GB2288775A

GB2288775A - Trailer coupling mounting

Info

Publication number: GB2288775A
Application number: GB9406385A
Authority: GB
Inventors: Stuart Cooper
Original assignee: Bradley Doublelock Ltd
Current assignee: Bradley Doublelock Ltd
Priority date: 1994-03-30
Filing date: 1994-03-30
Publication date: 1995-11-01
Also published as: GB9406385D0

Abstract

A trailer coupling comprises first and second 1 housing parts 20, 22 between which a bearing insert 34 is arranged to be positioned. The insert 34 is arranged to receive a draw tube 50, a first end 52 of which is arranged to be secured to a coupling head 53. A pin 54 may extend diametrically through the draw tube 50 to be arranged to pivotally support a brake link member 56, an opening 62 of which may be arranged to pivotally receive a link bar 65. Link bar 65 may be operatively connected to a brake cable of the brakes of the trailer. <IMAGE>

Description

COUPLING DEVICE FOR TAWABLE VEHICLE This invention relates to a coupling for a towable vehicle and particularly, although not exclusively, relates to a coupling for a trailer.

A known trailer coupling, shown in exploded view in Figure 1 of the accompanying diagrammatic drawings, comprises a cast or pressed and welded housing 2 arranged to be mounted on a trailer chassis (not shown). The housing 2 includes a cylindrical bore 4 which is arranged to slidably receive a draw tube 6. Sliding movement of the draw tube 6 in bore 4 is damped by means of a hydraulic damper 7. At one end 8, the draw tube 6 is arranged to be secured to a coupling head 10; at an opposite end 12, the draw tube includes a flanged abutment part 14. A pivoting link 16 of an overrun coupling is pivotally mounted on the housing 2.

In use, with coupling head 10 secured on a tow ball of a towing vehicle, a towing force from the towing vehicle is transmitted to the trailer by means of the flanged abutment part 14 of the draw tube 6 abutting rear end 16 of the housing 2.

It is an object of the present invention to provide an improved coupling device for a towable vehicle.

According to a first aspect of the present invention, there is provided a coupling device for a towable vehicle, the device comprising a coupling housing including a first housing part and a second housing part, and a shaft arranged to be operatively connected to a towing vehicle, bearing means being provided for supporting said shaft, said bearing means being positioned between said first and second housing parts.

Said bearing means is preferably clamped between said first and second housing parts.

Said bearing means preferably includes a first bearing member and a second bearing member, said bearing members being axially spaced apart. Thus, a gap is suitably defined between said first and second bearing members. At least one, preferably both, of said bearing members may include a cylindrical bore in which said shaft is received and supported therein. Said first bearing member may define a first abutment surface. Said first abutment surface preferably faces towards said second bearing member and is, therefore, suitably adjacent said aforementioned gap. Said first abutment surface preferably includes a substantially planar region. Said planar region preferably extends in a direction which is substantially perpendicular to an elongate axis of said first bearing member.

Said first and said second bearing members are preferably fixed to one another by a bearing member fixing means. Said bearing member fixing means preferably cooperates with said first and/or said second housing parts for positioning said bearing means therebetween.

Said first housing part, said second housing part and/or said bearing member fixing means preferably include aligned openings so that one or a plurality of passages extend through said coupling housing.

Said first and second bearing members and said bearing member fixing means preferably comprises a unitary component which may suitably be moulded from a plastics material.

Said first housing part preferably includes a region having a substantially semi-circular cross-section which region is arranged to cooperate with a correspondingly shaped region of said bearing means. Said first housing part preferably includes two of said regions which are axially spaced apart.

Said second housing part preferably includes a region having a substantially semi-circular cross-section which region is arranged to cooperate with a correspondingly shaped region of said bearing means. Said second housing part preferably includes two of said regions which are axially spaced apart.

Said first and second housing parts are preferably substantially identical.

Said shaft is preferably arranged to slide axially relative to said bearing means.

Said shaft preferably carries a shaft abutment means which is arranged to abut a part of said coupling housing (or a component of said coupling device translationally fixed relative to said coupling housing) for transmitting a towing force to a towable vehicle. Said shaft abutment means is preferably arranged to abut a part of said bearing means. Said shaft abutment means preferably includes a substantially planar abutment surface. Said shaft abutment means may comprise a projection, for example a pin, fixed relative to said shaft and an abutment member pivotally mounted on said projection which abutment member suitably includes said abutment surface.

