improves the strength and rigidity of the shank  130  as a whole.  
         [0040]     As shown in  FIG. 3D , the interface  144  between first strengthening member  136 , second strengthening member  134 , base plate  132 , and shank  130  is preferably radiused. The size and shape of the radius  144  that is used to connect the I-beam shank  130  to mounting surface  132  provides maximum strength and minimum interference with mounting hardware.  
         [0041]     In addition to providing a radiused interface  144  between the strengthening members, shank, and base plate, other corners and edges of the pintle mount may also be radiused so as to prevent injury to the operator.  
         [0042]     A second embodiment is shown in  FIGS. 5A-5F  and includes one or more strengthening bumps  150  which may be provided in the I-beam shank  130  to increase its overall strength.  
         [0043]     As shown in  FIGS. 5A, 5D , and  5 E, second strengthening member  134  may be configured to have a wider rim or edge  152  that provides a cross-sectional T-shape. This allows the lower gusset  134  to be made somewhat thinner and thus the weight of the pintle mount is decreased while the strength is maintained or increased by the presence of rim  152 . Additionally, a hole  154  may be provided through second strengthening member  134  to further decrease the weight without sacrificing its strength. Second strengthening member  134  and optionally first strengthening member  136  may also be flared so as to have an increased width at its upper and lower extent where it joins shank  130  and base plate  132 . These flares  158  may be provided throughout the thickness of the gusset or may be provided just in the portion of rim  152 . The flares improve the strength performance of the pintle mount while also reducing stresses due to heavy loads.  
         [0044]     Another feature that may be implemented to increase the strength of the pintle mount is to provide a second crossover gusset  156  within the I-beam shank  130 . Preferably, as shown in  FIGS. 5A and 5D , crossover gusset  156  is provided in the location of shank  130  where it interfaces with rim  152  of second strengthening member  134 . This second crossover gusset  156  maintains the strength of the pintle hook while allowing the weight of the shank to be reduced through the utilization of the I-beam construction.  
         [0045]     While the base plate  132  shown in the first and second embodiments is generally rectangular, base plate  132  may have a different shape as utilized in the third embodiment shown in  FIGS. 6A-6D . The shape of base plate  132  may be selected so as to reduce the weight of the pintle mount while maintaining its overall strength. Thus, base plate  132  may have a non-rectangular or, more specifically, a curved shape.  
         [0046]      FIG. 4A  shows the first step of mounting the draw bar and universal mount in a receiver that is attached to the bumper or chassis of the towing vehicle. In this first step, the shank or draw bar of the pintle mount is slid into the receiver to such a depth that the through-hole on the shank aligns with a through-hole on the receiver. Then, as shown in  FIG. 4B , a pin A is slid through the aligned through-holes. A spring clip B is then passed through a hole at the end of pin A so as to prevent pin A from becoming dislodged (see  FIG. 4C ). The pintle hook may then be mounted to the universal mounting base plate. Alternatively, the pintle hook may be secured to the pintle mount prior to the preceding steps. Furthermore, a variety of hitching mechanisms such as, for example, a ball-style receiver may alternatively be attached to the universal mounting base plate. Further, any type of current or future receiving mechanism may be affixed to the draw bar and universal mount and the invention is not meant to be limited to pintle hooks.  
         [0047]     The above description is considered that of the preferred embodiments only. Modifications of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and not intended to limit the scope of the invention, which is defined by the following claims as interpreted according to the principles of patent law, including the doctrine of equivalents.