Abstract:
A kingpin assembly comprises a housing having a recess located therein, a collar member operably coupled to the housing, and an integral single-piece kingpin having at least a portion located within the recess of the housing, wherein the housing and collar cooperate to rotationally secure the kingpin within the recess of the housing, and wherein the kingpin provides a sole rotational support for the kingpin with respect to the housing and the collar.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a kingpin assembly for use within a fifth wheel hitch assembly, and particularly to a kingpin assembly that includes a freely rotating kingpin that allows rotation of the kingpin separate from the remaining components of the assembly during operational use thereof. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention is to provide the kingpin assembly that comprises a housing having a recess located therein, a column member operably coupled to the housing member, and an integral single-piece kingpin having at least a portion located within the recess of the housing, wherein the housing and the collar cooperate to rotationally secure the kingpin within the recess of the housing, and wherein the kingpin provides a sole rotational support for the kingpin with respect to the housing and the collar. 
     Another aspect of the present invention is to provide a kingpin assembly that comprises an elongated post member having an outer surface, a tubular sleeve member rotationally received about the post member and having an inner surface facing the outer surface of the post member, and an outer wear surface adapted to abut a coupling mechanism of a fifth wheel hitch assembly. The kingpin assembly further comprises a locking member abutting the sleeve member and preventing axial movement of the sleeve member with respect to the post member. 
     Still another aspect of the present invention is to provide a kingpin assembly that comprises a housing having a recess located therein, a collar member operably coupled to the housing member, a kingpin having at least a portion located within the recess of the housing and a circumferentially-extending relief, wherein the housing and collar cooperate to rotationally secure the kingpin within the recess of the housing, and a retention assembly. The retention assembly comprises at least one linearly-adjustably securing member movable between a first position, wherein at least one securing member is positioned within relief of the kingpin, thereby rotationally securing the kingpin within the recess of the housing, and a second position, wherein the kingpin is removable from within the recess of the housing. 
     Still yet another aspect of the present invention is to provide a kingpin assembly that comprises an elongated first member adapted to be rotatably received within a kingpin housing, and having a longitudinally-extending threaded aperture, and an elongated second member having a neck portion adapted to couple to the coupling assembly of a fifth wheel hitch assembly, a distally-located head portion having a diameter larger than a diameter of the neck portion, and a proximally-located threaded portion that is threadably received within the aperture of the first member. 
     Another aspect of the present invention is to provide a kingpin assembly that comprises a housing having a recess located therein, a collar member operably coupled to the housing member, and a kingpin having at least one portion located within the recess of the housing, wherein the housing and the collar cooperate to rotationally secure the kingpin within the recess of the housing. The kingpin includes a cylindrically-shaped body portion having a first diameter, a neck portion having a second diameter that is less than the first diameter and a head portion having a third diameter that is greater than the first diameter and a ring portion that extends outwardly from the body portion that operably engages at least a select one of the housing and the collar member, thereby inhibiting axial displacement of the kingpin with respect to the housing. 
     The present inventive kingpin assembly allows free rotation of the kingpin by reducing operational wear of the same, allows easy access to and replacement of an associated kingpin subsequent to wear thereof, reduces the amount of maintenance typically required for fifth wheel hitch assemblies, and reduces wear due to debris entering the overall assembly. Further, the present inventive assembly is more durable, allows replacement of certain components thereof by even unskilled personnel, is extremely efficient in use, capable of a long operating life, and particularly well adapted for the proposed use. 
