GB2284498A

GB2284498A - Vehicle alarm system

Info

Publication number: GB2284498A
Application number: GB9324698A
Authority: GB
Inventors: Andrew Cope
Original assignee: Multitone Electronics PLC
Current assignee: Multitone Electronics PLC
Priority date: 1993-12-01
Filing date: 1993-12-01
Publication date: 1995-06-07
Also published as: GB9324698D0

Abstract

A vehicle alarm system includes an alarm transmitter and control unit which has a paging alert circuit for transmitting an alert signal indicative of an alarm condition to a radio paging receiver. The system also includes an absence pocket associated with the control bit and into which the paging receiver can be inserted. If the correct paging receiver is inserted into the absence pocket, an address detector disarms the alarm system. If the paging receiver is removed from the absence pocket, the alarm system is armed. The absence pocket may also be arranged to recharge the paging receiver's battery when the receiver is in the pocket. <IMAGE>

Description

VEHICLE ALARM SYSTEM The applicants have previously produced and sold a vehicle security system known as "Page Alarm", a product which has made use of paging systems technology.

Page Alarm consists of a compact control unit and radio transmitter in a single housing, which is fitted behind the dashboard on the vehicle, and a small radio paging receiver. The Page Alarm control unit will automatically initiate paging calls to the paging receiver on receipt of various stimuli. The paging receiver informs the wearer when the alarm has been armed or triggered or disarmed or the car phone has been called. When the alarm is armed the paging receiver informs the wearer of any unauthorised access to the vehicle.

The paging receiver responds with a different beep cadence to each of the four circumstances outlined above so that the wearer is fully aware of the situation.

Various options are available; the alarm can be armed/disarmed by a hidden switch and/or the vehicle central locking system and/or the ignition circuit and/or a radio key. The alarm can accept inputs from a vibration sensor, radar sensor, ultrasonic sensors and door/boot/bonnet switches. The paging transmission is made either via the existing car radio aerial or a purpose designed windscreen aerial.

In accordance with the present invention, the system further includes an absence pocket arrangement for removably receiving the paging receiver such that when the paging receiver is removed from the absence pocket arrangement, the alarm is armed and vice versa.

The absence (and charging) pocket is a known paging system ancillary into which the pager is placed on leaving the premises.

Whilst in the pocket the pager's internal battery is recharged, using power from the pocket, and the pager communicates via the pocket with the paging system to stop any paging calls from being initiated to that pager; more powerful systems allow the calls to be automatically redirected to an appointed deputy.

In a system embodying the invention, the controller is broadly similar to that of the known Page Alarm and may be similarly located behind the dashboard. Additionally, there would be an absence and charging pocket compatible with the supplied pager which would be fitted in an obvious location on the dashboard and could be combined with motion sensors.

The operation of the system is as follows, referring to the drawing. Assuming the car alarm is armed and the vehicle is immobilised, if the car door is opened the control unit is activated and starts to communicate with the absence and charging pocket for a given period of time. If during this time a pager is inserted in the pocket with the correct address then the alarm is disarmed and the car is mobilised; if not, the alarm is activated and the paging call initiated, the car remaining immobilised. Whilst the pager is present in the pocket, the rechargeable battery in the pager is charged from the car battery. On leaving the vehicle the driver removes the pager from the pocket thus arming the alarm and immobilising the vehicle.

It is envisaged that a POCSAG code format may be used for the paging system. This would give a total of 221 (namely over 2 million) different addresses thus giving effective security to the immobiliser.

Claims

1. A vehicle alarm system comprising a control unit for mounting in a vehicle, the control unit including a radio transmitter, and a paging receiver arranged to receive radio signals from the transmitter indicative of an alarm condition, wherein the alarm system further includes an absence pocket arrangement associated with the control unit for removably receiving the paging receiver, such that when the paging receiver is removed from the absence pocket arrangement, the alarm system is armed, whereas when the paging receiver is inserted in the absence pocket arrangement, the alarm is disarmed.

2. A vehicle alarm system according to claim 1, wherein the paging receiver responds to a predetermined address characteristic of that receiver, and wherein the absence pocket arrangement is operable to detect correct insertion only if the paging receiver being inserted has the predetermined address.

3. A vehicle alarm system according to claim 1 or claim 2, wherein the paging receiver includes a rechargeable battery, and wherein the absence pocket arrangement includes means for recharging the battery when the paging receiver is in the absence pocket arrangement.

4. A vehicle alarm system according to claim 1, claim 2 or claim 3, wherein the control unit is responsive to an indication that the vehicle is being entered thereby to activate an alarm if the paging receiver is not inserted into the absence pocket arrangement within a predetermined time.

5. A vehicle alarm system according to claim 4, wherein the alarm is provided by an alert indication of the paging receiver.

6. A vehicle alarm system according to claim 5, wherein the alert indication is a predetermined beep cadence.

7. A vehicle alarm system substantially as hereinbefore described with reference to the accompanying drawing.