| 摘要 |
A frame and cover for road surface installations has a one-piece cast metal frame member with an aperture therein to receive a cover member which can be used for catch basins, maintenance holes, valve chamber covers and underground vaults. The frame member has a side wall which extends smoothly downwardly between the upper and lower faces of the frame member and is free from laterally outer projections. Vibrations from vehicles moving over the frame and cover are transferred downwardly to the structure on which the frame is supported rather than to the adjacent asphalt, thereby extending the service life of the asphalt surrounding the frame. The cover member preferably has at least one lug extending laterally outwardly from its outer wall, the lugs adapted to be received in corresponding recesses formed about the aperture of the frame member. The lugs and the recesses in the frame members are provided with holes to permit the frame member and cover member to be secured to one another by a mechanical fastener. The outwardly directed lugs on the cover member do not interfere with movement of personnel and equipment through the open aperture.
|
