摘要 |
In an automatic coupling system, a threaded quill is connected to a rotating and advancing mechanism by a slip coupling and is biased toward a drill pipe by a spring. In the use of the system, the quill is advanced toward the drill pipe and is simultaneously rotated with respect to the pipe. When the quill engages the pipe, it slips relative to the advancing and rotating mechanism against the action of the spring until a quill advance terminating switch is closed. The rotation of the quill is continued until the torque on the quill reaches a predetermined limit.
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