| 摘要 |
<P>PROBLEM TO BE SOLVED: To eliminate a displacement in the direction of a collected core, which is caused by a twist in an inner pipe due to co-rotation with an rotating outer pipe, when it is intended to collect a core with a known direction by use of a double-pipe system. <P>SOLUTION: A double-pipe system is configured of: a rotary outer pipe 12; and an inner pipe which is placed coaxially and at a free-rotation state inside the rotary outer pipe. The inner pipe is a member whose center of gravity is eccentric with respect to the axis, so that the inner pipe, when the double-pipe is in a horizontal or a slightly slant position, maintains a vertically consistent posture under the effect of a gravitational downward force working on it. <P>COPYRIGHT: (C)2012,JPO&INPIT |
