Bank vault intruder alarm system - maintains overpressure inside enclosure and has electrical switch responding to pressure changes to actuate alarm

摘要

The break-in alarm system is for use with enclosed spaces, e.g bank vaults, safes, data stores, cars, etc. The enclosure is made air tight and an overpressure of underpressure is maintained in it by a compressor. The compressor may be situated inside the enclosure and be connected to the external air by a suction pipe. Alternatively the compressor may be mounted outside the enclosure. It acts together with a control device which measures the pressure within the enclosure. An electrical switch responds to changes in pressure within the enclosure to actuate an alarm. In the case of a car the compressor may be the air blower of the air conditioning system.