| 摘要 |
<p>The manhole cover is intended for a vertical shaft. The shaft ? forms a top shaft element (6), whose inner wall defines a shaft section. On the element is supported a cover frame (1), retaining the manhole cover with at least one intermediate equalising element (10). Then the frame is connectable downwards and inwards protruding extension (5) of the inner wall of the top shaft element. The extension is gripped by a spaced socket (3). The intervening space is filled with a flexible seal (7).</p> |
