| 摘要 |
The device has a peripheral watertight joint (8) of an elastomer material arranged on a horizontal blade (2) of a frame bordering an opening and proximate to a vertical blade (3). A cylindrical watertight joint (9) is mounted between two vertical walls (5) facing one on another with a manhole cover (4). The cylindrical joint has an end with a joint arranged on the corresponding horizontal blade of the frame. |
