| 摘要 |
The removable seal apparatus 2, primarily for use in manhole shafts during construction or repair, comprises a body portion to which at least one first support element 3a-d is mounted so that it is movable between a first condition where it does not engage the shaft and a second condition where it engages the shaft in order to fix the apparatus in place. The first support element(s) preferably comprises a rod which is pivotally or slidably mounted on the body, which itself preferably comprises a substantially planar support surface 4. The body may include a longitudinal lip which is designed to engage the shaft. The apparatus may include one or more second support elements 6 movable between a folded and an unfolded condition, the second support elements preferably being triangular elements connected to the body by hinges 12 such that that apparatus has a substantially square footprint when the second elements are unfolded. At least one of the first support elements may be mounted to a respective second support element. The apparatus also preferably comprises a compressible gasket disposed on a first face of the body which can be compressed by a compressing plate so that it extends to provide a seal between the body and the shaft. |
