WO1999061278A1

WO1999061278A1 - Control system for vehicle mounted auxiliary equipment

Info

Publication number: WO1999061278A1
Application number: PCT/GB1999/001193
Authority: WO
Inventors: Alan Barsby
Original assignee: Ratcliff Tail Lifts Ltd.
Priority date: 1998-05-27
Filing date: 1999-04-19
Publication date: 1999-12-02
Also published as: GB2337733A; GB2354213A; GB0028892D0; AU3615399A; GB9811369D0

Abstract

A system is described for controlling an electrical supply to auxiliary equipment such as a tail lift (10) attached to or within a vehicle. The system comprises means for supplying power to the auxiliary equipment when the vehicle's hazard warning lights (11, 12) are switched on. A latching device (15) is also included which is operable to maintain the power supply to the tail lift (10) when the hazard warning lights (11, 12) are subsequently switched off. Switching means (16, 17) are provided which are operable independently of the hazard warning lights (11, 12) to cut off the power supply to the tail lift (10). Thus, the system provides that the tail lift (10) is energised when the vehicle's hazard warning lights (11, 12) are switched on. It gives the vehicle's driver the capability to have the hazard warning lights (11, 12) operating throughout the time that the tail lift (10) is energised. Alternatively, the hazard warning lights (11, 12) can be switched off whilst leaving the tail lift (10) energised. In yet another alternative mode, the hazard warning lights (11, 12) can remain in operation whilst the tail lift (10) is switched off.

Description

CONTROL SYSTEM FOR VEHICLE MOUNTED AUXILIARY EQUIPMENT

The invention relates to an improved control system for auxiliary equipment mounted on road-gomg vehicles .

It is known to fit auxiliary equipment on to such vehicles to provide the capability of additional functions. These may include, for example, lifting machinery such as tail lifts and vehicle loading cranes. These auxiliary machines are generally used only when the vehicle is stationary and such equipment is normally isolated when not m use and particularly when the vehicle is being driven.

It may be of benefit m some circumstances to encourage the driver of the vehicle to switch on the vehicle's hazard warning lights when the equipment is m use, to warn other traffic of the potential obstruction caused by the subject vehicle. It is known, for example, m European patent EP 269210, to use a signal derived from a rear flashing lamp on a vehicle to turn on a vehicle's tail lift for such time as the light continues to flash. UK Application No. GB 9811369.9 refines this system by taking signals from both left and right hand flashing circuits m order to discriminate between, on the one hand turn signals, and on the other hand hazard warning signals. The tail lift is arranged to operate only when left hand and right hand lights are flashing simultaneously . However, although it may often be useful to have the vehicle's hazard warning lights flashing during use of the tail lift, several situations exist m which the lift may need to be operated without the hazard warning lights flashing. For example, UK law states that hazard warning lights may only be used when the vehicle represents an obstruction to traffic. It may be illegal to use hazard warning lights at any other time, e.g. when a vehicle is unloading m a lay- by. Furthermore, at night, m a narrow, poorly lit road, particularly under wet conditions, hazard warning lights can be very distracting to drivers of other vehicles. Indeed, flashing lights may create a greater danger than the hazard represented by the vehicle. Again, operators of large fleets of trucks or trailers may have situations m a loading yard where many vehicles are parked, and m these circumstances it is common practice to leave tail lifts switched on for extended periods so that they may be operated from time to time as required. To have hazard warning lights flashing continually on every vehicle under these circumstances is not generally acceptable to operators, firstly due to the consequent distraction from any real hazards that may exist and secondly due to the unnecessary discharge of vehicle batteries.

The converse situation exists m which the driver may require to operate the hazard warning lights but without having the tail lift m operation. This situation may arise, for example, if the vehicle were broken down on the highway, and the driver needed to leave the vehicle to seek assistance. In these circumstances it might well be unsafe to leave the unattended tail lift energised, as unauthorised persons could otherwise operate the unit in the driver's absence and so create safety risks.

The present invention gives the vehicle driver the ability to turn on the tail lift using the hazard warning light control switch. Having done so, he is enabled to turn off the hazard lights but allow the lift to continue to be operable. Alternatively, he is enabled to allow the hazard warning lights to continue to flash throughout the period in which the tail lift is in use. As a third option, the vehicle driver is enabled to cancel the activation of the tail lift whilst allowing the hazard warning lights to continue flashing.

