Device for sealingly fixing a tube or pipe to an end coupling

A coupling assembly for a motor vehicle heat exchanger, comprising a hose, an end coupling and a device for fixing said hose in fluid communication to said end coupling, said device including a generally cylindrical element having an internal surface, a portion of said internal surface being fixed to an external surface of said hose, the element having a free end portion generally positioned around the external face of said end coupling, said device further including an annular peripheral lip at the free end portion of the element located inwardly of the internal surface of the element for engaging the external face of the coupling, said annular peripheral lip having a deformable end portion curved toward and engaging said internal surface of said element and defining an annular chamber between said annular lip and said internal surface of said element, said deformable end portion further being curved inwardly to said annular chamber and effectively forming a valve for said annular chamber, said chamber being in fluid communication through said valve with said hose whereby said chamber is pressurized to an elevated fluid pressure by fluid pressure in the hose thereby forcing said annular lip into tight sealing engagement with the outer surface of said end coupling, and the chamber substantially maintaining the elevated fluid pressure during subsequent times of lower fluid pressure in the hose and end coupling.