| 摘要 |
<p>The tube (10) made with an outer covering (12) of a shock-absorbing material, and has one or more lengthwise grooves (16) in its outer surface to receive inward facing lips along a lengthwise slot in the covering. Once the covering has been fitted to the tube it is held in place by a wedging strip (14) which pushes the lips apart to engage with the double dovetail surface of the groove. The outer covering (12) is made from an elastomer shock-absorbing material of an appropriate thickness, and in a variant of the design the wedging strip has hooks at intervals along its length to support a net.</p> |
