Patent GB-190222570-A (GB)
Title: Improvements in or relating to Railway Signalling Apparatus.
Inventor: BEZER HENRY
Filed: 1902-10-16
Granted: 1903-10-15
Abstract: 22,570. Bezer, H. Oct. 16, A.D. 1901, [date applied for under Patents Act, A.D. 1901]. Semaphore signals lamp signals; controlling and locking signals; interlocking; indicators and repeaters, point or switch ; signalling and communicating between trains; contacts, electric.-Relates to railway signalling systems in which the signals are controlled and operated by electric means. Figs. 1 and 4 show the mechanism employed for operating a 'home' signal and a 'distant' signal on the same post. The rods 206, 207, which operate the usual semaphore arms and spectacles, are connected to the ends of a lever 249 pivoted on the end of the single actuating-rod 208, which is connected through the lever 220 and rod 219 to the crank 218 on the shaft 214. The lever 220 is pivoted on the upper end of the lever 221, which is itself pivoted near its upper end and carries at its lower end the armature 224 of the electromagnet D. When the electromagnet D is energized, it holds the lever 221 so that the cranks 218 can operate the signals, thus acting as a clutch magnet. When it is de-energized, the lever 221 is free to tilt on its pivot, and the signals remain at, or are returned by their counterweights &c. to, danger.' The shaft 214 is driven by the gearing 213 from the shaft 211, which has a resilient driving-connection with the wheel 210, this wheel being driven from the shaft 209 of a suitable electric motor &c. The resilient driving-connection consists of a spiral spring connected to the wheel 210 and to the shaft 211, and permits the motor to attain speed before the signal-operating mechanism is started, the subsequent driving movement being effected by the right-hand end of the part-ring 216 on the wheel 210 engaging the crank-pin 215 on the shaft 211. When the motor is de-energized, the spiral spring returns the parts to normal position, as shown, this movement serving to control an unlocking movement for the main shaft 214. Pawls 226. 227 respectively prevent forward and backward motion of the main shaft, by engaging the ratchet-wheels 224, 225 thereon, the pawl 226 being disengaged at the proper times by the cam 229 on the wheel 210 engaging the arm 231 on the spindle of the pawl. The pawl 227 has an arm 228, adapted to connect the contacts F in the motor circuit, each final opening of the motor circuit taking place at these contacts, so that sparking takes place at a point not relied upon for the initial closing of the circuit. The ratchet teeth in passing also produce a rubbing action, which serves to keep the contact surfaces clean. The distant-signal rod 207 is normally locked by the pivoted latch 259, 260, the first movement of the crank 218, after the circuits of the electromagnet D and the motor have been completed, forcing the rod 206 upwards to lower the home' signal. Near the end of this upward movement, the connections of the rod 206 lift the latch arm 260 and disengage the latch, so that the distant signal can then be put to safety,' by a further movement of the crank, when the circuits are in the proper condition for such movement. When the magnet D is de-energized, the signals are returned to ' danger ' by their counterweights. The return movement of the signals is retarded by annular brake magnets C, C', carried by spiders J, J<1> connected to the signal rods, and acting in conjunction with fixed disc armatures 242. If, when both signals are lowered, indicating ' two blocks clear,' the second block in front of the train becomes occupied, the distant' signal is put to ' danger,' the magnet D being de-energized, while the brake magnet C is more strongly energized, and serves as a clutch to hold the home' signal at ' safety.' The motor will also be energized and cause a forward rotation of the main shaft to force the distant' signal to ' danger,' in case its counterweight fails to effect this movement. The return of the home' signal is similarly ensured. Guide grooves and rollers are provided for the signal-rod connections, and act in addition to the ratchet mechanism on the main shaft to prevent the signals from being put to 'safety' by the weight of snow on the signal arms &c., and to prevent the ' home ' signal when at safety ' from lowering the distant' signal from danger.' Should the distant' signal from any cause fail to return to 'danger' when the magnet D is de-energized, the ' home' signal is still free to go to danger, and it becomes impossible to restore the actuating- mechanism to normal position until the ' distant signal has also been returned. The construction shown in Fig. 11 embodies a three-position signal such as is described in Specification No. 9494, A.D. 1898, in which the signal arm represents 'danger,' one block clear,' and two blocks clear,' by horizontal, oblique, and vertical positions, respectively. The spindle 197 of the signal arm is connected by the linkage 198, 199 to the operating-rod 208, and a single brake magnet C<2> is employed. Various arrangements, including relays, commutators, track and controlling circuits and batteries, for working both types of signal automatically by the trains, are fully described in the Specification. In some arrangements, the signal two blocks in advance of a train must be in condition to go to ' clear,' before the signal immediately in front of the train can give the two blocks clear' indication. In others, the signal two blocks in advance must be lowered before the signal immediately in advance can show two blocks clear.' The main commutator, which is varied in construction to suit the particular arrangement of working, is mounted on the main shaft 214, and works in conjunction with a series of fixed contacts and a movable contact f controlled by the signal rear relay. This relay consists of two opposed coils, and is combined with a similar switch rear relay G<2>, H<2>, as shown, when the signalling-circuits are put under the additional control of an indicator, switch lock, or similar switch-controlling means governing the entrance of a train from a siding to the block. The rails are employed as the con. ductors of the track circuits. The rails at the advance end of each block section are connected to a home-block front relay, energized when a train is in the second section in the rear, and to a home- and-rear-blocks front relay, energized (by a stronger current) when a train is in the block in the rear. At the rear end of each block section, the rails are connected to the signal rear relay, and, when a switch indicator, lock, or the like is employed, to the switch rear relay and the switch-controlling means. Sources of battery power are connected in opposition to the front and rear ends of the block, and are arranged so that, under certain conditions, a more powerful current is sent through the conductors at the rear end of the section, to ensure the operation of the relays at the advance end. Further provision is made, in addition to that described in Specification No. 16,198, A.D. 1902, also for preventing any of the signals from being held at safety by the action of foreign currents.