FR2535877A3 - Method and installation for monitoring closed premises and alarm. - Google Patents

Abstract

The method for monitoring the exits from premises consists in placing, at each exit, a sound source emitting an acoustic signal, in the event that the exit is opened, and in providing a listening post sensitive to the said acoustic signal and triggering an alarm signal. Application to monitoring premises.

Description

Method and installation for monitoring a closed room and alarm.

 The invention relates to a method and an installation for monitoring a closed room, and for alarm, and, more particularly, for monitoring the exits of a room and for alarm in the event of the opening of at least one these issues.

 The problem of detecting break-ins or attempted break-ins with a view to triggering an alarm comes down in practice to a problem of monitoring exits from a room to be protected. To monitor these exits, vibration detectors are generally placed or electrical contacts modifying the state of a circuit in the event of relative movement of mechanical parts during the opening of a door or window, for example. The installation of these detectors or contacts requires the provision of conducting wires responsible for routing a signal to the alarm center, and ensuring the electrical supply of the detectors or contacts which, in the standby state, are still on.

 This results in two consequences which can be considered as disadvantages. First of all, the supply of detectors results in an energy consumption which increases with the number of exits to be monitored. Then, the presence of the conductors can constitute a nuisance for the user of the installation, and can in certain cases, allow an intruder to neutralize a detector or even the power plant by electric means.

 An object of the present invention is to overcome this wire connection between the issues to be monitored and the alarm center.

 Another object of the invention is to dispense with the supply of detectors by providing a system for monitoring the exits which does not use electrical devices.

 The subject of the invention is a method of monitoring the exits of a room and of triggering an alarm in the event of the opening of at least one of these exits, consisting in placing at the right * of each exit a sound source emitting a acoustic signal when the exit is opened; and to provide a monitoring center, sensitive to the acoustic signals emitted by the sound sources, to trigger an alarm signal.

 The invention also relates to an installation for monitoring the exits of a room, and for triggering an alarm in the event of the opening of at least one of these exits, characterized in that it comprises: at the right of each exits, a sound source emitting an acoustic signal in the event of the opening of the exit; and at a distance from the exits, at least one monitoring center, sensitive to the acoustic signals emitted by the sound sources, to trigger an alarm signal.

According to other features of the invention
- the sound sources are pyrotechnic sources each comprising at least one firecracker, or primer;
- listening centers have an acoustic bandwidth of around 1,000 Hz, centered on 10,000 Hz
- The number of firecrackers or primers of each pyrotechnic source is preferably equal to four.

 According to the present invention, a pyrotechnic source is arranged at each exit from the room to be monitored. This source comprises for example four conventional primers, placed under a protective plastic sheath.

 The explosion of the primers is caused by a mechanical trigger at the opening of the exit. The primers in principle all explode at the same time by emitting specific acoustic signals.

 These signals are received by one or more monitoring centers located for example in the room. The bandwidth of listening centers is centered on 10,000 Hz for example, and its bandwidth is around 1,000 Hz.

After having received acoustic signals corresponding to this bandwidth, the monitoring center triggers, by any suitable conventional means, an alarm signal which can be audible and audible immediately, or transmitted remotely by cable or over the air.

 The invention is simple to carry out because it only comprises rustic and inexpensive elements. Pyrotechnic sources are easy to use and easy to replace after use. They require no maintenance, and remain effective for a very long time. In addition, they provide a usable signal when their volume is very small and they do not require any power supply.

 There is no wire connection between the monitoring station and the pyrotechnic sources, which allows the construction of monitoring installations of ~ very variable geometry.

 Finally, the monitoring installations according to the invention can either deliver an alarm signal on the spot, or remotely transmit an electrical alert signal capable of being exploited.

Claims (5)

REVLNDICATIONS  1. - Method for monitoring the exits of a room and triggering an alarm in the event of the opening of at least one of these exits, consisting in placing at the right of each exit a sound source emitting an acoustic signal in the event of opening of the issue; and to provide a monitoring center sensitive to the acoustic signals emitted by the sound sources, in order to trigger an alarm signal.  2. - Installation for monitoring the exits of a room, and triggering an alarm in the event of the opening of at least one of these exits, characterized in that it includes, at the right of each exit, a sound source emitting an acoustic signal when the Exit X is opened and at a distance from the exits, at least one monitoring center sensitive to the acoustic signals emitted by the sound sources, to trigger an alarm signal.  3. - Installation according to claim 2, characterized in that the sound sources are pyrotechnic sources each comprising at least one firecracker, or primer.  4. - Installation according to claim 2, characterized in that the monitoring centers have an acoustic bandwidth of about 1,000 Hz, centered on 10,000 Hz.  5. - Installation according to claim 3, characterized in that the number of firecrackers or primers of each pyrotechnic source is preferably equal to four.