Abstract:
A fifth wheel slider assembly comprises at least one rack member having a first side and a second side and is supportable above a vehicle frame, a hitch plate with a throat for receiving a kingpin of a trailer, and a pair of support brackets pivotally supporting the hitch plate and slidably abutting the first side of the at least one rack member. The slider assembly further includes a guide plate slidably abutting the second side of the at least one rack member and coupled to the pair of support brackets by a plurality of mechanical fasteners, and an engagement assembly releasably engaging the at least one rack member at incremental points along the length of the at least one rack member, thereby selectively positioning the hitch plate with respect to the at least one rack member.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/659,796, filed Mar. 9, 2005, entitled FIFTH WHEEL SLIDER ASSEMBLY, which is hereby incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to fifth wheel coupling assemblies, and in particular to a slider assembly for adjustably supporting a fifth wheel hitch assembly from a frame of an associated vehicle.  
         [0003]     Fifth wheel hitch assemblies are used in a wide variety of applications to releasably couple a trailer to an associated towing vehicle, including heavy-duty, over-the-road, tractors. The frames of the tractors, to which the fifth wheel assemblies are mounted, typically comprise a pair of longitudinally-extending C-shaped channel members that are supported by the wheel and axle members of the vehicle. The channel members are laterally spaced apart from one another such that they provide a planar surface for resisting normal and twisting forces after the fifth wheel is secured thereupon and placed in operation, thereby transferring the payload of the trailer equally onto each of the channel members. The fifth wheel hitch assembly can be mounted on the truck frame in a number of various ways, such as by utilizing drop-over angle brackets or flat mounting plates.  
         [0004]     The drop-over method utilizes an L-shaped angle member which conforms and communicates with the top and vertical edges of each of the channels, having a long vertical leg securely fixed to an outboard vertical side of the associated channel, and a horizontal leg of the drop-over bracket that typically includes an arcuately-shaped mounting bracket which is welded thereon. The arcuate mounting bracket lies generally above the top horizontal leg of the C-shaped channel, and includes a horizontally-aligned bore for accepting a coupling cross pin which is in communication with the fifth wheel frame work. Specifically, the fifth wheel frame work includes a flange on one or each peripheral edge that communicates with the arcuate mounting bracket, thereby allowing the flange ports on each flange to be horizontally aligned with the mounting bracket bore for pinning the fifth wheel to the drop-over angle mounting bracket and hence, to the tractor frame. Although the drop-over brackets transmit lateral inertial forces which are caused by curving and rocking of the fifth wheel into the frame, drop-over arrangements are best suited for resisting longitudinal forces and moments caused from acceleration, deceleration, as well as the downward forces acting on the ramps eccentric to the rear of the bracket pivot center during coupling.  
         [0005]     Alternatively, a flat plate mounting assembly includes a rectangular, planar plate of steel that is secured on top of each of the channel members, with the lateral sides of the plate extending slightly beyond each channel. In order to transfer loads from the plate to the frame, a section of L-shaped angle, typically referred to as the outboard angle, is used to support the plate directly below the overhang. The outboard angle member is also secured to the tractor channel and the flat mounting plate by securing a horizontal leg thereof to the bottom side of the mounting plate and securing a vertical leg thereof to the vertical wall of the associated channel. Similar arcuate mounting brackets to those discussed above are welded to the top of the mounting plate. The flat mounting plate method of attachment offers increased fatigue strength when compared to the drop-over mounting assembly because the lateral forces and moments that work upon the arcuate mounting bracket are first distributed throughout the entire flat plate surface area before they are distributed and transferred into the outboard angle member, thereby increasing the surface area over which the load is distributed. However, one significant disadvantage of the flat plat mounting arrangement is the use of a heavy steel plate adding to the weight and total cost of the overall assembly.  
         [0006]     Another significant disadvantage to each of these arrangements as discussed above is the significant welding the overall assemblies require, thereby increasing the manufacturing costs and decreasing the adjustability and variability of the overall assembly once installed. Still further, these designs typically extend below the upper surface of the associated vehicle frame or channel members, thereby requiring precise placement of laterally-extending structural frame members of either the truck frame or the fifth wheel slider assembly, and/or rerouting of associated electrical and hydraulic lines.  
