| 摘要 |
An apparatus for sealing a hole in a wall 4, the wall in use dividing a region of relative high pressure from a region of relative low pressure. The apparatus comprises an elongate stem 2 connected at one end to a sealing member 3, which extends substantially radially from the major axis of said stem in an extended state such that, in use, said relative high pressure acts to seal the sealing member in the extended state against the wall. The sealing member is resiliently deformable from said extended state into a collapsed state in which the sealing member is folded towards the stem, and into an everted state (Fig 5) in which the sealing means is folded away from the stem. Said sealing member, when in its extended state, may form a dome shape which acts to maintain an air gap around the hole during use. |
