DRILL TOOL (VERSIONS) Russian patent published in 2011 - IPC E21B10/16 

FIELD: gas-and-oil producing industry.

SUBSTANCE: drill tool consists of hollow case with blind orifices and flushing channels, and of rock cutting teeth with working head of the DHA (diamond hard alloy) kind and shank end secured in orifices of case by means of bushing. The bushing has an lengthwise slit and contacts a lower end of the working head, diametre of which is bigger, than diametre of the shank end. The flushing channels of the tool are communicated with lengthwise slits of the bushings via a circular boring formed between a bottom of the orifice and a lower end of the bushing. According to one version, the bushings have conic internal surface corresponding to external surface of the shank end of the rock cutting tooth, while according to another version the bushing has external conic surface corresponding to side surface of blind orifices of the case. Also, contact surfaces of the lower end of the working head of the rock cutting tooth and the upper end of the bushing are made as cone, while enter part of the orifices in the case and the working heads of the cutters have response flat facets.

EFFECT: raised efficiency of drilling operations due to more reliable fixation of teeth, simplified structure and reduced prime cost of drilling operations.

4 cl, 3 dwg