| 摘要 |
The wing piece (4) of the narrower ladder part, in the assembled position of the ladder, is located between the wing piece (3) of the wider ladder part, and fits against a cross component (5) joining the wider ladder part wing piece. This cross component can be a rung. The wing piece of the narrow ladder part also locates against stirrups on the inside of the wing piece of the wider ladder part. The recesses (10) on the inside of the wing piece of the wider ladder part have partly cylindrical bases (11) which, in the direction corresp. to the direction of movement of the pins (8) when the narrower ladder part (4) wing piece rotates or rolls around the wider ladder part wing piece connecting cross component, are limited by a surface (12) extending along a line (C) which is partly a tangent to the partly cylindrical surface. It is also partly a chord to a circle (B) with a centre (0) in the contact point between the narrower ladder part wing piece and the cross component (5). |