     These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims and appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevational view of a tractor and heavy duty trailer supported thereby; 
         FIG. 2  is a perspective view of a fifth wheel hitch assembly and kingpin assembly of the present invention; 
         FIG. 3  is a cross-sectional side view of the kingpin assembly taken through the line III-III,  FIG. 2 ; 
         FIG. 4  is a cross-sectional perspective view of a first alternative embodiment of the kingpin assembly; 
         FIG. 5  is a cross-sectional side view of the first alternative embodiment of the kingpin assembly; 
         FIG. 6  is an exploded perspective view of the first alternative embodiment of the kingpin assembly; 
         FIG. 7  is a cross-sectional perspective view of a second alternative embodiment of the kingpin assembly; 
         FIG. 8  is a cross-sectional side view of the second alternative embodiment of the kingpin assembly; 
         FIG. 9  is an exploded perspective view of the second alternative embodiment of the kingpin assembly; 
         FIG. 10  is a cross-sectional perspective view of a third alternative embodiment of the kingpin assembly; 
         FIG. 11  is a cross-sectional side view of the third alternative embodiment of the kingpin assembly; 
         FIG. 12  is an exploded perspective view of the third alternative embodiment of the kingpin assembly; 
         FIG. 13  is a cross-sectional side view of a fourth alternative embodiment of the kingpin assembly; 
         FIG. 14  is an exploded perspective view of a fourth alternative embodiment of the kingpin assembly; 
         FIG. 15  is a cross-sectional side view of a fifth alternative embodiment of the kingpin assembly; 
         FIG. 16  is an exploded perspective view of the fifth alternative embodiment of the kingpin assembly; 
         FIG. 17  is a cross-sectional perspective view of a sixth alternative embodiment of the kingpin assembly; 
         FIG. 18  is a cross-sectional side view of the sixth alternative embodiment of the kingpin assembly; 
         FIG. 19  is an exploded perspective view of the sixth alternative embodiment of the kingpin assembly; 
         FIG. 20  is a cross-sectional side view of a seventh alternative embodiment of the kingpin assembly; 
         FIG. 21  is an exploded perspective view of the seventh alternative embodiment of the kingpin assembly; 
         FIG. 22  is a cross-sectional side view of an eighth alternative embodiment of the kingpin assembly; 
         FIG. 23  is an exploded perspective view of the eighth alternative embodiment of the kingpin assembly; 
         FIG. 24  is a cross-sectional side view of a ninth alternative embodiment of the kingpin assembly; 
         FIG. 25  is an exploded perspective view of the ninth alternative embodiment of the kingpin assembly; 
         FIG. 26  is a cross-sectional side view of a tenth alternative embodiment of the kingpin assembly; 
         FIG. 27  is an exploded perspective view of the tenth alternative embodiment of the kingpin assembly; 
         FIG. 28  is a perspective view of the tenth alternative embodiment of the kingpin assembly, wherein a kingpin of the kingpin assembly is disassembled from the remaining portions of the assembly; 
         FIG. 29  is a perspective view of the tenth alternative embodiment of the kingpin assembly, wherein the kingpin is assembled with the remaining portions of the kingpin assembly; 
         FIG. 30  is a cross-sectional perspective view of an eleventh alternative embodiment of the kingpin assembly; 
         FIG. 31  is a cross-sectional side view of the eleventh alternative embodiment of the kingpin assembly; 
         FIG. 32  is an exploded perspective view of the eleventh alternative embodiment of the kingpin assembly; 
         FIG. 33  is a cross-sectional perspective view of a twelfth alternative embodiment of the kingpin assembly; 
         FIG. 34  is a cross-sectional side view of the twelfth alternative embodiment of the kingpin assembly; 
         FIG. 35  is an exploded perspective view of the twelfth alternative embodiment of the kingpin assembly; 
         FIG. 36  is a cross-sectional perspective view of a thirteenth alternative embodiment of the kingpin assembly; 
         FIG. 37  is a cross-sectional side view of the thirteenth alternative embodiment of the kingpin assembly; and 
         FIG. 38  is an exploded perspective view of the thirteenth alternative embodiment of the kingpin assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     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 ,  3 , and the like. 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. 
     The reference numeral  10  ( FIG. 1 ) generally designates a heavy duty tractor and trailer combination, wherein a tractor  12  operationally supports an associated trailer  14  via a fifth wheel hitch assembly  16  ( FIG. 2 ) and a kingpin assembly  18  cooperating therewith and generally embodying the present invention. In the illustrated example, the fifth wheel hitch assembly  16  includes a fifth wheel hitch plate  20  pivotally coupled to a frame  22  of the associated tractor  12  and including a tapered kingpin-receiving throat and a locking assembly (not shown) as well known in the art. 
