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A water inflow impervious manhole cover assembly includes a molded non-metallic frame, an imperforate manhole cover and a fastening mechanism releasably interconnecting the frame and the cover. The frame includes an annular peripheral frame wall defining a cover-receiving seat with a radially inward

A water inflow impervious manhole cover assembly includes a molded non-metallic frame, an imperforate manhole cover and a fastening mechanism releasably interconnecting the frame and the cover. The frame includes an annular peripheral frame wall defining a cover-receiving seat with a radially inwardly extending lip having a seating surface with an annular sealing channel formed therein. The fastening mechanism includes cams rotatable relative to the frame between a locked position wherein the cams engage the frame and an unlocked position wherein the cams are disengaged from the frame for removal of the cover. An annular watertight seal is formed between a bottom planar surface of the cover and the seating surface of the frame and a gasket retained within the annular sealing channel, when the cams of the fastening mechanism are disposed in the locked position.

대표청구항 ▼

1. A water inflow impervious manhole cover assembly comprising: a molded non-metallic frame comprising an annular peripheral frame wall having an upper end defining an access opening therethrough and a lower face upon which the frame sits on a supporting substrate, the upper end of the peripheral fr

1. A water inflow impervious manhole cover assembly comprising: a molded non-metallic frame comprising an annular peripheral frame wall having an upper end defining an access opening therethrough and a lower face upon which the frame sits on a supporting substrate, the upper end of the peripheral frame wall defining a cover-receiving seat therein, the frame having a radially outwardly extendedly extending rim with fastening points disposed thereon at circumferentially spaced apart locations;the seat including a radially inwardly extending lip circumscribing said access opening and having a seating surface with an annular sealing channel formed therein, the sealing channel receiving a gasket therein;an imperforate manhole cover received within the seat of the frame member and having a bottom planar surface which abuts the seating surface of the lip and covers the annular sealing channel;at least two adjustment risers disposed beneath the lower face of the peripheral frame wall for vertically spacing the frame away from the supporting substrate, and annular seal being disposed between at least two of the adjustment risers; anda fastening mechanism releasably interconnecting the manhole cover to the frame, the fastening mechanism including a number of cams rotatable relative to the frame between a locked position wherein the cams are matingly received within cam cavities formed in the peripheral frame wall such as to fasten the manhole cover to the frame, and an unlocked position wherein the cams are disengaged from the frame such as to permit removal of the manhole cover from the frame to expose said access opening, the fastening mechanism including fasteners for fastening the fram to the supporting substrate; andwherein an annular watertight seal is formed, between the bottom planar surface of the manhole cover and the seating surface of the frame having said gasket retained within the annular sealing channel, between the annular seal and the adjustment riser, and between the risers and the supporting substrate, when the cams of the fastening mechanism are disposed in the locked position, and when the fasteners extend axially through the rim of the frame at said fastening points radially aligned with the annular seal provided between the adjustment risers, through the adjustment risers, through the annular seal provided between the adjustment riser, and the into the supporting substrate. 2. The water inflow impervious manhole cover assembly as defined in claim 1, wherein the annular sealing channel defines a substantially frusto-conically shaped cross-section, the annular sealing channel having frusto-conical side walls such as to define a wider channel base with a greater radial width and a narrower open channel top having a smaller radial width. 3. The water inflow impervious manhole cover assembly as defined in claim 1, wherein each of the at least two adjustment risers comprises a transversely tapered ring having a flat surface on one side and an inclined surface on an opposed side, the inclined surfaces of each of the adjustment risers facing and abutting each other, the at least two adjustment risers being rotatable relative to each other about a common central axis such as to adjust an angular position of the frame relative to the supporting substrate. 4. The water inflow impervious manhole cover assembly as defined in claim 3, wherein the adjustment risers are retained together by an interlocking tongue and groove connection therebetween respectively formed in the inclined surfaces, the tongue and groove connection preventing relative lateral movement of the adjustment risers and the frame. 