Coupling for interconnecting corrugated plastic tubes

Claim 1

A plastic tube having spaced apart successive annular ribs with aNnular valley portions therebetween extending along the length thereof and defining annular corrugations on the periphery of the tube and a plastic coupling connected to an end of said plastic tube and in fluid communication therewith, said coupling comprising a generally tubular plastic body including an annular sleeve portion receiving an end of said plastic tube therein, said sleeve portion being tapered outwardly over its entire length to facilitate insertion of said tube therein with the diameter of the sleeve at the outermost end being about 0.001 inch greater than the diameter at the innermost end, said sleeve portion having integrally formed therewith a series of eight spaced apart latching projections circularly arranged in opposing pairs in a single row around the inner circumference of said sleeve portion and extending inwardly into a common valley portion on said tube for engaging the tube and effecting the connection between the coupling and the tube, said latching projections being of hollow construction and substantially hemispherical in shape and having a diameter of no more than about 1/4 inch as measured across the base interiorly of the sleeve portion and equal to about one-half the distance between corresponding points on successive ribs of said tube and extending inwardly from said sleeve portion for a distance equal to about one-half the depth of the valley portions between adjacent ribs on said tube, said hollow latching projections also having a wall thickness of less than about one-half of said inwardly projecting distance and being rigid so as to effect displacement of the surrounding adjacent sleeve portion when the tube is inserted in said sleeve portion for facilitating effecting the connection therebetween and to avoid deforming the latching projections, relatively small annular ridges formed integrally with said sleeve portion and located closely adjacent to and on opposite sides of said circularly arranged latching projections, said annular ridges serving to provide additional stability to said sleeve portion and to assist in maintaining the sleeve fully opened for readily receiving the end of said plastic tube therein, and inwardly extending stop means adjacent the innermost end of said sleeve portion for limiting the extent to which the plastic tube may be received in said coupling.