GB2287118A - Taxi meter - Google Patents

Abstract

Apparatus for preventing fraudulent use of a taxi meter 5 after the period for which rental paid for use thereof has expired includes a re-settable timer 3 connected in series with the meter 5 and receiving electricity from a battery 4. A back-up source of power may also be provided. The timer may be re-set by a key or smart card. <IMAGE>

Description

IMPROVEMENTS IN AND RELATING TO APPARATUS FOR USE WITH TAXI METERS This invention relates to apparatus for use with taxi meters.

Taxi meters are used by drivers of taxi cabs who are subject to the regulations of the Police Carriage Office to calculate fares on the basis of, inter alia, distance travelled and journey time. The rates used to calculate fares are determined by the Police Carriage Office and the meters, once set, are sealed to prevent tampering by unscrupulous users. The meters are regularly checked by officials of the Police Carriage Office and any evidence of tampering can result in the loss of a driver's operating licence A driver is not entitled to operate a taxi cab unless the meter is operating. These measures are taken to ensure that fares charged to the public are consistently applied.

Many taxi cabs are rented out to licensed drivers on, for example, a weekly basis. This entails the driver reporting to the rental company on a weekly or monthly basis either to return the rented vehicle or to renew his rental. In the event that a driver returns the rented vehicle to the rental company after the end of the current rental period, fees due for the overdue period are frequently deferred to a later date the potential loss of the rental company. It is also important to the rental company at weekly or monthly intervals that the rented vehicle be returned to ensure regular inspection of the vehicle.

Attempts have been made previously to include in a taxi meter a device able to monitor and account for rentals due on taxi cabs. Such devices have, however, been deemed to be unacceptable by the Police Carriage Office for fear that through their presence a driver might be able to gain access to the meter to alter the tariff set by the Carriage Office.

The present invention sets out to provide apparatus for use with taxi meters able to monitor rental periods and automatically to take action to disentitle a driver to take fares.

According to the present invention in one aspect there is provided apparatus for use with a taxi meter, the apparatus comprising a timer connected to a source of electrical power and operable automatically to isolate the meter from a source of power separate from that to which the timer is connected after a predetermined time interval.

In another aspect, the invention providing apparatus for use with a taxi meter connected to receive electricity from a battery, the apparatus including a re-settable timer connected in series with the taxi meter and to receive electricity from the battery and, in the event that the battery is disconnected, from a separate source of electricity, the timer being operable on expiry of a preset time to isolate the taxi meter from the battery.

The timer may be pre-set using a unique key.

Alternatively, a smart card may be employed. The timer may be decremented by series connected counters.

The invention will now be described by way of example only with reference to the accompanying diagrammatic drawings in which: Figure 1 schematically illustrates apparatus in accordance with the invention including a timer unit connected to a conventional taxi meter; Figure 2 schematically illustrates a display within a taxi cab which includes the apparatus illustrated in Figure 1; Figure 3 is a front view to an enlarged scale of the timer unit illustrated in Figures 1 and 2; and Figure 4 is a circuit diagram of the illustrated timer unit.

As illustrated in Figure 1, an electrical timer 1 operated by a key 2 through a switch 3 is connected in series between a conventional taxi meter 5 and a 6 or 12 volt battery 4 which supplies electrical power to the vehicle in which the timer is installed. An initiation switch 6 for the meter is provided to enable the user of the taxi cab selectively to switch the meter 4 on and off.

Turning of the key 2 resets the timer 1 for a predetermined period of time, for example 7 days. Other time periods can, of course, be set by means of the key 2. Also, means other that a key may be employed. Thus, the timer can be reset remotely or by use of a smart card.

As shown in Figure 2, the timer 1, switch 6 and taxi meter 5 are conventionally displayed on the front headboard of the driving cabin of the taxi cab to provide visual access to the information displayed and ease of resetting.

As will be appreciated, the timer is connected in series with the meter 5 but does not form an integral part of the meter.

As will be seen from Figure 3, the timer includes LED indicators 7, 8 which are respectively illuminated when the meter and/or timer are operating. Typically, the dimensions of the timer are 120mm by 65mm by 40mm in depth.

Turning now to Figure 4 of the drawings, the circuit illustrated comprises two series connected counters 9, 10 and a latch 11. The counter 9 includes an oscillator whose time period is set by a precision capacitor 12 and precision resistors 14. Typically, the set time period is 92O35 milliseconds. The time set is decremented by the counters 9, 10 with the counter 10 going "high" after 171.57 hours. The resistors 14 and the capacitor 12 provide, over a temperature range of between -40 C and +701C, a tolerance of + 1.1%, ie between 169.68 hours and 173.45 hours (a seven day period being 168 hours). When the counter 10 goes "high" the latch 11 switches a driver transistor 16 to activate a relay 15 and prevents an initialisation voltage reaching the meter 5.Thus, the driver 16 operates to close the contacts of the relay 15 to isolate the meter 5 from its source of power and to switch on the LED indicator 7 usually to indicate that the time period set by the key operated switch of the timer is over.

