Auto life-saving ladder

An auto safety escape system which serves as a means of escape from a building in case of fire, having a plurality of escape ladders each comprising a movable ladder, a rewinding mechanism and a safety bar which are located adjacent to an aperture of an exit veranda on an exterior wall of the building, in which the movable ladder can be folded and unfolded, and comprises a plurality of laterally spaced guard-railings in front of the aperture of the exit veranda, guardboards and footboards extending between laterally spaced guardrailings to serve as a means of connecting the guardrailings and also serving as a staircase when the movable ladder is unfolded in case of emergency;

• the rewinding mechanism comprises a rewinding wheel on which is wound a steel wire connecting a plurality of guardrailings, an idle wheel and a speed reducing motor, the idle wheel movably located within a sliding hole defined by a fixed plate with its position adjustable within the aforesaid sliding hole between a position operatively engaging the speed reducing motor, a position operatively engaging the speed reducing motor and the rewinding wheel, so as to enable the rewinding and folding the movable ladder by the speed reducing motor and a position operatively engaging only the rewinding wheel, so as to enable the manual folding of the movable ladder an end of a safety bar engaging the rewinding wheel, so as to fix the movable ladder in a folded position, means mounting the safety bar such that it is disengageable from the rewinding wheel thereby enabling the movable ladder to drop downward and unfold itself by force of gravity until it reaches a next, escape ladder on a lower floor level the unfolding ladder causing the disengagement of the safety bar of the lower escape ladder so as to enable the movable ladder of that floor level to also drop downwardly and unfold itself under the force of gravity whereby this movement is repeated floor after floor until all ladders below the initial ladder are unfolded.