Folding stowaway hinged attic staircase ladder - has guide rods and springs sharing bearing plates fixed to hatch frame

摘要

The attic staircase, which can be inserted and folded away, has stringers in the form of articulated shearing members, hinged to a hatch frame, and a trap-door, and external bolt-retained guide rods with slits and springs. The springs, engaging the guide rods and fixed to a frame component at the other end, are in the form of shank springs (12). On each side a shank spring and a guide rod are mounted on a common bearing plate (13) fixed to the hatch frame. The springs can be fitted concentrically round the guide rods bearing axis (16) and a rotatable and fixable socket (20) on the axis end can serve as a abutment for the spring end.