GB2424401A

GB2424401A - Fuel type reminder arrangement

Info

Publication number: GB2424401A
Application number: GB0505753A
Authority: GB
Inventors: Gordon Christopher Robi Luxton
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-03-21
Filing date: 2005-03-21
Publication date: 2006-09-27
Also published as: GB0505753D0

Abstract

An arrangement for deterring against use in apparatus such as a vehicle or generator of a wrong fuel type includes means for triggering provision of a visible and/or audible warning, when a user prepares the apparatus for refuelling. The warning may inform of the correct fuel type. The arrangement may comprise a filler cap containing circuitry incorporating the triggering and warning means. The triggering means may be a proximity sensor (50 see fig 4) or a switch 36 activated by grasping cap walls 16, 18. The warning means may be a board 30 containing a voice-messaging circuit delivering an appropriate verbal message when triggered, which in one modification is inside a car radio. If the apparatus is a diesel powered vehicle, for example, a filler door release switch may trigger a voice message circuit contained within a dashboard mounted unit also containing a speaker. Alternatively, the message may be communicated through an existing car radio speaker. A visual message may be displayed instead of or in addition to an audible message.

Description

ARRANGEMENT FOR DETERRING AGAINST ERRONEOUS REFUELLING

Field of the Invention

The present invention relates to an arrangement for deterring the user of an apparatus.

which runs off a particular fuel, from refuelling the apparatus with the wrong sort of fuel, and in particular an arrangement for deterring the driver of a diesel-powered motor vehicle from refuelling the vehicle with petrol.

Background of the Invention

Modern automobiles are highly developed, fuel-efficient pieces of equipment, which are designed to run off a particular type of fuel. Hence most cars are designed to run off either petrol or diesel and no mixture of the two is allowed. However, it is by no means unknown for a driver to inadvertently refuel his car with the wrong fuel, and with sometimes disastrous consequences. It is estimated that, in the United Kingdom alone, around 120,000 drivers each year suffer the embarrassment of having to call out the breakdown services after filling their cars with the wrong kind of fuel. Indeed, this type of mishap ranked as number 11 in the top 20 faults for the year 2004 in the records of the Automobile Association of Great Britain.

Apart from the embarrassment and inconvenience, there is also the financial penalty of not paying attention at the fuel pump The cost of repairing the damage done when the wrong sort of fuel has been dispensed depends on whether the car has been driven before the mistake is noticed. If the engine has not been started, then all that needs to be done usually is to drain the tank and refill with the correct fuel. On the other hand.

if the car has been dri'ven. major repairs may be needed and these may cost in the region of 3000 Whether the damage is major or minor, there is always the cost of refuelling with the correct fuel and also the cost of getting rid of the contaminated fuel.

Such fuel cannot be recycled in any way and therefore presents an environmental hazard Since it has to be disposed of at special disposal centres, there is a further cost penalty involved.

In an attempt to prevent accidental refuelling with diesel in petroldriven vehicles, the step was taken a number of years ago to employ different-sized filling nozzles for the two fuels. The diesel filling nozzle was made wider relative to the petrol, so that it would not fit into the neck of a petrol tank. While this certainly protected the owner of a petrol-driven vehicle from refuelling with diesel, it could not, by definition, prevent incorrect refuelling in the opposite direction, namely the dispensing of petrol into a diesel tank The risk of incorrect refuelling has been partly laid at the door of poor labelling methods or other ways of identifying the fuels concerned, It is true that fuel hoses have been colour-coded for a number of years now, but this has been done inconsistently across the industry. Hence, while many fuel companies in the UK employ green hoses tbr unleaded petrol, red for leaded and black for diesel, for example. other schemes are also prevalent - for instance the use of blue hoses for diesel.

It is not only colour-coding which can lead to confusion, but the names given to the various fuels can also lead to errors. One example is the name "UltimaterM" which has been applied to some BPAfue!s. This name has been used for both unleaded and diesel fuels. Hence, a driver looking solely at the name could easily confuse one with the other and refuel with the wrong kind of fuel Another suggestion has been for the filler caps themselves, and the area around the filler cap. to be more clearly marked and colour-coded. However, this solution and the use of consistent fuel-hose colour-coding have not yet seen widespread implementation, leaving the motorist with a very real risk of inadvertently dispensing the wrong sort of fuel.

