GB1559126A

GB1559126A - Semitrailer coupling

Info

Publication number: GB1559126A
Application number: GB31003/76A
Authority: GB
Original assignee: DELTA METALL FAHRZEUGTECH
Current assignee: DELTA METALL FAHRZEUGTECH
Priority date: 1975-08-06
Filing date: 1976-07-26
Publication date: 1980-01-16
Also published as: FR2320219A1; DE2535151C3; SE7608807L; SE407924B; DE2535151B2; FR2320219B1; DE2535151A1; IT1073402B; ZA764584B

Description

(54) SEMI-TRAILER COUPLING (71) We, DELTA METALL- UND FAHRZEUGTECHNIK GMBH Hauffstrasse 2, 8000 Mtinchen 70 Federal Republic of Germany, a German body corporate, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to a fifth-wheel coupling comprising a fifth-wheel plate for mounting on a towing vehicle and intended to support a bearing plate mounted on a semi-trailer.

In fifth-wheel couplings of conventional design the vertical supported load of the semi-trailer is transferred by the bearing plate connected to the towing vehicle. The high vertical forces generated thereby result in a correspondingly high pressure on the contact surfaces of the two plates. Accordingly, in order to avoid excessive abrasion, the surface of the fifth-wheel plate is as a rule equipped with lubricant grooves or pockets which are filled with grease in order to thereby bring about lubrication of the surfaces of the two plates which, when the curves are negotiated, are in sliding interengagement. However, the lubricating action hitherto attained in practice has been inadequate because of the inadequate adhesion of the grease to the surface in sliding interengagement so that the grease has been pushed to the outside in a short time as a result of the relative sliding movement between the two contact surfaces, both of which were smooth. In order to make possible the replenishment of the lubricant the lubricant grooves or pockets have been provided with apertures fitted on the underside of the fifth-wheel plate with lubricant nipples; however, these lubricant nipples are poorly accessible, and for this reason in practice the replenishment of lubricant is frequently neglected.

The aim of the invention is to provide an improved fifth-wheel coupling.

The invention provides a fifth-wheel coupling comprising a fifth-wheel plate for mounting in a towing vehicle and intended to support a bearing plate for mounting on a semi-trailer the coupling being so arranged that in its coupled state the bearing plate rests on the fifth-wheel plate, wherein the upper surface of the fifth-wheel plate is in the region of contact between the two plates provided with a plurality of upwardly open recesses for holding lubricant and with upwardly open lubrication grooves for supplying lubricant to the recesses.

The advantage of this is that the upper surface of the fifth-wheel plate contains a number of recesses each of which stores a small amount of lubricant which is by the relative movement of the two plates gradually transferred between the two plates, whereby the lubrication is improved.

In a preferred embodiment the lubrication grooves include inlet grooves. Each of the inlet grooves either extends to the vicinity of the lateral edge of the fifth-wheel plate where it is provided with an aperture fitted with a lubricant nipple which is accessible through an appropriate passage in the edge of the plate, or is provided with an aperture connected by way of a lubricant pipe to a lubricant nipple fitted in the edge of the plate. Advantageously the lubricant grooves passing over the surface are intersected by transverse grooves, the groove portions entering the transverse grooves from opposite sides being in axially staggered relationship.

In the following the invention will be further described, by way of example, with reference to the accompanying diagrammatic drawings. In the drawings:- Fig. 1 represents a diagrammatic illustration of a fifth wheel coupling in side elevation; and Fig. 2 represents a plan view of the surface of fifth wheel plate.

The fifth wheel plate 1 of the fifth wheel coupling is provided with open lubricant grooves 2 and 3 in that surface which faces the bearing plate on the semi-trailer. The lubricant grooves 2 are provided on that part of the plate 1 which faces away from the direction of travel, where as the lubricant grooves 3 are provided on that part of the plate 1 which is situated in the direction of travel. The vertical force generated by the semi-trailer is transmitted to mounting brackets 4 which, in a known manner, are pivoted to both sides of the plate 1 and which in turn are bolted onto the chassis of the towing vehicle. It is known that the zone of highest loads is situated above the mounting brackets 4, for which reason the load-bearing surface of the plate 1 in this region is not weakened in the illustrated embodiment by lubricant grooves.

The outwardly directed ends of the aforesaid lubricant grooves 2 and 3 are on both sides of this zone of high load, and communicate with apertures 5 and 6 in the plate 1. These apertures 5, 6 are each at their bottom end provided with a lubricant nipple with a 90 bend (not shown). The plate 1 is laterally provided with apertures 7 and 8, through which the lubricant nipples are readily accessible even when the semitrainer is hitched on.

The lubricant nipples instead of being connected directly to the apertures 5, 6 may also be fitted to the edge of the plate 1 and communicate with the apertures 5 and 6 of the lubricant grooves via appropriate pipe connections.

In this manner it is always possible to replenish the lubricant. In order to improve the distribution of the lubricant grease. the lubricant grooves 3 are traversed in a manner known per se by transverse open grooves 9. A novel feature is provided, however, by the fact that at the transverse grooves 9 the incoming lubricant groove 10 in each case is laterally offset relative to the outgoing lubricant groove 11. The result of this is, that the grease, when entering the transverse groove 9 through the incoming lubricant groove 10 is first laterally deflected, thereby being caused to spread through the entire transverse groove before entering the outgoing and outwardly leading lubricant groove 11. This results in a substantial improvement of the distribution of the lubricant. The surface of the semitrailer coupling is provided with a plurality of upwardly open recesses in honeycomblike arrangement, which in the illustrated embodiment are distributed over those areas of the plate 1 which carry the main load.

