| 摘要 |
<p>A tapping head has a body (10) with a cylindrical end portion (18) and slidably received on the end portion (18) is a lug member (26) including laterally projecting lugs (25). The free end of the end portion (18) includes a reaction means (28,46) whereby movement of the lug member (26) on the end portion may compress a seal (34) against the reaction means (28,46) for forming a substantially gas-proof seal in use. The reaction means (28,46) is a collar slidably received on the end portion which may be retained on the end portion by either projecting pads (24) on the end portion which are arranged to sit in corresponding blind slots (32) in the reaction collar (28), or a flange (48) on the collar which co-operates with a circlip (44) seated in a groove (42) on the end portion. <IMAGE></p> |
