| 摘要 |
A multi-way drainage inspection chamber has the side wall (12) of its polypropylene base portion (10) connected to a polypropylene extension portion (21) by means of a spigot and socket joint (22, 23) bonded or otherwise sealed, the lower end of the extension portion (21) having a flange (24) with outward and downward parts (28, 29) stiffened by webs (25), the spigot part (22) preferably being on the extension portion (21) so that a gap is needed between the spigot (22) and the webs (25) to receive the socket part (23), and the corners (30) of the webs (25) remote from both parts (28, 29) of the flange (24) are bevelled or rounded to provide a lead-in for the socket part (23). The hooked and webbed flange (24) both hides the spigot and socket joint (22, 23) and also affords adequate stiffness for the extension portion (21), whilst being simple to mould. <IMAGE> |