The LED indicator 8 is driven by the driver 16 from a pin of the counter 9. When the timer is running, the LED indicator 8 receives pulsed voltages from a pin of counter 9 and will flash at about one second intervals to give visual feedback that the timer is operating.

Thus, on completion of the period set in the timer 1 through the key operated switch 3, the meter is isolated from its initialisation voltage and cannot be used thereafter until the switch 3 is re-activated. The key 2 which operates the switch is retained by the rental company of the vehicle in question which means that the taxi cab must be returned to the rental company at the end of the rental period before it can be used for fare generating purposes.

One or more security devices may be provided to ensure that any unauthorised attempt to operate the switch 3 is either obvious to the rental company and/or will be unsuccessful.

Power to the meter will automatically be sustained for the duration of a fare in the event that the set time period expires during the course of that fare. The meter 5 will, however, automatically be isolated from its initialisation voltage thereafter by preventing resetting of the meter.

As will be explained below, the timer 1 has an independent source of electrical power and continues to operate until a reset line is activated using the key operated switch 3.

Two sources of electrical power are supplied, the first of these being the battery 2 whose stabilised voltage Vp is 8.2 volts at the point at which the relay 15 and the LED indicators 7, 8 receive their power. For this reason, when the battery 2 is disconnected, the relay 15 and LED indicators 7, 8 are inoperative.

The second source of power is a back-up source 19 comprising, for example, two 2/3AA size lithium batteries connected in series. These batteries are typically mounted on a printed circuit board. Although such batteries are not normally rechargeable, they have advantages over other types of batteries; for example, they have a shelf life of 10 years, a near flat discharge curve and a higher capacity. The timer circuit draws 160WA which means that a back-up source having a capacity of 1.5Ahr will operate the timer circuit continuously for 390 days.

A battery back-up switch 20 is provided to switch at an extremely fast rate between the two power supplies to whichever is currently at the highest voltage.

Thus, the battery 2 defines one input of electrical power and the back-up supply 19 defines the other input of electrical power. The output from the backup supply 19 powers is connected only to supply the timer circuit. With the initiation switch 6 in its "on" position, therefore, the battery 2 is connected and its output provides the necessary power to the timer 1, meter 5 and other electrical equipment of the vehicle. If the cab battery 2 or main battery source is disconnected however, the internal back-up power source 19 is switched on and becomes effective. A 200 mA fuse is fitted to the "in" or at the battery 2 connection point to protect the overall circuit.

The initiation switch 6 is a DPDT switch and effectively switches two different parts of the circuit with the same action. When in its "off" position, the back up power source 19 is disconnected and therefore no current can be drawn from it and the reset line is held "high" clearing the latch 11 and counters 9, 10.

When the key switch is in its "on' position, the reset line is released allowing the counters 9, 10 to start counting from zero. The internal back-up source 19 is always connected in circuit but may not be drawing any current.

To reduce interference, a varistor capacitor suppressor 21 is provided in the supply from the battery 2.

A low pass filter consisting of a resistor 22 and capacitor 23 is also provided. Mounting holes are provided on the corners of the printed circuit board, three of which are plated through and connected to Ov. This ensures adequate screening when mounting to the diecast box with screws.

It will be appreciated that the foregoing is merely exemplary of taxi meters in accordance with the invention and that modifications can readily be made thereto without departing from the true scope of the invention.

Claims (6)

1. Apparatus for use with a taxi meter, the apparatus comprising a timer connected to a source of electrical power and operable automatically to isolate the meter from a source of power separate from that to which the timer is connected after a predetermined interval.

2. Apparatus for use with a taxi meter connected to receive electricity from a battery, the apparatus including a re-settable timer connected in series with the taxi meter and to receive electricity from the battery and, in the event that the battery is disconnected, from a separate source of electricity, the timer being operable on expiry of a pre-set time to isolate the taxi meter from the battery.

3. Apparatus as claimed in Claim 1 wherein the timer is pre-set using a unique key.

4. Apparatus as claimed in Claim 1 or Claim 2 wherein the timer is preset using a smart card.

5. Apparatus as claimed in any one of Claims 1 to 4 wherein the timer is decremented by series connected counters.

6. Apparatus for use with a taxi meter substantially as herein described and as described with reference to Figures 1 to 4 of the accompanying diagrammatic drawings.