| 摘要 |
<p>A conventional center-latch elevator with smooth slip segments of the present invention is employed to grip and suspend a pipe without damaging the pipe surface. The slip segments (14) are made of aluminum or another material that is softer than the material of the pipe (15). The elimination of rough surfaces on the slip segments prevents damage to the external pipe surface. A threaded lift connector (20) is secured to the box end of the pipe to be lifted. The lift connector forces spring loaded slip segments down into the conical bowl (13) of the elevator to move the segments radially inwardly into gripping engagement with the pipe. The axial forces exerted by the elevator against the bottom of the lift connector are transmitted through the connector to the threads engaged in the pipe. The arrangement prevents the forces of the elevator from being transmitted to the base of the coupling from the threaded pipe end. The lift connector may be employed with a coupling-type elevator that closely surrounds the pipe and engages the bottom of the lift connector when the elevator is raised to raise the pipe.</p> |
