GB479928A - Improvements relating to electric alarm systems - Google Patents

Abstract

479,928. Fire and burglar alarm systems. HAYES, S. M., and BAKER, R. M. Aug. 19, 1936, No. 9155. [Class 47 (i)] [Also in Group XXXVIII] An automatic fire and/or burglar alarm system comprises a series of thermal and/or interference switches and a series of indicator boards in the several rooms or sections of a building, and ' a central alarm, the arrangement being such that a fire or interference in any room causes a general alarm to be given, and also a locality indication in each room. As shown, a thermal switch T<1>-T<6> and an indicator board E are arranged in each room, and solenoid switches B<1>-B<6> are provided. If the switch T<1> is closed, circuits from the mains M are completed through the indicators 1 in all the rooms, and the solenoid B<1> is energized. Consequent closure of the solenoid contacts closes a circuit through a main solenoid A, the contacts of which then close circuits through general alarm gongs G and through the lamps C<1>-C<3> of an exit and direction sign C. If the building has two exits, two direction arrows are associated with the exit notice, and thermal switches T<7>, T<8> are arranged near the exits. If the switch T<7> is closed, the indicators F in all rooms are energized and the solenoid B<7> is energized, breaking the circuit of the lamp of the corresponding direction, arrow, and closing the circuit of the main solenoid A. In a combined fire and burglar alarm, the indicators may show, by distinctive colours or otherwise, what emergency has arisen, and the burglar alarm is not given in the room in which interference has occurred. Extension circuits L to outside alarms or to fire &c. stations may be provided. Specifications 18771/09 and 24183/10, [both in Class 40 (i)], are referred to.