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Title:
TOWBAR COUPLING GUIDE ASSEMBLY
Document Type and Number:
WIPO Patent Application WO/1993/017886
Kind Code:
A1
Abstract:
A towbar coupling guide assembly (8) is mounted on a vehicle towbar or a trailer drawbar (16). A winch assembly (13) is provided on the other of the vehicle towbar or tailer drawbar (16). The towbar coupling guide assembly (8) comprises a triangular or V-shaped base (32) with a series of pulley wheels (34, 36, 38) mounted thereon. The cable (20) from the winch assembly (13) is passed over the pulley wheels (34, 36, 38) and its free end (26) hooked to an eye (28) adjacent the winch assembly (13). The winch is then operated to wind in the cable (20) to draw the vehicle towbar or trailer drawbar (16) toward the other of the vehicle towbar or trailer drawbar (16) and is self-centring to facilitate coupling the vehicle towbar and the trailer drawbar (16).

Inventors:
JONES COLIN ALEXANDER (NZ)
Application Number:
PCT/NZ1993/000017
Publication Date:
September 16, 1993
Filing Date:
March 15, 1993
Export Citation:
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Assignee:
EZI HITCH LTD (NZ)
International Classes:
B60D1/38; (IPC1-7): B60D1/38
Domestic Patent References:
WO1990010550A11990-09-20
Foreign References:
AU1882776A1978-04-27
AU4386879A1979-08-09
AU3195184A1985-03-07
US4466632A1984-08-21
US5009445A1991-04-23
AU7048687A1987-09-24
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Claims:
CLAIMS
1. A towbar assembly adapted to be mounted on or to form an integral part of a vehicle towbar or trailer drawbar, suitable for use in combination with a winch assembly mounted on the same or the other of the vehicle towbar or trailer drawbar, said winch assembly comprising a winch mounted on or adjacent to either said vehicle towbar or said trailer drawbar and a cable windable into or out of said winch, wherein said towbar assembly comprises: guiding means for guidingly receiving said cable from said winch assembly; and where required, mounting means for mounting said towbar assembly onto a said vehicle towbar or said trailer drawbar, the arrangement being such that in use when said cable is passed over said guiding means and its free end connected to or adjacent to said winch assembly, and said winch is operated to wind in said cable said trailer drawbar is drawn toward said vehicle towbar and is selfcentring to facilitate coupling said trailer drawbar to said vehicle towbar.
2. A towbar assembly according to claim 1 adapted to be mounted on said vehicle towbar.
3. A towbar assembly according to claim 1 adapted to be mounted on said trailer drawbar.
4. A towbar assembly according to claim 1, 2 or 3 wherein said guiding means comprises three pulley wheels, each rotatable about a vertical axis, the arrangement being such that the cable guided thereby is guided around the point at which said vehicle towbar and said trailer drawbar are coupled.
5. A towbar assembly according to claim 4, wherein said three pulley wheels are mounted on a triangular base which is fixed relative to the towbar or drawbar to which it is mounted.
6. A towbar assembly according to claim 4 wherein said pulley wheels are mounted on a V shaped base which is pivotal about a vertical axis with respect to the towbar or drawbar on which it is mounted.
7. A combination of a winch assembly comprising a winch mounted on or adjacent to a vehicle towbar or trailer drawbar and a cable windable into or out of said winch, and, a towbar assembly as claimed in any one of claims 1 to 6.
8. A combination according to claim 7 wherein said towbar assembly is adapted to be mounted on said vehicle towbar and said winch assembly is adapted to be mounted on said trailer drawbar.
9. A combination according to claim 7 wherein said towbar assembly is adapted to be mounted on said trailer drawbar and said winch assembly is adapted to be mounted on said vehicle towbar.
10. A combination according to any one of claims 7, 8 or 9 in which there is provided a guideway on said winch assembly through which said cable passes when it is being wound onto the drum of said winch.
11. A combination according to claim 10 wherein said guideway comprises a pair of guiding members on vertical axes mounted in the pathway of said cable from said winch so that said cable may pass between said members.
12. A combination according to claim 11 in which said guiding members are rollers.
13. A combination according to any one of claims 7 to 12 in the form of a kitset.
Description:
TOWBAR COUPLING GUIDE ASSEMBLY

Technical Field

This invention relates to a towbar assembly. More particularly, but not exclusively, it relates to a towbar assembly for use with a motor vehicle. The invention also relates to the combination of a winch assembly and a towbar assembly.

