GB161297A - Improvements in or relating to mine signalling or like systems in which the main signals are given by a number of impulses transmitted in succession - Google Patents

Abstract

161,297. Automatic Telephone Manufacturing Co., Ltd., and Remington, C. Jan. 9, 1920. Mine and colliery signalling systems; order apparatus.-Relates to the combination of a buzzersignalling and telephone system with mine-signalling apparatus operated by impulses, and. in particular to means for notifying to the operator when, after a group of impulses, sufficient time has elapsed to prevent the accumulation of signals. A time-lag device as described in Specification 118,330 is shown in Fig. 1, and consists of three slow-acting relays 15, 16, 17, of which the relay 15 is energized on receipt of a line impulse by the master relay 1, the relay 16 being energized by the action of 15, and relay 17 by the action of 16. When an impulse is followed by a sufficient pause to allow the relays 15, 16 to deenergize, the signal group is completed so that any further impulse will begin a fresh signal, as described in the Specification referred to. According to the present invention, a buzzing signal is given to the onsetter at the moment when the relay 16 has de-energized while the relay 17 has not. This is effected by the armature 2, on release, closing a circuit through the armature 3 and primary coil 4 of a buzzer with vibrating armature 40. The secondary 7 of the buzzer is in series with the onsetter's loud-speaking telephone receiver 9. Condensers 10, 12, prevent interference between the buzzer signals and the ordinary impulse signals. In a modification, a key is provided in connection with the buzzer for repeat or other signalling. A telephone set is added, the receiver at the engine-man's end being connected in series with the secondary 7, while the microphone, hook-switch, and local battery are in circuit with the primary 4.