Abstract:
An articulated selective adjustment apparatus carried within the pedestal of a fifth wheel assembly comprises a mounting plate pivotally connected to a plunger arm configured for selective extension and withdrawal from the pedestal, and having ends to which are pivotally connected first and second prongs having interior ends disposed toward the pedestal that are pivotally connected to the mounting plate ends.

Description:
BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. 
       FIG. 1A  is an exemplary tractor truck and trailer with a fifth wheel hitch; 
       FIG. 1B  is an exemplary fifth wheel hitch; 
       FIG. 1C  is an exemplary hitch plate; 
       FIG. 1D  is an exemplary prior art fifth wheel slide rail assembly; 
       FIG. 2  depicts an exemplary cylinder and plunger arm with a wedge assembly according to an embodiment of the present invention; 
       FIG. 3  depicts an exploded view of the articulated prong assembly; 
       FIG. 4  is an illustrative plan view of an exemplary articulated prong assembly; 
       FIG. 5  is a side view of a prong of the wedge assembly according to an embodiment of the present invention; 
       FIG. 6  illustrates engagement of exemplary wedge assembly prongs into gaps of an exemplary slide rail; and 
       FIG. 7  illustrates engagement of another embodiment of wedge assembly prongs. 
    
    
     DETAILED DESCRIPTION 
     The various embodiments of the present invention and their advantages are best understood by referring to  FIGS. 1 through 7  of the drawings. The elements of the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention. Throughout the drawings, like numerals are used for like and corresponding parts of the various drawings. 
     The drawings represent and illustrate examples of the various embodiments of the invention, and not a limitation thereof. It will be apparent to those skilled in the art that various modifications and variations can be made in the present inventions without departing from the scope and spirit of the invention as described herein. For instance, features illustrated or described as part of one embodiment can be included in another embodiment to yield a still further embodiment. Moreover, variations in selection of materials and/or characteristics may be practiced to satisfy particular desired user criteria. Thus, it is intended that the present invention covers such modifications as come within the scope of the features and their equivalents. 
     Furthermore, reference in the specification to “an embodiment,” “one embodiment,” “various embodiments,” or any variant thereof means that a particular feature or aspect of the invention described in conjunction with the particular embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases “in one embodiment,” “in another embodiment,” or variations thereof in various places throughout the specification are not necessarily all referring to its respective embodiment. 
     Terms such as “aft,” “rear,” “forward,” “front,” “lateral,” “inboard” or “outboard,” or the like, and variations or derivatives thereof, are to be understood in relation to the vehicle on which the fifth wheel is mounted. However, it is to be understood that the invention may assume various alternative orientations, 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. 
     Referring to the Figures, fifth wheel hitches are well known in the field of towing trailers using a truck or tractor.  FIGS. 1A through 1C  depict an exemplary tractor and trailer hitch arrangement employing a fifth wheel hitch. Tractor  100  is affixed with a fifth wheel hitch  103  to rear of tractor frame  105 . Fifth wheel hitch  103  includes a fifth wheel hitch assembly  110  pivotally mounted on pedestal  155 . Fifth wheel hitch assembly  110  comprises hitch plate  130  which houses a locking mechanism underneath (shown and described in greater detail below) with slot  135  opening toward the aft end of fifth wheel assembly  110  for receiving a kingpin  11  from trailer  19 . 
     Kingpin  111  typically extends downward from a trailer bearing plate  107 , which rests upon fifth wheel assembly, specifically, upon load area  145  of fifth wheel hitch plate  130 . Kingpin is, typically, a unitarily constructed article comprised of a lower flange  115  capping a shank  113  which extends from collar  117 . 
       FIG. 1D  depicts an example of the prior art slide rail where slide rail assembly  120   a  is comprised of left and right slide rail plates  102   a, b  tied in parallel by two or more tie bars  104   a, b  which form slide frame  121 . Left slide rail  151   a  is attached to the upper surface of left slide rail plate  102   a  and right slide rail  151   a  is attached to upper surface of right slide rail plate  102   b  such that fifth wheel hitch assembly  110  and pedestal  155  are located therebetween, inboard of the left and right slide rails  151   a, b . Slide rail plates  102   a, b  and slide rails  151   a, b  each have longitudinal axes which parallel the longitudinal axis of tractor  100 . Slide stop blocks  105   a - d  are located at each end of each slide rail plate  102   a, b . Slide stop blocks  105   a - d  prevent over travel of pedestal  155 . As is shown in the illustration, slide rails  151   a, b  of the prior art are typically a flange extending inboard of the assembly, slidably receiving flanges  114  of pedestal  155 . Slide rails  151   a, b  typically include gaps, or detents,  176  spaced along the length of the slide rail. 
