Patent GB-190412439-A (GB)
Title: Improvements in Electric Fire-alarm and the like Signalling Apparatus.
Inventor: HUBBER FRANK
Filed: 1904-06-01
Granted: 1904-07-21
Abstract: 12,439. Hubber, F., and Higgs, W. G. June 1. Indicators and annunciators.-Consists of a push, a continuously-ringing bell, and an indicator, a number of such instruments being so arranged in circuit that, when one of the pushes is pressed, the location of the call will be indicated, and an alarm given on all the other instruments in circuit. Fig. 2 shows an instrument with the numbered dial and the plate carrying the indicating-mechanism removed ; Fig. 3 shows the back of this plate, and Fig. 4 shows the connections. The instrument is described as one of an installation for twenty-nine rooms, and is intended for room 20. The circuit of a local battery 71, contact-maker 19, and an electromagnet 34 is completed by a push 61 placed under a glass cover, by a practice push 69 operated by passing a pin through a hole 70 in the cover, or by a thermostatic device 79. The magnet 34 attracts its armature 32 pivoted at 33, and thus removes a pin 35 which frees the clockwork-driven arm 25 and allows it to move over insulated studs 24. As soon as this arm reaches a stud which is connected with a lead 75,-there being twenty live studs in the instrument used in room 20, as shown, -a current passes from a line battery 72 through the revolving arm 25 and the lead 75, where it divides, one part passing through a relay 2 back to the battery, and another part through the terminal 67 and the relays of all the other instruments in parallel to earth, and back to the terminal 66. Each relay is thus made to close the circuit of its own bell 4, the current passing from the terminal 63, leads 77, 80, armature 6, lever 9, rod 12, contacts 20, 21, lead 81, armature and frame of relay 2, and the lead 82 to the terminal 64. On the first stroke of the hammer, a spring 17 acting on the rod 12 causes the lever 9 to slip from a pin on the armature 6 on to a spring 8, and at the same time the contacts 20, 21 and the switch 19 are opened, so that the magnet 34 and push 61, or its equivalent are cut out of circuit; the bell circuit now includes the battery 71, leads 77, 80, armature 6, spring 7, lead 83, lever 9, spring 8, leads 84, 82, and the terminal 64. Every time the revolving arm 25 passes over a live contact 24, an electromagnet 46 is thrown into the circuit of each local battery by the relays 2. The electromagnet 46 drives a ratchet-wheel 38, Fig. 3, through a pawl 40, and this ratchet-wheel with its pointer 39 passes, in the case considered, from the zero position to number 20 on the dial, indicating that the call has come from room 20. After a complete revolution of the arm 25, it is stopped by the pin 35 of the armature 32. To re-set the instrument, a knob 15 is pushed in ; this slides a bar 27 carrying (1) a rack 28 for winding the clockwork which drives the arm 25, and (2) a lug 58 taking against a slider 56, Fig. 3, which, through levers 50, 54, disengages the pawl 40 and dog 44, allowing the weight 49 to return the pointer 39 to its zero position. At the same time, the rod 13 through a bell-crank lever 10 pulls the rod 12 downwards, thus closing the contacts 20, 21 and switch 9 and raising the lever 9 on to the pin of the armature 6. In order to indicate in any room that there is a fire, say, in room 2, the contacts 24, instead of being joined in series, are connected to a number of studs 86, Fig. 6, arranged in a circle or straight line, so that, on covering two of them with a slider 87, the arm 25 passes over two live contacts only.