Patent GB-189910053-A (GB)
Title: Improvements in Apparatus for Controlling Traffic on Railways on the Staff System.
Inventor: THEOBALD CHARLES DANIEL
Filed: 1899-05-12
Granted: 1899-10-07
Abstract: 10,053. Theobald, C. D. May 12. Controlling traffic on railways, staff systems for- -Relates to apparatus for controlling traffic on single or double lines of railway on the staff system. Fig. 8 shows the internal mechanism and connections of the instrument employed at each end of a section, and Fig. 4 shows the form of the staff or authority K, (hereinafter called a "key"), which has the names of the section stations marked on its bosses or handles. The keys are arranged in a magazine formed by a horizontal prolongation of the vertical slot M, Fig. 8, of each instrument. For use on single lines, the terminals X are electrically connected by a metal strip. To issue a key at one station, say Y, for a train to proceed to the station, say Z, at the other end of the section, the operator at Y rings up Z, the needle of the polarized indicator gc of Z's instrument pointing to the white side of its dial at each stroke of the bell, and Z replies, the indicator of Y's instrument being similarly operated to show that the line is clear. Y then asks, by the bell code in use, for permission to withdraw a key, and Z in granting permission, by the operation of his plunger P, prolongs the last beat of the series. This causes the tongue 0 of the astatic relay A in Y's instrument to connect the contacts a<1>, a<2>, the tongue 0 being magnetized by the bell coil b. Y then withdraws a key K from his magazine and slips it down the slot M to the position K, 1, the shaft of the key actuating the lever V to break contact with the terminal d and to make contact with g, so completing the circuit of the magnet U, which withdraws the catch u from the rotating tumbler T. This allows Y to rotate the key into the position K, 2, the central boss of the key rotating the tumbler, and causing the pin t<2> thereon to actuate the switch lever R, which reverses the line connections by breaking the contacts n, s, and making the contacts n', s<1>. Y can now withdraw the key from the instrument, as shown at K, 3. If an attempt is made to issue a second key when the line connections are reversed, the indicator gc will point to the red side of its dial, and the tongue 0 of the relay A will move away from the contacts a<1>, a<2>, so that the circuit necessary for releasing the key will not be completed. The slot M is provided with guard plates, which prevent the withdrawal of the key except in the manner described. The insertion of the key in either instrument restores the line connections to their normal condition. The controlling- lever E of the tumbler T is connected by the spring f to a pin l<3>, which connects the contacts l<1>, l<2> in the line circuit. Should the spring break, the pin l<3> falls and breaks the circuit, so that a key cannot be issued until the fault is repaired. When a train does not stop at a block station, the key is placed in a clip on a wire loop or hoop, which is held by the signalman so that the driver can pass his arm through it, &c. For working double lines, the terminals X are connected to the indicator shown in Fig. 6. The key, when withdrawn from the single line instrument, is inserted in the slot M, Fig. 6, and rotated so as to raise the indicator slide S, which shows Cleared line,' or On line,' according to whether it is lowered or raised, the key being then returned to its own instrument. The slide is locked in its raised position by the electric lock EL and by the spring bolt BL. When the train arrives at Z, the operator there informs Y and holds down his plunger, on which Y slips his key down the slot M, Fig. 8, so as to cause the lever V to complete the circuit through the lock EL and release the latter. Y then withdraws the bolt BL, and allows the slide S to fall to its normal position. If one line is blocked through accident &c., the traffic can be worked through on the other line by the single line method. The instruments are enclosed in cases, which are provided with doors and covers suitably located to afford admission to the internal mechanism.