Said abutment member preferably comprises part of a brake link means of an overrun braking device.

Where said bearing means includes a first bearing member and a second bearing member between which a gap is defined, preferably said shaft abutment means is positioned within said gap and is suitably movable within said gap in dependence upon the position of said shaft.

When so disposed, said planar abutment surface of said abutment means is arranged to abut said aforementioned first abutment surface of said first bearing member for transmitting a towing force to a towable vehicle.

Shaft guide means is preferably provided for guiding movement of said shaft. Said shaft guide means is preferably arranged to fix the rotational position of said shaft relative to said bearing means. Preferably, a guide track is provided, suitably by at least one of said first or second housing parts, within which said shaft abutment means, more preferably said projection, is slidably received.

Said coupling device preferably includes coupling housing extension means secured to said coupling housing.

Said extension means is preferably made substantially of a plastics material.

Said coupling device preferably includes damping means for damping movement of said shaft. Said damping means preferably includes a first damping part and a second damping part wherein said first and second damping parts are movable relative to one another. Said first damping part is preferably fixed relative to, more preferably directly to, said shaft; and said second damping part is preferably fixed relative to, more preferably directly to, said coupling housing, suitably to said coupling housing extension means, when provided.

According to a second aspect of the present invention, there is provided a coupling device for a towable vehicle, the device comprise a coupling housing, a shaft arranged to be operatively connected to a towing vehicle and bearing means for supporting said shaft, said bearing means including first and second bearing members which are axially spaced apart so that a gap is defined therebetween, wherein a shaft abutment means is operatively connected to said shaft and is positioned within said gap, said shaft abutment means being arranged to abut a part of said coupling housing (or a component of said coupling device fixed relative to said coupling housing) for transmitting a towing force to a towable vehicle.

The device of said second aspect may include any feature of the device of the first aspect.

Specific embodiments of the invention will now be described, by way of example, with reference to Figure 2 of the accompanying diagrammatic drawings, which figure is an exploded view of a trailer coupling.

Referring to Figure 2, the trailer coupling comprises first and second pressed steel housing parts 20, 22 which are identical. Each housing part defines one half of the coupling housing and comprises spaced apart flange parts 24 between which is provided a semi-circular cross-section elongate tube part 26. The tube parts 26 of the housing parts include a cut-out region 28 on opposing elongate sides of which are defined elongate slots 30. Rectangular slots 32 are provided in a rearward part of each tube part 26.

A plastics moulded insert 34 is arranged to be positioned between the housing parts 20, 22. The insert 34 includes axially spaced apart first and second cylindrical bearing parts 36, 38. The bearing parts 36, 38 include respective inwardly facing flanges 40, 42.

Flange parts 44 of a shape which generally corresponds to the shape of the flange parts 24 of the housing parts 20, 22 are provided at diametrically opposing positions on the bearing parts 36, 38.

A draw tube 50 is arranged to be received within the bearing parts 36, 38 of the insert 34. A first end 52 of the draw tube 50 is arranged to be secured to a coupling head 53. A pin 54 which extends diametrically through the draw tube 50 is provided approximately midway along the extent of the draw tube. The pin 54 of the draw tube 50 is arranged to pivotally support a brake link member 56.

The member 56 includes aligned openings 58, arranged to receive the pin 54, and a downwardly extending leg 60 having an opening 62 therein which is arranged to pivotally receive a link bar 65. Link bar 65 is operatively connected to a brake cable of the brakes of the trailer. The member 56 further includes spaced apart planar abutment faces 63.

An hydraulic damper 70 is arranged to be fixed, adjacent its first end 72, to the draw tube 50 and, adjacent its second end 74, to a plastics moulded housing extension member 76.

The housing extension member 76 is generally cylindrical in shape and includes a central hollow region 77. Towards one end 78, it includes square cross-section projections 80 and a collar 82. Towards the opposite end 84, it includes a bore 86.

In the assembled coupling, the abovedescribed parts are arranged as described below.

The brake link member 56 is pivotally mounted relative to the draw tube 50 by the pin 54 of the draw tube engaging aligned openings 58 of the member 56. The draw tube is supported in the bearings 36, 38 of the insert 34 with the pin 54/link member 56 arrangement being disposed between the bearings. The insert 34 is clamped between housing parts 20, 22 with the pin 54 of the draw tube 50 being slidably received in elongate slots 30 of the housing parts. When so disposed, the leg 60 of the brake link member 56 hangs downwardly and is connected to the trailer brakes via the link bar 65.

