| 摘要 |
<p>Methods and apparatus for locating a member (27) within an aperture are disclosed. One preferred apparatus includes a housing (10) containing at least one rotatably connected ring (14), and a plurality of tie members (22) spaced evenly about the perimeter of the ring (14). The tie members (22) are connected to the rotating ring (14) and the housing (10) such that rotation of the ring (14) pulls the tie members (22) taut across the inside of the ring (14). Rotating the ring (14) in the opposite direction returns the tie members (22) to their initial orientation. When the tie members (22) are taut, they urge a member (27) passing through an opening towards the centre of the apparatus. When the apparatus is installed in a drilling rig floor, it results in a simple and effective pipe centring technology.</p> |
