A great deal of concern exists with residents of high rise buildings and fire departments all over the world about fires in those buildings. In the event of a fire, electricity is often turned off, cutting power to the elevators. Although enclosed stairways are usually available, the pathway to the stairs may be blocked by flames, the stairway may be filled with smoke and fumes, or the person may not be able to walk down ten or more flights of stairs.
Fire departments have acquired aerial ladders to reach higher floors but these are usually limited to ten stories or thereabouts. Above ten stories residents cannot obtain help from the fire department. Even when the local fire department has a ladder with sufficient reach, it takes a lot of time for each person to be evacuated, there may be many people to remove, and, therefore, it may take too long to rescue everyone.
The basic principle of a see-saw like single rope lowering device is well known. Applicant is not aware of any lowering device utilizing a flat slotted cable, a gear and a speed control or escapement mechanism.
Known frictional escape devices have problems. These are:
(a) Problems with weather changing the frictional characteristics; PA1 (b) Frictional drag must be adjusted for the specific weight of the evacuee; PA1 (c) A frictional device descends and is no longer available for a second person without hauling up cable; and PA1 (d) There is no guide rope to avoid building obstructions, etc.