US 12,337,948 B2
Bifold stair system for aircraft
Michael John Seibel, Wichita, KS (US); Jamie L. Taber, Wichita, KS (US); and Sidney Aloysius Mohr, Clearwater, KS (US)
Assigned to Textron Innovations Inc., Providence, RI (US)
Filed by Textron Aviation Inc., Wichita, KS (US)
Filed on Feb. 2, 2023, as Appl. No. 18/163,757.
Claims priority of provisional application 63/305,806, filed on Feb. 2, 2022.
Prior Publication US 2023/0242238 A1, Aug. 3, 2023
Int. Cl. B64C 1/24 (2006.01); A47B 5/04 (2006.01); A47B 31/06 (2006.01); B64D 9/00 (2006.01); H01F 7/02 (2006.01)
CPC B64C 1/24 (2013.01) [A47B 5/04 (2013.01); A47B 31/06 (2013.01); B64D 9/00 (2013.01); H01F 7/0252 (2013.01); Y10T 403/32319 (2015.01)] 20 Claims
OG exemplary drawing
 
1. A stairway for an aircraft, comprising:
a first portion of the stairway having a stair side with a first plurality of steps, wherein a first end of the first portion is hingeably pinned to one end of a doorway frame on the aircraft;
a second portion of the stairway having a stair side with a second plurality of steps, wherein a first end of the second portion is hingeably connected to a second end of the first portion;
a plurality of mechanical resistance mechanisms incorporated to decelerate relative motion between both (i) the first portion relative to the doorway frame, and (ii) the first portion relative to the second portion, comprising:
a primary damper which is attached at one end to a location on the aircraft above the stairway and attached at another end to an upper location on the first portion of the stairway, the primary damper biasing the stairway towards a stowed configuration; and
one or more secondary dampers disposed on a backside of the first portion to damp during deployment and in stowing of the stairway, wherein the one or more secondary dampers bias the stairway towards the stowed configuration to provide resistance against a rotation of the second portion relative to the first portion of the stairway; and
wherein, in the stowed configuration:
the second portion of the stairway and the plurality of mechanical resistance mechanisms are housed entirely within a fuselage of the aircraft; and
a side of the first portion of the stairway which does not include the steps has an angled wall surface that fits a contour of a fuselage wall.