There therefore remains a need for an effective deterrent against refuelling ith the wrong fuel, and in particular a need to deter the driver of a diesel-driven vehicle. and the user of diesel-powered apparatus in general, from dispensing petrol into their fuel tanks.

Summary of the Invention

In vie of this need the present invention, in a first aspect thereof, provides an arrangement for deterring the user of an apparatus, which runs off a particular kind of fuel, from refuelling the apparatus with the wrong kind of fuel, the arrangement comprising a triggering means for operation by the user when preparing to refuel the apparatus. and a warning means. connected to the triggering means. for providing a visible and/or audible warning to the user informing the user of the correct type of fuel to be dispensed or warning the user against dispensing an incorrect type of fuel, the warning being triggerable by operation of the triggering means.

The apparatus preferably comprises a filler cap. in which the triggering means is a switch means provided in or on the filler cap. the switch means being operable by the user when the user removes the filler cap. and the warning means comprises a voice- message delivering means provided in the filler cap. This arrangement has the advantage of being easily retrofitted to an apparatus. since the apparatus itself does not need to he altered.

The switch means ma be constituted by at least one switch provided in or on the filler cap, the at least one switch being located such that it is depressed when the user grasps the filler cap in order to remove it.

The switch means may be at least one proximity detector provided in the filler cap, the at least one proximity detector being located such that it is operated when the user grasps the filler cap in order to remove it.

The switch means may be constituted by a Hall-effect device, which is provided in the filler cap and is operable in conjunction with a permanent magnet provided on the body of the apparatus in the vicinity of the filler cap. n

The warning means may comprise a microchip connected to a sound transducer, the microchip being powered by a battery contained within the filler cap. n

The apparatus may comprise a filler cap protected by a normally locked cover, the triggering means being a release switch provided in or on the apparatus for the unlocking of the cover, and the warning means being a visual indication means and/or voice-message delivering means provided in or on the apparatus.

The apparatus may be a motor vehicle and the warning means may be provided on the dashboard. The warning means may be housed at least partially in a radio forming part of the motor vehicle.

The arrangement may consist of a combination of a filler-cap warning system and an in-car warning system. Thus the apparatus may he a motor vehicle comprising a filler cap protected by a normally locked cover: the triggering means may comprise, firstly, a release switch, which is provided in or on the apparatus for the unlocking of the cover and, secondly. a filler-cap switch, which is provided in or on the filler cap; and the warning means may comprise, firstly, a visual indication means andlor voice- message delivering means provided inside the motor vehicle and triggerable by the operation of the release switch and, secondly, a visual indication means and/or voice- message delivering means provided inside the filler cap and triggerable by the operation of the filler-cap switch.

In a second aspect of the invention there is provided an apparatus which runs off a particular type of fuel and comprising an arrangement as described above. The apparatus may be a motor vehicle or a diesel generator The invention also provides, in a third aspect thereof, a filler cap for an apparatus which runs off a particular type of fuel, the filler cap comprising: a switch disposed such that the switch is operated when a user of the apparatus grasps the filler cap in order to remove it: a voice-message delivering means connected to the switch, the voice- message delivering means being arranged to provide an audible warning to the 3() user informing the user of the correct type of fuel to be dispensed or warning the user against dispensing an incorrect type of fuel, and a battery for powering the voice- message delivering means. wherein the switch, when operated. triggers the start of a voice message provided h the voice-message delivering means.

In a fourth aspect of the invention, a method of deterring the user of an apparatus, which runs off a particular kind of fuel, from refuelling the apparatus with the wrong kind of fuel comprises the steps of: providing a triggering means for operation by the user and a warning means for providing a visible and/or audible warning to the user informing the user of the correct type of fuel to be dispensed or warning the user against dispensing an incorrect type of fuel: receiving a triggering signal from the operation of the triggering means when the user prepares to refuel the apparatus, and using the triggering signal to trigger the warning means, thereby initiating the warning.

