METHOD AND DEVICE FOR GEOLOGICAL BED DRILLING Russian patent published in 2007 - IPC E21B7/00 E21B10/40 

FIELD: special methods or apparatus for drilling, particularly drill bits with leading portions.

SUBSTANCE: device comprises rotary body, drill cutting members arranged on end surface of the body so that the cutting member may scrape away cut-off parts of geological bed. Device also has percussion unit, which is parallel to rotation axis and may reciprocate relatively the body to cut-off parts of geological bed to be drilled. The percussion unit has impact cutting members arranged on end surface of percussion part. End part of percussion unit has cross-section showed in fig. 2 and 4. End part of the body has cross-section complementary to that of end part of percussion unit so that end part of percussion unit may be guided with end part of the body in axial direction. Geological bed drilling method involves bringing percussion unit in contact with bed to be cut by imparting impact force thereto; scraping away cut-off parts of geological bed by means of drill cutting members of the device.

EFFECT: improved impact action transmission to percussion unit, increased uniformity of impact load distribution over face area and improved cut-off geological bed parts removal.

9 cl, 4 dwg