| 摘要 |
<p>Plastics tubes for use as guide rails are installed without the guiding surface being impaired by bolt or rivet heads. A longitudinal slits (2) is made at each fixing point along the length of the tube (1). These slits (2) terminate in circular holes to prevent any tearing of the pipe wall. These slits are then opened out to provide axis for a tube spanner (5) to tighten the fixing bolt (6) which passes through the opposite wall. On removing the spanner, the tube resumes its original shape.</p> |