1 0 Brief Description of the Drawings

Embodiments of the in'vention will now be described by way of example only, and with reference to the attached drawings. of which: Figs 1(a) and 1(b) are a side elevation and plan view, respectively, of a filler cap of a type commonly used in motor vehicles; Figs 2(a) and 2(b) are a side elevation and plan view, respectively, of a filler cap in a first embodiment of an arrangement for deterring erroneous refuelling according to the invention: Fig 3 is a schematic diagram of a voice-messaging circuit for use in the filler cap of Figs 2(a) and 2(b); Fig. 4 is a variant of the filler cap of Figs 2(a) and 2(b) in accordance with the first embodiment of the present invention; Fig. 5 is a schematic diagram of a voice-messaging circuit for use in the filler cap of Fig 4.

Fig 6 is a front view of a motor-vehicle interior featuring a second embodiment of an arrangement for deterring against erroneous refuelling according to the invention; Fig. 7 is a side elevation of a diesel generator installed with an arrangement for deterring against erroneous refuelling in accordance with the invention; Fig. 8 is a plan view of a filler cap in accordance with a fifth embodiment of the invention; Fig. 9 is a schematic diagram of a visual-messaging circuit for use in the filler cap of Fig. 8. and Figs 10(a) and 10(b) are a side elevation and plan view, respectively, of a filler cap in an arrangement for deterring erroneous refuelling according to the invention.

Detailed l)escriptionof Embodiments of the Invention Referring now to Figs 1(a) and 1(b). a typical filler cap for a diesel motor vehicle is shown, comprising a conventional thread portion 10 for engaging with a corresponding thread on the neck of the vehicl&s fuel tank conduit, a base portion 12 and a grasping portion 14. The grasping portion 14 in the example shown is a raised portion rising from the base portion 12 in a central region thereof The grasping portion 14 comprises two pairs of opposite walls 16. 18 and 20. 22 and a top section 24 joining the four walls The grasping portion 14 is grasped by the fingers on the walls 16. 18 when the vehicle is to be refuelled, and is turned generally anticlockwise in order to unscrew the cap from the tank conduit.

Figs 2(a) and 2(h) show a tiller cap in a first embodiment of the present invention.

The cap is essentially similar to that of Figs 1(a) and 1(b). in which the base portion 12 and grasping portion 14 are hollow. The base portion houses a voice-messaging circuit board 30 with integral speaker 32 and a battery 34. while the grasping portion 14 contains a switch means. which in the illustrated embodiment is constituted by a normally-open single-pole switch 36 The configuration of the voice-messaging circuit is as shown in Fig. 3. In Fig. 3 a voice-messaging board 30 contains circuitry 38 for producing a voice message. a one- shot multivibrator (flip-flop) 40. which supplies an enabling pulse Ve to the voicemessaging circuit 38. and a small speaker 32 fed by an output of the voice-messaging circuit. A battery 34 supplies power to the circuitry on the hoard 30. while a switch 36 triggers the one-shot 40.

In the illustrated embodiment, the switch 36 is mounted between the walls 16 and 18 of the grasping section with the base of the switch secured to the wall 18.

Alternatively, the switch base could he secured to the wall 16. The walls 16. 18. or at least the wall to which the base of the switch is not secured, are thin enough to be flexible, so that. when grasped. these walls bend towards each other. An actuator part 42 of the switch 36 touches, or almost touches, the wall 16.

In use, the driver of the diesel-powered vehicle drives up to the filling pump. climbs out of the vehicle and grasps the tiller cap in order to unscrew it. This very grasping action causes the walls 16. 18 to approach each other, thereby depressing the actuator 42. Hence, as the driver unscrews the cap the switch is operated. which triggers the one-shot 40. thereby outputting a pulse Ve to the voice- messaging circuit 38. This starts off the message stored in the circuit 1 8. The message is any message suitable for warning the driver about the correct (or incorrect) fuel to be dispensed. An example of a suitable message is the sentence Please refuel with diesel" or, alternatively, Warning - diesel only to be used!". or similar. A shorter message will result in longer battery life, so this would normally be preferred. provided a short message communicates the warning sufficiently well. An example of a concise message is Warning - diesel only!'. This message is preferably spoken several times in order to give the driver sufficient warning about the correct fuel to be dispensed. The number of times in one realization of this circuit is governed by the width of the pulse Ve.

