Pickard core barrel

Pickard core barrel

[′pik·ərd ′kȯr ‚bar·əl]
(mining engineering)
A type of double-tube core barrel; the distinguishing feature of the barrel is that when blocked the inner barrel slides upward into the head, closing the water ports and stopping the flow of the circulating liquid, without irreparably damaging the bit until the barrel is pulled and the blocked inner tube cleared.