GB2149169A - Hazard warning means for road vehicles - Google Patents

Abstract

A hazard warning system for a road vehicle (10) includes, for causing periodic illumination of the amber warning lights (16-22) of the vehicle, an automatic switch (34) which comprises (a) one or more sensors each responsive to a selected parameter of the vehicle and each operative to produce an output signal whenever the value of that parameter reaches a predetermined 'hazard' level, and (b) a switching means responsive to the production of any such output signal and operative in response thereto to initiate said periodic illumination. Said parameters may include, for example, the rate of deceleration of the vehicle. Other parameters are also mentioned (e.g. engine (or other) temperature; steering wheel movement; loss of oil; tyre deflation; manual switch). In a modified arrangement, the automatic switch 34 may also activate a radio transmitter, and if desired, an audible tone generator for emitting radio and audible hazard signals respectively. <IMAGE>

Description

SPECIFICATION Hazard warning means for road vehicles This invention relates to a hazard warning means for installation in road vehicles, and to such vehicles provided with such warning means.

It is known to provide warning means on road vehicles for giving warning to road users of the existence on the road ahead of a hazard. Such warning means are constituted by amber coloured warning lights disposed around the peripheral parts of the vehicle, which lights when operative are illuminated intermittently in a regular manner. Such warning means are intended to be brought into operation, by manual actuation of a hazard warning switch, whenever the vehicle is stationary on or adjacent a carriage way in a position which may be dangerous to oncoming vehicles.

Another form of hazard warning light system is that known as the motorway brake warning light system. That system is rendered operative, again by manual actuation of an appropriate switch, so as to cause more powerful illumination of the normal red, rearmounted brake warning lights, or illumination of a special motorway set of more powerful rear-mounted brake warning lights. The more powerful illumination of the motorway brake warning system renders the brake warning lights of the vehicle visible to a following vehicle when spaced a substantial distance from those lights, which distance is such as to enable the safe braking and deceleration of the following vehicle, and in good time. Such a more powerful brake warning system is of especial value in conditions of reduced motorway visibility, as for example in conditions of heavy rain and/or fog.

However, brake warning light systems merely advise the driver of a following vehicle that the vehicle ahead is braking, but give him no indication of the actual magnitude of braking, and hence deceleration, being achieved by the vehicle ahead. Hence, the driver of the following vehicle has no indication of how much braking effort he should himself exert in order to avoid collision with the decelerating vehicle ahead.

Moreover, other conditions may arise in a vehicle, which conditions may cause the driver or the vehicle rapidly to change course and/or speed, which change or changes may constitute hazards for vehicles following behind. Examples of such conditions will be mentioned later in this specification.

According to one aspect of the present invention, the said hazard warning light system is also provided with an automatic actuation means for automatically initiating periodic illumination of the hazard warning lights, which actuation means includes (a) one or more sensing means which or each of which is responsive to the value of a selected predetermined operating parameter of the vehicle, and which or each of which sensing means is arranged to produce an output signal whenever the value of the relevant operating parameter reaches a 'hazard' level, and (b) a switching means responsive to the or each said output signal and operative to effect said periodic illumination of said warning lights in response to the production of such an output signal by the or any one such sensing means.

One such sensing means may advantageously comprise a vehicle deceleration sensing means, in which case the said periodic illumination of the warning lights would be initiated whenever the vehicle deceleration rate reaches or exceeds a predetermined high value, whether by the use of a very high braking effort, or by collision with a vehicle ahead.

The initiation of such periodic illumination of the warning lights automatically would serve to warn the driver of a following vehicle that extreme care will be necessary in approaching the vehicle ahead.

Preferably, said switching means is of the manually resettable, latching kind, so that said hazard warning lights continue to be periodically illuminated until the switching means has been manually reset.