     The kingpin assembly  18  ( FIG. 3 ) is adapted for use within a trailer skid plate  26  mounted to an underside of the associated trailer  14 . The trailer skid plate  26  includes an aperture  28  extending therethrough and that receives the kingpin assembly  18  therein. The kingpin assembly  18  includes a housing  30  having a recess in the form of a centrally-located aperture  32  extending therethrough, and a plurality of threaded bolt-receiving apertures  34  spaced about the aperture  32 . The recess  32  further includes a step wall  36 . The kingpin assembly  18  further includes a ring-shaped collar member  38  including a centrally-located aperture that defines a cylindrically-shaped first portion  40  and an axially arcuately-shaped second portion  44  defining a radius r 1 . The collar member  38  further includes a circumferentially-extending step or groove  46  located along a length of the second portion  44  of the aperture  40 . The collar member  38  further includes a plurality of bolt-receiving apertures  48  spaced about the aperture  40  and that are co-aligned with the apertures  34  of the housing  30  when the collar member  38  is coupled with the housing  30 , as described below. 
     The kingpin assembly  18  further comprises a kingpin  50  that includes an upper head portion  52 , a lower head portion  54 , a body portion  56 , and a lock assembly-receiving portion  58 . The upper head portion  52  of the kingpin  50  includes a cylindrical first portion  60  and an axially arcuately-shaped second portion  62  located between the first portion  60  and the body portion  56 . The second portion  62  of the upper head portion  52  defines a radius r 2 . The lock-assembly receiving portion or neck portion  58  is reduced in size relative to the overhead portion  54  and the body portion  56 , and is adapted to receive the locking jaws (not shown) of an associate fifth wheel lock assembly thereabout. 
     In assembly, the housing  30  is placed above the aperture  28  of the trailer skid plate  26  and welded thereto about a circumference  66 . The kingpin  50  is placed within the collar member  38  with the collar member  38  being secured to the associated housing  30  via a plurality of bolts  68 . It is noted that a seal member in the form of an O-ring  70  is located within the groove  46 , and that a wear disk  35  comprising a friction reducing material is located between the first position  60  of the kingpin  50 , and the collar member  38 . It is further noted that the radius r 1  of the second portion  44  of the collar member  38  and the radius r 2  of the second portion  62  of the upper head portion  52  of the kingpin  50  are each varying in distance about their respective arcs, and that the radii r 1 , r 2  vary with respect to one another, such that the total area of the mating surfaces of the respective parts are reduced, thereby reducing the associated operational wear. 
     The kingpin assembly  18  further includes a dirt cover  72  welded within the aperture  32  of the housing  30 , thereby preventing contamination of the pivoting couple between the kingpin  50  and the collar member  38 . Alternatively, the dirt cover could be integrally formed with the housing  30 . 
     In operation, the kingpin  50  is coupled to the associated fifth wheel hitch assembly  16  when locking jaws of the fifth wheel hitch assembly  16  are received about the lock assembly-receiving portion  58  of the kingpin  50  defined between the lower head portion  54  and the body portion  56  thereof. As the tow vehicle or tractor  12  turns out of alignment with respect to the towed trailer  14 , the kingpin  50  is allowed to pivot with the components of the tractor  12  and the associated fifth wheel hitch assembly  16  without requiring movement of the housing  30 , the collar member  38 , nor any other component of the kingpin assembly  18 . 
     The reference numeral  18   a  ( FIGS. 4-6 ) generally designates another embodiment of the present invention, having a housing  30   a , a collar  80 , and a kingpin  50   a . Since kingpin assembly  18   a  is similar to the previously described kingpin assembly  18 , similar parts appearing in  FIG. 1  and  FIGS. 4-6  respectively are represented by the same, corresponding numeral, except for the suffix “a” in the numerals of the latter. The housing  30   a  includes a recess or pocket  82  within which the collar  80  is affixed by a plurality of bolts  68   a . The collar  80  comprises an outer member  84 , a pair of coupling members  86 , and a retainer member  88 . The outer member  84  includes a bore  90  within which the coupling members  86  and the retainer member  88  are received. Each coupling member  86  is arcuately-shaped and includes a circumferentially-extending rib  92 . The retainer member  88  is disk-shaped and includes a central aperture  94  within which the kingpin  50   a  is rotationally received. The retainer member  88  further includes a plurality of bolt-receiving apertures space circumferentially thereabout. The kingpin  50   a  includes a cylindrically-shaped body portion  98  with a circumferentially extending groove  100  located near a proximal end  102  thereof. The kingpin  50   a  further includes a lower head portion  54   a  located near a distal end  104  thereof. 
