Patent ID: 6974162
Filing Date: 2005-12-13
Classification: F16L

Abstract:
1. A coupling for connection of a polymeric pipe, comprising: a hollow body having external threads and an inner surface; a nut adapted to threadably engage said body external threads, said nut having an internal cavity and at one end and internal threads co-operable with said body external threads, said nut including a hooked projection adapted to extend over at least part of said body inner surface, said projection including a first inner surface generally parallel to said body inner surface and a second outwardly converging surface extending from the inner edge of said inner surface, said nut second surface having a first taper angle; and a deformable grip-ring having a first surface generally parallel to said body inner surface and having a second outwardly converging outer surface extending from said first surface, said grip-ring second surface having a second taper angle, said grip-ring including radially inward barbs, wherein upon tightening of said nut, said nut second surface abuts against and exerts a force on said grip-ring second surface both in the longitudinal and radial directions to thereby cause said grip-ring to be urged both radially and longitudinally into said body, said nut first surface sliding alongside said body first surface, and wherein said body inner surface is tapered and diverges outwardly of said body such that upon tightening of said nut as said grip-ring moves into said body, a portion of the nut first surface abuts against said body inner surface.