| 摘要 |
<p>A tubular structure has an expandable section which is contracted to pass the structure through the channel which is to be sealed. The expandable section is then enlarged by relative movement of components of the structure in a sliding motion. This then allows the edge of the stopper to be clamped against the edge of the aperture which allows access to the walls of the channel which has been sealed. The expanding unit consists of a solid base with cylindrical walls split into blades and covered by a flexible sealing material which overlaps the top of the blades.</p> |
