Patent GB-111184-A (GB)
Title: Improvements in and connected with Electrically Operated Signal Indicators for use in Mine Haulage, Winding, and the like Operations.
Inventor: FORSTER JOHN PERCIVAL
IPC: B66B19/06
Filed: 1916-12-04
Abstract: 111,184. Forster, J. P. Dec. 4, 1916. Mine signalling systems.-In mine signalling apparatus of the kind in which a predetermined signal, such as men to ride," is visually recorded in the engine room until complied with, a switch is provided under control of the banksman whereby the transmitting-apparatus at any desired level may be put in communication with the engine room, the level in communication being visually indicated. The first signal impulse sent from any level cancels any previous signal shown on the receiving instrument but leaves a visual record if the cancelled signal is " men to ride," which record is only cancelled when complied with, and then only when the " men " signal has been confirmed on a second receiver by the banksman, and a danger signal is provided which can be operated at any time from any level. Arrangement also is made for independent signalling between banksman and engine room. Signals may be sent to the banksman's apparatus from the various levels by keys d having trip contacts f momentarily closed during the first, but not subsequent, movements of the key. Each impulse rings one of the bells a<2>, b<2>, c<2> corresponding to the level sending the signal, and at the same time energizes a relay serving to close the corresponding switch h<1> h<2>, h<3>. The banksman may signal to any level by a bell a<1>, b<1>, c<1> and a corresponding key e. A pivoted switch arm k can be placed in co-operation with any one of a number of radially disposed sets of contacts corresponding to the different levels, to put the desired level in communication with the engine room. An impulse bell r is rung at each change over of the switch k, and a level indicator s<1>, s<2>, s<3> corresponding to the position of the arm k remains energized until the arm is again moved. If signals are sent from the level corresponding to the position of the arm k, operation of the switch h<1>, h<2>, or h<3> transmits impulse to a bell p, and operates a relay switch y<2> whereby the impulses are registered on a stepby-step indicator y, momentary closing of the contact f in the first impulse having energized the release coil 1 and cancelled the previous signal. The banksman's signal is given by a key t<1> operating a bell u and a relay switch w<2> controlling an indicator z. Signals registered on the indicators y, z also are cancelled when complied with by any suitable engine-controlled device, such as is described in Specification 104,828, which energizes coils 5 closing switches 3, 4 in the circuits of the release coils 1, 2. When an indicator registers the " men " signal, a circuit is prepared through the armature 11 of the release coil, the indicating pointer, and a fixed contact 9. When the release coil is energized to cancel the signal, a coil in parallel with the release coil operates a quickacting armature 13, closing the circuit through a lamp 18 and coils 8, 17, before the armature 11 breaks contact. The coil 8 operates a switch 15 to close an alternative circuit so that the lamp and coils 8, 17 remain eneraized and a record of the " men " signal is retained. Coil 17 closes a switch 19 (or 22). The lamps 18 are extinguished when the signal is complied with by opening a normally closed switch 14 by means controlled by the engine. As described, the switch 14 is opened by a coil 20 shunted by an inductance 21, the circuit including a battery 24, a circuit-breaking device 23 (which may be a blade contact opened by a governor), and the switches 19, 22, which must both be closed before the cancellation can be effected. The current from the battery 24 is insufficient to open the switch 14, this operation being effected by the inductive discharge from the inductance 21 when the circuit is broken at 23. The engineman can signal on a bell t by a key u<1>. A danger-signal lamp G<3> is energized each time of the keys d, t<1> is depressed, the danger signal being given by holding down the key. The signals between the levels and the banksman may be mechanical instead of electrical, the switches transmitting the signals to the engine room being mechanically operated.