| 摘要 |
The invention relates to a device for closing, without a surge, one end of a core barrel installed in a mining or oil drilling rig, optionally equipped with a turbine. This device comprises a tubular element in whose bore there is guided a sliding member which provides a passage for the drilling liquid under pressure, this sliding member being movable in the above-mentioned bore under the influence of a variation in the flow of drilling liquid between a first position in which it keeps a closing member such as a ball remote from a seat provided at the above-mentioned end of the core barrel and, when it has engaged in the second section of the bore allows the closing element to be held in the first section of the bore, and a second position in which it allows the closing element to pass from the first section of the bore into the second section thereof and to place itself on the seat of the core barrel when the sliding member returns to its starting position.
|
