| 摘要 |
The fixing system consists of two brackets (2, 3) connecting the handle to rungs of the ladder, equipped with bushes in which the handle can slide vertically between its extended and retracted positions. The bush on the lower bracket has four grooves in it in diametrically opposite pairs, two of which are in the upper part of the bush only, while the other two pass right through it. The handle has a pair of diametrically opposite lugs (51) which can pass through one set of grooves in the lower bush and engage with the other, supporting the handle in its extended position. When the handle is required for use it is pulled upwards so that its lugs pass through the first set of grooves in the lower bush and is then rotated through 90 degrees so that lugs can rest in the second pair of grooves, providing a reliable support for a person starting to descend the ladder. The handle is returned to its original position by reversing the procedure. ADVANTAGE - Design simplicity and more convenient to use.
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