Ski lift monitoring

Abstract

A plurality of ski lifts are individually monitored and the information displayed at a central location for each of the ski lifts, and further displayed at a common location for all of the ski lifts. Each of the ski lifts is shut down in response to various unsafe conditions automatically with simultaneous production of a corresponding safety signal introduced in the common ski lift power control circuit, each of which safety signal is assigned a frequency or current so that it may be separated at a central location from other signals carried in the circuit for processing display. The safety devices will open switches to reduce the current carrying capacity of the closed power circuit and thereby disconnect the power to the ski lift drive while maintaining a substantially lower current carrying capacity in the circuit for passing the safety signals along the circuit to the central location. Such safety signals relate to cable derailment, excess cable slack or cable breakage, safety manual stoppage, passenger unloading failure, low gear box oil pressure, overspeed, and bullwheel derail, for example. The number of passenger carrying units, the number of passengers, and the number of loaded passengers carrying units per unit time are compared to obtain various efficiencies. At the central and common locations, the information is visually displayed and selectively printed for a permanent record on demand, periodically and automatically.

Dependencies are inferred from the claim text.