Core Barrel Inner Assembly for Geological Testing and Exploration.

摘要

1,191,548. Boring earth &c. MINDRILL Ltd. 4 Dec., 1968 [6 Dec., 1967], No. 57600/68. Heading E1F. A core drill has a core barrel 26 rotatably mounted on a spindle 13, 14 slidable within a casing 12, upward movement of the spindle and barrel relative the casing 12 being prevented during lowering of the drill in the borehole so that movement of the barrel does not expose the core lifter (not shown). During lowering of the drill, balls 36 carried by the spindle engage shoulder 43 in the casing to prevent the upward movement. Drilling fluid supplied to the spindle moves a piston 28 downwardly to free the balls and permit the upward movement of the barrel, openings 42, 44 tying aligned so that the fluid passes to the bit (not shown).