Patent GB-190618279-A (GB)
Title: Improvements in and relating to Electric Railway Systems
Filed: 1906-08-14
Granted: 1907-07-04
Abstract: 18,279. British Thomson-Houston Co., [Kintner, C. J.]. Aug. 14. Electric railways on the sectional third - rail system, in which the track rails, one of which may be insulated and sectioned, and the wheels and axles of the cars automatically complete local lowvoltage circuits through switch-operating solenoids so as to connect the sections to the feeders, means being combined therewith by which the third rail in the rear of the car is prevented from being connected to the feeder, and warning-bells are operated. Switching-arrangements are also provided by which any two adjoining third - rail sections and the other corresponding parts may be joined in series relation so as to operate as one section, or any section of the third rail may be permanently connected to the feeder. Conductors; switches.-Figs. 2 and 3 show a double-track railway in which the third rails 3 are supplied with energy from the generator d through the feeder 4. The track rails 2 are sectioned and insulated, and electrically connected to the other track rails through solenoids n and batteries b. The connexion between the third rails and the feeder is normally broken by the springs shown, but, when a vehicle passes on to a section, the corresponding solenoid n is energized and the switch closed through the completion of the battery circuit by the wheels and axles of the car. To prevent the third rail behind the one on which the car is moving from becoming energized, a safety solenoid m, placed in series with the battery b and between the track rail section in advance and the earthed track rail 1, is adapted to act on an auxiliary arm of the main switch lever. This solenoid, acting along with the spring, is able to overcome the action of the solenoid n. Low-toned bells. u with parabolic reflectors are placed in parallel with the safety solenoids m so as to indicate to the drivers that there is a car upon the preceding section, and high-toned bells v placed in parallel with the solenoids n warn the public that that particular third rail is alive. The switches shown are in position for a car working on the middle section of the three shown on both tracks, the plain arrows indicating the main switch-operating circuits and the wavy arrows the safety solenoid circuits. When it is desired to lengthen any section, it is only necessary to reverse the switch s and open the switch r, the two adjoining sections then acting as a single section. The bells, in addition to acting as danger signals, also indicate when the batteries should be replaced or recharged. Figs. 5 and 6 show a modified arrangement in which both track rails are left continuous and a supplemental set of yielding sectional conductors 2 are used, connected up as shown. A second set of these conductors may also be used for the return circuit. In a further modification, an alternating-current circuit extends over the line, and converters placed at intervals corresponding to the sections have the primaries in multiple therewith, the secondaries being substituted for the batteries in the local circuits. Fig. 8 shows a modification of the arrangement in which yielding conductors are used. In this case, there are two sets of yielding conductors on the same support, the upper one forming a guard or protection for the lower one. The flanges of the passing cars complete the circuit by pressing the upper one against the lower one. In a further modification, the track rails and wheels and axles of the cars do not form part of the local circuits, the two yielding conductors being the two ends of the circuit which is completed when they are pressed together.