Patent GB-190601867-A (GB)
Title: Improvements in and relating to Electrically Operated Signals for Railways, Tramways, and the like.
Filed: 1906-01-24
Granted: 1907-01-24
Abstract: 1867. Allgemeine Elektricitõts - Ges. Jan. 25, 1905, [date applied for under Patents Act, 1901]. Semaphore &c. signals; controlling and locking signals. - Relates to electricallyoperated semaphore and like signals for railways, tramways, &c., of the kind in which solenoids are employed to move the signals. The power current is reduced for purposes of economy to a smaller "holding" value after the movement of the signal to the 'clear' position i completed, this being effected by a time-switch. Fig. 1 shows a mercury time-switch consisting of a vessel having two chambers k<1>, k<2> connected by passages l<1>, l'. When the chamber k is raised by the depression of the rod s, it takes an appreciable time for the mercury to flow into the chamber k<2>, and it is not until the greater part of the mercury has been so transferred that the vessel swings over sufficiently to break the switch contact Q. The mercury may itself make and break the circuit between two insulated contact points, but in this case a relay is preferably used to actaate the switch that breaks the short-circuit of the resistance used to reduce the power current to the holding value. As an alternative, a thermo-spring Tf, Fig. 5, may be used as a time-switch. The current received by the heating-coil Hz depends on the value of the resistance Tw. As soon as the spring Tf reaches a sufficient temperature, contact is broken at v, w, and the current through the solenoid Sf is reduced by the introduction into the circuit of the resistance W. The following part of this abridgment relates to subject-matter contained in the Specification in the original form as published under the Act of 1901, but not appearing in the Complete Specitication as accepted :- Locking-devices are provided for holding the signal in the 'danger' position. In the arrangement represented diagrammatically in Fig. 1#, the semaphore F is shown in the 'danger' position, to which it has been brought by its own weight coupled with the upward pull of the solenoid Sh. The signal is locked in this position by the device v, and the switch k breaks the circuit of the solenoid Sh. To lift the semaphore into the safety' or upwardly inclined position, the solenoid Sf is energized by moving the switch h over to the contact b. The lock v is first removed and the semaphore is then raised. After the movement of the semaphore is complete, a time-switch O breaks a short-circuit across the terminals of the resistance W, thereby reducing the current through the solenoid Sf. Fig. 2# shows the locking-device, which is diagrammatically represented at v in Fig. 1#. The locking-piece k is normally held by the spring f in engagement with the fixed pin e. During the downward movement of the rod N, the locking-piece is disengaged from the pin e. It subsequently abuts against the boss i and raises the semaphore. In the arrangement shown in Fig. 11#, the post carries three semaphores F<1>, each of which has an operating-solenoid Sf for setting it to safety.' Only one of the semaphores has a 'danger' setting solenoid Sh. The connexions are slotted as shown so as to provide for the known relation between interdependant signals.