| 摘要 |
<p>The device is used to level and stabilise a ladder 100 having mutually-spaced rungs 101, 103 extending between a pair of substantially parallel side rails 102. The device includes a pair of extensible hydraulic rams 1 secured to lower ends of respective side rails linked by a conduit establishing a fluid passageway between the rams. A fail-to-safe manually-operable valve is normally closed to hydraulically isolate the rams from each other. A backplate 10 is fixed to each side rail 102 to provide mutually- spaced upper and lower ram attachments 3 and 4. The upper ram attachment 3 includes a pivotal connection which attaches the ram to the backplate for angular movement in the plane of the ladder. The lower ram attachment 4 includes a pair of stays containing L- shaped slots arranged to hold the ram in an angular position relative to the backplate. The slots are also arranged to raise the stays when the rams are moved inwards to a stowed position.</p> |
