GB2086325A

GB2086325A - Trailer Coupling Aid

Info

Publication number: GB2086325A
Application number: GB8131788A
Authority: GB
Original assignee: SCORPION PLASTICS Ltd
Current assignee: SCORPION PLASTICS Ltd
Priority date: 1980-10-27
Filing date: 1981-10-21
Publication date: 1982-05-12

Abstract

An aid for use when coupling a towing vehicle to a trailer, e.g. a car to a caravan, has a pair of upstanding rods 21, 17 each mounted, in use, on or adjacent to the drawbar 11 or towing bar 14 of the vehicle and trailer respectively so that their upper ends are preferably above the respective hitch elements, e.g. the vehicle towing ball 12 and the trailer hitch socket 16. Their upper ends may be illuminated, or be provided with distinctively coloured tips, or target and aiming shapes 24, 20, e.g. a knob or sphere co-acting with a hollow or trough like target, proximity or contact between which is visible to the vehicle driver and indicates the desired alignment of the hitch elements for coupling to be effected. The upstanding rods may be telescopic and may also serve as a radio aerial. The upstanding rods may be resiliently mounted and may be detachably mounted by magnets, spring clips, clamps, or socket formations. <IMAGE>

Description

SPECIFICATION Trailer Coupling Aid This invention relates to the process of coupling a caravan or other trailer, e.g. a boat trailer, to a car or other towing vehicle. Often a caravan or loaded trailer is difficult or impossible to manoeuvre to align its tow bar hitch element with that of the towing vehicle and this is especially the case where it is not on a hard standing, for example in a grass field or on a beach. Thus it is commonly necessary to bring the respective hitch elements into the correct alignment solely by manoeuvering the vehicle, which involves backing it up to the trailer in precise longitudinal alignment and with the trailer tow bar jacked to the correct height.

The towing vehicle hitch element is commonly a towing ball and the trailer hitch element is commonly a corresponding socket adapted to fit over and releasably lock in engagement with the ball.

The operation is particularly frustrating as the hitch elements are well out of vision of the vehicle driver if the vehicle is a car, van or truck and even with guidance from a helper stationed by the tow bar coupling may take some time to achieve, often a time consuming and frustrating trial and error procedure precedes success, and any excessive inaccuracy may result in damage to the towing vehicle and/or trailer.

The object of the invention is to provide an aid which will facilitate the coupling operation and even make single-handed coupling possible.

According to the invention there is provided an aid for use in aligning the respective hitch elements of a towing vehicle and a trailer in the correct relationship to effect coupling together, said aid comprising a first sighting element adapted to be mounted on the trailer in predetermined relationship to the trailer hitch element and so that a marker portion of it will be readily visible to a driver of the vehicle while backing towards the trailer, and a second sighting element adapted to be mounted on the vehicle in predetermined relationship to the vehicle hitch element so that a marker portion of the second element will also be so visible, the proximity of the marker portions to each other being indicative of the proximity of the respective hitch elements.

Preferably the sighting elements are upstanding rods whose lower ends are operatively secured to or adjacent to the respective hitch elements, their upper tips (which may be distinctively coloured and/or be formed as interrelating target and aiming shapes), serving as marker portions and being positioned vertically above the respective hitch elements.

The sighting elements may be telescopic or collapsible and/or may be releasably mounted by means of magnetic bases, spring clips, clamps, or location in socket formations.

In another aspect of the invention provides a method of aligning hitch elements in said relationship including the steps of mounting a first sighting element on the trailer in predetermined relationship to the trailer hitch element so that a marker portion of it is readily visible to the vehicle driver while backing towards the trailer, mounting a second sighting element on the vehicle in predetermined relationship to the vehicle hitch element and so that a marker portion thereof is also so visible, and manoeuvering the vehicle until the proximity of the marker portions to each other indicates said correct relationship of the hitch elements for coupling to be effected.

Practical embodiments of the invention together with certain alternative features thereof are now more particulary described with reference to the accompanying drawings wherein: Figure 1 is a side elevation showing a first form of coupling aid fitted to a car and caravan, Figure 2 is an enlarged perspective view of sighting elements of the aid of Figure 1, Figure 3 shows another form of sighting element, Figure 4 shows a further form of sighting element.

Figure 5 shows an alternative mounting for part of the aid onto a vehicle towing ball, and Figure 6 shows an alternative mounting for part of the aid onto a trailer hitch socket.

