Patent ID: 7392989

Claim:
A manhole assembly, comprising: a manhole having generally cylindrical sidewalls, the sidewalls being defined between an outside surface and an inside surface separated by a wall thickness; a wall opening communicating the outside and inside sidewall surfaces of the manhole for insertion of a mating pipe; the wall opening defining a peripheral surface relatively perpendicular to the outside and inside sidewall surfaces; a ring shaped elastomeric gasket having a body formed of rubber, retained in position on the peripheral surface of the wall opening in the manhole, the ring shaped elastomeric gasket having a substantially homogeneous composition and having a pair of relatively rigid retaining rings embedded within the rubber of the gasket body which circumscribe the ring shaped elastomeric gasket at a circumferential location, the location of the rings being precisely determined to allow the gasket to be obliquely inserted within the wall opening of the manhole and to be subsequently snap-fitted into position on the peripheral surface, whereby the gasket is securely retained in a locked-in position with respect to the wall opening in the sidewall of the manhole; wherein when the peripheral surface of the manhole is viewed in cross section, the location of the retaining rings appear below the peripheral surface of the wall opening once the gasket is in place, whereby the relatively rigid retaining rings serve to more securely anchor the gasket within the manhole wall opening and thereby make the gasket more resistant to deformation during installation of the mating pipe within the wall opening; and wherein the pair of embedded rings straddle the sidewall opening in the manhole.