| 摘要 |
<p>The securing mechanism is for ladders fixed in position by supports which can be extended and splayed to any position, without firm angle-setting connection between ladder and supports. Each stringer (2, 3) is linked movably to its support (4, 5) by a retainer strip (7) or cable, with one end firmly fixed to stringer or support and other end to a weight (10) or spring running in the other element, which is tubular. At the point of emergence from the tube, the strip runs across a two-armed swivelling lever (9). Tension on the lever end exerts a rotary moment, while the lower arm presses the strip against the tube walling, to arrest it. This prevents the relative setting of the elements from changing.</p> |