Each said sensing means may comprise any appropriate and suitable kind. For example, said deceleration sensing means may comprise the deceleration sensor already fitted on some, especially large, goods vehicles to control the braking effort, applied in response to the driver's depression of his brake pedal, in a manner such as to avoid locking and skidding the road wheels of the vehicle. Alternatively, the deceleration sensing means may comprise a sensor which incorporates a spring-biased mass or pendulum arranged to be deflected to a predetermined position by an excessive deceleration, or otherwise a gravity-biased ball arranged to be deflected up an incline by such a deceleration.

The output signal of the or each respective sensing means may comprise an electrical signal, or a mechanical signal, or even a pneumatic or a hydraulic signal.

Other features of the present invention will appear from the description that follows hereafter, and from the Claims appended at the end of that description.

One vehicle fitted with an automatically operating hazard warning system according to the present invention will now be described by way of example and with reference to the accompanying diagrammatic drawing, in which: Figure 1 shows in outline form only a motor car as seen in side elevation, with the various components of the hazard warning system shown positioned around and interconnected in the car; Figure 2 shows a schematic circuit diagram of the hazard warning system, and the associated direction indicating system; and Figure 3 shows diagrammatically and in side elevation one form of deceleration sensor as used in the circuit arrangement of Figure 2.

Referring now to the drawings, the car 10 is provided, in conventional manner, at its respective front and rear corner portions with (a) front and rear pairs of side lights 12, 14 (appropriately white and red in colour), and (b) front and rear pairs of amber-coloured warning lights 16, 18, 20, 22; and at its respective rear corner portions with red brake warning lights 24.

The side and brake warning lights are supplied and controlled in conventional manner, so that no further description of the means for supplying and controlling those lights will be given here.

The amber warning lights 16-22 are supplied and controlled in conventional manner by a direction indicating system for the purpose of indicating, by operation of a conventional driver-operable direction switch 26 mounted on the steering column 25 of the car and the consequent periodic illumination of the relevant side pairs of those warning lights, the direction in which the car is about to be driven by the driver.

Furthermore, those warning lights 16-22 are connected in a hazard warning system for the purpose of indicating to traffic ahead and behind the existence of a hazard, by the continued periodic illumination of all four amber warning lights. The hazard warning system incorporates a driver-operable maual switch 30, mounted for example on the instrument panel 32 of the car, and an automatic switch 34 mounted on the car in a convenient, appropriate position, both such switches being effective when in an 'operated' condition to effect the said continued periodic illumination of the amber warning lights 1622, and such lights being unenergised and hence not illuminated when those switches are both in their respective 'unoperated' conditions.

Thus, warning of the existence of a hazard can be given by the driver in appropriate circumstances by operation of the manual switch 30, and/or automatically when appropriate conditions are detected by the automatic switch 34, as will be explained later.

Figure 2 shows schematically, by way of example, a circuit arrangement which constitutes the said direction indicating and hazard warning systems.

That circuit arrangement is connected for supply to one terminal of the car battery 36 via a normally-closed, spring biased 'reset' push button switch 35, and a conventional pulsing ('flasher') unit 40 of the kind that is normally used for effecting continu t~periodic illumination (flashing) of the amber warning lights 16-22. The right hand side front and rear warning lights 1 6 and 20 have their respective supply terminals interconnected at conductor 42 and fed through the normallyopen 'right turn' pole R of the direction switch 26 from the flasher unit 40, the other terminals of those lights being connected to the other terminal of the supply battery via earth connections 44.The left hand side front and rear warning lights 18 and 22 are likewise interconnected at a conductor 46, and are fed through the normally-open 'left turn' pole L of the direction switch 26, and the associated earth circuit connections 44. The part of the circuit arrangement so far described constitutes the said direction indicating system.

The said hazard warning system includes the said manual and automatic switches 30 and 34, each for independently connecting the said warning light interconnecting conductors 42 and 46 with the flasher unit 40, directly in the case of the manual switch and indirectly in the case of the automatic switch.

