Patent GB-190111667-A (GB)
Title: Improvements in or relating to Automatic Fire Alarm Systems.
Inventor: CORTLAND HARVEY
Filed: 1901-06-07
Granted: 1902-06-07
Abstract: 11,667. Cortland, H. June 7. Alarms, fire.-Relates to an automatic firealarm which transmits an alarm to a central station. Combined with the alarm apparatus is an annunciator to indicate the locality of the fire. The apparatus also indicates if a wire is cut or broken, or if the current supply fails. The connections of the switching-mechanism are so arranged that, in the normal position, the wiring of a building is all in series, while, if the conditions change, the connections are so changed that wires are in multiple. Fig. 8 shows the initial arrangement of the connections for an eight-floor house. The wire A runs in series through all the floors of the building, beginning at binding-post a and returning to the binding-post b. Commencing at the binding-post c and running through the first floor parallel with the series wire is an annunciator wire B, the return end of which is connected to the binding-post d, this arrangement being carried out throughout the various floors. The battery D is connected to the posts a and t. The current from the battery passes from the binding-post a through the series wire A to the binding-post b, thence to the brush 87, across the contact-plate 108 to the brush 86, through the electromagnet 53 to the brush 85, across the contact-plate to the brush 84 to the binding-post r through the annunciator of the eighth floor to the brush 83, and similarly through the annunciator wires of the other floors back to the binding-posts t and the battery. The magnet 53, when thus energized, sets an automatic switch ready to give an alarm in case of fire or a broken wire. Between the wire A and the annunciator wires are placed thermostats, such as 119, between the wires A and B. In case of fire, connection is made between the wires A and B by the expansion of a concave metal disc in the thermostat. This short-circuits the electromagnet 53, and releases the spring-actuated switch, which rotates the contact-plates into the position shown in Fig. 9. The result of this movement is that both terminals of each annunciator are connected to one contactplate, as the wire B to 99. The current from the wire A through the closed thermostat to the wire B passes to the contact-plate 99, thence by a connecting-wire to the plate 111, and then through the wire F to one of the magnets 2 of the annunciator, and thus (by rotating an index arm) indicates the locality of the fire. The current in the return wire G from the magnet 2 passes to the plate 109, then by a wire to the plate 106, then through the magnet 53, and then by the plate 107 to the magnet 56 on the indicator, this magnet actuating a device which releases the index arm. The spring switch, which changes the connections from the position shown in Fig. 8 to that shown in Fig. 9, is shown in vertical section in Fig. 2. The disc 36 is rotated, when released, by a clockspring 10 connected to the disc by a train of gearing. A stud on the underside of the disc 36 strikes a lever, which effects a displacement of the disc 5 on which contact-plates are mounted. The detent lever 42 is controlled by the electromagnet 63 and the spiral spring 45.