| 摘要 |
A self-levelling ladder has a pair of spaced-apart side rails and a plurality of spaced-apart rungs extending between the side rails. A pair of elongated sleeves slidably embrace the bottoms of the rails. Each sleeve has opposite sides. One of the sides has a plurality of spaced-apart teeth thereon. A pawl connected to each of the rails engages one of the teeth on one said sleeve.
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