Safety cable system for aerial cable=ways - has line connected to battery and DC generator at opposite ends and to current flow magnitude and direction sensor

摘要

In an aerial transport system such as ski-lifts cable-cars etc. a derailment detector (2) is located at each support tower and its opening inserts a resistance (3) into the safety cable linking the upper and lower stations. A battery (5) at the upper station is connected to the cable via a ballast resistance (6) and switch (7). Leakage from the line to ground is represented by a further resistance (4). At the lower station a d.c. generator can be connected to the line via a detector indicating both the magnitude and the direction of the current flow. The generator can also be disconnected and the detector connected to a loading resistance so that a circuit is completed via the ground to the battery at the upper station. Such an arrangement permits various levels of current (in one or other of the two directions of flow) to be registered by the detector in such a way as to define normal and emergency conditions on the line. In the latter case, relay circuits disconnect power from the driving motor and appropriate time -delays and manual operations follow. The generator can recharge the battery via the line when the installation is out of use, e.g. at night.