Joint for coupling plastic corrugated pipes

A joint for coupling segments of pipe having pluralities of spaced annular protrusions extending outwardly therefrom, in an end-to-end fashion, comprising:

• a segment of the pipe having an outer surface of a first diameter, and a plurality of substantially annular protrusions spaced axially therealong, said protrusions having outer surfaces of a second diameter;
• said segment having a spigot portion at an end thereof, wherein said protrusions are partially removed to form annular bosses having outer surfaces of a third diameter, less than said second diameter;
• a cylindrical coupling having an inner surface of a diameter greater than said third diameter and having an outer surface of a diameter substantially equal to said second diameter, said coupling being positioned over said spigot portion wherein an annular gap is formed between said coupling inner surface and said annular bosses of said spigot portion;
• and
• a substantially annular gasket of elastomeric material positioned on said spigot portion, said gasket having a portion positioned in said gap, and said gasket abuts said coupling inner surface such that said gasket forms an air-tight seal between said spigot portion and said coupling and such that said gasket retains said spigot portion within said coupling;
• said gasket being shaped to fit between first and second ones of said annular bosses and said gasket includes a radially inner annular groove shaped to receive a third one of said annular bosses, said third annular boss being positioned axially between said first and second annular bosses.

A joint for end-to-end coupling of pipe segments used for lining sewer pipes or casings comprising:

• a segment of pipe having an outer surface of a first diameter, and a plurality of substantially annular protrusions spaced axially therealong, said protrusions having outer surfaces of a second diameter;
• said segment including a spigot portion at an end thereof, wherein said protrusions have been partially removed to form annular bosses having outer surfaces of a third diameter, less than said second diameter;
• a cylindrical coupling having an inner surface of a diameter greater than said third diameter and an outer surface of a diameter substantially equal to said second diameter, said coupling being positioned over said spigot portion wherein a first annular gap is formed between said coupling inner surface and said spigot portion;
• and
• a substantially annular gasket of elastomeric material having a axial ends, a radially inner annular groove, and a barb-shaped annular rib extending about an outer radial surface of said gasket;
• said gasket being positioned on said spigot portion and being fitted between first and second selected annular bosses, such that said gasket ends respectively abut said first and said second annular bosses;
• said annular groove receives a third selected annular boss positioned between said first and second bosses, such that said gasket is prevented from sliding relative to said spigot portion;
• and
• said rib gives said gasket a radial thickness greater than a radial distance between said coupling inner surface and said segment outer surface, such that said gasket forms an air-tight seal between said spigot portion and said coupling and resists separation of said spigot portion from said coupling.