The latter is connected to supply the operating coil 45 of a relay 50 which has three sets of normally-open contacts 52, 54, and 56 connected in the circuit arrangement in the manner shown. The contacts 52 constitute selfretaining contacts for maintaining the coil 48 energised independently of the subsequent condition of the automatic switch 34 after being energised thereby. The contacts 54 and 56, on being closed, connect all four warning lights 1 6 to 22 with the flasher unit via the conductors 42 and 46 respectively so as to cause them to be periodically illuminated.

The said manual switch 30 has two sets of changeover contacts 58 and 60, being normally-open and normally-closed respectively, and being of the break-before-make kind. The contacts 55 are connected in parallel with the contacts of the automatic switch 34, so as to enable the relay coil 48 to be energised by the operation of the manual switch 30 to the operated condition. The normally-closed contacts 60 are connected in series with the said self-retaining contacts 52, so that the relay 50 cannot retain itself in the operated condition, but is dependent for its continued energisation on the manual switch 30 being in the operated condition. Thus, return of the manual switch to the unoperated condition de-energises the relay coil 48, and disconlinuea the periodic illumination of the warning lights under the control of the flasher unit 40.

The automatic switch 34 is intended to automatically Initiate the periodic illumination of the four amber warning lights 16 to 22 whenever it senses a predetermined condition or state of the car, which state constitutes a potentially hazardous condition for a vehicle following close behind.

Thus, the automatic switch may be arranged to sense any ofle bt more of a plurality of predetermined hazardous conditions in the car; for example (a) the occurrence of an excessively high temperature in the engine or in the engine or other compartment of the car; (b) a turning of the steering wheel at too high a rate when the car is travelling at a speed within a predetermined range of high speeds; (c) sudden loss of engine oil; (d) an excessively high acceleration rate of the car in a direction transverse to the direction of the road; (e) a sudden deflation of one or more tyres when the car is travelling at high speeds; (f) actuation of an emergency push button positioned for easy reach by the driver and operation by him when an emergency situation arises;; (g) a sudden and excessive rate of deceleration caused by the driver's rapid and heavy braking, as when the car enters a mist or fog bank on a motorway or when there is a sudden collision of vehicles ahead, or caused by collision of the car with a vehicle ahead.

For each such hazardous condition to be sensed, the automatic switch 34 includes (i) a sensor for detecting the existence of that hazardous condition and for producing in response thereto an output signal, and (ii) a switching means actuated or controlled by that sensor output signal and effective in response to that signal to set up a circuit connection for causing the relay coil 48 to become energised.

For simplicity's sake, in the Figures 2 and 3 the automatic switch 34 is shown as comprising primarily a deceleration sensor 62, which sensor is arranged to close a first set of contacts 64 of the automatic switch 34 whenever a spring-pivoted, spring-biased pendulum 66 reaches a predetermined large angle of deflection from its biased or rest position.

Screw-operated adjustment means 67 are provided for adjusting the bias force which is applied to the pendulum by a compression spring 70, whereby to adjust the rate of deceleration of the car that will cause the pendulum to close the contacts 64.

That form of deceleration sensor may be replaced, if desired , in modified forms of the circuit arrangement described by any other form of deceleration sensor.

The automatic switch 34 may, if desired, also include other hazardous condition sensors, e.g. 68 and 70, which are responsive to various other selected parameters of the car, and which are arranged to close their respective contact sets, e.g. 72 and 74, connected in parallel with the contact set 64 of the deceleration sensor whenever the relevant sensed value reaches a 'hazard' level. Thus, any of the selected sensed parameters, on reaching the relevant 'hazard' level, will cause the relay coil 48 to become energised, and the amber warning lights to become illuminated periodically.

Whereas in the above description the circuit arrangement has been described as being composed of discrete circuit components interconnected by wiring, equivalent circuit arrangements may be constructed using printed circuit board and integrated circuit techniques and components.

