| 摘要 |
The shutter for a cover (2) set in a surrounding frame (1), e.g. let into a road surface, has hinges on which the cover can pivot when opened and closed. Each hinge comprises a fixed member (3) welded to the surrounding frame to receive a hinge pin (41) which also engages with a clearance with a rotating member on the cover. The rotating members of the hinges are attached to the cover by nuts and bolts so the cover can be detached when required. The cover can be optionally fitted with a gas cylinder to compensate for its weight. |
