GB2078373A

GB2078373A - Level indication system for towed vehicles

Info

Publication number: GB2078373A
Application number: GB8020622A
Authority: GB
Original assignee: LEVY HYME AIME
Current assignee: LEVY HYME AIME
Priority date: 1980-06-24
Filing date: 1980-06-24
Publication date: 1982-01-06

Abstract

A system for indicating when the transverse axis of a towed vehicle, e.g. a caravan, is on level ground, comprises a mercury switch (10) mounted so that it makes a connection between two electrical terminals (21, 22) thereof when the towed vehicle is level. The switch (10) is incorporated in a circuit which includes a plug and socket connection (13, 14) between the towed and towing vehicles and a light (11) mounted within the towing vehicle in the sight of the driver thereof. <IMAGE>

Description

SPECIFICATION Level indication system for towed vehicles The invention relates to a level indication system for towed vehicles, e.g. caravans.

Hitherto, when arriving at a caravan site the operation of finding a position at which the caravan is level along the tranverse axis has been relatively time-consuming. A spirit level provided on the caravan has been used to indicate when the caravan is setup in a level position. However finding a level position has involved a trial and error procedure whereby the caravan may be towed to different positions and its levelness checked each time by the driver getting out of the towing vehicle and looking at the spirit level. This procedure is made more difficult in the dark.

The invention provides a level indication system for towed vehicles comprising means for mounting on the towed vehicle and which are adapted to be actuated when the transverse axis of the vehicle is level to produce a signal indicative thereof, indication means for mounting at a remote location, e.g.

on the towing vehicle, and means for connecting said first mentioned means to said indication means for transmitting said signal to said indication means to actuate those latter means to provide an indication at the remote location that the towed vehicle is level as aforesaid.

The level responsive means may be a mercury switch adapted to be mounted in a horizontal position transversely of the towed vehicle. Said indication means may comprise a light which is electrically connected to said level responsive means whereby it is illuminated when an electrical circuit is connected by the level indication means when the towed vehicle is in said level position. A switch may be incorporated at the remote location so that the electrical circuit is only completed to provide the level indication of the towed vehicle when required at a site where the towed vehicle is to be located, The electrical connection between the indication means and the level responsive means may include a plug and socket connection which is made between the towing and the towed vehicle.

An advantage of the invention is that it greatly facilitates positioning of a caravan at a site in a level position. The indication means, for example an indicating light, can be located in the towing vehicle in sight of the driver so that when the level indication system is actuated the driver merely drives his vehicle around likely level areas of the site until the indication means are actuated to show that the transverse axis of the caravan is level. There is therefore no need to keep stopping and starting the towing vehicle for the driver to get out each time and inspect a spirit level on the caravan.

An embodiment of the invention will now be described by way of example and with reference to the accompanying drawings in which: Figure 1 is a diagrammatic illustration of a system according to the invention mounted on a car and caravan towed thereby; Figure 2 is a circuit diagram of the system of the Figure 1; and Figure 3 is a diagrammatic illustration of a mercury switch used in the system of Figure 1.

Referring to the drawings a level indication system comprises a memory "level" switch 10 for mounting on the caravan, a switch and indicating light unit 11 for mounting on the towing vehicle dashboard, a plug and socket connection 12 in an electrical connection between the switch 10 and the unit 11.

The plug 13 is mounted at the forward end of the caravan and the socket 15 is located at the rear of the towing vehicle for connection to the plug when the towing vehicle is hitched to the caravan, The side of the light/switch unit 11 remote from the socket 14 is connected to the vehicle earth and the side of the switch 10 remote from the plug 13 is connected to a live electrical terminal on the caravan.

The mercury level switch 10, as shown in Figure 3, comprises a sausage-shaped glass container 20 which is evacuated and is mounted so that a central portion thereof is at the lowest level when the caravan is in a level position with portions of the container extending upwardly of the central portion on each side thereof. At the base of the central portion are two spaced depressions 21 and 22 each containing an electrical contact and to which external wire connections are made. The container 20 contains a small quantity of mercury 23 which when the device is in a level position is located in the central portion of the glass tube 20 to bridge the connections in depressions 21 and 22 and thereby make an electrical contact.When the caravan, and therefore the tube 20, is not in a level position the mercury moves to one or other side of the central portion of the tube 20 thereby breaking the connection.

The switch 10 is fixed in the caravan at a suitable location preferably as high as possible, for example inside the front locker, with the tube 20 extending in the transverse direction of the caravan and in a position so that the contact is made when the transverse axis is at a horizontal attitude. A spirit level can be used in order to set the mercury switch in the required position.

In caravans having only a single seven-pin plug it will probably be necessary to provide a separate single plug and socket connection for an indication system according to the invention. In caravans fitted with two seven-pin plugs one of the spare pins of the plug 13 can be used for connection to the mercury switch. Similarly the switch/light unit 11 is connected to the supplementary socket 14 or a spare connection on an existing seven-pin socket at the vehicle tow bar. The connections are made using single core wire.

It will be appreciated that, at arriving at a caravan site, the switch of the unit 11 is turned to the "on" position thereby actuating the indication system.

The vehicle is driven over likely level areas. When the caravan is in a level position the mercury in the switch 10 will make a contact between the two connections of the switch 10 thereby illuminating light 11 on the dashboard immediately indicating the level position to the driver without the previous tedious operation of having to check numerous possible positions of the caravan by stopping the vehicle and inspecting a spirit level thereon.

Claims

1. A level indication system for towed vehicles comprising level responsive means for mounting on the towed vehicle, which are adapted to be actuated when the transverse axis of the vehicle is level to produce a signal indicative thereof, indication means for mounting at a location remote from said level responsive means and means for connecting said first level responsive to said indication means for transmitting said signal to said indication means to actuate those latter means to provide an indication at the remote location that the towed vehicle is level as aforesaid.

2. A system as claimed in claim 1, wherein the level responsive means comprise a mercury switch adapted to be mounted in a horizontal position transversely of the towed vehicle.

3. A system as claimed in claim 1 or claim 2, wherein said indication means comprise a light which is electrically connected to said level responsive means whereby it is illuminated when an electrical circuit is completed by the indication means when the towed vehicle is in said level position.

4. A system as claimed in claim 2 wherein a switch is incorporated at the remote location so that the electrical circuit is only completed to provide the level indication of the towed vehicle when required at a site where the towed vehicle is to be located.

5. A system as claimed in any preceding claim wherein an electrical connection provided between the indication means and the level responsive means includes a plug and socket connection which can be made between a towing and a towed vehicle.

6. A level indication system substantially as hereinbefore described with reference to the accompanying drawings.

7. A road vehicle or towed and towing vehicle combination, when fitted with a system as claimed in any preceding claim.