Abstract:
An adjustable fifth wheel hitch includes a support frame having base rails that are secured to the frame of a vehicle and a pair of spaced guide rails that bridge between the base rails. The fifth wheel hitch also includes a head assembly having a jaw assembly for engaging a king pin on a trailer. A head support includes a pair of uprights having sets of rollers for mounting the head assembly for relative fore-and-aft sliding movement along the guide rails between the towing position and a maneuvering position. A releasable lock secures the head assembly in either selected position.

Description:
[0001]    This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/313,299 filed on Aug. 17, 2001. 
     
    
     
       TECHNICAL FIELD  
         [0002]    The present invention relates generally to the trailer towing field and, more particularly, to an improved fifth wheel hitch that is adjustable to conveniently allow enhanced maneuverability in limited or tight operating areas when required.  
         BACKGROUND OF THE INVENTION  
         [0003]    Fifth wheel hitches for towing a trailer behind a towing vehicle have long been known in the art. Examples of state-of-the-art fifth wheel hitches include those presently manufactured by Reese Products, Inc. of Elkhart, Indiana under U.S. Pat. No. 5,707,070.  
           [0004]    These state-of-the-art fifth wheel hitches include a support frame having base rails that are secured to the bed and/or frame of the towing vehicle and a pair of spaced guide rails that bridge between the base rails. These fifth wheel hitches also include a head assembly having a jaw assembly for engaging a king pin on a trailer. A head support and a pair of uprights mount the head assembly for relative fore-and-aft sliding movement along the guide rails between a towing position and a maneuvering position. Load bearing shoes formed from nylon, polytetrafluoroethylene or other known low friction material are provided in each upright to slide over the surface of the guide rails and allow smooth movement of the head assembly. A releasable lock secures the head assembly in either selected position.  
           [0005]    While such state-of-the-art fifth wheel hitches provide excellent overall performance and dependable operation, it is believed that further design improvements are still possible.  
         SUMMARY OF THE INVENTION  
         [0006]    In accordance with the purposes of the present invention as described herein, an adjustable fifth wheel hitch is provided for towing a trailer behind a motor vehicle. The adjustable fifth wheel hitch includes a support frame having a first guide rail, a head assembly including a first upright and a jaw assembly for engaging the king pin of a trailer. A first set of three rollers is held for relative rotation on the first upright. The three rollers ride on the first guide rail so as to allow selective displacement of the head assembly on the support frame between a towing position and a maneuvering position. A lock releasably locks the head assembly in either of the towing and maneuvering positions.  
           [0007]    Still further describing the invention, the first upright includes a first end and a second, opposite end. The first end of the upright and the guide rail upon which the upright rides form an obtuse angle of between substantially 91-140° and more typically about 122°. The second end and the guide rail form an angle of between about 75-89° (typically about 80°). Still further, the first set of three rollers includes one roller adjacent the first end of the upright and two rollers adjacent the second end of the upright.  
           [0008]    In accordance with an additional aspect of the present invention the adjustable fifth wheel hitch may be described as comprising a support frame including a first guide rail, a second guide rail and a head assembly including a first upright, a second upright and a jaw assembly. A first set of three rollers is held for relative rotation on the first upright. The first set of three rollers rides on the first guide rail. A second set of three rollers is held for relative rotation on the second upright. That second set of three rollers rides on the second guide rail. Together the first and second sets of three rollers allow selective displacement of the head assembly on the support frame between a towing position and a maneuvering position. A lock is provided for releasably locking the head assembly in either of these two positions as desired.  
           [0009]    Still other aspects and features of the present invention will become apparent to those skilled in this art from the following description wherein there is shown and described a preferred embodiment of this invention, simply by way of illustration of one of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The accompanying drawings incorporated in and forming a part of the specification, illustrate several aspects of the present invention and together with the description serve to explain the principles of the invention. In the drawings:  
         [0011]    [0011]FIG. 1 is an exploded perspective view of the fifth wheel hitch of the present invention for towing a trailer behind a motor vehicle;  
         [0012]    [0012]FIG. 2 is a side elevational and partially cross-sectional view showing the hitch of FIG. 1 in the towing position with the head support and head assembly removed;  
         [0013]    [0013]FIG. 2 a  is a partially sectional detail showing the mounting of the leaf spring in an upright;  
         [0014]    [0014]FIG. 3 is a view similar to FIG. 2 but showing the dual bar latch pivoted or flipped to allow sliding movement of the head assembly of the hitch to the maneuvering position;  
         [0015]    [0015]FIG. 3 a  is a top plan view of the hitch showing the offset of the latch bars and the cooperating apertures in the underlying spaced guide rails (again, the head support and head assembly are removed for clarity);  
         [0016]    [0016]FIG. 4 is a view similar to FIGS. 2 and 3 but showing the hitch locked in the maneuvering position; and  
         [0017]    [0017]FIG. 5 is a detailed, partially sectional view showing the mounting of one roller in one upright. 