     The kingpin assembly  18   a  is assembled with the overall trailer assembly  14   a  in a manner similar to that of kingpin assembly  18   a  as described above. With reference to this particular embodiment, the body portion  98  of the kingpin  50   a  is placed within the central aperture  94  of the retainer member  88 . The cooperating coupler members  86  are then placed about the body portion  98  such that the ribs  92  are located within the groove  100 . The kingpin  50   a , the coupler members  86  and the retainer member  88  are then placed within the bore  90  of the outer member  84  and are held into position by a plurality of bolts  106  located within the apertures  96  and threadably received into the outer member  84 . The outer member  84  is then placed within the recess or pocket  82  of the housing  30   a  and secured thereto by a plurality of bolts  68   a . It is noted that the kingpin  50   a  of the kingpin assembly  18   a  has a relatively narrow diameter along the entire length thereof, thereby allowing the kingpin  50   a  to be machined from a single piece of bar stock and avoiding relatively costly forging manufacturing methods while providing a kingpin with the necessary structural integrity. 
     The reference numeral  18   b  ( FIGS. 7-9 ) generally designates another embodiment of the present invention, including a kingpin assembly  18   b . Since the kingpin assembly  18   b  is similar to the previously-described kingpin assembly  18  and kingpin assembly  18   a , similar parts appearing in  FIG. 3  and  FIGS. 7-9  and  FIGS. 10-12  respectively, are represented by the same, corresponding numeral, except for the suffix “b” in the numerals of the latter. The kingpin assembly  18   b  includes a collar member  38   b  having a central bore  108  and a plurality of apertures  48   b  spaced circumferentially thereabout. The central bore  108  includes a cylindrically-shaped upper portion  110 , a conically-shaped middle portion  112 , and a cylindrically-shaped lower portion  114 . The kingpin assembly  18   b  further includes a housing lid  116  having a centrally-located and cylindrically-shaped guide portion  118  extending downwardly from a plate-shaped body portion  120 . The body portion  120  of the lid  116  includes a plurality of apertures spaced around the circumference thereof. The kingpin assembly  18   b  further includes a kingpin  50   b  that includes an upper head portion  52   b , a lower head portion  54   b , a body portion  56   b , and a lock assembly-receiving portion  58   b . The upper head portion  52   b  is generally conically-shaped, and includes a centrally-located, cylindrically-shaped aperture  124 . 
     In assembly, the kingpin  50   b  is placed within the collar member  38   b  and the lid  116  is placed thereon such that the guide portion  118  is aligned with and received within the aperture  124 . The kingpin  50   b , the collar member  38   b  and the lid  116  are then positioned within the recess  82   b  of the housing  30   b  and held in position by a plurality of bolts  68   b  extending through the apertures  48   b  and the apertures  122  of the lid  116 , and threadably received within the apertures  34   b.    
     The reference numeral  18   c  ( FIGS. 10-12 ) generally designates another embodiment of the present inventive kingpin assembly. Since the kingpin assembly  18   c  is similar to the previously described kingpin assembly  18   b , similar parts appearing in  FIGS. 7-9  and  FIGS. 10-12  respectfully are represented by the same, corresponding reference numeral, except for the suffix “c” in the numerals of the latter. In the illustrated example, the kingpin assembly  18   c  includes an upper locking member  126 , a lower locking member  128 , a pair of locking retainer members  130 , and the kingpin  50   c . The upper locking member  126  and the lower locking member  128  are each plate-shaped and include a centrally-located, cylindrically-shaped recess  132 , and a plurality of bolt-receiving apertures  48   c  spaced about the circumference thereof. Each locking retainer member  130  is arcuately-shaped and includes a circumferentially-extending isosceles trapezoidal-shaped guide rib  136 . The kingpin  50   c  includes a body portion  56   c  having a isosceles-trapezoidal-shaped groove  138  extending circumferentially thereabout and located near the proximal end  102   c.    
     In assembly, the locking retainer members  130  are placed about the kingpin  50   c  such that the ribs  136  are received within the groove  138 . The upper locking member  126  and the lower locking member  128  are placed about the kingpin  50   c  and the locking retainer members  130  such that the locking retainer members  130  are positioned within the recesses  132  of the upper locking member  126  and the lower locking member  128 . The kingpin  50   c , the upper locking member  126 , the lower locking member  128  and the locking retainer members  130  are then placed within the recess  82   c  of the housing  30   c  and are secured thereto by a plurality of bolts  68   c  that extend through the apertures  48   c  and are threadably received into the apertures  34   c.    
