Corrugated tube coupling means

Claim 1

In combination, a thermoplastic tubing having corrugations along the length thereof and a thermoplastic fitting telescopically received thereupon with fluid communication therebetween, said corrugated tubing including crests and roots connected by walls, said fitting including an elongated generally cylindrical body having at least one generally smooth-walled mouth, the diameter of the mouth being slightly greater than the outside diameter of the tubing to permit the tubing to enter the mouth and be rotatable with respect thereto; a plurality of resilient retaining means positioned axially inwardly from the extremity of the mouth and protruding radially inwardly into said mouth for retaining the tubing in the fitting, the effective diameter defined by the retaining means being less than the crest diameter and greater than the root diameter of the corrugated tubing; said retaining means comprising a plurality of cleats which include a camming surface disposed at an angle with respect to said walls and converging inwardly toward said body, the thickness of the material defining the camming surface being substantially uniform over the length thereof, a locking face integral with said camming surface and extending between the inner extremity of said camming surface and said wall; said locking face being disposed between adjacent crests of the corrugated tubing; said locking face being disposed at a greater angle to the wall than the angle of the camming surface whereby less force is required to insert the tubing by moving the crest of the corrugated tubing over the camming surface and into the mouth than is required to remove the tubing by moving the crest over the locking face; abutment means positioned axially inwardly from the locking face a distance at least as great as the distance between corresponding points on adjacent crests of the corrugated tubing; said abutment means protruding radially inwardly a distance sufficient to engage a crest of the corrugated tubing to arrest inward axial movement thereof and terminating at a point which is outside of the flow path of the corrugated tubing as defined by the roots thereof.