     
    
       [0018]    Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0019]    Reference is now made to FIG. 1 showing the fifth wheel hitch of the present invention. The hitch  10  includes a support frame, generally designated by reference numeral  12 , comprising a pair of spaced parallel base rails  14  of conventional design. These base rails  14  are bolted (note bolts  15 ) or otherwise fastened to the frame of the motor vehicle, such as a pickup truck, in a manner well known in the art. Additionally, the support frame  12  includes a pair of spaced guide rails  16  that are mounted so as to bridge between the transversely extending base rails  14  and thereby extend parallel to the longitudinal axis of the motor vehicle. More particularly, each guide rail  16  is formed from a four-sided tube constructed from steel or other appropriate high strength material. A downwardly depending mounting tab  18  may be welded, fixed with bolts or mounted in some other manner at each end of the guide rails  16 . Each mounting tab  18  is adapted for receipt in a matching slot  22  formned in the base rails  14 . A connecting pin  24  may be passed through aligned cooperating apertures in each of the base rails  14  and tabs  18 . A pin clip or other means  26  may then be utilized to secure each connecting pin  24  and, therefore, the guide rails  16  in position.  
         [0020]    As is known in the art, the fifth wheel hitch  10  also includes a head assembly generally designed by reference numeral  28 . The head assembly  28  carries a jaw assembly, generally designated by reference numeral  30 , for releasably engaging the king pin of a trailer to be towed by the motor vehicle equipped with the hitch  10 . Such jaw assemblies  30  are well known in the art. One such jaw assembly  30  that may be utilized is disclosed in U.S. Pat. No. 5,516,137 to Kass et al. also owned by the assignee of the present invention. The disclosure in this patent is fully incorporated herein by reference. It should be appreciated, however, that jaw assemblies of other design may also be incorporated into the present invention.  
         [0021]    The head assembly  28  also includes first and second side brackets or uprights  32 ,  34 . One upright  32 ,  34  is mounted for sliding movement along each guide rail  16 . As should be appreciated, the first upright  32  includes a first set of three rollers  36 ,  36 ′,  36 ″ (see also FIGS. 2,3,  4  and  5 ). Each of the rollers  36 ,  36 ′,  36 ″ is mounted for relative rotation in the first upright  32 . More specifically, each of the substantially cylindrical rollers  36 ,  36 ′,  36 ″ includes a shoulder  38  adjacent each end thereof. The portion  37  of each roller  36 ,  36 ′,  36 ″ projecting outwardly from beyond the shoulder  38  is captured in an aperture  40  in opposing side walls of the first upright  32  (see FIG. 5 illustration).  
         [0022]    Similarly, a second set of three rollers  42 ,  42 ′,  42 ″ is held for relative rotation on the second upright  34 . The rollers  42 ,  42 ′,  42 ″ also include a shoulder at each end. The portion of the rollers  42 ,  42 ′,  42 ″ projecting beyond the shoulder are captured in cooperating apertures  46  in opposing side walls of the second upright  34 .  
         [0023]    The faces  48  of the first set of rollers  36 ,  36 ′,  36 ″ engage, roll over and follow the upper wall  50  of a first of the guide rails  16 , while the faces of the second rollers  42 ,  42 ′,  42 ″ engage, roll over and follow the upper wall  54  of a second of the base rails  16 . Together, the rollers  36 ,  36 ′,  36 ″ and  42 ,  42 ′,  42 ″ allow smooth, selective displacement of the head assembly  28  between a towing position for properly distributing the weight of the trailer for high speed over-the-road towing and a maneuvering position for providing added clearance between the body work of the motor vehicle and the trailer. This added clearance provides the necessary space to allow the operator to negotiate tight corners without the trailer interfering with and engaging the body work. Hence, greater maneuverability is provided for vehicle operation in confined areas such as are often encountered in parking lots, trailer parks, campgrounds and the like.  