The housing extension member 76 fits within bearing 38 with collar 82 abutting the bearing. The projections 80 on the member 76 cooperate with the slots 32 in the housing parts 20, 22 in order to secure the member 76 in position. When in position, it will be appreciated that part of the draw tube 50 extends into hollow region 77 of the member 76.

The hydraulic damper 70 is fixed between bore 86 of the housing extension member 76 and a forward part of the draw tube 50.

In use, a towing force from a towing vehicle is transmitted to a trailer having the abovedescribed coupling by the planar abutment faces 63 of the brake link member 56 abutting flange 40 of bearing 36. When the towing vehicle decelerates, the draw tube slides within its bearings 36, 38, the pin 54 of the draw tube thereof slides within slots 30 and the overrun brakes are operated, via link bar 65.

As an alternative to the coupling described above, only the bearings 36, 38 may be clamped between housing parts 20, 22 with other parts of the insert 34 described above being omitted. However, it is preferred to provide insert 34 since this may advantageously add strength to the coupling housing.

The housing parts 20, 22 may include cooperating indentations in order to provide joining points for the housing.

It should be appreciated that the coupling described may be relatively easy to manufacture and assemble.

Furthermore, the coupling may allow the transmission of towing forces between towing vehicle and towable vehicle with reduced wear on abutting force transmitting members.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A coupling device for a towable vehicle, the device comprising a coupling housing including a first housing part and a second housing part, and a shaft arranged to be operatively connected to a towing vehicle, bearing means being provided for supporting said shaft, said bearing means being positioned between said first and second housing parts.

2. A device according to claim 1, wherein said bearing means includes a first bearing member and a second bearing member, said bearing members being axially spaced apart so that a gap is defined therebetween.

3. A device according to claim 2, wherein said first bearing member defines a first abutment surface which faces said second bearing member and is adjacent said gap.

4. A device according to claim 2 or claim 3, wherein said first and second bearing members are fixed to one another by a bearing member fixing means.

5. A device according to claim 4, wherein said first and second bearing members and said bearing member fixing means comprise a unitary component.

6. A device according to claim 5, wherein said unitary component is made from a plastics material.

7. A device according to any preceding claim, wherein said first housing part includes a region having a substantially semi-circular cross-section which is arranged to cooperate with a correspondingly shaped region of said bearing means.

8. A device according to any preceding claim, wherein said second housing part includes a region having a substantially semi-circular cross-section which is arranged to cooperate with a correspondingly shaped region of said bearing means.

9. A device according to any preceding claim, wherein said first and second housing parts are substantially identical.

10. A device according to any of preceding claim, wherein said shaft carries a shaft abutment means which is arranged to abut a part of said coupling housing (or a component of said coupling housing translationally fixed relative to said coupling housing) for transmitting a towing force to a towable vehicle.

11. A device according to claim 10, wherein said shaft abutment means is arranged to abut a part of said bearing means.

12. A device according to claim 10 or claim 11, wherein said shaft abutment means comprises a projection fixed relative to said shaft and an abutment member pivotally mounted on said projection which abutment member is arranged to abut a part of said bearing means.

13. A device according to claim 12, wherein said abutment member comprises part of a brake link means of an overrun braking device.

14. A device according to claim 12 or claim 13 when either is dependent upon claim 2, wherein said shaft abutment means is positioned within said gap and is moveable therewithin in dependence upon the position of said shaft.

15. A device according to any preceding claim, wherein a shaft guide means is provided for fixing the rotational position of said shaft relative to said bearing means.

16. A device according to any preceding claim, including coupling housing extension means secured to said coupling housing.

17. A device according to any preceding claim, including damping means for damping movement of said shaft.

18. A coupling device for a towable vehicle, the device comprising a coupling housing, a shaft arranged to be operatively connected to a towing vehicle and bearing means for supporting said shaft, said bearing means including first and second bearing members which are axially spaced apart so that a gap is defined therebetween, wherein a shaft abutment means is operatively connected to said shaft and is positioned within said gap, said shaft abutment means being arranged to abut a part of said coupling housing (or a component of said coupling housing fixed relative to said coupling housing) for transmitting a towing force to a towable vehicle.

19. A coupling device for a towable vehicle substantially as hereinbefore described with reference to Figure 2 of the accompanying diagrammatic drawings.