         [0007]     Still further, typical fifth wheel assemblies that provide for slidable adjustment of the associated fifth wheel hitch plate with respect to the vehicle frame members require the use of separate stock members affixed to either a component of the fifth wheel assembly or the frame rails, in order to limit the travel of the fifth wheel hitch plate with respect to the vehicle frame rails, thereby adding to the costs associated with the manufacture of the fifth wheel hitch assembly.  
         [0008]     A fifth wheel hitch assembly is desired that reduces the number of components necessary to provide a slidable adjustment of an associated hitch plate with respect to supporting vehicle frame rails, while simultaneously providing for easy adjustment and replacement of worn or damaged components. The fifth wheel hitch assembly should further reduce the associated weight, reduce manufacturing costs by eliminating welding and other time consuming processes, provide a modular design that allows easy assembly and/or retrofitting, and allows for use with various truck frame designs without requiring significant reworking to either the hitch assembly of the truck frame.  
       SUMMARY OF THE INVENTION  
       [0009]     One aspect of the present invention is to provide a fifth wheel slider assembly that comprises at least one rack member having a first side and a second side and supportable above a vehicle frame, a hitch plate with a throat for receiving a kingpin of a trailer, and a pair of support brackets pivotally supporting the hitch plate and slidably abutting the first side of the at least one rack member. The fifth wheel slider assembly further includes a guide plate slidably abutting the second side of the at least one rack member and coupled to the pair of support brackets by a plurality of mechanical fasteners, and an engagement assembly releasably engaging the at least one rack member at incremental points along a length of the at least one rack member, thereby selectively positioning the hitch plate with respect to the at least one rack member.  
         [0010]     Another aspect of the present invention is to provide a fifth wheel slider assembly that comprises a pair of mounting brackets adapted to respectively mount to a pair of vehicle frame rails, a pair of rack members each having a first side and a second side and fixably secured to the mounting members, a hitch plate with a throat for receiving a kingpin of a trailer, and a pair of support brackets pivotally supporting the hitch plate. The fifth wheel slider assembly further includes a guide plate coupled with the support brackets by a plurality of mechanical fasteners such that the support brackets slidably abut the first sides of the rack members and the guide plate slidably abuts the second sides of the rack members, and an engagement assembly releasably engaging the rack members at incremental points along the length of the rack members, thereby selectively positioning the hitch plate with respect to the rack members.  
         [0011]     The present inventive fifth wheel hitch assembly reduces the number of components necessary to provide a slidable adjustment of an associated hitch plate with respect to supporting vehicle frame rails, while simultaneously providing for easy adjustment and replacement of worn or damaged components. The hitch assembly further reduces the associated weight, reduces manufacturing costs by eliminating welding and other time consuming processes, provides a modular design that allows easy assembly and/or retrofitting, allows for use with various truck frame designs without requiring significant reworking to either the hitch assembly of the truck frame, is economical to manufacture, and is particularly well adapted for the proposed use. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  is a top perspective view of a fifth wheel slider assembly embodying the present invention;  
         [0013]      FIG. 2  is a top plan view of the fifth wheel slider assembly;  
         [0014]      FIG. 3  is a partial cross-sectional view of the fifth wheel slider assembly, taken along the line III-III,  FIG. 2 ;  
         [0015]      FIG. 4  is a side view of the fifth wheel slider assembly;  
         [0016]      FIG. 5  is a top perspective view of a first alternative embodiment of the fifth wheel slider assembly;  
         [0017]      FIG. 6  is a top plan view of the first alternative embodiment of the fifth wheel slider assembly;  
         [0018]      FIG. 7  is a partial cross-sectional end view of the first alternative embodiment of the fifth wheel slider assembly, taken along the line VII-VII,  FIG. 6 ;  
         [0019]      FIG. 8  is a top perspective view of a second alternative embodiment of the fifth wheel slider assembly;  
         [0020]      FIG. 9  is a top plan view of the second alternative embodiment of the fifth wheel slider assembly;  
         [0021]      FIG. 10  is a partial cross-sectional view of the second alternative embodiment of the fifth wheel slider assembly, taken along the line X-X,  FIG. 9 ; and  
         [0022]      FIG. 11  is a side view of the second alternative embodiment of the fifth wheel slider assembly. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]     For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in  FIGS. 1, 5  and  8 . However, it is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.  
