IMPROVEMENTS IN PIPE COUPLINGS AND COUPLED PIPE JOINTS

摘要

A pipe coupling has a body (1) with a sleeve at one end to receive plastic pipe (P). The sleeve has annular saw-tooth profile serrations and a groove housing an O-ring. A radial compression clamp (3) is used to force pipe (P) onto the serrations and in this action considerable movement takes place in the tightening and arrangements are provided to ensure that there is no side-strain or binding on the bolt (6). This is achieved in the following manner; The clamp lugs (7) are laterally machined in the form of a segment of a circle (8). Located in these segments are half round blocks (9) centrally drilled to accept the bolt (6) and free to axially rock in the circular segment (8). The clamp lugs (7) are bored with a clearance hole (10) sufficiently large to provide clearance on the bolt when the lugs have undergone maximum movement due to closing. In the fully tightened position the bolts are correctly longitudinally loaded, and no side-strains or binding arises due to the closing action of the clamp. The bolts are tightened by action on the nuts (11), located one at each end of the bolt.