Patent ID: 9435126
Filing Date: 2016-09-06
CPC Classification: E04F

Claim Text:
1. A downwardly opening, folding stairway, for installation in a ceiling of a building, comprising: a flap pivotably connected to a door frame via at least one hinge mechanism, the flap for closing an opening in the door frame mounted in the ceiling; ladder stair segments, including a first ladder stair segment and at least a second ladder stair segment, each of the ladder stair segments comprising stringers pivotably coupled by high-axle hinges located at joints between said ladder stair segments; and a plurality of connecting rod assemblies pivotably coupling the flap to the first ladder stair segment, the plurality of connecting rod assemblies providing at least two four-bar linkages; wherein each of the connecting rod assemblies includes a first member having a first and a second end and a second member having a first end and a second end, the first end of the first member pivotably coupled to the first ladder stair segment, the second end of the first member pivotably coupled to the first end of the second member, and the second end of the second member non-pivotably affixed to the flap; wherein, when moved into a folded position, the connecting rod assemblies are configured to move the flap proximate the first ladder stair segment; and wherein, when moved into an unfolded position, the connecting rod assemblies position the flap away from the first ladder stair segment; and wherein a major longitudinal length of the first ladder stair segment remains substantially parallel to a major longitudinal length of the flap while moving between said positions.