| 摘要 |
The staircase comprises hinged stair sections, the top one being hinged to a frame (2) fastened to the ceiling. A device (4) is provided for holding the staircase extended and returning it to the retracted position. The device includes two guides (5) each with one end pivotally attached to the stringer ends of the top stair section (1). Two bolts (7) are fixed to the frame via a plate (9) and cooperate with an elongate groove (10) at the other ends of the guides, to allow vertical guide movement. Two return springs are each connected to a retainer (12) fixed to the plate and to the guide adjacent its connection to the stringer end.
|