5. The water inflow impervious manhole cover assembly as defined in claim 4, wherein the interlocking tongue and groove connection between the adjustment risers is located at a radially outermost point of the transversely tapered rings. 6. The water inflow impervious manhole cover assembly as defined in claim 4, wherein an uppermost one of the adjustment risers is matingly engaged with the lower face of the peripheral frame wall by the tongue and groove connection to laterally retain the adjustment risers and the frame together. 7. The water inflow impervious manhole cover assembly as defined in claim 3, wherein the lower face of the frame wall includes a sealing assembly for sealingly engaging at least an uppermost one of the adjustment risers such as to prevent water ingress between the frame and the adjustment risers. 8. The water inflow impervious manhole cover assembly as defined in claim 7, wherein the sealing assembly includes at least one of an interlocking tongue and groove connection and an annular seal disposed between the lower face of the frame wall and the uppermost one of the adjustment risers. 9. The water inflow impervious manhole cover assembly as defined in claim 3, wherein the annular seal is disposed between each of the adjustment risers and between an uppermost adjustment riser and the frame, the annular seal preventing water ingress between the adjustment risers and between the frame and the uppermost adjustment riser, the annular seal comprising an annular channel formed therein within which is disposed a gasket. 10. The water inflow impervious manhole cover assembly as defined in claim 1, wherein the cams of said fastening mechanism are rotatably mounted to the manhole cover, the cams being rotatable about respective axes of rotation which are substantially perpendicular to the bottom planar surface of the manhole cover. 11. The water inflow impervious manhole cover assembly as defined in claim 10, wherein the fastening mechanism includes three or more of said cams equally circumferentially spaced apart around the manhole cover. 12. The water inflow impervious manhole cover assembly as defined in claim 1, wherein the frame is composed entirely of at least one of a structural rubber and a composite material. 13. The water inflow impervious manhole cover assembly as defined in claim 1, wherein the manhole cover is a composite material. 14. The water inflow impervious manhole cover assembly as define in claim 1, wherein the imperforate manhole cover is formed from a material selected from the group consisting of: cast iron; ductile iron; fiber reinforced polyester (FRP); glass-fiber reinforced polyester (GRP) high-density Polyethylene (HDPE); and concrete. 15. The water inflow impervious manhole cover assembly as defined in claim 1, wherein the annular seal provided between the adjustment risers includes an annular channel formed in an upper surface of each of the adjustment risers, the annular channel having a sealant therein and being radially aligned with said fastening points and therefore with said fasteners extending through the adjustment risers. 16. The water inflow impervious manhole cover assembly as defined in claim 1, wherein the fastening points are identified by fastening indicia disposed on the peripheral frame wall, the fastening indicia visually indicating a circumferential and radial location of each of the fastening points, such that a fastening bolt used to fasten the frame to the supporting substrate is insertable at each of said marked fastening points. 17. The water inflow impervious manhole cover assembly as defined in claim 1, wherein the frame includes a plurality of gussets angularly extending between the peripheral frame wall and a radially outwardly extending rim, the gussets being hollow and each defining a cavity therein so as to reduce a thickness of the frame member and thereby reduce a curing time of the moldable material during the molding of the frame and to reduce the overall weight of the frame. 18. The water inflow impervious manhole cover assembly of claim 17, wherein the peripheral frame wall has a height above the radially outwardly extending rim that is greater than that of the gussets, such as to define a gusset-free annular outer wall portion on an upper external surface of the peripheral frame wall. 19. The water inflow impervious manhole cover assembly of claim 1, wherein the cam cavities formed in the frame include a flat radially extending wall at one circumferential end of the cam cavity and a curved wall at an opposed circumferential end of the cam cavity, the curved wall providing a progressive opening into the cam cavity for receiving the cam therein and the flat radially extending wall providing a stop to prevent further rotation of the cam when the cam abuts against the flat radially extending wall.