GB2246331A

GB2246331A - Reversing aid for use when reversing a vehicle coupled to a trailer, e.g. a caravan

Info

Publication number: GB2246331A
Application number: GB9111263A
Authority: GB
Inventors: Steven David Buckley
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-05-25
Filing date: 1991-05-24
Publication date: 1992-01-29
Also published as: GB9011793D0; GB9111263D0

Abstract

The reversing aid comprises a mechanical, optical, electrical, magnetic or inductive detector means to detect the relative angular orientation of the vehicle and trailer, and a display means, which responds to a signal from the detector means and provides the driver with information regarding the relative angular orientation of the vehicle and trailer. The detector means may be situated at the towing connection and comprise an array of magnetically operable reed switches 20 acted upon by a magnet 19 and the display means may have a series of lamps 25-27 to indicate which switch or switches are activated and a buzzer 28 to warn the driver e.g. of imminent jack-knifing. The display means may be located on the dashboard, rear parcel shelf or on the rear window. <IMAGE>

Description

Reversing Aid for a Caupled catRYan or other Trailer The present invention is a device for assisting the driver of a vehicle to which a caravan or other trailer is coupled, when he wishes to perform a manoeuvre in reverse.

The difficulty of reversing a vehicle coupled to a caravan or other trailer is well known. Once the trailer and vehicle movie out of relative alignment by more than a limited angle (which may be of the order of 45 degrees), the vehicle-trailer canbination is liable to fold into a "jack-knife" about the point of coupling. One source of difficulty is that it can be difficult to assess the angular extent of the misalignment of the vehicle and trailer while at the same time driving the vehicle in reverse.

It is an object of the present invention to provide a reversing aid in the form of a device which assists the vehicle driver in assessing the angle between the vehicle and trailer.

The reversing aid according to the present invention comprises a detector means, mounted to detect one or more positions of relative angular orientation about a generally vertical axis of a vehicle and a trailer coupled to the vehicle, and a display means, electrically connected to the detector means and responsive to a signal fran said detector means, to indicate the receipt of a said signal and thereby provide information regarding said relative angular orientation.

By means of the reversing aid, a driver of the vehicle is able to receive information regarding the alignment or otherwise of the vehicle and trailer while he is carrying out a reversing manoeuvre, and thus avoid getting into a position in which jack-knifing of the vehicle/trailer ccmbination is likely to occur.

The detector means may, at its simplest, merely detect the position of mutual alignment of the vehicle and trailer, such that the driver will merely be advised whether or not the combination is properly aligned. However, it is much preferred that the detector means be designed to detect at least tWD relative positions, for example two limiting positions in which the possibility of jack-knifing is imminent, and more particularly several such positions, representing a range of relative orientations of the vehicle and trailer.

The detector means itself may take a wide variety of forms, which may for example involve a mechanical, electrical Optical, magnetic or inductive link between the vehicle and the trailer, whereby to detect the relative orientation of the vehicle and trailer. Thus in one preferred form of the invention, a number of reed switches mounted upon either the vehicle or the trailer within the region of the point of coupling are individually operable by a magnet mounted upon the trailer or the vehicle respectively. The switches may be mounted in an arcuate array, such that the particular switch operated by the rnagnet is an indication of the position of the magnet relative to the arcuate array and thus of the relative angular position of the vehicle and trailer.

In a further form of the invention, the detector means canprises a light source and a range of light detectors upon which light fram the light source can impinge in succession as the angle between the vehicle and trailer changes. As an alternative, light frau a light source upon the vehicle or trailer may impinge upon one of a range of reflectors on the trailer or vehicle respectively and the reflected light may then be detected as an indication of the vehicle/ trailer alignment.

In yet another form of the invention, the detector means may comprise two relatively movable parts which together operate a rheostat or produce in some other way a continuously or step-wise variable electrical signal indicative of their relative positions.

Whatever the form of the detector means, it is particularly preferred that it should comprise a first part associated with a tow-ball and a second part associated with a coupling for the tow-ball, and that the two parts should be so mounted that their distance apart is substantially unchanged by relative angular movement of the tow-ball and coupling. It is further particularly preferred that at least one of these two parts be pivotted about a generally horizontal pivot, in order to compensate for relative vertical angular movement of the vehicle and trailer.

The display means in the reversing aid according to the present invention is electrically connected to the detector means to receive a signal fran the detector means and to indicate to the vehicle driver that a said signal has been received. The indication may be wholly visual or wholly audible but there is particular merit in a combination of the two. Thus, for example, a visual indication may be given that the vehicle and trailer are aligned and/or that any deviation fran true alignment is by a limited acceptable angle, an audible indication then being given as the position of possible jack-knifing is approached.In one preferred form of the invention, a succession of lamps or the like, for example LED's, may be illuminated in turn as the deviation from true alignment increases. The lamps or the like may be of the same or different colours and may be supported or supplemEnted by one or more audible signals as indicated.

The display means is preferably mounted within the vehicle, especially in a position in which it can readily be seen by the driver while reversing. Thus, while the display means may possibly be incorporated in the vehicle dash-board, it is preferably mounted within the region of a rear window of the vehicle, for example on a rear parcel shelf or by means of a suction pad on the rear window itself.

It may then be observable by the driver either by looking over his shoulder or via a rear view mirror.

Power for the operation of the reversing aid according to the invention may be provided direct frgn the car battery or by a battery specifically provided for the purpose. It is preferred that the reversing aid be electrically connected into the reversing light circuit of the towing vehicle, so that the reversing aid, like the reversing light or lights, is powered automatically when the driver of the vehicle selects reverse gear.