which in turn is controlled by the value of the RC time constant defined by the resistor R and capacitor C connected to the one-shot 40. Hence the pulse Ve acts as a gating pulse Thus, even if the driver removes the cap quickly and lays it down on a nearby surface - or. as is more olten the case with modern vehicles, simply lets it hang by a lilament connecting the cap to the fuel-conduit neck - there will always be a sufficient number of warning messages spoken at each refuelling operation. It will normally be advisable to limit the number of messages enunciated in order to reduce the possible nuisance effect of such a message to other drivers present in the forecourt area of the filling station.

The embodiment Just described is a preferred embodiment. which has the advantage of being retrofittable to a diesel-powered vehicle. That is, no changes are necessary to the vehicle itself only to the filler cap. which is a separately manufactured item. An additional advantage of the!rst embodiment as described is that, by incorporating the switch fully inside the cap. any risk of accidental ingress of diesel, oil or grease is minimized. Hence the reliability of the circuitry is enhanced. As regards the voice- messaging circuit, it has been found that a small-sized circuit board with small speaker provides adequate sound output for warning purposes. Indeed, in an initial prototype of the invention produced by the inventor, a readily available greetings-card type voice circuit was mounted in the base portion of an existing off-the-shelf filler cap and was found to be more than adequate. except of course for the inappropriate message.

In a variant of the arrangement shown in Figs 2(a), 2(b) and 3. the mechanical switch 36 is replaced by a capacitive proximity detector (not shown), in which an electrode plate is mounted on the inside of one or both of the walls 16, 18. When the driver grasps the filler cap by the grasping section 14, the presence of his body changes an electric field associated ith the electrode and this change in electric field is used to trigger the one- shot 40 A further variant of the first embodiment is illustrated in Fig. 4 and involves the use of a magnetic proximity detector in the form of a Hall-effect sensor 50. The Hall-effect sensor 50 is mounted standing up from the circuit board 30. so that it occupies part of the internal space between the walls 16 and 18 of the grasping section 14 and close to one of the walls 20, 22 Mounted on the vehicle body close to the periphery of the filler cap base portion 12. and angularly displaced from the sensor in the fully screwed-in position of the cap. is a permanent magnet 52. The operation of this variant is as follows When the drivers grasps the filler cap and turns it anticlockwise.

the wall 22, and therefore also the Hall-effect sensor 50, approaches the fixed magnet 52 until eventually the Hall-effect sensor and magnet are close enough for the magnet to actuate the Hall-effect sensor. When this occurs the Hall-effect sensor outputs a voltage which, again. can be used to trigger the one-shot 40.

Fig 5 shows the voice-messaging circuit modified to take advantage of this variant. It is assumed here that the Hall-effect sensor 50 has an open-collector or drain output, as is often the case in practice. In view of that, a load resistor 54 is connected between the sensor output and the positive supply rail +V and a Schmidt trigger 56, which may be inverting, as shown. depending on the sense of the trigger input of the one-shot 40.

is interposed between the sensor output and the one-shot. In use, when the magnet actuates the sensor, the open-collector goes low resistance, sending the Schmidt trigger input low, which in turn sends a positive triggering signal to the trigger input of the one-shot 40. This triggers the voice-messaging circuit as described earlier. Use of a Schmidt trigger provides a necessary level of hysteresis in the triggering operation.

This variant, while still as effective as the first two described, requires modifications to the car body in order to accommodate the permanent magnet. Hence the first two variants - and in particular the first - are to be preferred.

A second embodiment of the invention is now explained by reference to Fig. 6 Fig. 6 is a partial front view of a typical car interior on the driver's side. with a diesel filler- door release actuator shown as item 60. It is assumed here that the car in question is of the type in which the filer cap is enclosed within a space closed off by a hinged door (not shown) on the rear nearside or offside of the vehicle. In this arrangement.

operation of the actuator 60 unlocks the door, allowing the driver to gain access to the filler cap for refuelling. When the driver pulls up by the fuel pump, he operates the actuator 60 and then gets out of' the car in order to refuel. Operation of the actuator 60 triggers a voice- messaging circuit contained in a unit 62 mounted to. for example, the underside of the dashboard 64 During the time that the driver is getting out of the car.

the unit 62 will have annunciated the voice message several times, thereby providing an effective warning fhe voice-messaging circuit is in all essential respects the same as that of the first embodiment in the first variant thereof. assuming that the actuator is a button-type itch operating a solenoid. or similar, to unlock the filler-cap door This switch (or a dedicated pole therein) will then function as the switch 36 in Fig. 3 The warning message given to the driver may be the same as that for the first embodiment.