Accordingly, the present invention provides a system for controlling an electrical supply to auxiliary equipment attached to or within a vehicle, comprising means for supplying a signal to the auxiliary equipment when the vehicle's hazard warning lights are switched on, a latching device operable to maintain the signal to the auxiliary equipment when the hazard warning lights are subsequently switched off, and switching means operable independently of the hazard warning lights to cut off the power supply to the auxiliary equipment.

Preferably, the latching device is arranged so that it maintains the power supply to the auxiliary equipment only if the hazard warning lights are switched off within a pre-determmed period of time. If, on the other hand, the hazard lights are switched off after the said pre-determined period of time, the latching device is rendered in-operative, and the power supplied to the auxiliary equipment is cut off concurrently with, or shortly after, the switching off of the hazard warning lights.

A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying figures, in which: Figure 1 is a logic diagram for the control system of the type described in the co-pending application GB 9811369.9; and

Figure 2 is a logic diagram for a control system according to an embodiment of the present invention.

In accordance with the system described in GB 9811369.9, as shown in Figure 1, the electrical signal to supply power from the power source 8 to the control circuit 9 of the auxiliary equipment, such as a tail lift 10, is derived from both the nearside and offside amber flasher lamps 11, 12. The control system comprises a circuit into which the signals are fed and which may be designed to have a high input impedance, so that the circuit will not have any influence on the vehicle's flasher system. The signals are fed into a co-incidence checker 13, effectively an AND gate, which gives an intermittent output signal if both first and second inputs are pulsing simultaneously. The AND gate provides an output signal, therefore, if the flasher lights are switched on and operating as hazard warning lights (i.e. flashing together) but not when either light is flashing alone (i.e. as an indicator during a turn) . If neither flasher is operating, there will be no signal to the control circuit of the auxiliary equipment .

The signals may be taken via a conductor from the electrical supply to at least one offside and one nearside lamp circuit. Alternatively, the signals may be derived from at least one offside and one nearside flasher circuit by inductive pick-ups. In yet another alternative, the signals may be derived from at least one offside and one nearside flasher light using optical sensors.

The intermittent output signal from the coincidence checker 13 is processed by a signal converter 14 into a continuous signal which in turn is used to energise the control and/or power circuits of the tail lift via run switch 20.

The system of the present invention is shown in Figure 2, and provides the feature of allowing the auxiliary equipment, such as a tail lift 10, to be operated while the hazard warning lights are not flashing. To achieve this objective, a latching device 15 is provided which is arranged to maintain an alternative power supply to the tail lift 10 after the hazard warning lights 11,12 and therefore the run- switch 20, have been switched off.

In such a situation, the power to the tail lift 10 may be subsequently switched off independently of the hazard warning lights 11,12 in any convenient manner, for example by a simple stop control or 'cancel' button 16, preferably located in the vicinity of the tail lift controls.

Alternatively, or in addition, a signal may be derived from a rear brake light circuit 17 of the vehicle. Such a signal would disable the latching device 15 and so turn off the tail lift 10 at the next application of the vehicle's brakes.

In a preferred embodiment of the invention the latching device 15, is operated to maintain the power supply to the tail lift 10 only if the hazard warning lights 11,12 are switched off within a pre-determined period of time as measured by the latch cancelling timer 18. In this embodiment, if the hazard warning lights 11,12 remain in operation for longer than the pre-determined period of time, the latching device 15 is cancelled and the tail lift 10 remains energised, via the run switch 20, until such time as the hazard warning lights 11,12 are switched off. At that time, the tail lift 10 will be switched off immediately, or after a short pre-determined delay.

In practice, when the driver intends to switch on the tail lift 10, he will first actuate the hazard warning light switch.

If the driver considers it inappropriate to have the hazard warning lights 11,12 flashing throughout the intended use of the tail lift 10, he will turn off the hazard warning control almost immediately, enabling the latching device 15 to maintain power to the tail lift 10 until such time as the 'cancel' button 16 or the brake switch 17 is activated to switch off the power supply to the tail lift 10.

