Folding stairs, especially light wooden stairs
AssigneeFakro Pp Sp. Z.O.O.
InventorsBoguslaw Kasinski, Bartlomiej Mos
Life of this patent
Estimating the term…
Abstract
There is provided folding stairs having three segments of ladder stairs connected to one another with hinges. The first segment of stairs is connected with an articulated joint to a door frame using hinge holders fitted on the inside wall of the door frame, such that, during unfolding of these stairs rotation axle of the first segment of stairs does not change its position against the door frame. A flap is suspended to the first segment of stairs with at least two pairs of connecting rods, which together with the first segment of stairs and the flap form four-bar linkage.
Claims15
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.
Dependencies are inferred from the claim text.