Patent GB-189903325-A (GB)
Title: Improvements in or relating to Railway Signalling and Switching Apparatus.
Inventor: BOULT ALFRED JULIUS
Filed: 1899-02-14
Granted: 1900-04-14
Abstract: 3325. Boult, A. J., [Continental Hall Signal Co.]. Feb. 14 Semaphore &c. signals; controlling and locking signals; interlocking; contacts, electric.-Relates to electrical apparatus for interlocking or controlling railway signals and switches, so that the operating-levers cannot be changed in position in either direction until the track switch has made its complete movement. The points and signals are operated and interlocked in the manner described in Specifications Nos. 3176 and 3597, A.D. 1899. Fig. 2 shows the arrangement of the switch-operating levers 4. Each lever is connected through a link 5 to a slide 2, on which is mounted a second slide 1, provided at each end with a lug 11. 12, Fig. 3. One or other of these lugs is engaged by the corresponding latch 13 or 14, when the slide 1 has been moved to mid-position from either reversed or normal position. On the movement of the slide 2, the slide 1 is also moved, through its spring connections 9, 10, with the slide 2, to the mid-position, where it is held by one of the latches, while the further movement of the slide 2 to the extreme position compresses the spring 9 or 10. The slide 2 is then locked by the pawl 18, to prevent the lever 4 from being again operated until the track switch has made its complete movement. When the switch has completed its movement, one or other of the electromagnets 15, 16 is energized and releases the corresponding latch 13 or 14. The spring 10 or 9 then moves the slide 1 to the extreme position, where the slide releases the pawl 18 and frees the lever 4 for another operation. The operating- circuits are completed between the contacts 56 or 59 and 55<a>, by the lever 55 operated by the lever 4. The set-screw 17 ensures that, when one latch is raised by its electromagnet, the other latch will be disengaged from the other electromagnet, so nullifying any effects of residual magnetism. The signal-operating levers are similarly controlled, but are locked by a single latch for one direction only, viz., towards the normal or 'danger' position. The latch is released by a current generated in the armature of the signal-operating motor, when the signal is going to 'danger' by the action of its counterweight. The distant signal circuit passes through a circuit-closer operated by the home signal, so that the distant signal cannot be reversed until the home signal has completed its corresponding movement. The electric gearing described in Specification No. 3176, A.D. 1899, for lowering the signals, is adapted to operate a pair of signals, by an arrangement of ratchet gearing on the motor shaft. One signal is lowered when the motor is rotated in one direction, and the other when the rotation is in the opposite direction. Fig. 9 shows a polarized relay for reversing the signal-operating motor. The tongue 43 is provided with two insulated arms 41, 42, which make contact with the posts 44, 45, or with the posts 46, 47. Fig. 8 shows a track relay, in which the armature 50 is mounted on a knife-edge 54, and counterbalanced by a weight 51 on an inclined arm. This mechanism can be adjusted to obtain any desired separation of the contacts 52, 53, and requires small battery power to work it. The electrical connections and operation of the various parts of the system are fully described in the Specification.