In a variant of the aboe-descrihed embodiment, the voice message is delivered by a car radio speaker system. which is a standard accessory in most vehicles. This, of course. Lnvolves an interconnection between the unit and the radio (the unit therefore containing flO speaker) It is even envisaged that the voice-messaging circuit may be contained within the radio itself the radio then having an input merely for receiving the triggering signal provided by the switch 60.

A third embodiment of the invention is based on a combination of the first and second embodiments. In this case a filler cap in accordance with, for example. Figs 2(a), 2(b) and 3 or Figs 4 and 5 is provided, and at the same time the filler-door switch 60 is wired to a unit 62 or. as mentioned in the preceding paragraph, to the normal car radio adapted to include a voice-messaging circuit delivering the fuel-warning message. In this embodiment the drier is given a double warning not to use the wrong fuel.

Firstly. as soon as he operates the hutton 60 he receives an initial warrnng through the unit 62 or the car radio Subsequently, once he has got out of the car and has started to unscrew the filler cap. he receives a further message similar to the first, which therefore reinforces it. As a result. the likelihood that the driver will fill up with petrol is greatly reduced The present invention in at least the first embodiment thereof is applicable not only to motor vehicles, but to an situation in which it is vital to ensure that only the correct sort of fuel is used and in which a fuel tank is closed off by a filler cap. One such situatioii is the refuelling of a diesel-powered electrical generator. This is illustrated in Fig 7. in which refuelling of the generator takes place by unscrewing the filler cap 70 The cap 70 is in all essential respects similar to that described earlier for use with a motor vehicle. Thus. when the generator is to be refuelled, the refueller unscrews the cap 70, thereby triggering the voice-messaging circuit and initiating the voice message.

The triggering method may be any of those previously described - e.g. a simple switch, a capacitive proximity detector or a Hall-effect sensor, etc In the latter case.

and as already described, the sensor will be mounted inside the cap. while the magnet will be mounted close to the periphery of the cap. and external thereto on the body of the generator.

A fourth embodiment of the invention is also shown in Fig. 7 and takes the form of a filler cap which has n circuit board, hut is instead equipped with a permanent magnet 72 The magnet 72 is preferably mounted inside the grasping portion 14 of the filler cap, or alternatively inside the base section 12, in order to protect the magnet from the S elements. The magnet is located near the periphery of the cap. A Hall-effect sensor 74 is mounted inside a unit 76. which contains a voice-messaging circuit board containing a speaker 78 The unit is secured to the side of the generator.

Since the voice-messaging circuit is mounted to the generator rather than inside the filler cap in this embodiment, it is possible to power the unit 76 from a power source which may be provided on the generator itself instead of from its own small battery.

Furthermore, there are tè constraints on the size of the speaker, so that the unit 76 can be made quite large I lence in this embodiment the message can be communicated at considerable volume, leading to a possibly enhanced effectiveness of the warning system.

A fifth embodiment of the invention is illustrated in Fig. 8 In Fig. 8 a filler cap of the conventional type illustrated in Figs 1(a) and 1(b) is provided with a visual-message circuit board 80 in the base section 12 of the cap and a visual message display 82 displaying the word "dicsel'. The circuit board contains a circuit in which a one-shot triggers a flashing source of illumination for the "diesel" message. In this case the voicemessage circuit" 38 of the first embodiment may be replaced by a multivibrator (astable flip-flop) stage 84. as shown in Fig. 9. The stage 84 may power a display driver stage 86 consisting of transistors 88 and 90 connected in cascade Transistor 88 is in common-emitter mode, while transistor 90 is in common collector mode (emitter- follower) providing the power for the display 82. Multivibrator stage 84 has a repetition period determined by an RC network 92. as shown, and the one-shot 40 provides a gating pulse allowing the multivibrator to oscillate for a time determined, as previously explained. b an RC network 94.

instead of bipolar transistors FETs may he used.

