| 摘要 |
A segmented adjustment riser for maintenance holes has a plurality of similar elongated one-piece segments. Each segment has two opposite ends provided with respective interengaging formations, and the segments are placed together end to end to form an endless riser member having planar upper and lower sides. The formations interengage and resist lateral displacement of each end of each segment relative to the adjacent end of each adjacent segment. The segments can be manufactured relatively easily and with greater economy than the corresponding one-piece riser member and facilitate handling and installation. |
