Improved Safety Devices for Guard Wires of Trolley Wires and other Conductors.

摘要

17,383. Munro, D. S. Aug. 30. Electric railways and tramways with safety appliances for overhead conductors. Conductors; switches. -Several arrangements of switches and connections for the trolley and guard wires are described. They are such that the feeder circuit is broken in case of breakage of the wires or short-circuiting by fallen wires &c., but not in case of failure of supply or variations of pressure in the feeders. In the various Figures, T, T' are the trolley wires, G, G1 the guard wires, P, P' the pilot wires, S, S' the feeder switches, F the feeder, and E earth or return connections. In Fig. 1, the switch S is broken by an excess current in the coil I, or by current through the coil H to earth when current, failing in the pilot wire and coil B, allows the switch C to drop. The coil has a laminated core to act quickly, or a weak spring allows the switch C to earth the coil H only momentarily. Preferably, however, the pilot magnets are wound with opposidg coils A, B, such as are shown in Fig. 2. Opposing coils A, B are also shown in Figs. 3 and 4, connected between earth and the guard and trolley wires, lamp or other resistances R, R1 being placed between the two wires and between the trolley wire and its coil to reduce the currents. Other arrangements are also made so that one safety appliance is used for two sections, and one form is shown in Fig. 5, where the coils act as a light armature L and a heavy armature H, the latter checking the former in case of excess current in either coil, but allowing it to act if one coil loses current. Various modifications and the action of the several appliances are fully oescribed in the Specification. Fig. 6 shows an appliance which may be used with the safety appliances described in Specification No. 2877, A.D. 1901. A small insulation carries springy wire loops L, A connected to the guard and trolley wires &c. and coming into contact when the normal pull between them ceases.