GB2162352A

GB2162352A - Space protection device

Info

Publication number: GB2162352A
Application number: GB8417865A
Authority: GB
Inventors: R M Picking; B Brown
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-07-13
Filing date: 1984-07-13
Publication date: 1986-01-29
Also published as: GB8417865D0

Abstract

A portable device for giving warning of intruders in a protected space. The device is free-standing and has a detector 14 mounted on a support 10. When the detector detects an intruder, it operates a flashing light alarm 32, or another type of alarm. A second detector 18 detects movement of the device itself and operates an alarm if the device is moved. <IMAGE>

Description

SPECIFICATION Space protection device Field of invention This invention relates to a space protection device for protecting against intruders. The device is intended to raise an alarm when an intruder is detected.

Background to the invention.

Intruder alarms are widely known and operate on a number of different technical principles. In the main however, the detectors of such alarms are mounted in a fixed position, at a position where it is hoped that intruders are bound to pass. There is however, a need for a form of alarm system which is portable and to which can be set up from time to time at any desired location.

Summary of the invention.

According to the present invention, there is provided a space protection device comprising a support, a first detector mounted in the support and sensitive to an activity field in front of the support, circuit means responsive to an output from the detector for generating an alarm signal from selected output signals therefrom; second detector means operable in response to any movement of the support to generate the same (or another) alarm signal and means for priming the circuit means and the detectors to render the device into an operating mode.

The support is preferably in the form of a post mounted on a base.

The first detector may be an infra-red detector mounted near the top of the post. Any suitable type of infra-red detector which is sensitive to the surrounding heat temperature may be used.

There may be a single such detector which can be "aimed" in a desired direction.

Alternatively a single detector may be mounted so that it can rotate about a vertical axis to maintain serveillance over a circular area around the device.

In a further alternative there could be more than one detector mounted on a support, with the different detectors "aimed" in different directions.

The device is preferably self-powered and may have batteries in the base. Conveniently the batteries are rechargeable, and a suitable charger may also be mounted in the base together with a mains socket to allow the device to be plugged into the mains to be recharged.

The second detector may be a mercury switch. The mercury will move if the device itself is moved, and open or close a circuit.

The circuit means may be an contained in a printed circuit board connected to the mercury switch.

The device may include one or more of a variety of different alarm-generating units. For example there may be a flashing light; there may be a built-in sound alarm generator or there may be a built-in transmitter with an aerial which transmits an alarm signal to a remote location.

Additionally, the device may be switched on/off by an attitude-sensitive switch which switches off when the device is laid on its side (after passing through an alarm-generating mode).

The invention will now be further described, by way of example, with reference to the accompanying drawing which is a schematic drawing of a device in accordance with the invention.

Detailed description of drawings.

The device shown comprises a post 10 on a base 1 2. The weight of the base 1 2 is sufficient to make the device reasonably stable.

A passive infra-red detector 14 is mounted near the top of the post. As shown, there is a single such detector which senses its surroundings through a window in a wall of the post.

Below the detector 14 is an anti-tamper printed circuit board 1 6 connected to a mercury switch 1 8. An attitude-sensitive on/off switch 20 is mounted somewhere on the shaft of the post 10. At the bottom of the post are the heavier components, namely an audible alarm emitter 22, rechargable batteries 24, a battery charger 26 and a transmitter 28. A mains socket 30 is also provided. At the top of the post is a flashing lamp 32.

To use the device, it is set upright on its base. The printed circuit board which generates alarm signals is arranged to allow the mercury switch 1 8 and the infra-red detector 1 4 time to settle down immediately after the device has been put into position. Thereafter, any change in the heat picture viewed by the detector 1 4 or any movement of the post 10 will cause an alarm signal to be generated either in response to a signal from the detector 1 4 or in response to operation of the switch 18.

Depending on the equipment actually available, the alarm signal may cause the transmitter 28 to emit an alarm signal to a remote location through an aerial 34, or the sound alarm 22 may be activated or the light 32 may flash (or all or any combination of these).

It is to be noted that the post 10 of the device is typically made of plastics material so that the internal aerial 34 can transmit without too much attenuation.

If the device is laid on its side, the mercury switch 1 8 will be activated to initiate an alarm. However, this will be a relatively short duration, because the on/off switch 20 will thereafter switch the power off from the detectors.

This free-standing self-sufficient device can be moved around to provide an intruder alarm at any desired location. For example if a particular area in a warehouse has to be protected, then it can be surrounded by some of these devices to protect the location. When not required, the devices can then be put on their sides and stored without any drain on their batteries.

Should it be necessary, additional weight can be provided in the base 1 2 by adding a suitable form of ballast.

Claims

1. A space protection device comprising a support, a first detector mounted in the support and sensitive to an activity field in front of the support, circuit means responsive to an output from the detector for generating an alarm signal from selected output signals therefrom; second detector means operable in response to any movement of the support to generate an alarm signal and means for priming the circuit means and the detectors to render the device into an operating mode.

2. A device as claimed in Claim 1, wherein the first and second detector means are arranged to generate the same alarm signal.

3. A device as claimed in Claim 2, wherein the first and second detector means are arranged to generate different alarm signals.

4. A device as claimed in any preceding claim, wherein the support is in the form of a post mounted on a base.

5. A device as claimed in Claim 4, wherein the first detector is an infra-red detector mounted near the top of the post.

6. A device as claimed in Claim 5, wherein there is a single detector which can be "aimed" in a desired direction.

7. A device as claimed in Claim 5, wherein a single detector is mounted so that it can rotate about a vertical axis to maintain surveillance over a circular area around the device.

8. A device as claimed in Claim 5, wherein more than one detector is mounted on the support, with the different detectors "aimed" in different directions.

9. A device as claimed in any preceding claim which is self-powered and has batteries in the base.

10. A device as claimed in Claim 9, wherein the batteries are rechargeable, and a suitable charger is mounted in the base together with a mains socket to allow the device to be plugged into the mains to be recharged.

11. A device as claimed in any preceding claim, wherein the second detector is a mercury switch.

1 2. A device as claimed in Claim 11, wherein the circuit means is contained in a printed circuit board connected to the mercury switch.

1 3. A device as claimed in any preceding claim, including a flashing light alarm signal.

14. A device as claimed in any preceding claim, including a sound alarm generator.

1 5. A device as claimed in any preceding claim, including a built-in transmitter with an aerial which transmits an alarm signal to a remote location.

1 6. A device as claimed in any preceding claim, wherein the device can be switched on/off by an attitude-sensitive switch which switches off when the device is laid on its side (after passing through an alarm-generating mode).

1 7. A space protection device substantially as herein described, with reference to the accompanying drawings.