Referring first to Figures 1 and 2 a towing vehicle is shown as a car 10 having a drawbar 11 including a ball type hitch element 12 while the trailer is shown as a caravan 1 3 having a drawbar 14 provided with a screw jacking wheel 1 5 and a socket type hitch element 1 6.

A first sighting element comprises an upstanding metal rod 1 7 mounted on trailer drawbar 14 by its lower end being removably located in a socket formation of a mounting 1 8 fixed adjacent hitch element 16. The upper end of the rod constitutes a marker portion including a target shape 20 in the form of an elongated trough some 130-1 50 mm long and 50 mm wide mounted generally vertical with its open front directed forwardly, and rod 1 7 is angled so that target shape 20 is spaced directly above hitch element 1 6.

A second sighting element comprises another upstanding rod 21 locating in a socket formation of a mounting 22 fixed to the car towbar 11. The second sighting element further comprises a marker portion having a spherical or knob-shaped aiming shape 24 some 40mm in diameter at the upper end of rod 21 and spaced directly above the ball hitch element 12. Shapes 20 and 24 are given contrasting colours, e.g. the interior of the trough is bright red and shape 24 is yellow.

Target shape 20 and aiming shape 24 are at a height to be readily visible to a driver or car 10 while reversing the vehicle toward the front of the caravan 13 and all the driver has to do is manoeuvre the car until the aiming shape 24 nests in the open trough of target shape 20. In this position ball hitch 1 2 will be in longitudinal alignment with the socket of hitch element 16 and at the correct height for the coupling to becompleted by lowering the caravan towbar by means of its jacking wheel 1 5 until the two hitch elements are engaged.

The marker portions may take other forms and the means of mounting the sighting elements on the vehicle and trailer might also be varied. It is not essential that the marker portions are positioned directly above the respective hitch elements though this gives the most accurate display of the relationship between the latter, and gives the same facility for accurate coupling even if the vehicle approaches the trailer at an angie.

The effective length of rods 17 and 21 may be altered by cutting to suit the vehicle/trailer to be fitted and the positioning and angling of the mounting sockets will also be selected to suit.

Conveniently the rods are provided with initial lengths of 90 to 11 5 cm. Mountings 18 and 22 are fixed by screws and may be provided with slots to facilitate angular adjustment, as well as wedges for positioning behind them, if needed.

The lower ends of one or both rods 17 and 21 may include pivotal joints or stiffly bendable portions to facilitate angling.

Use of resilient mountings is also contemplated for avoidance or damage, though it is found in practice that the rods themselves are sufficiently resilient to withstand normal usage and it is preferred that they are removed from mountings 1 8 and 22 and stored safely while travelling or not requred for use.

When fitting the aid it is recommended that the vehicle and trailer are positioned so that the hitch elements are aligned in correct relationship for coupling, i.e. with the trailer socket hitch element 16 at least 50 mm above the vehicle ball element 1 2. The aid is adjusted so that this relationship brings aiming shape 24 within the upper position of the target shape 20 so as to allow for any drop in height of the vehicle drawbar 11 when car 10 is loaded. The preferred vertical elongation of the target shape 20 allows for variation in effective height of the vehicle drawbar for this reason while still determining the tolerance range of height (especially the maximum vehicle drawbar height) at which the coupling can be safeiy and conveniently carried out.

It is contemplated that one or both of the sighting elements might serve a duai purpose, for example be adapted for use as a radio aerial. Rods 1 7 and 21 may be telescopic or otherwise adjustable in effective length and/or hinged so that they can be closed up or folded when not in use.

Figure 3 shows a telescopic sighting element 30 having three extendable sections 32, 33, 34, a marker portion including a coloured tip 35 at the upper end, a swivel joint 36 at its lower end, and a mounting 37 including a magnetic base which will adhere to the drawbars or hitch elements which are normally of steel. Base 37 may be circular in shape with a hole or recess in its lower surface to accommodate spherical or uneven surfaces.

In Figure 4 a sighting element 40 is shown in the form of three sections of rod 42, 43 and 44 having spigot and socket engagement, with a distinctively coloured and/or shaped tip 45 and a magnetic base or other mounting 47.

The tips or other marker portions of the sighting elements may include reflective or fluorescent materials or, for use at night, illuminated tips for better visibility. It is also contemplated that electrical means might be incorporated in one or both marker portions for indicating or signalling by audible and/or visible means the proximity to each other or contact between the marker portions.

One or more pairs of sighting elements might be positioned on parts of the vehicle and trailer other than on or adjacent the drawbars or hitch elements, although such an arrangement will not normally be as convenient.