The invention will now be further described, by way of example only, with reference to the accompanying drawings, wherein Figs. 1 and 2 respectively illustrate, in perspective view, the components which together form the detector means of one preferred embodiment of the reversing aid according to the present invention; Fig. 3 illustrates, in perspective view, the components of Figs. 1 and 2, duly assembled on coupling of the vehicle and trailer; Fig. 4 is a view of the assembled components of Fig. 3, in elevation and partly in section; and Fig. 5 is a perspective view of the display means of this preferred embodiment of the reversing aid.

The illustrated reversing aid comprises a magnet unit 10, which is mounted, in the direction of the arrow 11 in Fig. 1, upon a coupling 12 extending from a caravan or other trailer.

The reversing aid also calgrises a reed box 13, which is mounted upon a bracket 14 which is retained between a tow-ball 15 and tow-bar 16 extending fram the rear of a vehicle such as a car, of which only the rear kssper 17 is seen. The reed box 13 contains an array of reed switches 20 (Fig. 4), set along an arcuate path behind a curved surface 18 of the reed box and each operable by a magnet 19 of the magnet unit when the magnet is close to the respective reed switch.

The magnet 19 is pivoted at 21 upon a hodd 22, which in turn is pivotally mounted at 23. The positioning of the two pivots 21 and 23 is such that, when the vehicle and trailer are coupled together by means of the tow-ball 15 and coupling 12, the magnet is able to traverse the surface 18 of the reed box 13 and remain in contact with that surface throughout any relative angular movement of the vehicle and trailer about either a horizontal or a vertical axis.

The reed switches 20 and the display unit illustrated in Fig. 5 are connected into the reversing light circuit of the vehicle, so that, when the driver selects reverse gear, power is supplied to the reversing aid from the vehicle electrical supply. The link from the reed box 13 to the display unit is identified by the reference numeral 24 in Fig. 5.

The display unit comprises, in the illustrated embodiment, a series of seven LED's 25, 26, 27 and a buzzer 28. The T,T4D 25 is coloured green, lED's 26 are yellow and LED's 27 are red.

Each of the Tsins corresponds to one of seven reed switches 20 in the array within the reed box 13. An additional reed switch, electrially linked to the buzzer 28, is disposed at each end of the array of reed switches.

When the vehicle reverse gear is engaged, the magnet 19 activates an adjacent reed switch 20, depending upon the relative angular positions of the vehicle and trailer,and the corresponding Twn is illuminated. Thus the green lED 25, when illuminated, advises the driver that the vehicle and trailer are in true alignment. Any small departure from that alignment is indicated by illumination of one of the yellow LED's 26. Illumination of one of the red lE:D's 27 warns of an approach towards a position in which jack-knifing could occur. Further angular deviation, in which jack-knifing is an imninent risk, is indicated by the sounding of the buzzer 28.

A stainless steel keep 29 for the magnet 19 is provided on the magnet unit 10. The magnet may rest upon the keep during normal forward movement of the vehicle, to reduce wear on the surface of the reed box and also to assist in preserving the magnetism of the magnet.

In experimental use of the reversing aid illustrated in the drawings, I have established that it is possible to detect a deviation from alignment as little as two degrees of arc, a deviation which would not be noticeable to the driver' s naked eye. I have also carried out experimental reversing operations and established that the time required for a given manoeuvre may be halved by use of the reversing aid.

Claims

ClAIMS

1. A reversing aid for assisting in reversing a coupled vehicle and trailer, comprising a detector means, mounted to detect one or more positions of relative angular orientation about a generally vertical axis of a vehicle and a trailer coupled to the vehicle, and a display means, electrically connected to the detector means and responsive to a signal fran said detector means, to indicate the receipt of a said signal and thereby provide information regarding said relative angular orientation.

2. A reversing aid as claimed in claim 1, wherein the detector means is mounted to detect at least two said positions of relative angular orientation.

3. A reversing aid as claimed in either of claims 1 and 2, wherein the detector means involves a mechanical, electrical, optical, magnetic or inductive link between the vehicle and the trailer.

4. A reversing aid as claimed in claim 3, wherein the detector means comprises a number of reed switches mounted upon either the vehicle or the trailer within the region of the point of coupling and said reed switches are individually operable by a magnet mounted upon the trailer or the vehicle respectively.

5. A reversing aid as claimed in claim 4, wherein said reed switches are mounted in an arcuate array.

6. A reversing aid as claimed in claim 3, wherein the detector means comprises a light source and a range of light detectors upon which light frcm said light source can impinge in succession as the angle between the vehicle and the trailer changes.

7. A reversing aid as claimed in claim 3, wherein the detector means comprises a light source, a range of reflectors, and a detector for light reflected from said reflectors.

8. A reversing aid as claimed in claim 3, wherein the detector means comprises two relatively movable parts which together operate a rheostat or produce in sane other way a continuously or step-wise variable signal indicative of their relative positions.

9. A reversing aid as claimed in any of the preceding claims, wherein the detector means comprises a first part associated with a tow-ball and a second part associated with a coupling for the tow-ball, and the two parts are so mounted that their distance apart is substantially unchanged by relative angular movement of the too-ball and coupling.

10. A reversing aid as claimed in claim 9, wherein at least one of said two parts is pivotted about a generally horizontal pivot.

11. A reversing aid as claimed in any of the preceding claims, wherein the display means provides a visual and/or an audible indication of the receipt of a signal fram the detector means.

12. A reversing aid as claimed in claim 11, wherein the visual indication is provided hy a number of LED' s.

13. A reversing aid as claimed in any of the preceding claims, wherein the display means is provided with a suction pad to enable it to be mounted within the vehicle.

14. A reversing aid as claimed in any of the preceding claims, electrically connected into the reversing light circuit of the vehicle.

15. A reversing aid, substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.