     The reference numeral  18   d  ( FIGS. 13 and 14 ) generally designates another embodiment of the present inventive kingpin assembly. Since the kingpin assembly  18   d  is similar to previously-described kingpin assembly  18  and kingpin assembly  18   c , similar parts appearing in FIGS.  3  and  10 - 12  and  FIGS. 13 and 14 , respectively, are represented by the same, corresponding reference numeral, except for the suffix “d” in the numerals of the latter. In the illustrated example, the kingpin assembly  18   d  includes a collar  80   d  and a kingpin  50   d . The collar  80   d  includes an upper support ring  140  and a lower support ring  142 . The upper support ring  140  includes a stepped bore  144  within which the upper head portion  52   d  of the kingpin  50   d  is received. The lower support ring  142  includes a cylindrically-shaped alignment portion  146  that cooperates to rotatably guide the kingpin  50   d  therewith, as described below. The upper support ring  140  and the lower support ring  142  each include a plurality of bolt-receiving apertures  48   d  spaced circumferentially thereabout. The kingpin  50   d  includes the upper head portion  52   d , the lower head portion  54   d , the body portion  56   d , and the lock assembly receiving portion  58   d . The upper head portion  52   d  includes a radially outwardly-extending portion  148  having a downwardly-extending, cylindrically-shaped alignment portion  150  spaced from the body portion  56   d.    
     In assembly, the upper head portion  52   d  is received within the bore  144  of the upper support ring  140 , while the alignment portion  146  of the lower support ring  142  and the alignment portion  150  of the kingpin  50   d  are coupled with one another such that the alignment portion  146  is aligned radially inward from the alignment portion  150  and rotatably guides the same. A wear disk  152  comprising material similar to the wear disk  35 , is located with the bore  144  and between the upper head portion  52   d  of the kingpin  50   d  and the upper support ring  140 . The kingpin  50   d , the upper support ring  140  and the lower support ring  142  are positioned within the recess  82   d  of the housing  30   d  and secured therein by a plurality of bolts  68   d  extending through the apertures  48   d  of the upper support ring  140  and the lower support ring  142 , and threadably received within the apertures  34   d  of the housing  30   d.    
     The reference numeral  18   e  ( FIGS. 15 and 16 ) generally designates another embodiment of the kingpin assembly. Since the kingpin assembly  18   e  is similar to the previously-described kingpin assembly  18  and kingpin assembly  18   b , similar parts appearing in FIGS.  3  and  7 - 9  and  FIGS. 15 and 16  respectfully are represented by the same, corresponding reference numeral, except for the suffix “e” in the numerals of the latter. In the illustrated example, the kingpin assembly  18   e  includes the housing  30   e  having a recess  82   e  and the plurality of apertures  34   e  spaced circumferentially thereabout. The collar member  38   e  is similar in configuration to the collar member  38   b  as described above, with the most notable exception being the configuration of the bolt apertures  48   e , and particular that the bolt apertures  48   e  are threaded and extend downwardly into the collar member  38   e . The kingpin  50   e  is also similar to the kingpin  50   b  as described above with the most notable exception being the removal of the aperture  124  therefrom. The kingpin assembly  18   e  further includes an upper support ring  154  having an upper flange  156  and an alignment portion. This particular configuration allows a top-down replacement of the kingpin  50   e . Specifically, an access aperture extends through the associated trailer floor  162 , thereby allowing the kingpin  50   e  to be moved downwardly into the collar member  38   e , and the upper support ring  154  to be located such that the alignment portion  158  extends downwardly through the access aperture  160  and into the recess  82   e  of the housing  30   e . The upper support ring  154  is held in position by a plurality of bolts  68   e  that extend downwardly through the plurality of circumferentially-spaced apertures  164  within the upper support ring  154 , a plurality of apertures  166  circumferentially spaced about the access aperture  160  within the trailer floor  162 , the plurality of apertures  34   e  extending through the housing  30   e , and the threaded apertures  48   e  of the collar member  38   e . As is best illustrated in  FIG. 15 , a wear disk  152   e  is located between the upper support ring  154  and the kingpin  50   e . This particular configuration allows the kingpin  50   e  to be removed from the interior of the associated trailer. 
