US 5,067,751 AGranted

Gasket for field adaptable push-on restrained joint and joint thus produced

AssigneeAmerican Cast Iron Pipe Company

InventorsVan T. Walworth, Steve L. DeBoalt

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Abstract

A self-actuating restraining gasket having optional integral sealing means is provided which is used particularly in bell-and-spigot pipe joints or joints employing pipe appurtenances, and more particularly in joints to be assembled in the field, the bell end of the pipe or pipe appurtenance to be employed having an annular recess adapted to receive the gasket therein, the gasket further employing a plurality of pairs of cooperating metal retaining elements embedded in the elastomeric gasket, the pairs of retaining elements being spaced apart around the circumference of the gasket, each pair of retaining elements comprising a wedging member and a backing member for the wedging member, and wherein the pairs of retaining elements act as the self-actuating retention or restraining elements, and an optional compressible back part of the gasket acts as a fluid seal when a pipe spigot is inserted in the bell.

Claims39

Dependent claims

A gasket for use in retaining a spigot disposed at one end of a piping element within a bell disposed at one end of another piping element, comprising:

an annular ring of elastomeric material adapted to seat in an annular recess in an interior of said bell wherein a front end of said ring is adapted to be disposed nearest an opening at the end of the bell;
a plurality of paired mutually cooperating retaining elements, each pair of retaining elements being spaced apart from other pairs around a circumference of said elastomeric ring, said pairs of retaining elements being captively retained by said elastomeric ring;
each of said plurality of paired cooperating elements comprising a backing member disposed at said front end of said annular ring and adjacent a radial outer surface of said front end, and an associated wedge member disposed radially inwardly of said backing member, said wedge member having at least one serrated tooth disposed on a radial inner surface thereof, and said wedge member having a radial outer surface, at least a portion of which diverges from said radial inner surface in a direction from the front end of said annular ring to a back end of said annular ring, wherein the wedge member is movable relative to said backing member, and wherein said backing member presents a bearing surface to said radial outer surface of said wedge member and
wherein, when said annular ring is positioned in the bell, said at least one tooth on each of said wedge members is positioned to engage an outer surface of a spigot of a piping element to be inserted into said bell.

1 more element

A piping joint comprising:

a first piping element having a bell end, said bell end having an opening of a predetermined size and an annular recess in an interior surface thereof;
a second piping element having a spigot end inserted and retained in said bell end of said first pipe,
a gasket disposed in said bell end of said first piping element comprising an elastomeric annular ring, said gasket being seated in said annular recess in said interior surface of said bell end of said first piping element, a front end of said gasket being disposed nearest said opening in said bell;
said gasket having a plurality of paired mutually cooperating retaining elements captively retained therein and spaced apart around a circumference of said annular ring, a first element of each pair comprising a backing member disposed at said front end of said gasket adjacent a radial outer surface of said front end, a second element of each pair comprising a wedging member disposed radially inwardly of said backing member, a radial outer surface of each of said wedging members being in contact with a bearing surface of an associated backing member said wedge members being tapered radially outwardly over at least a portion thereof in the direction extending axially inwardly into said first piping element from said bell opening, each of said wedging members increasing in thickness in said direction over said tapered portion, each of said wedging members having at least one tooth extending from an inner radial surface, said at least one tooth on each of said wedging members being in biting engagement with said outer surface of said spigot end of said second piping element, and
wherein said plurality of paired cooperating retaining elements coact to restrain said bell end and said spigot end from separating when axial forces tending to separate said bell end and said spigot end are experienced.

2 more elements

A self-actuating restraining gasket adapted to retain a spigot end of a first section of a piping element within a bell end of a second section of a piping element comprising:

an annular ring of elastomeric material, said annular ring being adapted to seat in an annular recess in an interior of said bell, a front end of said ring being adapted to be disposed nearest an opening at the bell end of said second piping element,
a plurality of associated pairs of retaining elements, said associated pairs of retaining elements being spaced apart around a circumference of said elastomeric ring, said associated pairs of retaining elements being captively retained in said elastomeric ring;
each of said plurality of pairs of associated elements comprising a backing member disposed in said front end of said annular ring adjacent a radial outer surface of said front end, and an associated wedge member disposed radially inwardly of said backing member, each of said wedge members having at least one tooth disposed on an inner surface thereof, at least a gripping portion of each of said at least one tooth on each wedge member being exposed to engage a spigot end of a first piping element to be inserted into a bell end of a second piping element in which said annular ring is adapted to be disposed.

Dependencies are inferred from the claim text.