Quick opening manhole cover assembly
Patent 4279356 Issued on July 21, 1981. Estimated Expiration Date: 
November 1, 1999. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
November 1, 1999. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 1324981 1473408 2335309 2488524 2891694 2991904 3386612 3916800 Latching arrangement for manhole cover Patent #: 4175781 InventorsAssigneeApplicationNo. 06/090287 filed on 11/01/1979US Classes:220/314, Crossbar carries closure and serves as closure fastener404/25, Vault cover-closure49/465Releasable means on closureExaminersPrimary: Byers, Nile C. Jr.Attorney, Agent or FirmInternational ClassesF16J 13/00 (20060101)F16J 13/20 (20060101) AbstractA quick opening manhole cover including a clamping flange (16) which captures the ears (48) of a locking ring (46) upon rotation of the locking ring with respect to a manhole cover (40). The manhole cover has an O.D. less than the I.D. of the manhole for axial movement into the manhole. A gasket (42) about the manhole cover is clamped between the locking ring (46), manhole cover (40) and against the manhole surface upon axial movement of the manhole cover towards the locking ring.Field of SearchVault cover-closure | |