         [0024]    As should be appreciated from reviewing drawing FIGS. 2 and 3, the first and second uprights  32 ,  34  each include a first end or front wall  56  and an opposing second end or rear wall  58 . The first end  56  is angled from bottom to top toward the second end  58  thereby forming an obtuse angle A with the guide rail  16  upon which the upright  32 ,  34  rests. This angle is between 91-140° and more typically is about 122°. The second end  58  of each upright  32 ,  34  forms an angle B of between about 75-89° (typically about 80°) with the guide rail  16  upon which it rests. This angular orientation of the end walls  56 ,  58  creates an aesthetically pleasing and aerodynamic appearance when viewed from the side. The angular orientation of the first and second ends  56 ,  58  also results in a greater distribution of the trailer weight toward the second end  58 . This is the reason that only one roller  36 ,  42  is provided in the respective uprights  32 ,  34  adjacent the first end wall  56  while two rollers  36 ′,  36 ″ and  42 ′,  42 ″ are provided in the respective first and second uprights adjacent the second end wall  58 . A reinforcing plate  60  may be welded or otherwise secured to each of the opposed side walls of the first and second uprights  32 ,  34  to reinforce and strengthen the side walls in the area of the rollers  36 ′,  36 ″ and  42 ′,  42 ″. Each of the reinforcing plates  60  may also include an aperture  62  for receiving and holding the projecting mounting ends of the rollers  36 ′,  36 ″,  42 ′,  42 ″ if desired.  
         [0025]    The head assembly  28  also includes a cross member or head support  64  of a type known in the art to bridge between and interconnect the uprights  32 ,  34 . Preferably, the head support  64  includes a U-shaped mounting bracket  65  at each end. Each mounting bracket  65  includes a series of vertically spaced apertures  63  that receive mounting pins or bolts  67  that allow height adjustment to enhance the versatility of the hitch  10  in interconnecting motor vehicles and trailers of various height dimensions. As is further known in the art, the head assembly  28  is pivotally mounted to the head support  64  (note pivot pins  69  and cooperating cradles  71 ). This pivotal connection may be accomplished by means well known in the art including but not limited to that disclosed in U.S. Pat. Nos. 5,509,682 to Lindenman et al. and 5,529,329 to McCoy, also both owned by the assignee of the present invention. The disclosure in both of these patents is fully incorporated herein by reference.  
         [0026]    As should further be appreciated, the hitch  10  includes a means, generally designated by reference numeral  66  for releasably locking the head assembly  28  in the towing and maneuvering positions (see FIGS. 2, 3 and  4  respectively). The locking means  66  comprises at least one dual bar latch  68 . More preferably, two dual bar latches  68  are provided, one pivotally mounted within an internal cavity formed in each upright  32 ,  34 .  
         [0027]    Each dual bar latch  68  includes a hub  70  comprising a mounting trunion  72  about which the dual bar latch  68  is pivoted and a square through-hole  74  for receiving a square cross-sectioned control handle  76 . Additionally, each latch  68  includes a pair of outwardly projecting bars  78 ,  80 . Preferably the bars  78 ,  80  are substantially L-shaped. The proximal legs  82  of the bars  78 ,  80  engage the hub  70  and define an included angle therebetween of approximately 30°. The distal legs  84  of each bar  78 ,  80  include a tip adapted for receipt in one of two cooperating locking apertures  86 ,  88  formed in the upper walls  50 ,  54  of the guide rails  16 . A smoothly curved, arcuate surface  90  defines the outer surface of the intersection of the proximal and distal legs  82 ,  84 .  
         [0028]    The locking means  66  also includes a biasing means in the form of a leaf spring  92 . As shown, like the dual bar latch  68 , one leaf spring  92  is secured in the cavity formed in each upright  32 ,  34 . More specifically, it should be appreciated that the uprights  32 ,  34  are formed from two half sections. The front and rear walls of the two half sections include aligned, cooperating slots  94  that secure the notched distal ends of the leaf spring  92  so that the leaf spring is held in a position bridging across the cavity overlying each dual bar latch  68  (see FIG. 2 a ). Aligned cooperating apertures  96  in the side walls of the two half sections of the uprights  32 ,  34  are sized to receive the trunion  72  so as to allow pivotal movement of the dual bar latch  68  received therebetween.  
         [0029]    During construction, one side of the trunion  72  of the dual bar latch  68  is positioned in the aperture  96  of one of the half sections of the uprights  32 ,  34 . At the same time, a leaf spring  92  is positioned so that the distal ends thereof fit in the slots  94  in that same half section of the uprights  32 ,  34 . The projecting, mounting portions  37  of the rollers  36 ,  36 ′,  36 ″ or  42 ,  42 ′,  42 ″ are also positioned in the cooperating apertures  40  or  46  in that same half section. The other half section is then positioned against the first half section so that the opposite end of the trunion  72  is received in the aperture  96  in that half section, the notched ends  95  of the leaf springs  92  are likewise received in the slots  94  of that half section and the projecting mounting portions  37  of the rollers  36 ,  36 ′,  36 ″ or  42 ,  42 ′,  42 ″ are received in the cooperating apertures  40  or  46  of that half section. The two half sections of the upright  32  or  34  are then welded or otherwise secured together thereby capturing the leaf spring  92 , dual bar latch  68  and rollers  36 ,  36 ′,  36 ″ or  42 ,  42 ′,  42 ″ in position (see FIGS. 2 a  and  5 ).  