Whereas in the above-described embodiment, the automatic switch 34 has been arranged simply to cause automatic illumination of the amber warning lights of the vehicle, (i.e. to cause a visible hazard warning signal to be given to other drivers), in another embodiment that automatic switch 34 is arranged to activate in addition, or even in substitution, a radio signal transmitting device which is arranged when activated to emit distress or hazard signals, which signals may be picked up by any nearby vehicle carrying radio receiver equipment, or otherwise by road traffic control radio receivers or sensors positioned alongside or in the locality of the motorway or road. Such signals could thus be relayed to a traffic control and emergency centre without delay.

Thus, in the Figure 2, the output line from the flasher unit 40 may be connected as indicated through a further normally-open contact 76 of the relay 48 to a radio transmitter 78 carried on the vehicle.

If desired, a tone generator 80 may be connected in parallel with the radio transmitter 78, so that automatically initiated audible warnings can also be given. Furthermore, such a tone generator (not shown) may, if desired, be connected for activation by the manually-operable switch 30 so as to provide simultaneously visual and audible hazard warnings on operation of the switch 30.

Claims (14)

1. A road vehicle having a hazard warning system and a manually operable activation switch for causing activation of that warning system (referred to hereinafter as the primary warning system). characterised in that there is provided in addition an automatic activation means arranged to cause automatic activation of that primary warning system,and/or a secondary warning system also carried on the vehicle,on detection of a predetermined hazardous or potentially hazardous condition that may occur during movement or collision of the vehicle, which automatic activation means includes a sensor for sensing the presence/ absence of that condition and providing an output signal indicative thereof, and an auto matic switching means responsive to that out put signal and arranged to cause automatic activation of that primary and/or secondary warning system whenever said sensor detects the presence of that condition.

2. A road vehicle according to claim 1, wherein said automatic activation means includes one or more such sensors and associated switching means, each such other sensor being arranged to sense the presence/absence of another such predetermined hazardous or potentially hazardous condition, and the associated switching means being arranged to cause in like manner such automatic activation of that primary and/or secondary warning system whenever its associated sensor detects the presence of the relevant condition.

3. A road vehicle according to claim 1 or 2, wherein each said sensor is arranged to sense a selected relevant operating parameter of the vehicle, and to produce a substantial change in its output signal whenever the value of that parameter reaches a hazard level, and wherein the associated switching means is arranged to activate the primary and/or secondary warning system in response to such a substantial change in output signal.

4. A road vehicle according to any preceding claim, wherein said automatic activation means has a latching characteristic, and there is provided a manually-operable resetting means for deactivating said primary and/or secondary warning system as required.

5. A road vehicle according to any preceding claim, wherein one said sensor is arranged to detect the presence of a predetermined excessive rate of vehicle deceleration in the normal direction of vehicle travel.

6. A road vehicle according to any preceding claim, wherein one said sensor is arranged to detect the presence of a predetermined excessive rate of vehicle acceleration in a direction transverse to the normal direction of vehicle.

7. A road vehicle according to any one of the claims 1 to 5, wherein onesaid sensor is arranged to detect any one of the following hazardous or potentially hazardous conditions, namely: (a) sudden loss of engine oil; (b) sudden deflation of a tyre; (c) excessive engine temperature; and (d) excessive rate of steering wheel rotation whilst the vehicle is traveling at high speed.

8. A road vehicle according to any one of the claims 1 to 5, wherein one said sensor is arranged to detect the operated state of an 'emergency' push button.

9. A road vehicle according to any preceding claim, wherein said primary warning system comprises a visual warning system.

10. A road vehicle according to claim 9, wherein said secondary warning system comprises a visual warning system.

11. A road vehicle according to claim 9, wherein said secondary warning system comprises a radio signal emitting warning system.

1 2. A road vehicle according to claim 9, wherein Said secondary warning system comprises an audible warning system.

1 3. A road vehicle according to any one of the claims 9 to 12, wherein said primary warning system also includes an audible warning system.

14. A road vehicle according to any preceding claim, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.