Restrained joint having elastomer-backed locking segments

A pipe joint comprising:

• a first piping element having a bell end, said bell end having an opening of a predetermined size, and a first annular recess in an interior surface thereof, said bell end having a radially inwardly protruding shoulder disposed axially inwardly of a front end of said first annular recess, a front axial portion of said first annular recess being bounded by a tapered wall such that said recess, in said front part, increases in diameter moving in an axially inward direction;
• a second piping element having a spigot end adapted to be inserted in and retained in said bell end of said first piping element;
• fluid seal means for providing a fluid seal between said spigot end of said second piping element and said bell end of said first piping element, said fluid sealing means being disposed axially inwardly of said first annular recess;
• locking ring means separate from said fluid seal means for retaining said spigot end of said second piping element within said bell end of said first piping element, said locking ring means comprising at least one locking member, said at least one locking member comprising an elastomeric backing member having a plurality of segments abuttingly engaging said elastomeric backing member at a front end of said elastomeric backing member, said locking ring means being so constructed and arranged to seat in said first annular recess in said bell end such that said bell end exerts a residual circumferential compressive force on said elastomeric backing member, and wherein said elastomeric backing member is disposed axially inwardly of said plurality of locking segments, said elastomeric backing member further being seated against said shoulder of said first annular recess wherein an outer radial surface of each of said plurality of locking segments is resiliently urged into contact with said tapered wall of said front axial portion of said first annular recess, each of said plurality of said locking segments having means for engaging said spigot end of said second piping element to retain said spigot end within said bell end.

A locking member for axially restraining a spigot end of a piping element in fluid sealed engagement with a bell end of another piping element, said locking member being an element separate from a fluid seal means operating between said spigot end and said bell end, the locking member comprising:

• an arcuate elastomeric backing member adapted to seat in an annular recess in said bell end and against a radially inwardly protruding shoulder in said bell end;
• and
• at least one arcuate locking segment bonded to and extending axially outwardly of said elastomeric backing member when said elastomeric backing member is seated in said annular recess, said locking segment having means for engaging said spigot end to retain said spigot and within said bell end;
• wherein said elastomeric backing member of said locking member is so constructed and arranged to urge an outer radial surface of said at least one locking segment into contact with a tapered wall at a front axial portion of said annular recess when said elastomeric backing member is seated against said shoulder in said bell end.