However, this surface configuration may also be extended over the entire upper surface of the plate 1. The honeycomb-like arrangement of the recesses in the surface results in a substantially improved adhesion of the lubricant grease on the surface as compared with the adhesion on a smooth surface, whereby the distribution of the lubricant between the trailer plate and the coupling is improved.

The illustrated recesses are substantiallysquare-shaped in plan but they may also be e.g. rectangular or circular in plan and be distributed evenly over the surface at intervals of a few millimetres. These recesses are preferably formed by the impression of an appropriately shaped tool because the cold hardening resulting therefrom in the steel surface provides a further improvement of the wear characteristics.

WHAT WE, CLAIM IS: 1. A fifth-wheel coupling comprising a fifth-wheel plate for mounting on a towing vehicle and intended to support a bearing -plate which is mounted on a semi-trailer, the coupling being so arranged that in its coupled state the bearing plate rests on the fifth-wheel plate, wherein the upper surface of the fifth-wheel plate is in the region of contact between the two plates provided with a plurality of upwardly open recesses for holding lubricant and with upwardly open lubrication grooves for supplying lubricant to the recesses.

2. A coupling according to Claim 1 wherein the lubrication grooves include inlet grooves, the latter extending each to the vicinity of the lateral edge of the fifth-wheel plate where it is provided with an aperture fitted with a lubricant nipple which is accessible through an appropriate passage in the edge of the plate.

3. A coupling according to Claim 1 wherein the lubrication grooves include inlet grooves, the latter being each provided with an aperture connected by way of a lubricant pipe to a lubricant nipple fitted in the edge

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. Fig. 2 represents a plan view of the surface of fifth wheel plate. The fifth wheel plate 1 of the fifth wheel coupling is provided with open lubricant grooves 2 and 3 in that surface which faces the bearing plate on the semi-trailer. The lubricant grooves 2 are provided on that part of the plate 1 which faces away from the direction of travel, where as the lubricant grooves 3 are provided on that part of the plate 1 which is situated in the direction of travel. The vertical force generated by the semi-trailer is transmitted to mounting brackets 4 which, in a known manner, are pivoted to both sides of the plate 1 and which in turn are bolted onto the chassis of the towing vehicle. It is known that the zone of highest loads is situated above the mounting brackets 4, for which reason the load-bearing surface of the plate 1 in this region is not weakened in the illustrated embodiment by lubricant grooves. The outwardly directed ends of the aforesaid lubricant grooves 2 and 3 are on both sides of this zone of high load, and communicate with apertures 5 and 6 in the plate 1. These apertures 5, 6 are each at their bottom end provided with a lubricant nipple with a 90 bend (not shown). The plate 1 is laterally provided with apertures 7 and 8, through which the lubricant nipples are readily accessible even when the semitrainer is hitched on. The lubricant nipples instead of being connected directly to the apertures 5, 6 may also be fitted to the edge of the plate 1 and communicate with the apertures 5 and 6 of the lubricant grooves via appropriate pipe connections. In this manner it is always possible to replenish the lubricant. In order to improve the distribution of the lubricant grease. the lubricant grooves 3 are traversed in a manner known per se by transverse open grooves 9. A novel feature is provided, however, by the fact that at the transverse grooves 9 the incoming lubricant groove 10 in each case is laterally offset relative to the outgoing lubricant groove 11. The result of this is, that the grease, when entering the transverse groove 9 through the incoming lubricant groove 10 is first laterally deflected, thereby being caused to spread through the entire transverse groove before entering the outgoing and outwardly leading lubricant groove 11. This results in a substantial improvement of the distribution of the lubricant. The surface of the semitrailer coupling is provided with a plurality of upwardly open recesses in honeycomblike arrangement, which in the illustrated embodiment are distributed over those areas of the plate 1 which carry the main load. However, this surface configuration may also be extended over the entire upper surface of the plate 1. The honeycomb-like arrangement of the recesses in the surface results in a substantially improved adhesion of the lubricant grease on the surface as compared with the adhesion on a smooth surface, whereby the distribution of the lubricant between the trailer plate and the coupling is improved. The illustrated recesses are substantiallysquare-shaped in plan but they may also be e.g. rectangular or circular in plan and be distributed evenly over the surface at intervals of a few millimetres. These recesses are preferably formed by the impression of an appropriately shaped tool because the cold hardening resulting therefrom in the steel surface provides a further improvement of the wear characteristics. WHAT WE, CLAIM IS:

1. A fifth-wheel coupling comprising a fifth-wheel plate for mounting on a towing vehicle and intended to support a bearing -plate which is mounted on a semi-trailer, the coupling being so arranged that in its coupled state the bearing plate rests on the fifth-wheel plate, wherein the upper surface of the fifth-wheel plate is in the region of contact between the two plates provided with a plurality of upwardly open recesses for holding lubricant and with upwardly open lubrication grooves for supplying lubricant to the recesses.

of the plate.

4. A coupling according to Claim 2 or 3 wherein the lubrication grooves passing over the surface are intersected by transverse grooves, the groove portions entering the transverse grooves from opposite sides being in axially staggered relationship.

5. A coupling according to any one of the preceding claims wherein the recesses are distributed spaced apart in a honeycomb-like arrangement.

6. A coupling according to any one of the preceding claims wherein the recesses are formed by cold deformation.

7. A fifth-wheel coupling constructed, arranged and adapted to operate substantially as herein described with reference to, and as illustrated in, the accompanying drawing.