Vertically movable emergency egress system

摘要

An emergency escape elevator features a release device for releasing the elevator from its tethering cable, allowing the elevator to descend under the force of gravity. A vertical descent control apparatus controls the rate of descent of the elevator by measuring the rate of descent of the elevator and applying a brake to keep the elevator falling at a desired safe rate. The elevator guiderails are tapered inward at the bottom of the elevator shaft to apply friction to the elevator to slow it down. The elevator shaft can turn at the bottom and become horizontal to aid in slowing and stopping the elevator.