| 摘要 |
<p>The rigidity of square or rectangular section tubing is ensured by internal bracing, thus providing strength while retaining the aesthetic advantages of a smooth outer profile. For hand assembly, two angle section pieces are welded back to back to form an X-shape, which is then slid inside the tube. Further strength is obtained by an assembly process suited to industrial production. An X-section length is formed and then cooled, while the tube is simultaneously heated. The X-section is then slid inside the tube, and when the tube cools it shrinks to give a tight fit over the X-section insert.</p> |
