GB1570288A - Taximeters - Google Patents

Description

(54) IMPROVEMENTS IN OR RELATING TO TAXIMETERS (71) We, THE PLESSEY COMPANY LIMITED, a British Company of 2/60 Vicarage Lane, Ilford, Essex, and FRANCIS RAYMOND HERITIER, a British Subject of 218 Lordship Road, London N16 5HQ, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following state ment:- This invention relates to taximeters.

At the present time, taximeters as used on taxis, are used to determine a fare to be charged in dependence upon the distance travelled and/or the time of a journey (elapsed time), the fare to be charged also being dependent upon the fare charge rate or tariff in force at the time.

In such taximeters, and especially in electronic type taximeters it is desirable that means be provided to inhibit its operation consequent upon reverse movement of the taxi and/or consequent upon any tampering thereof.

Therefore, in accordance with the present invention there is provided taximeter apparatus for use in a taxi the apparatus comprising fare indicating means; transducer means for providing distance related information for fare computing purposes and means Tes- posive to signals derived from the transducer means for inhibiting the fare indicating means in the event of the said signal indicating reverse motion of the taxi and/or that the transducer means, although still operative to provide said signals is not arranged in a predetermined positional manner.

In a preferred apparatus according to the invention, the transducer means will take the form of a pair of transducers,"for affording respective distance related output signals which are phase displaced relative to one another, comparator means being provided operable on the phase displaced outputs from the pair of transducers for inhibiting operation said fare indicating means when the relationship between the phase displaced output signals departs from a predetermined relationship.

In one arrangement the comparator means may take the form of a phase comparator which inhibits operation of said fare indicating means when other than an expected phase relationship exists between the phase displaced outputs from the pair of transducers and in another arrangement the comparator means may take the form of an amplitude comparator which inhibits operation of said fare indicating means when other than an expected amplitude relationship exists between the phase displaced outputs from the pair of transducers.

In carrying out the invention, warning means e.g. a warning light, may be provided, which is caused to operate when operation of said fare indicating means is inhibited.

The foregoing and other features of the invention will now be described with reference to an exemplary embodiment.

The "distance travelled" parameter which is normally applied to a taximeter is usually derived from one or more transducers which are associated with some moving part e.g. wheel or more normally the gearbdx of the taxi to derive a rectangular pulse train which is proportional to distance travelled.

In order to indicate reverse motion of the taximeter and/or incorrect disposition of the transducer means such as might occur if the transducer means has been tampered with it is envisaged in accordance with a feature of the invention that two transducers be provided disposed at different angular positions around a wheel of the taxi so that two pulse trains will be obtained, which will be phase displaced relative to one another. Thus, it may be arranged that when the taxi is moving in a forward direction, the pulse trains are obtained having a predetermined phase relationship whereas if the taxi is moved in a reverse direction the phase relationship will be changed. Therefore, if means is provided to sense the change in phase between the pulse trains, this can be used to inhibit operation of the fare indicating part of the taximeter.

Also, under normal conditions, it may be arranged that the outputs afforded by the two transducers will be similar apart from the phase displacement between them, and it may also be arranged that these outputs will change if the position of the transducer is varied such as might happen if the transducer is tampered with. Therefore by providing a comparator circuit to compare say the amplitude and/or the relative phase of the pulses afforded by the two pulse trains an output may be derived to indicate that the transducers have been tampered with and may be used to cause an alarm e.g.

a visual warning light on the taximeter to be raised.

It should be appreciated that the provision of two transducers to afford a direction sensing facility and also an indication when the transducer has been tampered with is given by way of example only and it should be appreciated that any suitable form of transducer or transducer arrangement for effecting these requirements is deemed to be included within the scope of the present invention.

WHAT WE CLAIM IS: 1. Taximeter apparatus for use in a taxi the apparatus comprising fare indicating means; transducer means for providing distance related information for fare computing purposes and means responsive to signals derived from the transducer means for inhibiting the fare indicating means in the event of the said signals indicating reverse motion of the taxi and/or that the transducer means, although still operative to provide said signals is not arranged in a predetermined positional manner.

2. Taximeter apparatus as claimed in claim 1, in which the transducer means takes the form of a pair of transducers for affording respective distance related output signals which are phase displaced relative to one another.

3. Taximeter apparatus as claimed in claim 2, comprising comparator means operable on the phase displaced outputs from the pair of transducers for inhibiting operation of said fare indicating means when the relationship between the phase displaced output signal departs from a predetermined relationship.

4. Taximeter apparatus as claimed in claim 3, in which the comparator means takes the form of a phase comparator which inhibits operation of said fare indicating means when other than an expected phase relationship exists between the phase displaced outputs from the pair of transducers.

5. Taximeter apparatus as claimed in claim 3, in which the comparator means takes the form of an amplitude comparator which inhibits operation of said fare indicating means when other than an expected amplitude relationship exists between the phase displaced outputs from the pair of transducers.

6. Taximeter apparatus as claimed in any preceding claim, comprising warning means which is caused to operate when operation of said fare indicating means is inhibited.

7. Taximeter apparatus as claimed in claim 6, in which the warning means takes the form of a warning light 8. Taximeter apparatus as claimed in claim 1 and substantially as hereinbefore described.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. the phase displacement between them, and it may also be arranged that these outputs will change if the position of the transducer is varied such as might happen if the transducer is tampered with. Therefore by providing a comparator circuit to compare say the amplitude and/or the relative phase of the pulses afforded by the two pulse trains an output may be derived to indicate that the transducers have been tampered with and may be used to cause an alarm e.g. a visual warning light on the taximeter to be raised. It should be appreciated that the provision of two transducers to afford a direction sensing facility and also an indication when the transducer has been tampered with is given by way of example only and it should be appreciated that any suitable form of transducer or transducer arrangement for effecting these requirements is deemed to be included within the scope of the present invention. WHAT WE CLAIM IS:

1. Taximeter apparatus for use in a taxi the apparatus comprising fare indicating means; transducer means for providing distance related information for fare computing purposes and means responsive to signals derived from the transducer means for inhibiting the fare indicating means in the event of the said signals indicating reverse motion of the taxi and/or that the transducer means, although still operative to provide said signals is not arranged in a predetermined positional manner.

2. Taximeter apparatus as claimed in claim 1, in which the transducer means takes the form of a pair of transducers for affording respective distance related output signals which are phase displaced relative to one another.

3. Taximeter apparatus as claimed in claim 2, comprising comparator means operable on the phase displaced outputs from the pair of transducers for inhibiting operation of said fare indicating means when the relationship between the phase displaced output signal departs from a predetermined relationship.

4. Taximeter apparatus as claimed in claim 3, in which the comparator means takes the form of a phase comparator which inhibits operation of said fare indicating means when other than an expected phase relationship exists between the phase displaced outputs from the pair of transducers.

5. Taximeter apparatus as claimed in claim 3, in which the comparator means takes the form of an amplitude comparator which inhibits operation of said fare indicating means when other than an expected amplitude relationship exists between the phase displaced outputs from the pair of transducers.

6. Taximeter apparatus as claimed in any preceding claim, comprising warning means which is caused to operate when operation of said fare indicating means is inhibited.

7. Taximeter apparatus as claimed in claim 6, in which the warning means takes the form of a warning light

8. Taximeter apparatus as claimed in claim 1 and substantially as hereinbefore described.