The display may take any convenient form. In the example shown it is a 7segment LED display. This has an advantage over an LCD display. in that it generates its own light and is therefore effective at night. On the other hand. it takes much more current than an LCD display. and this will have a negative effect on battery life.

In a variant of this fifth embodiment, the visual display is used along with the afore- mentioned voice message. In this case the circuit board 80 will have the same circuitry as that of either Fig 3 or Fig. 5. but with the additional components of the multivibrator 84 and driver stage 90. for example.

Various modifications of the embodiments so far described are envisaged within the scope of the present invention. Thus, the first realization of the first embodiment may alternatively take the form o! a pair of switch contacts rising vertically from the circuit board 30 and terminating between the walls 16 and 18 of the grasping portion 14. This is shown in Figs 1 0(a) and 10(b). where the reference numeral 37 represents the pair of switch contacts equivalent in function to the switch 36 in Fig. 2(a) and 2(b) and reference numeral 1 7 represents spacers affixed to the walls 16, 1 8 in order to reduce the wall movement needed before the contacts 17 come into physical contact with each other in order to trigger the voice message. The advantage of this configuration is that the switch is convenienhl\ mounted on the board 30 itself and no separate way of mounting the switch has to he found. as is the case with the first variant illustrated in Figs 2(a) and 2(h).

Secondly. although the first embodiment in the first realization thereof, and in the modification just described, employed a switch fully inside the filler cap, it is also possible to form a swtahl\ shaped hole (not shown) in one of the walls 16. 1 8 of the grasping portion and mount the switch in that hole, the switch then being secured on the other side of the wall inside the grasping portion. In this manner the actuator of the switch is external to the tiller cap and is directly operated by the driver, This.

however, has the drawback that the risk of contamination of the switch and other circuitry inside the cap increased, unless some means is provided to avoid this. One such means is to appl\ some form of protective film over the filler cap. the film being taken round underneath the base portion 12. Such a film could be heat-shrunk onto the cap to form a tight fit. thereby effectively preventing the ingress of contaminants This. however, increases the cost of the cap.

While the one-shot stage shown in Figs 3 and 5 has been described as enabling (gating") the voice11esag1jg circuit over a given period of time, during which the message is delivered a suitable number of times, it may alternatively be arranged to output simply a short lrlggel'iiig pulse to the voicemes5agijg circuit, which is then aiange to deliver a predetermined number of repetitions of the message automatically without a gating action. Furthermore although the voicemessaging circuit has been sho11 to liae a permanent Positive power rail +V applied to it. this rail may alternativ'el\ he provided by the output of the one-shot stage, preferably buffered in order to decrease the output impedance of the oneshot and ensure adequate cuent capacity for the voicemessagjng stage. In that configuratjo it will be necessary for the onc-slmi to have the afore_mentiofled gating action.

Whereas it has been assuilieci that the filler cap will have a single switch for operatioii by the user, it is possible depending on the design of the cap - that operation of a single switch may he lincertaiii In such situations it is envisaged that two or more switches may be incorpoi*j1ed into the filler cap, suitable spaced apart and connected in parallel, so that operati,i of either or any of the switches will trigger the audible and/or visual message.

In those embodiiieiits in hicli a mechanical switch iS employed in the filler cap, it is appreciated that, for saIt\ i casons, some form of spark suppressjoii may be advisable, depending on the magnitule of the currentflowing through the switch during the triggering process and depending also on the fuel concerned. To this end, the invention provides for the Connection of. for example, a capacitor across the contacts of the switch. This nia\ not he so critical in diesel applicatjois which is the primary field of use of the invention, but it may be felt to be necessary in other, more flammable. env1ronnenis Although the language ol the voice message communicated to the driver has been assumed to he English. ii ma equally be any other language. Hence each country of use could be provided ith filler caps having voice-message circuitry giving the warning message in its own particular language. The same applies to the visual warning message also.

