| 摘要 |
<p>The post structure comprises two hollow coaxial tubular parts one extending from the other. It has a long weakened part (1) which helps the structure to be crushed. The two ends of the weakened sections are fitted into the two parts of the structure. The weakened section comprises two tubular parts (2) which have threads at their opposite ends and which are fixed to each other by a threaded fixing component (3).</p> |