     The reference numeral  18   f  ( FIGS. 17-19 ) generally designates another embodiment of the present inventive kingpin assembly. Since the kingpin assembly  18   f  is similar to the previously-described kingpin assembly  18  and kingpin assembly  18   e , similar parts appearing in  FIGS. 3 ,  15  and  16  and  FIGS. 17-19 , respectively are represented by the same, corresponding reference numeral except for the suffix “f” in the numerals of the latter. In the illustrated example, the kingpin assembly  18   f  is similar to the kingpin assembly  18   e  with the most notable exceptions being the bottom-up assembly of the kingpin assembly  18   f , and the inclusion of a mechanical-type bearing assembly  168 . The bearing assembly  168  is positioned between the upper head portion  52   f  of the kingpin  50   f  and the stepped bore  170  extending through the collar member  38   f  and within which the kingpin  50   f  is rotatably received. 
     The reference numeral  18   g  ( FIGS. 20 and 21 ) generally designates another embodiment of the present inventive kingpin assembly. Since the kingpin assembly  18   g  is similar to the previously-described kingpin assembly  18 , similar parts appearing in  FIG. 3  and  FIGS. 20 and 21  respectfully are represented by the same, corresponding reference numeral, except for the suffix “g” in the numerals of the latter. The kingpin assembly  18   g  includes the collar member  38   g  and the kingpin  50   g . This particular configuration allows a top-down replacement of the kingpin  50   g  from within the overall kingpin assembly  18   g . The central bore or aperture  32   g  of the housing  30   g  includes an upper threaded portion  172 , a cylindrically-shaped upper portion  110   g , a conically-shaped middle portion  112   g , and a cylindrically-shaped lower portion  114   g , while the upper head portion  52   g  of the kingpin  50   g  includes a corresponding cylindrically-shaped portion  111   g , a conically-shaped portion  113   g  and a cylindrically-shaped lower portion  115   g . The collar member  38   g  is cylindrically-shaped and includes a threaded outer surface  180 . In assembly, the housing  30   g  is weldably secured to the overall trailer assembly  14   g  via a plurality of welds  66   g . The kingpin  50   g  is rotatably received within the bore  32   g  of the housing  30   g  in a top-down manner, and the collar member  38   g  is threadably coupled into the upper threaded portion  172  of the housing  30   g , thereby rotatably securing the kingpin  50   g  within the housing  30   g.    
     The reference numeral  18   h  ( FIGS. 22 and 23 ) generally designates another embodiment of the present inventive kingpin assembly. Since the kingpin assembly  18   h  is similar to the previously described kingpin assembly  18  and kingpin assembly  18   g , similar parts appearing in  FIGS. 3 ,  20  and  21  and  FIGS. 22 and 23  are respectively represented by the same, corresponding reference numeral, except for the suffix “h” in the numerals of the latter. The central recess or bore  82   h  of the housing  30   h  includes a beveled upper portion  182 , a cylindrical portion  184 , and a cylindrically-shaped, threaded lower portion  186 . The collar member  38   h  includes a beveled upper surface  194  and a threaded outer surface  190 . The upper head portion  52   h  of the kingpin  50   h  is isosceles trapezoidal-shaped and includes an upper beveled surface  190  corresponding to the beveled surface  182  of the housing  30   h , a cylindrically-shaped portion  192  corresponding to the cylindrically-shaped portion  184  of the housing  30   h , and a lower beveled surface  188  corresponding to the beveled surface  194  of the collar member  38   h . In assembly, the kingpin  50   h  is rotatably held within the recess  82   h  by the collar member  38   h  when the threaded outer surface  190  of the collar member  38   h  is threadably coupled with the threaded portion  186  of the recess or bore  82   h  of the housing  30   h.    
