Patent GB-190525955-A (GB)
Title: Improvements relating to Signalling on Railways.
Inventor: JACOBS CHARLES MARK
Filed: 1905-12-13
Granted: 1906-12-13
Abstract: 25,955. Jacobs, C. M., and Insell, R. J. Dec. 13. Contacts, electric and mechanical; controlling traffic on railways, staff and ticket systems for.- The signalling-arrangements described in Specification No. 12,661, A.D. 1905, are modified by the inclusion of a polarized relay in the engine circuit to give three instead of two separate indications as the engine passes the ramp, namely danger,' 'clear,' and no signal. The invention is.applied to a staff system and is described in connexion with the system described in Specification No. 1263, A.D. 1889. Fig. 1 shows engine apparatus, differing only from that of the prior invention in that the circuit from the ramp e<1> passes through the polarized relay g and not through the clear' signal, which in the case shown is the bell i. Switches are arranged so that the ramp e<1> can be connected to either pole of a battery e<2>, e<3> if the 'danger' signal is not to be given. The direction of the current through the relay g determines whether the 'line clear' signal is given, or whether the engine shall pass without receiving any signal, but in both cases the giving of a 'danger' signal is prevented by the energization of the magnet b. Fig. 2 shows the application to the staff system described in Specification No. 1263, A.D. 1889, the object being to allow a train to pass, after receiving a staff, from station B to station A without receiving a signal at the ramp D. The staff in-. strument is shown without its details; the magnet u, wbich ordinarily would unlock the staff when a current in the proper direction is transmitted, is now controlled by the polarized relay p, which is connected in the position usually occupied by the magnet u, and by the switch k, which is locked in its two positions by a magnet r in the local circuit controlled by the relay p. The operation is as follows, the train being supposed to proceed from B to A:-The operator at station A turns his switch 2 and closes a circuit from his battery n through contacts k<3>, k<4>, indicator m, and line, to station B, indicator m, and relay p. This current, if in the right direction, energizes the relay p and causes it to close the local circuit to the magnet r, which thus unlocks the switch k at station B. The contacts of the said switch are then moved by the operator to the position shown in dotted lines, and he also turns his switch 1, thus switching the magnet u into the line circuit through the switch 4, indicator m, switches 2, 1, terminals m', k<2>, k<1>, and magnet u, &c. A staff can then be withdrawn at station B, and the switches 3, 4 are turned to the dotted-line positions, while the switch 1 is automatically returned. The current from the line t then flows through the switch 4, relay p, and indicator m in reverse direction, thus de-energizing the magnet r and re-locking the switch k, which in this new position connects the battery o to the ramp D in such a way that the engine passing it receives no signal, since its polarized relay is energized to keep the clear' signal circuit open. The operator at station A can give either the 'danger' or the clear' signal by controlling the switch l which connects the battery s to the ramp. The handles of the switches k, l are interlocked, so that both batteries o, s cannot be connected to the ramp at the same time. The staff being inserted at station A on the arrival of the train enables a current to be sent to unlock the switch k, which can then be restored to its original position.