| 摘要 |
A cable-type core barrel comprising, within a set of outer tubes provided lowerly with a drill bit, an inner tube provided at its bottom with an extractor cone and at its top with a hooking head provided with an upper cone frustum hook and a release cone, the inner tube being lockable in the core boring position by a tongue latch supported by a tubular latch support which is rigid with the inner tube and does not affect the release of this latter. The core barrel is fitted with an inshot comprising a lower longitudinally slotted bell member connected to a rod extending upwards, an upper hooking head comprising an upper cone frustum hook and rigid with an intermediate tube extending downwards, a helical spring housed between the intermediate tube and the rod, and resting on supports on said intermediate tube and said rod, and a threaded ring which is screwed on to the intermediate tube and when in its lower position surrounds the bell member. The inshot is designed to cooperate with the latch support to lower the inner tube within the set of outer tubes.
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