Patent GB-190226640-A (GB)
Title: Improvements in Electrical Apparatus for Automatically Actuating Signals on and Stopping Railway Engines and Trains
Inventor: GERSTMANN HEINRICH
Filed: 1902-12-03
Granted: 1903-12-03
Abstract: 26,640. Gerstmann, H. Dec. 3. Signalling and communicating between trains; signals on engines and trains; stopping engines and trains; crossing-gate signals; contacts, electric.- Relates to electrical apparatus for actuating a signal. releasing or brake.applying mechanism on two trains, when they travel into dangerous proximity on the same line or at crossing tracks. The signal or brake-applying mechanism is operated, in known manner, by the diminution of a current through a circuit on the train, as, for example, by a galvanometer adapted to actuate an annunciator, or by a solenoid or other relay. The train circuit terminates in two shoes or brushes, which make contact with the contact rails or conductors 1, 2, Fig. 1, arranged along side the ordinary rails e. The conductors are divided into insulated sections, each connected to a battery a through resistances b, in comparison with which the resistance of the conductors is of little moment. With one train on a section, the full normal battery current passes through the train circuit ; but, with two trains on the section, only one-half the current passes through each train circuit, and the signals or brake-applying, mechanisms on both trains are consequently operated. At the boundaries g of each section, the ends 5, 7 of the conductors are overlapped to twice the braking distance of a train, resistances c, d being interposed in the overlapping branches, so that the total current strength in the overlapped parts is only equal to the normal current strength in each main conductor 1 or 2. Fig. 2 shows the arrangement for two crossing tracks. The conductors 1, 2 branch at 9, 10, the branches 13, 12 being led aside, or insulated underground &c., and returning, on the other side of the crossing, to normal position close to the rails e. The second branches 13<1>, 14 include impedance coils d, and form continuations of the main conductors. The conductors 1<1>, 2<1> of the cross-line are similarly branched at 9<1>, 10<1> into the deflected branches 18, 19 and the direct branches 20, 17. The conductors 13', 14 are connected to branches 15, 16 overlapping the conductors 17, 20, which are similarly connected to branches 27, 26 overlapping the conductors 13<1>, 14, the overlapping parts extending to braking distance on all sides of the crossing. If two trains travel on to the overlapped conductors 5, 7, Fig. 1, or on to any of the overlapped conductors, Fig. 2, each train receives a current diminished below the normal strength, and the train signals or brakes are operated. Where several lines cross, a branch from each conductor is overlapped with the direct branch of each cross line, the current strength in each branch being-reduced by resistances, so that the total strength is only equal to normal. Instead of employing resistances to diminish the current strength at the overlapped parts, the main conductors may each consist of several wires, of which some may be led aside at the overlaps, and the rest used as conductors. When a greater number of tracks cross, the crossing is preferably made into a block section, by including a separate battery or batteries connected to conductors, which extend on all sides to braking distance beyond the crossing. At foot crossings, the conductors 1, 2, Fig. 5, are connected to wires 41, 42, which, when the barrier 43 is open, as shown, are connected at the contact 30, so that the signal &c: on an approaching train will be operated. When the barrier is closed, the contact 30 is opened by the projection 31 on the post 32.