If, on the other hand, the driver considers that it is appropriate to display his hazard warning lights 11,12 throughout the loading or unloading operations of the tail lift 10, he will simply carry out these operations and turn off the hazard warning lights 11,12 when they are complete. In doing so he will,

(assuming that these activities have required a period longer than the said pre-determined time) turn off the power supply to the tail lift 10.

In the event that the driver requires to operate the hazard warning lights 11,12 without the tail lift 10 remaining energised, he would simply turn the hazard warning lights 11, 12 on and immediately press the brake pedal or operate the manual 'cancel' button 16. Reference to Figure 2 illustrates that either of these actions will provide a 'stop' instruction to the run switch 20, which will override the continuing presence of the 'on' signal derived from the signal converter 14. In such a case, to operate the tail lift 10 again would require that the hazard warning lights 11, 12 be turned off, to reset the system, and then turned on again.

Throughout this specification, the invention has been described for example only with reference to a tail lift. However, the invention covers a control system for any vehicle-mounted auxiliary equipment which is required to function only while the vehicle is stationary.

Claims

CLAIMS ;

1. A system for controlling an electrical supply to auxiliary equipment attached to or within a vehicle, comprising means for supplying power to the equipment when the vehicle's hazard warning lights are switched on, a latching device operable to maintain the power supply to the tail lift when the hazard warning lights are subsequently switched off, and switching means operable independently of the hazard warning lights to cut off the power supply to the equipment .

2. A system as claimed in claim 1, further comprising means for controlling the operation of the latching device such that the device remains effective only if the hazard warning lights are switched off within a pre-determined period of time.

3. A system as claimed in claim 2 in which, when the hazard warning lights are switched off after the said pre-determined period of time, the power supplied to the auxiliary equipment is cut off concurrently with the switching off of the hazard warning lights.

4. A system as claimed in claim 2 in which, when the hazard warning lights are switched off after the said pre-determined period of time, the power supplied to the auxiliary equipment is cut off after a pre-determined delay following the switching off of the hazard warning lights.

5. A system as claimed in any one of the preceding claims, wherein the operation of the hazard warning lights is detected by signals from at least one offside and one nearside hazard warning light.

6. A system as claimed in claim 5, wherein the signals are taken by conductors from the electrical supplies to at least one offside and one nearside light circuit.

7. A system as claimed in claim 5, wherein the signals are derived from at least one offside and one nearside light circuit by inductive pick-ups.

8. A system as claimed in claim 5, wherein the signals are derived from at least one offside and one nearside light using optical sensors.

9. A system as claimed in any one of claims 5 to 8, wherein the signals from at least one offside and at least one nearside light or light circuits are combined in a logic device to give an intermittent output signal whenever the hazard warning lights are operating but no signal when either the at least one offside or at least one nearside lights is flashing independently of the other, nor when neither of such lights is flashing.

10. A system as claimed in claim 9, wherein the intermittent output signal from the logic device is converted into a continuous signal which in turn is used to energise the control and/or power circuits of the auxiliary equipment.

11. A system as claimed in any one of the preceding claims, wherein the switching means operable to cut off the power supply to the auxiliary equipment independently of the hazard warning lights comprises a manually operable switch.

12. A system as claimed in claim 11, wherein the switch is located in the vicinity of the auxiliary equipment .

13. A system as claimed in any of claims 1 to

10, wherein the switching means operable to cut off the power supply to the auxiliary equipment independently of the hazard warning lights utilises a signal derivable from the vehicle's rear brake light circuit.

14. A system as claimed in any one of the preceding claims, wherein the auxiliary equipment is a tail lift.

15. A system as claimed in any of claims 1 to 13, wherein the auxiliary equipment is a lorry loading crane .

16. A system as claimed in any of claims 1 to

13, wherein the auxiliary equipment is a winch.

17. A system as claimed in any of claims 1 to 13, wherein the auxiliary equipment is a suspension lowering device.

18. Equipment for the control of auxiliary vehicle-mounted equipment comprising the system as claimed in any one of the preceding claims.

19. A system for controlling an electrical supply to auxiliary equipment attached to or within a vehicle substantially as hereinbefore described with reference to Figure 2 of the accompanying drawings.