     The reference numeral  18   i  ( FIGS. 24 and 25 ) generally designates another embodiment of the present inventive kingpin assembly. The kingpin assembly  18   i  includes a post member  200  surrounded by an outer sleeve member  202 . The post member includes a plate-shaped body portion  204 , and a cylindrically-shaped, downwardly-extending post portion  206 . The post portion  206  includes a step  208  located along the length thereof, while the outer sleeve member  202  includes a longitudinally-extending central bore  210  having a corresponding step  212  located along the length thereof. The outer sleeve member  202  further includes a lower head portion  54   i , a body portion  56   i , a lock assembly-receiving portion  58   i  and a counter-sunk relief  214  extending into a distal end thereof. The kingpin assembly  18   i  still further includes a locking collar  216  having a threaded aperture  218 . 
     In assembly, the body portion  204  of the post member  200  is weldably secured to a portion of the corresponding trailer, such as the trailer floor  162   i  by a plurality of welds  66   i , such that the post portion  206  of the post member  200  extends downwardly through an aperture  160   i  within the trailer floor  162   i . The outer sleeve member  202  is then positioned about the post member  200  by locating the bore  210  about the post portion  206 . The outer sleeve member  202  is held in its rotatable position by the locking member  216  that is threaded about a plurality of threads  220  located at a distal end of the post portion  206 , and such that a beveled surface  222  of the locking collar  216  abuts a corresponding beveled surface  224  of the bore  210 . A seal member such as an o-ring  226  may be positioned between the post member  200  and the outer sleeve member  202  and received within circumferentially-extending apertures  228  located therein. A wear disk  152   i  may be placed between the post member  200  and the outer sleeve member  202 . 
     The reference numeral  18   j  ( FIGS. 26 and 27 ) generally designates another embodiment of the present inventive kingpin assembly. Since the kingpin assembly  18   j  is similar to the previously described kingpin assembly  18 , similar parts appearing in  FIG. 3  and  FIGS. 26-29  respectively are represented by the same, corresponding reference numeral, except for the suffix “j” in the numerals of the latter. The kingpin assembly  18   j  includes an upper support member  240 , a collar member  242 , and a kingpin  50   j . The upper support member  240  includes a centrally-located, cylindrically-shaped pocket  244 , a pair of downwardly-exposed, juxtaposed guide channels  246 , a pair of spring-relief pockets  248 , and a plurality of bolt-receiving apertures  250  spaced about the circumference thereof. The collar member  242  includes a pair of guide channels  251  that are aligned with the guide channels  246 , a recess  253 , and a plurality of release bolt-receiving apertures  254  spaced about the circumference thereof. The body portion  56   j  of the kingpin  50   j  includes a recess  256  extending circumferentially thereabout and located near the proximal end  102   j . The kingpin assembly  18   j  further includes a pair of arcuately-shaped locking members  260  located within the recess  253  of the collar member  242 , and including a channel  252  located along the length thereof and beveled outer surface  262 . 
     In assembly, the overhead portion  52   j  of the kingpin  50   j  is located within the pocket  244  of the upper support member  240 , while the body portion  58   j  of the kingpin  50   j  extends through an aperture  40   j  of the collar support member  242 . The kingpin  50   j  is held in rotatable cooperation with the remaining portions of the assembly by the locking members  260 . Specifically, the locking members are positioned such that at least a portion of the locking members extend into the recess or groove  256  of the kingpin  50   j  thereby preventing axial movement of the kingpin  50   j  with respect to the upper support member  240  and collar member  242 . The locking members  260  are held into position by a plurality of tension adjustment bolts  264  threadably received within the apertures  254  of the collar member  242 . Each of the adjustment bolts  264  include a beveled end  266  that impinge or engage upon the beveled surface  262  of a respective locking member  260 , thereby forcing the locking member  260  into engagement within the recess or groove  256  of the kingpin  50   j . The locking members  260  are held in alignment with the upper support member  240  and the collar support member  242  by a key member (not shown) received within the guide channels  246 ,  251 ,  252  respectively thereof. As is best illustrated in  FIGS. 28 and 29 , a pair of coil springs  268  are positioned between and abut each of the locking members  260 , thereby biasing the locking members  260  in a radially outward direction. When the adjustment bolts  264  are retracted from within the apertures  254 , the coil springs  268  force the locking members  260  radially outward, thereby allowing the kingpin  50   j  to be removed from within the upper support member  240  and the collar member  242 . 
