PIPE COUPLING

摘要

A pipe coupling (10) for joining together the ends of two adjacent pipes includes a housing (12) which defines a generally central bore (13) along a central axis of the housing for receiving the ends of the two adjacent pipes, and a locking arrangement (14) at each end of the housing (12) for locking the pipes to the coupling (10). Each locking arrangement (14) includes an annular chamber (23) within the housing, an inlet (48) for allowing fluid into the chamber (23), an annular seal (24) which is arranged to move within the annular chamber (23) axially of the housing, and a plurality of grippers (30) which are radially moveable towards the central axis of the housing (12) from an inoperative condition to an operative condition. Each gripper (30) includes a gripping formation (36) for operatively gripping a pipe inserted into the bore (13) of the housing, and a locking formation (38) for operatively engaging a corresponding locking formation (40) on the housing (12) so as to axially lock the gripper to the housing. Each locking arrangement (14) also includes a locking ring (26) between the annular seal (24) and the grippers (30) for locking the grippers to the housing (12) and to a pipe end within the housing. The locking ring (26) includes a sloping inner surface (28) which is engageable with a corresponding sloping outer surface (32) on each of the grippers (30) so that axial displacement of the locking ring (26) under fluid pressure within the annular chamber (23) causes radial displacement of the grippers (30) into the operative condition, axially locking the grippers to the housing and clamping the pipe end within the housing.