Patent GB-138968-A (GB)
Title: Improvements in or relating to signalling systems for use in mines and for similar purposes
IPC: B66B19/06
Filed: 1919-01-20
Abstract: 138,968. Sterling Telephone & Electric Co., Bell, F. G., and Davey, W. C. Jan. 20, 1919. Mine signalling systems.-A mine signalling system is provided with means for sending an emergency stop signal and simultaneously cancelling existing signals. When several levels are concerned, the sending of the emergency stop signal disconnects all the other onsetters, in order that the onsetter sending such signal may be the only person able to cancel such a signal. Specifications 13062/14, 108,373, 112,497, and 115,590 are referred to. The depression of the emergency key EK, Fig. 1, energizes a relay SR which locks up over a contact SR2 and a contact c of the main signalling-relay R in such a manner that the energization of the relay R by the sending of an ordinary signal cancels the emergency stop signal A. The circuit of the stop signal A is closed at the contact SR1 of the relay SR, while a contact SR3 of this relay cancels the existing signals on the indicator. To indicate the origin of the emergency stop signal, the depression of the emergency key EK, Fig. 2, energizes the level indicator relay over the main signalling-line L' and a relay ER over the line L. The operation of the relay ER opens the circuit of the main signalling- relay R at the contact d, locks itself up over contacts f, g, and energizes the relay SR over contact e. The relay SR locks itself up over contact h and contact k of relay R, closes the circuit of the stop signal A at contact SR1, and opens the contact SR3 to cancel existing signals on the indicator. Fig. 3 shows the invention applied to the arrangement shown in Fig. 1 of Specification 112,497. When the key EK is operated, the relays ER, R1 are energized initially in series; but the operation of the relay ER short-circuits the relay R1 at the contact m., opens the circuit of the existing signals at contact n, closes a locking- cirouit for itself over contact f and contact 2, and energizes the relay SR of the stop signal A over contacts e, k. Fig. 4 shows the invention applied to the arrangement shown in Fig. 2 of Specification 112,497. When the key EK is operated, the level relay OR1 is energized over one of the contacts of the relay CR. The relay OR1 operates to energize the impulse relay R1 over the contacts 116, 117 of the relays OR3, OR2 respectively, and the contact 120 of the relay OR1. The operation of relay R1 energizes the relay SR over its contact p, contact 121 of relav OR1, indicator 149, and contact 02 of key OK1. The relay SR operates to complete a locking-circuit for itself and relay R1 over contact q, to energize the stop signal A over contact SR1, to open the circuit of existing signals at contact SR3, and to energize the cut-off relay CR over contact r. The energization of the relay CR breaks the circuit of the level relays OR1, OR2, OR3 at its front contacts, and closes the circuit of the " engaged " indicators 142, 145, 149 at the various levels. The stop signal may be cancelled by the next signal of the onsetter sending the stop signal, since the hold-up circuit of the relays SR, R1 is broken at the contact 02 of the key OK1. The operating-element of the emergency switch may consist of a plunger t on the lid of the usual signalling-switch, this plunger being normally covered by a pivoted hood v; or it may be operated by a pull device on the lid.