Thin resin tube connecting coupling with flanged insert

Abstract

A coupling for a resin tube is provided with a body having opposed front and rear ends. The large diameter chamber extends into the rear end and a communication hole extends into the front end. A small diameter chamber connects the communication hole and the large diameter chamber. A seal is disposed in the small diameter chamber for sealing engagement with both the body and the resin tube to be coupled. A split annular grip with an inwardly directed annular pawl also is disposed in the small diameter chamber and is dimensioned for surrounding the tube. The outer circumference of the grip is tapered to define a minor diameter adjacent its rear end. A holding member has a front end with an internal taper engaged with the grip. The rear end of the holding member is releasably engaged with the rear end of the body. The tube can easily be inserted in a forward direction through the split annular grip for engagement by the seal. However, withdrawal forces cause the opposed tapers of the grip and the holding member to urge the annular pawl of the grip into tight engagement with the tube.