Background Art

A difficulty experienced while attempting to connect a trailer or caravan to a vehicle is manoeuvring the towbar of the vehicle and the drawbar of the trailer or caravan so that they are in alignment so that the drawbar hitch of the trailer may be simply dropped on to the towball on the vehicle towbar. This operation generally requires two people, one to drive the vehicle and the other to direct the driver while reversing. A further difficulty arises where the trailer or caravan is on muddy ground. Attempting to pull a heavy trailer out once it is hitched to a car may result in both the vehicle and the trailer or caravan being stuck.

New Zealand Patent Specification 209128 discloses a powered winch to be mounted on the back of a towing vehicle. The winch housing has an opening to the rear in which is releasibly mounted a wedge shaped link member having a towing ball mounted on to it. This link member is released from the winch housing and withdrawn with the two winch cables to a trailer drawbar. The trailer or caravan can then be winched into the housing.

A disadvantage of the invention described in that patent specification is that the towball retracting assembly itself forms an integral part of the linkage between the towing vehicle and the towed trailer or caravan. It has to be sufficiently robust to comply with the necessary safety standards for a towing assembly.

It is an object of this invention to go some way towards overcoming one or other of these disadvantages or at least to offer the public a useful choice.

Disclosure of Invention

In a first aspect the present invention provides a towbar assembly adapted to be mounted on or to form an integral part of a vehicle towbar or trailer drawbar, suitable for use in combination with a winch assembly mounted on the same or the other of the vehicle towbar or- trailer drawbar, said winch assembly comprising a winch mounted on or adjacent to either said vehicle towbar or said trailer drawbar and a cable windable into or out of said winch, wherein said towbar assembly comprises: guiding means for guidingly receiving said cable from said winch assembly; and

where required, mounting means for mounting said towbar assembly onto a said vehicle towbar or said trailer drawbar, the arrangement being such that in use when said cable is passed over said guiding means and its free end connected to or adjacent to said winch assembly, and said winch is operated to wind in said cable said trailer drawbar is drawn toward said vehicle towbar and is self centring to facilitate coupling said trailer drawbar to said vehicle towbar.

The invention may also be said broadly to consist in the combination of a towbar assembly as defined above and a winch assembly as defined above.

The invention consists in the foregoing and also envisages constructions of which the following gives examples.

Brief Description of the Drawings

Preferred forms of the invention will now be described with reference to the drawings in which: Figure 1 is a schematic plan view of a winch assembly and towbar assembly when assembled,

Figure 2 is a side elevational view of a first embodiment of the towbar assembly, Figure 3 is a top plan view of said first embodiment, Figure 4 is an end elevational view of said first embodiment, Figure 5 is a top plan view of a second embodiment of a towbar assembly, mounted on the rear of a towing vehicle,

Figure 6 is a detailed plan view of the second embodiment, Figure 7 is a perspective view of the second embodiment, Figure 8 is a side elevation of a preferred embodiment of a winch assembly forming a part of the invention, and

Figure 9 is a front elevation of the embodiment of Figure 8.

Best Mode for Carrying out the Invention

A preferred embodiment of the invention is shown in Figures 1 to 4. The towbar assembly 8 is mounted on the towbar 12 of a vehicle. The towbar assembly 8 is adapted to be used in combination with a winch assembly 13 which comprises a winch 14, mounted on a corresponding drawbar 16 of a trailer or caravan (not shown) which is to be towed, and a cable 20. Preferably cable 20 is plastic covered wire rope. The trailer or caravan to be towed includes a drawbar 16 which extends forwardly from the trailer and ends in a vehicle hitch 18. A winch 14 is mounted on the drawbar 16. Winch 14 may be manually operable by crank 46 or it may be power driven. Winch 14 includes a drum 24 onto which cable 20 is wound. At the free end of cable 20 a hook 26 is

provided which is adapted to hook into the a corresponding eye 28 provided at the vehicle hitch end of a drawbar 16. A towball 30 corresponding to vehicle hitch 18 is provided on the trailing end of towbar 12.

The towbar assembly 8 comprises a triangular shaped base 32. Guide means for cable 20 which comprise a plurality of pulley wheels 34, 36, 38 arranged in a substantially triangular configuration are provided within or on base 32. Each pulley wheel is held in position within or on base 32 by pins 40 each of which acts as an axle about which each pulley wheel can freely rotate. Base 32 may further comprise an extended portion 48 which is fork shaped to fit around the towball 30. Base 32 is mounted on towbar 12 forward of towball 30 so that front pulley wheel 36 forms the apex of a triangle and rear pulley wheels 34 and 38 together lie in a horizontal line perpendicular to the towbar 12. Base 32 is secured to the towbar 12 by suitable means such as nuts and bolts 42 and 44. In this way base 32 is substantially immobilised with respect to the towbar 12. It will be seen that in this embodiment the assembly 8 forms no part of the towbar linkage and does not need to conform to the safety standards that the towbar 12 and towball 30 do.

