Over a five-year period in the USA, there were at least 18 documented cases of ascending elevators striking the overhead structure. In some cases, the accidents resulted in serious injuries or fatalities. These accidents occurred on counter-weighted elevators as a result of electrical, mechanical, and structural failures. Elevator cars are fitted with safeties that grip the guide rails and stop a falling car; however, these devices do not provide protection in the upward direction. Rules and regulations applying to elevator safety have come under review in response to these accidents. Some governing authorities have already revised their regulations to require ascending car overspeed protection. Basic elevator design, hazards, regulations, and emergency braking systems designed to provide ascending car overspeed protection are discussed. A case-study report on a pneumatic rope brake system installed and tested on a mine elevator is also discussed.
展开▼
