Folding fire escape stairway

Claim 1

IN COMBINATION WITH A WALL STRUCTURE HAVING AN EXIT OPENING FORMED THEREIN ELEVATED ABOVE A SUPPORT SURFACE DISPOSED BELOW SAID OPENING ON THE OUTSIDE OF SAID WALL STRUCTURE AND EXTENDING AWAY FROM THE LATTER AT LEAST ONETHIRD THE DISTANCE SAID OPENING IS ELEVATED ABOVE SAID SURFACE, A FOLDING FIRE ESCAPE STAIRWAY ASSEMBLY INCLUDING OPEN BOTTOM UPSTANDING HOUSING MEANS SECURED TO THE OUTER SURFACE OF SAID WALL STRUCTURE DEFINING A PAIR OF UPSTANDING GUIDES ON OPPOSITE SIDES OF SAID OPENING, AN ELONGATED STAIRWAY STRUCTURE INCLUDING TWO PAIRS OF LONGITUDINALLY EXTENDING AND GENERALLY PARALLEL OPPOSITE SIDE MEMBERS, A PLURALITY OF VERTICALLY SPACED GENERALLY HORIZONTALLY DISPOSED TREAD MEMBERS PIVOTALLY SECURED BETWEEN SAID PAIRS OF OPPOSITE SIDE MEMBERS FORMING A PARALLELOGRAM LINKAGE SYSTEM WITH SAID STAIRWAY STRUCTURE MOVABLE BETWEEN A COLLAPSED POSITION WITH THE CORRESPONDING SIDE MEMBERS ON EACH SIDE OF THE STAIRWAY STRUCTURE SPACED CLOSELY ADJACENT EACH OTHER AND SAID STAIR TREADS ALSO DISPOSED CLOSELY ADJACENT EACH OTHER AND AN EXTNDED POSITION WITH SAID CORRESPONDING SIDE MEMBERS AND ALSO SAID STAIR TREADS SPACED APART, SAID STRUCTURE BEING TELESCOPINGLY RECEIVABLE UPWARDLY THROUGH THE BOTTOM OF SAID HOUSING ONLY WHEN IN A COLLAPSED CONDITION, MEANS CARRIED BY THE UPPER END OF SAID STAIRWAY STRUCTURE ENGAGEABLE WITH SAID HOUSING MEANS WHEN SAID STAIRWAY STRUCTURE IS IN THE EXTENDED POSITION AND INCLINED DONWARDLY AND OUTWARDLY AWAY FROM THE LOWER PORTION OF SAID EXIT OPENING AND OPERABLE TO SUPPORT SAID UPPER END OF SAID STAIRWAY STRUCTURE FROM SAID HOUSING MEANS, THE UPPERMOST TREAD OF SAID STAIRWAY STRUCTURE BEING GENERALLY HORIZONTALLY DISPOSED AND ALIGNED WITH SAID SPACED OUTWARDLY OF THE LOWER EXTREMITY OF SAID OPENING WHEN SAID STAIRWAY STRUCTURE IS IN THE EXTENDED AND DOWNWARDLY AND OUTWARDLY INCLINED POSITION.