| 摘要 |
<p>A fitting is disclosed which is usable as an adapter or as a bearing and is formed of a short hollow cylindrical tube having at least two annular grooves spaced apart in parallel planes at right angles to the axis of the tube, the grooves being open on the radially outward side and extending inward a small fraction of an inch and the outer surface of the tube, other than the grooves, being a smooth cylinder.</p> |
