Abstract: A coupling for a corrugated conduit has a housing of a rigid plastics material with two resilient spring catches on opposite sides to engage between corrugations on the conduit. A layer of a softer, elastomeric material is continuously joined on both the interior and exterior of the housing. On the interior, the softer material extends on a tapering surface to diametrically seal with a range of conduits. On the exterior, the layer of softer material forms both a flange on an annular ledge to seal with a cooperating coupling and manual gripping regions.

Abstract: A coupling for a corrugated pipe has two retainers hinged integrally with the coupling so that they can be folded down to project through apertures in the coupling and engage between corrugations on the pipe. When folded down in full engagement with the pipe, spring levers on opposite sides of the retainers engage under ledges in the aperture. The levers cannot engage when a retainer does not fully engage between the corrugations thereby making it apparent that the retainer is not fully engaged.

Abstract: A coupling for the end of a corrugated pipe has two catches integrally moulded with the housing of the coupling. The catches are hinged at one end and have a tooth at their other end that engages between the corrugations on the pipe. Two undulating webs link the other end of the catches with the housing to provide an additional resilient restoring force acting on the catches.

Abstract: A coupling for a corrugated pipe is moulded from a plastics material with two locking arms on opposite sides. The locking arms are hinged at one end and have an inwardly-projecting tooth at their other end shaped to extend between corrugations on the pipe. One side of each locking arm is formed with a stop that projects beyond the tooth and is adapted to contact a corrugation on the pipe when force is applied to pull the pipe out of the coupling, so as to limit inward deflection of the locking arms.

Abstract: A coupling for a corrugated conduit has a housing moulded of a rigid plastics material with two spring catches on opposite sides to engage between corrugations on the conduit. A continuous layer of a softer, elastomeric material is moulded on top of the rigid material extending on both the outside and inside of the housing. On the inside, the softer material extends on a tapering surface to seal with the end of the conduit. On the outside, the layer of softer material forms both a flange on an annular ledge to seal with a cooperating coupling and manual gripping regions.