BigPatents India

A screw-threaded joint for pipes comprises a first pipe length (10) having a male screw-threaded portion (11) at one end. A second pipe (20) has at one end a female portion having a complementary screw-threaded portion. The pipe lengths are adapted to inter-engage along the greater part of the axial length of the threaded portions the screw threads thereof being inclined in the same direction and at an acute angle to the longitudinal axis of the pipe length. The male thread (11) extends to a male stop shoulder (15) adjacent a complementary stop shoulder on the other portion. The complementary stop shoulder has a recess in the form of a cone receiver having a rounded apex. A first conic surface (13), substantially parallel to the axis of the pipe of the conic stop shoulder of the male portion or of the cone receiver of the female portion, includes one or more curved portions (24). (FIG. - 2)