GB180541A - Improvements in electric burglar alarms - Google Patents

Abstract

180,541. Polyp Ges. f³r Apparatebau der Feinmechanik Ges., and Wittwer, G. May 4, 1921. No Patent granted (Sealing fee nov paid). Burglar and like alarms. - When the safetycontacts 24 are closed, an alarm bell 17 is rung from a battery 14 and simultaneously a relay 2 is actuated to close a contact 3 whereby a solenoid 4 is energized from power mains 40. The relay 2 is brought into the bell circuit by means of a detent switch 29, which is released when the bell rings and there pon bridges the contacts 19, 28. A link 42 carried by the core 41 then opens an air valve 5, so that compressed air from a pipe 45 is admitted to sound hooters connected to the pipe 43. As soon as the hooters come into action, an arm 44 on the core 41 reverses a switch arm 35 so as to divert the power current from the solenoid to a branch circuit containing signal lamps 39. These lamps and the hooters remain in action until the arm 35 is restored to its original position. The solenoid 4 may be replaced by a spring which is adapted to be released by the action of the relay 2, and may also close a switch in the circuit of the lamps 39.