In an alternative embodiment, shown in figures 4 to 7 the towbar assembly comprises a base 56 mounted on towbar 12 below vehicle bumper 52. The base 56 is a substantially V-shape having an apex 51 and two arms 49, 50. In this embodiment the pulley wheels 34 and 38 are positioned at the ends respectively of arms 49 and 50 and pulley wheel 36 is positioned at the apex 51. Pulley wheels 34 and 38 are attached to the base 56 by pins 40 as described for the preferred embodiment. The base 56 is mounted on towbar 12 so that the apex 51 is positioned below vehicle bumper 52 and arms 49, 50 extend to either side of towball 30 and is fixed to the towbar 12 by passing a pin 54 through the towbar 12 and base 56 and through pulley wheel 36 so that both the pulley wheel 36 and the base 56 at the apex 51 thereof are pivotal about pin 54. A split pin 55 secures pin 54 in position.

It is envisaged that the towbar assembly of the invention may be sold as a separate component where it is to be used to tow a trailer already having a winch such as a boat trailer. In another embodiment a modified form of the towbar assembly can form an integral part of the towbar.

It will be apparent that in an alternative embodiment the towbar assembly may be mounted on the drawbar of a trailer or caravan and the winch assembly may be mounted on a towing vehicle arm of a vehicle. In use an operator backs the towing vehicle to a suitable distance from the trailer dependent on the length of cable 20. The cable 20 is unwound from drum 24 of the winch 14 and then is fed around each of the pulley wheels 34, 36, 38 so that each is in

contact with a portion of the cable. The free end of cable 20 is connected by hook 26 onto eye 28 on drawbar 16. The cable 20 is held taut against the pulley wheels 34, 36 and 38 by operating winch 14 to wind in any loose cable. With reference to Figure 1, when drawbar 16 is even further to the right with respect to vehicle towbar 12 so that if cable 20 was passed around the outside of pulley wheels 34, 36, 38 the cable 20 would pass directly from hook 26 to pulley wheel 36 without making contact with pulley wheel 38, the cable 20 is arranged so that it passes around pulley wheel 38 on the inside 60 thereof. The towing vehicle is then immobilised by application of the brakes and gears. When cable 20 has been correctly positioned the winch 14 is started. Operation of the winch 14 to draw in cable 20 causes the trailer to be winched towards the towing vehicle. The endless loop of cable 20 passing around pulley wheels 34, 36 and 38 causes the towing hitch 18 to be self-centring with respect to towball 30. The height of drawbar 16 is adjusted by means of jack and wheel assembly conventionally provided on heavy trailers so that hitch 18 rides over the top of towball 30. Winching is continued until the vehicle hitch 18 on the drawbar 16 is positioned over the corresponding towball 30 on the towbar 12 of the towing vehicle. Hitch 18 is then lowered onto and coupled with towball 30 in a conventional manner.

A preferred embodiment of winch assembly 13 is illustrated in Figures 8 and 9. To accommodate cable 20 being wound in at extreme angles drum 24 has an axial length from end to end which is greater than that of conventional drums on such winches. The housing 47 is also fitted at its front end with a pair of guiding members 53 and 57 arranged on vertical axes. These may be rollers or rails preferably fitted with hard wearing low friction surfaces.

In another variation from the embodiment of Figure 1 hooks 45 are welded on each side of housing 47. A wire ringlet 23 is fitted at the end of cable 20. In addition a foam rubber hand guard 21 is fitted above the ringlet 23.

In Figure 8 the end of axle 25 on which drum 24 is mounted can be seen in the side of housing 47. Crank 46 is attachable to the opposite end as can be seen in Figure 9. In operation ringlet 23 is fed out between guiding members 53 and 57. It is passed around pulley wheels 34, 36 and 38 as in the other embodiments and hooked onto the hook 45 on the side of the winch housing to which it is returned. The cable 20 may be wound onto drum 24 over a guiding member 53 or 57 no matter how acute the angle of the trailer drawbar to the vehicle towbar. It is envisaged that the towbar assembly and winch assembly may be provided as a kitset.

Industrial Applicability

Thus, at least in the preferred embodiments, the invention has the following advantages: it provides an inexpensive demountable towbar assembly; and, it enables a trailer such as a caravan to be pulled out of a muddy area without the requirement for the towing vehicle to go into the muddy area.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.