Classifications

• • G—PHYSICS
  • G08—SIGNALLING
  • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
  • G08B13/00—Burglar, theft or intruder alarms
  • G08B13/16—Actuation by interference with mechanical vibrations in air or other fluid
  • G08B13/1609—Actuation by interference with mechanical vibrations in air or other fluid using active vibration detection systems
  • G08B13/1618—Actuation by interference with mechanical vibrations in air or other fluid using active vibration detection systems using ultrasonic detection means
• • G—PHYSICS
  • G08—SIGNALLING
  • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
  • G08B13/00—Burglar, theft or intruder alarms
  • G08B13/02—Mechanical actuation
  • G08B13/04—Mechanical actuation by breaking of glass

Definitions

• the present invention relates to an alarm apparatus, Preferably in a window structure including at least one glass pane.
• One object of the present invention is to achieve an alarm function which is not triggered without proper cause and which cannot be forced by some penetration method without the alarm being triggered, while at the same time the alarm also functions on laminated multilayer structures. It is important that the alarm function is combined with a glass structure which takes a long time to force. When the alarm is triggered at the beginning of the break-in on the first attack attempt, much time and work must pass before the object comes accessible. This can usually only be achieved with multilaminated structures, and so far there has not been any satisfactory a.larm apparatus for such structures. In accordance with the invention it is possible to create a solution to the above mentioned problems with the aid of ultrasonics. The distinguishing features of the present invention are apparent from the accompanying claims.
• the risk of false alarm is minimum in the cases where the ultrasound is transmitted and registered in the glass pane in a multipane structure where the pane is inwards in the room or premises which is to be protected. If a laminated multipane structure is used, the risk of false alarm is even less, since the laminations can isolate the ultrasound solely to the inmost glass pane, simultaneously as each crack, hole or the like in the area of glass directly triggers the alarm. Naturally, the ultrasound can be used on other glass but a deteriorated function is then obtained.
• a window structure is illustrated on the drawing, and includes three glass panes 1-3, which ar e kept together by two laminate layers 4,5.
• a transmitter 6 of the ultrasonics type is mounted at a first place, preferably at the inner glass pane 1, i.e. on the inside 10 of the window structure, and so that it is bedded into the laminate 4 contiguous with the inner glass pane 1, the transmitter 6 preferably engaging directly against the actual surface of the glass pane 1 with one of its surfaces.
• a receiver 7 of the ultrasound sent in the glass pane 1 is mounter in an other place against the glass pane 1 for registering impulses received from this pane.
• An alarm unillustrated on the drawing is connected to the receiver 7 via connection cables 9, and the transmitter 6 is in turn connected via.
• connection cables 8 to an unillustrated, suitable source of energy.
• the window structure is conventionally mounted in a. rebate 11.
• the receiver 7 can also be placed in the laminate 4 contiguous to the inner glass pane 1 at a distance from the transmitter 6, and then suitably in an area of the glass pane 1 which is in the rebate 11.
• the transmitter 6 can send an ultrasonic wave with a secret pulsation so that it cannot be got past and the transmitter can be of the Pico crystal type.
• the transmitter 6 is suitably placed such that only one pane is subjected to the ultrasonic wave, if a multipane laminated window structure is used. If a single pane is used the risk of false alarm increases.
• the placing of the receiver 7 on the pane 1 should be made so that the best possible registration of the ultrasonic wave sent in the glass pane 1 is achieved, and thus the receiver should be at a suitable distance from the transmitter 6.
• the nature, size, thickness, resistance and impedance etc of the glass enables the ultrasonic wave, which is sent from the transmitter 6, to be received in the receiver 17 in a certain way.
• the transmitter 6 is preferably fused tightly against the inner pane 1 for sending the ultrasonic wave in the best way through the pane.
• the laminate layer 4 also beds in the transmitter crystal so that the ultrasonic wave can penetrate into the outer panes 2 and 3 to the minimum extent. In this way the risk of false alarm is limited to a minimum, since exterior damaging action is not capable of affecting the impedance in the innermost pane 1.
• the system can be compared with a swimming pool where a transmitter males waves in the water. The waves are deflected against walls, the bottom, corners etc and create a certain wave state depending on the resistance in the water, walls etc, which can be regarded as the impedance of the pool.
• the entire wave movement pattern 15 changed, which is registered by the receiver or receivers.
• the change triggers the alarm. If the pool leaks over to an other pool, via a channel, the change can act on the inner basin so that an alarm is triggered.
• the electronics can remedy this phenomenon by adjusting the time factor upwards or downwards.
• the outmost pane 3 does not actuate the alarm if a hand is laid on it, as is the case when a single glass pane is used, and thus a false alarm is practically completely excluded.
• Each crack, hole or the like in the glass packet does trigger the alarm, however.
• the electronics can also be combined with other sensing patterns than ultrasonics for further improving the function of the alarm.
• a transmitter 6 or a receiver 7 can also be placed on the edge or short side of the pane 1 or the panes 2, 3.
• the ultrasonics used can of course be replaced by impulses of some other kind, which can be transmitted and received by the intermediary of at least one glass pane included in a window structure, or by a similar sheet-like element.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Burglar Alarm Systems (AREA)
• Joining Of Glass To Other Materials (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20367784

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (1)

Citations (7)

• 1987
  • 1987-03-06 SE SE8700952A patent/SE456951B/sv not_active IP Right Cessation
• 1988
  • 1988-03-07 DE DE88902594T patent/DE3884943T2/de not_active Expired - Fee Related
  • 1988-03-07 WO PCT/SE1988/000105 patent/WO1988006774A1/en active IP Right Grant
  • 1988-03-07 EP EP19880902594 patent/EP0349565B1/de not_active Expired - Lifetime
  • 1988-03-07 AU AU13978/88A patent/AU1397888A/en not_active Abandoned
• 1989
  • 1989-09-05 FI FI894188A patent/FI98964C/fi not_active IP Right Cessation

Patent Citations (7)

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