         [0024]     The reference numeral  10  ( FIGS. 1-4 ) generally designates a fifth wheel slider assembly embodying the present invention. In the illustrated example, the fifth wheel slider assembly is supported by a pair of vehicle frame rails  12  each having an outer vertical surface  14  and a top horizontal surface  16 . The slider assembly  10  includes a pair of L-shaped angle brackets  18  each having a downwardly-extending vertical leg  20 , an inwardly-extending horizontal leg  22 , a first end  24  and a second end  26 . A pair of laterally-extending structural support members  28  extend between the first ends  24  and the second ends  26  of the angle brackets  28 , and are preferably fixedly secured thereto by welding, or the like. A pair of rack members  30  are fixedly secured by a weld to a horizontal leg  22  of a respective angle bracket  18 . Each rack member  30  includes a plurality of notches  33  spaced incrementally along the length thereof. Each rack member  30  is provided with a T-shaped cross-sectional configuration having a top surface  32 , an inner lip  34 , and an outer lip  36 .  
         [0025]     The slider assembly  10  further includes a pair of support brackets  38  slidably engaging and extending upwardly from a respective rack member  30 . Each support bracket  38  includes a bushing housing  40  each having an aperture  41  extending therethrough, a base plate member  42  having a plurality of bolt receiving apertures  44  extending therethrough, and a plurality of support arms  46  extending between the bushing housing  40  and the base plate member  42 . The base plate member  42  includes a longitudinally-extending outwardly and downwardly-curled guide edge  48  that slidably receives the outer lip  36  of the respective rack member  30  therein. An inwardly-extending lip  50  of the base plate member  42  includes the apertures  44  and is divided into a first portion  43  and a second portion  45 , thereby defining a gap  47  therebetween. Each support bracket  38  includes a tilt stop member  52  extending upwardly from a support arm  46  and the base plate  42 . As in the illustrated example, the tilt stop member  52  is preferably integrally molded with the support bracket  38 . In assembly, a two-piece bushing  54  having a first portion  56  and a second portion  58  divided from one another at a center line  60 . The division of the bushing  54  into the first portion  56  and the second portion  58  provides easier assembly and/or replacement due to the narrowing draft of the aperture  41 , as well as reduces the need for cleaning the inner bore of the aperture  41  of cast parting lines formed during the manufacture of the support bracket  38 .  
         [0026]     The slider assembly  10  further includes a hitch plate (not shown) that is pivotally coupled to the support brackets  38  by at least one pivot pin that extends into the bushing  54  in a manner as know in the art. During operation, the tilt stop members  52  limit the amount of tilt travel of the hitch plate with respect to the support brackets  38 .  
         [0027]     The slider assembly  10  further includes a guide plate  62  having a first end  64 , a second end  66 , a centrally-located aperture  68  and a recessed side relief  70  functioning to reduce the overall weight of the guide plate  62 . The first end  64  and second end  66  of the guide plate  62  are secured to the inner lip  50  of each base plate member  42  by a plurality of bolts  72 . The guide plate  62  is configured such that the first end  64  and the second end  66  guide beneath the outer lip  36  of a respective rack member  30 .  
