| 摘要 |
A manhole assembly including a frame and at least a pair of cover plates that are receivable in and disengageable from the frame to permit selective closing and opening of an aperture, the periphery of which is defined by the frame. The cover plates substantially occupy the aperture when received in the frame. A first cover plate of a pair thereof is smaller than a second cover plate of the pair. The first cover plate is hingeable relative to the second cover plate, while the latter is received in the frame, from a closed position received in the frame to an open position in which a first part of the aperture is open. The second cover plate is removable from the frame, when the first cover plate is disengaged from the frame, to open a second part of the aperture. |
