EP 0219466 A2 19870422 - Improved apparatus for indicating the passage of an intruder across the boundary of a predetermined region.
Title (en)
Improved apparatus for indicating the passage of an intruder across the boundary of a predetermined region.
Title (de)
Vorrichtung zur Anzeige des Durchganges eines Eindringlings über die Grenze eines bestimmten Gebietes.
Title (fr)
Dispositif pour indiquer le passage d'un intrus à travers la ligne de démarcation d'une région déterminée.
Publication
Application
Priority
IT 6784385 A 19851004
Abstract (en)
The alarm apparatus for indicating the passage of an intruder across the boundery of a predetermined region comprises at least one pair of yieldable fluid-filled tubes (2, 4) for burying side by side along the boundary of the region, a diaphragm-type, two-directional differential pressure transducer (8) connected to one end of each tube and arranged to output an electrical signal as a result of the deformation of the diaphragm means (16a, 16b) caused by a difference between the pressures in the two tubes, valve means (22) mounted in at least one bypass duct (18) of the transducer and arranged to put the two tubes suddenly into fluid communication when the difference between the pressures in the two tubes exceeds a predetermined threshold value, and capillary means (24) which put the two tubes into fluid communication and are interposed in the bypass duct hydraulically in parallel with the valve means.
IPC 1-7
IPC 8 full level
G08B 13/20 (2006.01)
CPC (source: EP)
G08B 13/20 (2013.01)
Designated contracting state (EPC)
AT BE CH DE ES FR GB GR LI LU NL SE
DOCDB simple family (publication)
EP 0219466 A2 19870422; EP 0219466 A3 19881123; IT 1182588 B 19871005; IT 8567843 A0 19851004
DOCDB simple family (application)
EP 86830277 A 19861001; IT 6784385 A 19851004