| 摘要 |
The boring (2) is sealed using a plug (5) which has a mantle surface region (8) conically tapered towards its rear end (7), and which contains a channel (11) extending between its front and rear ends (6,7). At least one O-ring (18,19) placed around the conical mantle surface region can move with the plug when it is inserted into the boring, but which forms a tight seal against the plug when the latter is pulled out of the boring. |
