HEAT CUTTING HEAD WITH BOTTOMHOLE STRIPPER Russian patent published in 2012 - IPC E21B7/14 E21B10/36 

FIELD: mining.

SUBSTANCE: device comprises a body with a crown ring separated with washing channels to sectors-bottomhole strippers, washing channels and self-sharpening cutters, blades of which form a common plane parallel to the plane of the crown end. Cutters made of a heat resistant hard or ultrahard tooling material are connected at the front to the crown ring so that the plane of the cutters blade matches or is below the plane of the crown end by the depth of wear of sector-strippers at the period of crown sharpening.

EFFECT: increased efficiency of drilling.

3 cl, 4 dwg