Connecting joint for corrugated plastic tubing

Claim 1

A joint construction for plastic pipe comprising: a first length of corrugated, hollow and generally cylindrical plastic pipe having an internal wall surface defined by adjacent circumferentially extending, longitudinally spaced peaks and valleys with the internal diameter of said first length measured diametrically between opposite peaks between opposite valleys being equal to d and the internal diameter measured diametrically between opposite valleys being equal to D wherein D is greater than d; a first portion of said first length defining an end therefor having an internal diameter j measured diametrically between opposed peaks which is greater than d but less than D and a maximum internal diameter measured diametrically between opposed valleys which is substantially equal to D, said first portion including at least one integral stop member and at least one integral locking member disposed in a spaced apart cooperative relationship with each other in one of the first portion valleys and extending radially inward therefrom for defining a locking area therebetween, said at least one locking member being defined by first and second inclined side walls meeting at an apex area with said first side wall having an angle of inclination less than that of said second side wall for defining a cam surface and with said second side wall defining a lock surface which comprises one side of said locking area, said first portion further including a plurality of sets of longitudinally aligned grooves formed in at least the peaks spaced from said one valley toward the outer free end of said first portion in a non-aligned relationship with said locking area; a second length of hollow plastic pipe having a generally cylindrical corrugated portion and a smooth walled cylindrical second portion which defines an end of said second length and has an outer diameter which is slightly less than j; at least two sets of cleat members extending outwardly from the outer surface of said second length second portion with sets axially disposed from each other therealong, said cleat members having a configuration and location to permit them to move longitudinally into the aligned grooves in the first length first portion so that a portion of said second length is received in said first length first portion with the cleat members of one set being located in said one valley and the cleat members of the other set being located in another valley of the first length first portion; and, said cleat members and said at least one locking member being relatively dimensioned from said second length second portion and said first length first portion respectively such that there is an interface relationship therebetween as said first and second lengths are rotated relative to each other after said second length second portion has been received in said first length first portion, at least one of said locking and cleat members being resiliently deformable as the associated of said cleat members engages said locking member cam surface to permit said associated cleat member to be passed into said locking area during further forced rotation between said first and second lengths until said associated cleat member is lockingly received in said locking area between said at least one stop member and said locking member lock surface, the incline of said lock surface then preventing rotation between said first and second lengths in the opposite direction unless a rotational force greater than the rotational force required to move said associated cleat member over said cam surface and into said locking area is applied thereto.