Claims

An arrangement for deterring the user of an apparatus, which runs off a particular kind of fuel, from reilielling the apparatus with the wrong kind of fuel, the arrangement comprising: - a triggering means for operation by the user when preparing to refuel the apparatus. and

- a warning means. connected to the triggering means, for providing a visible and/or audible warning to the user informing the user of the correct type of fuel to be dispensed or warning the user against dispensing an incorrect type of fuel, the warning being triggerable hy operation of the triggering means.
2 Arrangement as claimed iii claim 1. wherein the apparatus comprises a filler cap. the triggering means is a sitch means provided in or on the filler cap, the switch means being operable by the user when the user removes the filler cap, and the warning means comprises a voice-message delivering means provided in the filler cap.
3 Arrangement as claimed in claim 2, wherein the switch means is at least one switch provided in or on the tiller cap, the at least one switch being located such that it is depressed when the user grasps the filler cap in order to remove it.
4. Arrangement as claimed in claim 2. wherein the switch means is at least one proximity detector pros idecl in the filler cap. the at least one proximity detector being located such that it is operated when the user grasps the filler cap in order to remove it
5. Arrangement as claimed in claim 2. wherein the switch means is a Hall- effect device provided in the filler cap and operable in conjunction with a permanent magnet provided on the both of the apparatus in the vicinity of the filler cap
6 Arrangement as claimed in any one of claims 3 to 5. wherein the warning means comprises a microchip connected to a sound transducer, the microchip being powered by a battery contained \\ithiil the filler cap.
7 Arrangement as claimed in claim 1, wherein the apparatus comprises a filler cap protected by a normally locked cover, the triggering means is a release switch provided in or on the apparatus for the unlocking of the cover, and the warning means is a visual indication means and/or voicemessage delivering means provided in or on the apparatus.
8 Arrangement as claimed iii claim 7. wherein the apparatus is a motor vehicle and the warning means is provided on the dashboard.
9 Arrangement as claimed in claim 8. wherein the warning means is provided at least partially in a radio provided in the motor vehicle.
Arrangement as claimed in claim I. wherein the apparatus is a motor vehicle comprising a filler cap protected by a normally locked cover: the triggering means comprises, firstly. a release switch which is provided in or on the apparatus for the unlocking of the cover and, secondly, a filler-cap switch which is provided in or on the filler cap: and the arning means is. firstly, a visual indication means and/or voice-message deli\ ci iiu means provided inside the motor vehicle and triggerable by the operation of the release switch and, secondly, a visual indication means and/or voice-message delivering means provided inside the filler cap and triggerable by the operation of the killer-cap sitch.
11. A motor vehicle which runs off a particular type of fuel and comprising an arrangement as claimed in any one of claims I to 7.
12. A diesel generator comprising an arrangement as claimed in any one of claims I to 7.
13. A filler cap for an apparatus vhich runs off a particular type of fuel, the tiller cap containing - a switch disposed Licl] that the switch is operated when a user of the apparatus grasps the killer cap in order to remove it: - a voice-message delivering means connected to the switch, the voice- message delivering means being arranged to provide an audible warning to the user informing the user of the correct type of fuel to be dispensed or warning the user against dispensing an Incorrect type of fuel, and - a battery for powerine the voice-message delivering means, wherein the switch. hen operated. triggers the start of a voice message provided by the voice-message deII\ering means.

14 A method of deterring the user of an apparatus, which runs off a particular kind of fuel, from refuelling the apparatus with the wrong kind of fuel, the method comprising the steps of - providing a triggering means for operation by the user and a warning means for providing a visible and/or audible warning to the user informing the user of the correct type of fuel to he dispensed or warning the user against dispensing an incorrect type of tuiel.

- receiving a triggering signal from the operation of the triggering means when the user prepares to refuel the apparatus, and - using the triggering signal to trigger the warning means, thereby initiating the warning An arrangement for deterring the user of an apparatus, which runs off a particular fuel, from refuelling the apparatus with the wrong type of fuel, the arrangement being substantially as shon in. or as hereinbefore described with reference to. Figs 2(a).

2(b) and 3 or Fig. 4 and Fig 5 or Fig. 6 or Fig. 7 or Figs 8 and 9 of Fig. 10 of the attached drawings