| 摘要 |
<p>The plastic access hole for cleaning waste water drainage systems, is connected to a pipe and has a lockable cover. The upper shaft edge is enclosed by the rim of the cover. Any fittings in the shaft susceptible to damage are protected. In the region of the upper shaft there is a reinforced region enclosed by the cover rim (4). The reinforcing material can be a metal (1) and is firmly connected with the shaft wall. The reinforcement is placed close to the inner surface of the shaft edge and also forms the top face of the shaft rim.</p> |