         [0028]     The slider assembly  10  further includes an engagement assembly  74  including a pneumatic cylinder  76  having a housing  77  with a first end  78  and a rod  79  with a second end  80 . The engagement assembly  74  further includes a first lock member  82  and a second lock member  83  each slidably received within the respective gap  47  and each having a plurality of engagement teeth  84  that are releasably engaged within the notches  33 , thereby fixing the location of the support brackets  38  with respect to the rack members  30 , and in turn fixing the location of the hitch plate with respect to the frame rails  12 . Preferably, at least one of the lock members  82 ,  83  includes an extended slot aperture  86  extending therethrough and that receives a mechanical fastener such as a bolt  88  securing the end  78 ,  80  to the lock member  82 ,  83  and allowing slight movement of the couple therebetween.  
         [0029]     The slider assembly  10  further includes a stop member  90  located proximate the first end  64  and a stop member  91  located proximate the second end  66  of the guide plate  62  and secured thereto via the mechanical fasteners or bolts  72 . Each of the stop members  90 ,  91  are juxtaposed across the guide plate  62  from one another and are positioned so as to abut the structural support members  28 , thereby limiting the travel of the support brackets  38  with respect to the rack members  30 , and as a result, the travel of the fifth wheel hitch plate with respect to the frame rails  12 .  
         [0030]     The slider assembly  10  further includes a bulkhead bracket  92  having a guidepost  94  and a U-shaped clip  96  integrally formed with the guidepost  94  and that frictionally engages structural support member  28 . The guide post  92  includes an aperture  98  extending therethrough, and through which hydraulic, electrical, and other communication/control lines extending between the trailer and towing vehicle are guided so as to reduce the possibility of damage thereto.  
         [0031]     The reference numeral  10   a  ( FIGS. 5-7 ) generally designates another embodiment of the fifth wheel slider assembly. Since the slider assembly  10   a  is similar to the previously described slider assembly  10 , similar parts appearing in  FIGS. 1-4  and  FIGS. 5-7 , respectively are represented by the same, corresponding reference numeral except for the suffix “a” in the numerals of the latter. The slider assembly  10   a  is similar to the slider assembly  10  with the main exception being the replacement of the L-shaped angle brackets  18  with planar outboard mounting plates  100 , and the addition of mounting angles  101 . In the illustrated example, the mounting plates  100  includes a plurality of apertures  102  spaced along the length thereof and that are adapted to receive mounting hardware such as bolts (not shown) therein to secure the mounting plates  100  and thereby the slider assembly  10   a  to the associated mounting angles  101 . The mounting angles  101  extend longitudinally along the associated frame rails  12   a  and each include a first portion  103  and a second portion  105  extending orthogonally downward from the first portion  103  and secured to the associated frame rail  12   a.    
         [0032]     The reference numeral  10   b  ( FIGS. 8-11 ) generally designates another alternative embodiment of the fifth wheel slider assembly. Since the slider assembly  10   b  is similar to the previously described slider assembly  10 , similar parts appearing in  FIGS. 1-4  and  FIGS. 8-11 , respectively are represented by the same, corresponding reference numeral except for the suffix “b” in the numerals of the latter. The slider assembly  10   b  is similar in construction to the slider assembly  10 , with the main difference being the addition of a pair of over the frame mounting plates  104  welded to the top of the horizontal leg  22   b  of each angle bracket  18   b . In the illustrated example, each over the frame mounting bracket  104  includes a plurality of notches  106  extending and spaced along the length of the mounting plate  104 . The slider assembly  10   b  is secured to the associated frame rails  12   b  by welding the angle brackets  18   b  to the frame rails  12   b.    
         [0033]     The present inventive fifth wheel hitch assembly reduces the number of components necessary to provide a slidable adjustment of an associated hitch plate with respect to supporting vehicle frame rails, while simultaneously providing for easy adjustment and replacement of worn or damaged components. The hitch assembly further reduces the associated weight, reduces manufacturing costs by eliminating welding and other time consuming processes, provides a modular design that allows easy assembly and/or retrofitting, allows for use with various truck frame designs without requiring significant reworking to either the hitch assembly of the truck frame, is economical to manufacture, and is particularly well adapted for the proposed use.  
         [0034]     In the foregoing description, it will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed herein. Such modifications are to be considered as included in the following claims, unless these claims by their language expressly state otherwise.