     The kingpin  50   j  is positioned such that the upper head portion  52   j  is located within the pocket  244  of the upper support member  240 . The adjustment bolts  264  are then threaded into the apertures  254  until they impinge upon the locking members  260 , thereby overcoming the biasing force exerted on the locking members  260  by the coil springs  268 , and forcing the locking members  260  into engagement within the recess  256  of the kingpin  50   j.    
     The reference numeral  18   k  ( FIGS. 30-32 ) generally designates another embodiment of the present inventive kingpin assembly. Since the kingpin assembly  18   k  is similar to the previously described kingpin assembly  18  and kingpin assembly  18   h , similar parts appearing in  FIGS. 3 ,  22  and  23  and  FIGS. 30-32  respectively are represented by the same, corresponding reference numeral, except for the suffix “k” in the numerals of the latter. The kingpin assembly  18   k  is similar in construction and assembly to the kingpin assembly  18   h  with the most notable exception being the inclusion of an upwardly-extending alignment portion  280  of the kingpin  50   k , and an alignment receiving portion  282  of the recess or bore  82   k  of the housing  30   k  that receives the alignment portion  280  therein. The alignment portion  280  includes a aperture  284  extending therethrough, while the portion  282  of the bore  82   k  includes an circumferentially-extending groove  288  aligned with the aperture  284 . The assembly further includes a quick-connect assembly  290  comprising a pair of bearings  292  and a biasing spring member  294 . In assembly, the quick-connect assembly allows temporary assembly of the kingpin  50   k  within the housing  30   k , while allowing the operator to use both hands to complete the task of permanently securing the kingpin  50   k  within the housing  30   k . Specifically, the bearings  292  and the spring member  294  are positioned within the channel  284 , and the kingpin  50   k  is then placed within the bore  82   k  of the housing  30   k  until the bearings  292  are biased outwardly by the spring  294  and engage the groove  288  of the housing  30   k . The collar member  38   k  is then positioned about the kingpin  50   k  and threadably received within the housing  30   k  thereby rotatably securing the kingpin  50   k  within the housing  30   k.    
     The reference numeral  18   m  ( FIGS. 33-35 ) generally designates another embodiment of the present inventive kingpin assembly. Since the kingpin assembly  18   m  is similar to the previously described kingpin assembly  18   k , similar parts appearing in  FIGS. 30-32  and  FIGS. 33-35  respectively are represented by the same, corresponding reference numeral, except for the suffix “m” in the numerals of the latter. The kingpin assembly  18   m  is similar in construction of assembly to the kingpin assembly  18   k  with the most notable exception being the removal of the quick-connect assembly  290  and the addition of an alignment ring  298 . The alignment ring  298  extends upwardly from the upper head portion  52   m  of the kingpin  50   m , and is received within a corresponding ring-shaped channel  300  extending into an upper surface  302  of the recess  82   m  of the housing  30   m . The alignment ring  298  assists in maintaining axial alignment of the kingpin  50   m  with the housing  30   m  and the collar member  38   m.    
     The reference numeral  18   n  ( FIGS. 36-38 ) generally designates another embodiment of the present inventive kingpin assembly. Since the kingpin assembly  18   n  is similar to the previously described kingpin assembly  18   d , similar parts appearing in  FIGS. 13 and 14  and  FIGS. 36-38  respectively are represented by the same, corresponding reference numeral, except for the suffix “n” in the numerals of the latter. In the illustrated example, the kingpin assembly  18   n  is similar in construction and assembly to the kingpin assembly  18   d  with the most notable exception being the bifurcation of the kingpin  50   n  into two parts, including an upper portion  304 , that includes the upper head portion  52   n  and the body portion  56   n , and a lower portion  306  that includes the lower head portion  54   n  and the lock assembly receiving portion  58   n . The upper portion  304  includes a threaded bore  308  that receives a threaded portion  310  of the lower portion  306  therein thereby allowing replacement of the portion of the kingpin  50   n  most likely to require replacement due to normal wear. 
     The present inventive kingpin assembly allows free rotation of the kingpin by reducing operational wear of the same, allows easy access to and replacement of an associated kingpin subsequent to wear thereof, reduces the amount of maintenance typically required for fifth wheel hitch assemblies, and reduces wear due to debris entering the overall assembly. Further, the present inventive assembly is more durable, allows replacement of certain components thereof by even unskilled personnel, is extremely efficient in use, capable of a long operating life, and particularly well adapted for the proposed use. 
     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.