| 摘要 |
<p>The invention concerns a blocking device for obstructing the opening of an inlet pipe in a sewer manhole, so that rats and like rodents are restrained. The blocking device comprises a ball or pear-shaped floatable blocking body for automatic blocking of the pipe opening by gravity when there is no flow of waste material into the manhole, said blocking body being pivotally suspended from a supporting means which by means of a tightening member is secured above the pipe opening by being wedged between opposite wall portions of the manhole. The blocking device also has a stopping means for limiting the penetration depth of said blocking body in the inlet pipe.</p> |
