| 摘要 |
A ladder comprises a frame 2 designed to pivot between its upper and lower positions, to which frame foot-treads 3 are connected by means of hinges 9 which, in the frame's upper position, allow the foot-treads to lie in the plane of the frame, and when the frame is lowered to its lower position, allow the foot-treads automatically to swing out to an active position, projecting from and at right angles to the frame. The ladder frame 2 is connected to a horizontally mountable cassette 14 via two pivot pins 15 projecting laterally from the frame, each pin being engaged in its guide 16 in the cassette. At a distance from a stop 21 fitted at one end of the guides, a holding device 20 is arranged below the guides, whereby the holding device, the guides and the pivot pins force the frame 2 into one and the same plane as the cassette as long as the pivot pins are further from the said stop than the distance between the holding device 20 and the stop 21. However, they allow the frame to be lowered to its lower position as soon as the pivot pins reach the area between the holding device 20 and the stop 21. <IMAGE> |
