Patent GB-190101929-A (GB)
Title: An Improved Electric Burglar or like Alarm.
Inventor: FREED HENRY FELIX
Filed: 1901-01-28
Granted: 1901-10-12
Abstract: 1929. Freed, H. F., Freed, I., and Spring, S. 0. Jan. 28. Alarms, burglar and like.-Relates to an electric alarm system for the protection of safes, vaults, houses, &c. Fig. 1 shows diagrammatically the application of the system to a safe &c. A, which is equipped with inrer and outer doors, fitting respectively to the jambs a, b, the walls c, d of the structure being separated by an insulating- layer e. The contact 15 in the jamb a is normally open, and is closed when the inner door is opened, while the contact b<1> in the jamb b is normally closed, and is opened when the outer door is opened. The system comprises the main switchboard P, the switch-box D, which is furnished with a locked door, the primary signal-box 1 located inside the building, and the auxiliary signal-box 2, which may be located on the outside of the building, or at a police station, &c. Each signal-box contains an alarm bell B and a signal lamp C, which may be mounted in the chambers 99<c>, 99<d> of the door 99<a> of the box, as shown in Fig. 5. The partition 99<b> of the door may be furnished with a reflector 99<j>, to direct the light from the lamp C through the aperture 99<f> in the base of the chamber 99<d>. The door is perforated at 99<g> for the emission of the sound. The main circuit 10 is energized from a suitable generator at W, and is normally closed through the switch T, the fuses S, the lamps Q, R, which show that the circuit is in order, the electromagnets 9, 8, the armature 7<1> of the electromagnet 7, the electromagnet 6, the latch K and armature G of the electromagnet F, and the contact b<1>. Should the outer door of the safe &c. be opened, the circuit 10 is broken at the contact b<1>, and the armatures of the electromagnets 6, 8, and 9 fall. The armatures 6<1>, 8<1> complete the circuits of the bells B and lamps C in the signalboxes 1, 2, while the armature 9<1> completes the circuit 11 through the electromagnet F, the armature G of which is attracted and releases the latch K from its hook M. The latch K then falls and breaks the circuit 10, so that the alarm continues even if the door of the safe &c. be closed again. The latch K can be reset by an authorized person opening the door of the switch-box D, and actuating the resetting arm 0, N. The arm N and the switches 17, 25', 26<b>, 27<a> are placed outside a coverplate, which is inside the door of the switch-box. If an unauthorized person obtains access to the switch-box, and attempts to cut out the alarm mechanism by reversing the switches, the movement of the switch 26<b> closes a shunt circuit 26 of the main circuit 10, with the results that the fuses S are destroyed, and the alarm mechanism is operated by the consequent breaking of the main circuit. If an attempt is made to drill the safe, the connection of the walls c, d complete the shunt circuit 26, 27, which will also destroy the fuses S. If the outer door of the safe &c. has been opened without operating the alarms, the opening of the inner door closes the contact 15 and completes the circuit 12 of the electromagnet 7, which then breaks the main circuit by attracting the armature 7<1>, and so effects the completion of the alarm circuits. The various wires to the switchboard P, including the extensions 12<1> of the circuit 12, are twisted or wrapped together, so that any attempt to cut them will short-circuit the system and actuate the alarms. The system can be put out of action by an authorized person opening the switchbox D, closing the switch 25<1>, which shunts the circuit 10 through the connections 25, and opening the switch 17, which makes the circuit 12 inoperative when the inner door of the safe &c. is opened.