THREAD SEAL

摘要

2078997 9213219 PCTABS00014 A thread seal comprises a helical rib (6) for use with a threaded member (1). The end portions (7) of the rib (6) are axially staggered and are joined by a transverse thread bridging member (8) which engages a crest (9) of the thread between sucessive turns of the groove (2). The rib (6) has a tapering cross-section to project radially into the groove (2) and to form a lip seal over a limited axial width of the groove (2) throughout the greater part of the circumferential length of the rib (6). The end portions (7) together with the bridging member (8) are shaped to form a seal over the full axial width of the thread profile. By limiting the area of contact between the rib (6) and groove (2) over the greater part of the circumferential length of the rib (6) the frictional force between them is reduced.