| 摘要 |
A swivel for use in conjunction with directional drilling consisting of a first tubular housing and a second tubular housing positioned in end to end relation with the first tubular housing. The first tubular housing and second tubular housing are maintained in axial alignment while permitting relative rotation. An axial bore has a first portion extending through the first tubular housing and a second portion extending through the second tubular housing. The first portion has two axial grooves and the second portion has an inwardly projecting tongue. A tubular screw having exterior threads is rotatably mounted within the axial bore. A member is disposed within the axial bore. The member has a first end, a second end, and thread engaging means for engaging the exterior threads of the tubular screw. The member has two radial tongues adjacent the first end which mate with the axial grooves in the first portion of the axial bore such that the member moves axially along the first tubular housing in response to rotation of the tubular screw. The member has a spiral-form groove which extends between the first end and the second end and which mates with the inwardly projecting tongue in the second portion of the axial bore. In response to axial movement of the member the radial tongue travels along the spiral path provided by the spiral groove thereby incrementally rotating the second tubular housing relative to the first tubular housing.
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