     The pedestal  155  may include a means for selectively locking the pedestal in position longitudinally with respect to the slide rail assembly. One example, shown in  FIG. 1D , is a pneumatic cylinder  177  mounted in the pedestal from which laterally extend plunger arms  173   a, b . A wedge  179  is typically mounted to the respective lateral ends of plunger arms  173 , where each wedge includes one or more projections, or prongs,  181  that insert into the slide rail gaps  176  when the plungers arms are extended. The engagement of the projections  181  into the gaps  176 , thus, prevents longitudinal movement of the pedestal, and, therefore, the fifth wheel assembly. The wedges may be withdrawn and the pedestal moved along the slide rail assembly to a different desired position, and the fork members extended again to different gaps in the slide rails. 
       FIG. 2  depicts an embodiment of the present invention intended to be incorporated into a pedestal  155  or one like it. Depicted in  FIG. 2  is an exemplary pneumatic cylinder  177  from which extends plunger arms  173   a, b . In this embodiment, however, instead of a solid, unitary wedge such as the prior art example discussed above, wedge assembly includes an articulated prong assembly that is pivotally connected to the lateral end of plunger arm  173   a . In  FIGS. 3 and 4 , the articulated prong assembly  223  is presented in greater detail where prongs  225   a, b  are shown in an exploded view to be pivotally connected to a mounting plate  227 . Mounting plate  227  is pivotally connected to plunger arm  173 . 
     As shown in  FIG. 4 , prongs  225   a, b  are connected to mounting plate  227  so as to allow prongs to pivot somewhat in either direction from a perpendicular orientation with respect to the mounting plate  227 . Likewise, mounting plate  227  is connected to the end of plunger arm  173  in order to allow the mounting plate  227  to pivot in either direction from perpendicular with respect to the plunger arm  173 . Accordingly, the assembly allows each prong of the assembly to move independently in the horizontal plane. This independent movement allows each prong to seat more completely in the gaps of the slide rail. 
     With reference to  FIGS. 3 and 5 , prongs may be configured with a ledge portion  229   a, b  which receives the mounting plate  227 . When assembled, the mounting plate  227  loosely abuts the wall  231  defining the ledge portion  229 . This allows the prongs to be mounted lower, keeping them in line with the plunger  173  extending from the pneumatic cylinder  177 , which in turn allows the cylinder  177  to be mounted as low as possible in the pedestal. 
     In addition, prongs may be tapered toward their respective lateral ends to allow them to seat deeper into the slide rail gaps.  FIG. 6  presents an exemplary slide rail  605  in which gaps  612  are tapered from the inboard side to the outboard side. The advantages of this feature are that typical fifth wheel slide mechanisms which are disposed between the parallel mounted slide rails, i.e., toward the inboard sides, include the laterally extendable prong members  225   a, b  which insert into the gaps  612 , and are locked in the extended position, preventing sliding of the fifth wheel. Over time, wear on the prongs  225   a,b  results in a narrowing of the prong member portion that is inserted in the gaps  612 . Tapering the gaps  612 , as shown in  FIG. 6 , means that over time, more of the prong member  225  may be inserted into the gap  612  and maintain secure positioning of the fifth wheel. 
       FIG. 7  illustrates a further embodiment wherein exemplary slide rail  705  includes gaps  712  with parallel walls. Prong members  725   a, b  are configured to have parallel sides to fit within the gaps  712 . This advantageously provides support for the wedge assembly in the forward and rearward direction in the lateral area. 
     As described above and shown in the associated drawings, the present invention comprises an articulated fifth wheel selective adjustment means. While particular embodiments of the invention have been described, it will be understood, however, that the invention is not limited thereto, since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. It is, therefore, contemplated by the following claims to cover any such modifications that incorporate those features or those improvements that embody the spirit and scope of the present invention.