| 摘要 |
A safety ladder comprises a vertical central ladder stringer and a plurality of horizontal rungs attached thereto, wherein the central ladder stringer has a substantially C-shaped cross section with a front longitudinal slot, a rear transverse piece lying opposite to the longitudinal slot, this rear transverse piece having rounded longitudinal edges. The rungs are attached from the outside to the central ladder stringer and are bent with their free outer members forward. In order to provide a better distribution of the climbing forces without impairing any corrosion protection measures or obstructing the interior of the longitudinal slot, the rungs are provided with a preferably equal sided, trapezoidally shaped recess for the rear transverse piece, by which the rungs sit riderlike on the central ladder stringer contacting only in the vicinity of the longitudinal edges of the ladder stringer and the rungs are attached to the central ladder stringer by a fastening means. The fastening means preferably comprises at least one rivet which penetrates the rear transverse piece and the rung.
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