WO1993000248A1

WO1993000248A1 - Bearing

Info

Publication number: WO1993000248A1
Application number: PCT/AU1992/000312
Authority: WO
Inventors: John Raymond Crewdson
Original assignee: John Raymond Crewdson
Priority date: 1991-06-24
Filing date: 1992-06-24
Publication date: 1993-01-07

Abstract

A bearing plate (1) of low-friction synthetic plastics material is mounted on a top plate of a fifth wheel coupling of a tractor, with its shape substantially conforming to the shape of the top plate.

Description

TITLE: BEARING

FIELD OF THE INVENTION:

This invention relates to a bearing.

BACKGROUND TO THE INVENTION:

It is the usual practice to provide an articulated vehicle with what is known as a fifth wheel coupling in which a prime mover has a top plate which is slotted rearward of the vehicle to enable a king pin fitted to a trailer of the articulated vehicle to enter that slot and be captured by jaws associated with the top plate. The trailer of the articulated vehicle is normally provided with a skid plate which bears on the top plate.

Before the trailer is hitched to the prime mover it is the usual practice to apply grease to the top plate and if this is not done excessive wear may occur and binding of the skid plate on the top plate may occur. When such binding occurs, there is a tendency for the trailer to steer the prime mover rather than to be steered by the prime mover and this is a dangerous condition and can be very tiring on the driver of the prime mover who must use extra effort to steer. Further, wear and tear of parts may more^' rapidly occur.

SUMMARY OF THE INVENTION:

The present invention provides a prime mover of an articulated vehicle having a fifth wheel coupling comprising a top plate for carrying load applied in use by a trailer of the articulated vehicle and wherein a bearing is mounted on the top plate and generally conforms in shape to the shape of the top plate and wherein the bearing is ^"a plate of a low friction synthetic plastics material.

The present invention also provides a bearing for a fifth wheel coupling comprising a top plate of a prime mover of an articulated vehicle which conforms in shape to the shape of a top plate of a prime mover of an articulated vehicle and which is a plate of a low friction synthetic plastics material.

PREFERRED ASPECTS OF THE INVENTION:

Preferably the synthetic plastics material has a co¬ efficient of friction of less than 0.30 more preferably less than 0.20 and most preferably less than 0.15 measured by ASTM D 1894 and less than 0.30, more preferably less than 0.20 and most preferably less than 0.12 measured by ASTM D 1895.

Preferably the synthetic plastics material has substantial abrasion resistance, Izod impact strength and Shore hardness.

Preferably the synthetic plastics material is an ultra high molecular weight polyethylene. Preferably the molecular weight is in excess of 1 million g/mol, preferably in excess of 2 million g/mol and most preferably about 4 million g/mol. Suitable such polyethylenes are sold by Dotmar Plastics a department of Brown & Dureau International Ltd. and Poly-HI Products under the trade mark "TIVAR", and by Ultra Poly Inc of Tacoma, Washington USA under the trade mark "ULTRA POLY"

Preferably the plate is greater than 3mm thick and about 6mm is preferred. The plate is preferably secured to the top plate by bolts set in counterbored holes in the plate. The bolts preferably have head caps of such synthetic plastics material.

BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWINGS:

Specific constructions of bearings in accordance with this invention will now be described by way of Example with the aid of the accompanying drawings in which:-

Figure 1 is a side elevational view of a first bearing in accordance with this invention,

Figure 2 is a plan view of the first bearing;

Figure 3 is a side elevational view of a second bearing in accordance with this invention,

Figure 4 is a plan view of the second bearing,

Figure 5 is a side elevational view of a third bearing in accordance with this invention;

Figure 6 is a plan view of the third bearing; and

Figure 7 is a schematic view of a fixing.

INTEGER LIST

1. Bearing

2. Bearing 3. Bearing

6. Slot

21. Top plate

DETAILED DESCRIPTION WITH RESPECT TO THE DRAWINGS:

The bearing 1 shown in Figure 1 and Figure 2 is made of ultra high molecular weight polyethylene and is shaped to conform to the shape of a well known top plate and has a slot 6 for a kingpin to enter.

The bearings 2 and 3 shown in Figures 3 and 4 and Figures 5 and 6 are similar to bearing 1 but differ slightly in shape to conform to the shape of other well known fifth wheel top plates.

Figure 7 shows a method of fixing the bearings 1, 2 and 3 to fifth wheel top plates.

In Fig 7 is shown a top plate 21, the bearing 1, a through bore 22, a counter sink 23, a bolt 24 having a cap 26 of ultra high molecular weight polyethylene, washers 27 and 28 and nut 29.

The above described bearings are considered to be useful. Finally, it is to be understood that the inventive concept in any of its aspects can be incorporated in many different constructions so that the generality of the preceding description is not to be superseded by the particularity of the attached drawings. Various alterations, modifications and/or additions may be incorporated into the various constructions and arrangements of parts without departing from the spirit and ambit of the invention.

Claims

1. A prime mover of an articulated vehicle having a fifth wheel coupling comprising a top plate for carrying load applied in use by a trailer of the articulated vehicle and wherein a bearing is mounted on the top plate and generally conforms in shape to the shape of the top plate and wherein the bearing is a plate of a low friction synthetic plastics material.

2. A prime mover as claimed in Claim 1, wherein said plate has a slot therein through which a king pin fitted to a trailer may pass.

3. A prime mover as claimed in Claim 1 or Claim 3, wherein said plate is secured to the top plate by bolts.

4. A prime mover as claimed in Claim 3, wherein said bolts have heads which are counterbore in said plate.

5. A prime mover as claimed in Claim 4, wherein the heads of said bolts are capped by a low friction synthetic plastics material.

6. A prime mover as claimed in any preceding claim, wherein the synthetic plastics material is an ultra high molecular weight polyethylene.

7. A prime mover as claimed in any preceding claim, wherein said plate is about 6mm thick.

8. A bearing for a fifth wheel coupling comprising, a top plate of a prime mover of an articulated vehicle which conforms in shape to the shape of a top plate of a prime mover of an articulated vehicle and which is a plate of a low friction synthetic plastics material.

9. A prime mover or a bearing substantially as hereinbefore described with reference to any one of the accompanying drawings.

10. The steps, features , compositions and compounds referred to or indicated in the specification and/or claims of this application, individually or collectively, and any and all combinations or any two or more of said steps or features.