| 摘要 |
<p>A manhole head assembly (1) of the type having a substantially vertical axis and being intended to be mounted on a conventional manhole member (M) made of non-elastic material. This head assembly (1) comprises a stack of rings (R) substantially coaxial with said vertical axis, whose: a lower ring (11) made of non-elastic material and provided with a lower and an upper parts, the lower part being shaped to be stacked on an upper part of the aforesaid conventional manhole member (M); one or several upper rings (17) made of resilient elastomeric material and each provided with a lower and an upper parts, the lower part of each of said upper rings (17) being shaped to be stacked either on the upper part of the lower ring (11), or on the upper part of a neighboring upper ring (17) positioned underneath; means (31) for fastening the lower part of one upper ring (17) against the upper part of the lower ring (11); means for fastening the lower part of any of said other upper ring(s) with the upper part of a neighboring upper ring positioned underneath, when there is more than one upper ring; a manhole cover (23) provided with a lower (25), lateral(s) (27) and an upper parts (29); and means positioned in the upper part (21) of the upper ring (17) which is located at the top of the stack for receiving the lower (25) and lateral(s) (27) part(s) of the manhole cover (23) while positioning the upper part (29) of said manhole cover (23) substantially flush with the upper part (21) of this uppermost upper ring (17). A manhole ring (317) having an omnidirectional upper part (321) and a method of use of said manhole ring (317).</p> |
