US 4,600,977 AGranted

Surveillance signal apparatus

AssigneeReinhold Barlian

InventorsReinhold Barlian, Martin Fischle, Karl-Heinz Lux

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Abstract

The surveillance signal apparatus is preferably provided a signal lamp, as an illuminated switch or as an illuminated key. It comprises a casing with electrical and electronic connections and with an apparatus heat disengageably disposed at the casing. The apparatus head comprises a signal part provided with electric voltage and preferably an illuminating element. A voltage limiter and a current limiter are disposed in an explosion-proof and pressure tight encapsulated space of the casing and they are electrically predisposed to the signal part in the apparatus head via a feed part. The apparatus head with the signal part and the feed part are formed by the output of the voltage limiter and by the output of the current limiter as an explosion protection self safety unit.

Claims19

Dependent claims

A surveillance apparatus comprising

electrical terminal connectors;
a casing providing an explosion-proof space having attached the electrical terminal connectors;
an apparatus head disengageable attached to the casing;
a voltage limiter disposed in the casing;
a current limiter disposed in the casing;
a feed part;
a signalling part disposed in the apparatus head and supplied with electrical power from the terminals of the apparatus head, where the voltage limiter and the current limiter are electrically predisposed to the signalling part via the feed part and where the apparatus head with the signalling part and the feed part from the output of the voltage limiter and of the current limiter are provided as an explosion-proof self-safety unit;
and
a printed circuit board disposed in the explosion-proof encapsulated space of the casing;
an electrical fuse disposed on the printed circuit board;
connections provided between the feed part of the explosion-proof self safety unit and the printed circuit board in the explosion-proof space of the casing.

8 more elements

Dependencies are inferred from the claim text.