         [0030]    The operation of the hitch  10  will now be described in detail. As shown in FIG. 2, the hitch  10  is in the towing position. More specifically, the head assembly  28  is positioned toward the front end of the hitch  10  toward the left of the figure where the weight of the trailer is better distributed for stable, over-the-road towing at road speeds. In this position, the uprights  32 ,  34  each engage a stop  98  that may be secured to or integrally formed on the guide rails  16 . Additionally, the first or rearwardly projecting bar  78  of each latch  68  is received in the first or forward locking aperture  86  in the adjacent guide rail  16 . It should be appreciated, the arcuate surface  90  on the second or forwardly disposed bar  80  engages the leaf spring  92  “over-center” so that the first bar  78  is reliably secured and biased into engagement in the locking aperture  86 . Thus, it should be appreciated that the head assembly  28  is reliably secured in the towing position.  
         [0031]    Upon reaching the desired destination, low speed maneuver-ability may become a more desired operating characteristic than high speed towing stability. As pointed out above, in order to allow sharper cornering the clearance between the trailer and the body work of the motor vehicle must be increased. This may be done by means of a simple process. First the operator stops the motor vehicle. The operator then gets out and manipulates the control handle  76  so as to pivot the dual bar latch  68  in a counterclockwise direction as shown by action arrow F in FIG. 3. As this is done, the arcuate surface  90  on each first or rearwardly projecting bar  78  engages the associated leaf spring  92  over-center. Thus, the leaf spring  92  biases the distal leg  84  of the second or forwardly directed bar  80  downwardly toward the surface of the underlying guide rail  16 .  
         [0032]    The operator then gets back into the vehicle and pulls the vehicle forward while engaging the trailer brakes. As a result of this action, the head assembly  28  held on the uprights  32 ,  34  moves rearwardly (note action arrow R) to the maneuvering position shown in FIG. 4. Smooth, non-binding movement is ensured by the two sets of rollers,  36 ,  36 ′,  36 ″ and  42 ,  42 ′,  42 ″. Further, it should be appreciated that each second bar  80  is prevented from engaging the first locking aperture  86 . This is because the second bar  80  and the first aperture  86  are offset with respect to the longitudinal centerline underlying the guide rail  16  (note particularly FIG. 3 a ). Thus, each first bar  78  will only align with and engage in the first cooperating aperture  86  whereas each second bar  80  will only align with and engage in the cooperating second aperture  88 .  
         [0033]    As the head assembly  28  moves rearwardly, the uprights  32 ,  34  engage the foot or base of the mounting tabs  18  and substantially simultaneously the tapered tip of the distal leg  84  of each second bar  80  is biased down into the corresponding second locking aperture  88  by the force generated by the associated leaf spring  92 . The trailer is then secured in the maneuvering position with a significant increase in clearance of, perhaps, nine inches between the trailer and the body work of the motor vehicle. This added space or clearance allows for sharp cutting so that the operator may negotiate in tight areas where maneuverability is required.  
         [0034]    Of course, a similar, simple procedure may be utilized to return the head assembly  28  to the towing position. When the added clearance for utmost maneuverability is no longer required, the operator stops the motor vehicle, gets out and rotates the control handle  76  in a clockwise direction. This pivots the latches  68  causing each forwardly projecting second bar  80  to pivot out of the cooperating second locking aperture  88 . The arcuate surface  90  of each second bar  80  is then placed in over-center engagement with the associated leaf spring  92  so that the distal end of each first bar  78  is biased downwardly and into engagement with the upper surface or wall  50 ,  54  of the underlying guide rail  16 . The operator then gets back into the vehicle and backs the vehicle toward the trailer with the trailer brakes engaged. This causes the head assembly  28  held on the uprights  32 ,  34  to slide forward along the guide rails  16  on the smoothly turning first and second set of rollers  36 ,  36 ′,  36 ″ and  42 ,  42 ′,  42 ″. This forward sliding movement continues until the uprights  32 ,  34  engage the stops  98 . Substantially simultaneously the leaf springs  92  bias the tapered ends of the first bars  78  back into the cooperating first locking apertures  86 . Of course, the first bars  78  are prevented from hanging up in the second locking apertures  88  because of the offset arrangement described above and shown in FIG. 3 a.    
         [0035]    The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiment was chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.