Patent ID: 6962235
Filing Date: 2005-11-08
Classification: A62B

Abstract:
1. An evacuation apparatus for enabling a person within a prescribed weight range to descend from an origin at a predetermined height in a multistory building to a lower supporting surface and to attain a descent speed of less than four feet per second to land injury-free, the apparatus comprising: a harness securable to the person; a housing affixed to the harness; a cable within the housing, of predetermined length sufficient to reach from the origin to the lower supporting surface, the cable having a free end which includes a securing member for attaching the free end to a fixed anchorage proximate the origin; and a descent-slowing energy-dissipating mechanism within the housing, driven by the playout of the cable from the housing as the person descends, which enables the person to attain automatically within his descent a descent speed of less than four feet per second without the person's control, the descent speed being determined by the intersection of the graph of the curve that describes, for the amount of remaining cable, the rate of energy dissipated as a function of the descent speed and the graph of the line that describes the rate of potential energy released by the total amount of descending weight as a function of the descent speed, and where the slope of the graph of the rate of energy dissipated curve exceeds the slope of the graph of the rate of potential energy released line in the vicinity of the intersection.