Abstract:
A preassembled bearing element including a Teflon disc attachable directly to the trailer plates of existing fifth wheel rigs.

Description:
BACKGROUND OF THE INVENTION 
     The fifth wheel bearing attachment of the present invention is an improvement on the bearing attachment disclosed in my U.S. Pat. No. 3,887,251, dated June 3, 1975, wherein there is disclosed a fifth wheel bearing attachment including a grooved plate interposed a pair of bearing plates, and having suitable fittings for introducing a lubricant between the plates. While the bearing attachment disclosed in the aforementioned patent proved satisfactory for its intended purpose, after further research and experimentation, the bearing attachment of the present invention has been devised which eliminates various components contained in the bearing attachment disclosed in my aforementioned patent, resulting in a bearing attachment having relatively few parts, constructed for long and continued use, and adapted for fabrication at less expense. 
     The fifth wheel bearing attachment of the present invention comprises, essentially, a Teflon disc interposed a pair of bearing plates; a flanged bushing, adapted to receive the trailer king pin, is welded to one of the bearing plates which bearing plate is detachably connected to the trailer plate. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a side elevational view of a tractor-trailer rig upon which the fifth wheel bearing attachment of the present invention is adapted to be used; 
     FIG. 2 is a sectional view of the bearing attachment of the present invention connected to the bottom wall of the trailer body; and 
     FIG. 3 is a fragmentary, bottom plan view of the assembly shown in FIG. 2. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, and more particularly to FIGS. 1 and 2, there is shown a tractor 1 coupled to a semi-trailer 2 by a fifth wheel unit designated generally by reference numeral 3. The chassis 4 of tractor 1 mounts a conventional lower fifth wheel plate 5 which includes a slot for receiving a depending king pin 6 secured to and extending through the bottom wall 7 of the trailer. 
     As will be seen in FIGS. 2 and 3, the fifth wheel bearing attachment of the present invention is shown attached to the bottom wall 7 of the trailer, and comprises a top plate 9 detachably connected to the bottom wall 7 of the trailer by machine screws 10. The plate 9 is provided with a central aperture 11 which receives the upper end of a bushing 12 welded to the plate 9 as at 13. The lower end of the bushing 12 is provided with a flange or collar 12a which supports a bottom plate disc 14 having a central aperture 15 through which the bushing 12 extends. The bottom surface of disc 14 will have direct, face-to-face bearing engagement on the fifth wheel tractor plate 5, with the plate disc 14 being freely rotatable about the bushing 12. To insure as complete an anti-friction, mounting of the assembly as possible, the adjacent faces of plates 9 and 14 are engaged and spaced apart by Teflon bearing plate disc 16 centrally apertured, as shown, to fit over the bushing 12. The upper and lower faces of plate 16 are directly opposed the bearing plates 9 and 14 in load-bearing relation thereto and therebetween. To enhance the face-to-face engagement of the Teflon plate disc 16 with the bearing plates 9 and 14, a plurality of circumferentially spaced, flanged blocks 17 are secured to plate 9 by screws 18, the flanged portion 17a of each block supporting the plate disc 14 along its peripheral edge. 
     To assemble the bearing attachment of the present invention, the disc 14 is slipped onto the bushing 12 and is seated on the flange 12a. The Teflon disc 16 is then slipped over the bushing 12 and is seated on the flange 12a. The Teflon disc 16 is then slipped over the bushing 12 and is positioned in face-to-face engagement with the disc 14. The plate 9 is then slipped onto the bushing and welded to the upper edge thereof as at 13, and the flanged blocks 17 are then connected to the plate 9. The bearing attachment can then be mounted, as a unit, onto the trailer 2 by slipping the bushing 12, and attached plates 9, 14 and 16, onto the king pin 6 and securing the attachment to the bottom wall of the trailer by screws 10. 
     When in the operative position, the tractor plate 5 of the fifth wheel assembly is frictionally engaged with the bottom bearing plate 14, and the tractor plate is rotatably locked in place on king pin 6, whereby the tractor plate and the bearing plate 14 will substantially function as an entity, with the load being carried by the Teflon disc 16 thus providing a minimum of frictional rubbing between the lower fifth wheel plate 5 and the bottom wall 7 of the trailer. 
     It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or scope of the subjoined claims.