DOUBLE CORE EQUIPMENT Russian patent published in 2009 - IPC E21B25/00 

FIELD: mining.

SUBSTANCE: invention refers to boring tool, particularly to means for boring boreholes for core sampling. The object of the invention is obtained like follows: the double core equipment consists of a mechanical screw drive of the core-holding device. Also the core-holding device presents a screw shaft screwed into an upper sub, and a lower end of the sub is equipped with cams, while pass-through lengthwise slots are made in the lower part of the screw shaft; a fixing element interacting with the cams of the sub is arranged in the slots. The fixing element is made in form of a bushing with radial projections and a seat for a trip valve located in the cavity of the shaft, the bushing is spring loaded against the shaft with preliminary compression, which facilitates its maintaining in an upper position in the process of boring.

EFFECT: upgraded reliability of core-holding device and core equipment operation in general at boring holes with application of fluid, as well as gaseous, cleaning agents.

2 dwg