Figure 5 shows another form of mounting means for use with the vehicle ball hitch 1 2. A telescopic sighting element 50 is attached by way of a universal swivel joint 52 to a spring clip 53 which can be snap engaged around a neck portion of the hitch immediately below the ball.

In Figure 6 a like sighting rod 60 is provided with a universal joint 62 which is attached to a horizontal base member 65. Member 65 has a pair of downwardly directed horizontally spaced spring clips 66 which can be snap engaged onto the handle 67 of the trailer socket hitch element 16.

The marker on the vehicle may also be useful in other reversing situations without the traiier, e.g.

backing into a restricted parking space or garage; and both markers can also be used as a warning to other drivers and pedestrians of the presence of the hitch elements of the vehicle and trailer when separated from each other, e.g. when parked separately.

Claims

1. An aid for use in aligning the respective hitch elements of a towing vehicle and a trailer in the correct relationship to effect coupling together, said aid comprising a first sighting element adapted to be mounted on the trailer in predetermined relationship to the trailer hitch element and so that a marker portion of it will be readily visible to a driver of the vehicle while backing towards the trailer, and a second sighting element adapted to be mounted on the vehicle in predetermined relationship to the vehicle hitch element so that a marker portion of the second element will also be so visible, the proximity of the marker portions to each other bring indicative of the proximity of the respective hitch elements.

2. An aid as in Claim 1 in which the sighting elements are rods, and including mounting means for operatively securing lower ends of said rods to or adjacent to the respective hitch elements so that they are upstanding with the marker portions provided by or on their upper ends.

3. An aid as in Claim 2 wherein each rod is provided with a marker portion including a distinctively coloured tip.

4. An aid as in Claim 2 wherein the marker portion of the first sighting element includes a target shape and the marker portion of the second sighting element includes an aiming shape which will inter-relate with the target shape.

5. An aid as in Claim 4 wherein the aiming shape is spherical or knob-shaped and the target shape defines a hollow for receiving the aiming shape.

6. An aid as in Claim 5 wherein the target shape is in the form of an elongated trough.

operatively mounted generally vertically.

7. An aid as in any preceding claim in which the marker portions include reflective or fluorescent materials.

8. An aid as in any preceding claim wherein the marker portions include means for illumination.

9. An aid as in any preceding claim wherein at least one marker portion include electrical means for indicating or signalling their relative proximity or contact between them.

10. An aid as in any preceding claim wherein at least one of the sighting elements is a telescopic rod.

11. An aid as in any preceding claim wherein at least one of the sighting elements is a collapsible or sectionally jointed rod.

12. An aid as in any preceding claim wherein at least one of the sighting elements its selectively dismountable from its position of use.

1 3. An aid as in any preceding claim including mounting means for the attachment of a respective sighting element in the form of a bracket including a socket for location of a lower end of said element.

14. An aid as in any preceding claim including mounting means for one of the sighting elements including a magnetic base for adherence to a drawbar, hitch element or other part of the vehicle or trailer.

1 5. An aid as in any preceding claim including mounting meuns for attachment of one of the sighting elements including one or more spring clips for releasable attachment to the hitch or some other part of the vehicle trailer.

16. An aid as in any preceding claim wherein at least one of the sighting means includes a resilient mounting.

1 7. An aid as in any preceding claim wherein at least one of the sighting means includes a universal or other swivel joint.

1 8. An aid as in any preceding claim wherein one of the sighting elements is adapted for use also as a radio aerial.

1 9. A vehicle and trailer coupling aid substantially as hereinbefore described with reference to and as shown in any of the accompanying drawings.

20. A towing vehicle and trailer fitted with a coupling aid according to any preceding claim.

21. A method of aligning the respective hitch elements of a towing vehicle and a trailer in the correct relationship to effect coupling together including the steps of mounting a first sighting element on the trailer in predetermined relationship to the trailer hitch element so that a marker portion of it is readily visible to the vehicle driver while backing towards the trailer, mounting a second sighting element on the vehicle in predetermined relationship to the vehicle hitch element and so that a marker portion thereof is also so visible, and manoeuvering the vehicle until the proximity of the marker portions to each other indicates said correct relationship of the hitch elements for coupling to be effected.

22. A method as in Claim 21 wherein the sighting elements are disposed so that their respective marker portions are spaced directly above the respective hitch elements.

23. A method of aligning towing vehicle and trailer hitch elements substantially as hereinbefore described with reference to the accompanying drawings.