BORE BIT (VERSIONS) Russian patent published in 2009 - IPC E21B10/02 

FIELD: mining.

SUBSTANCE: invention refers to rock destroying tool, particularly to bits for boring with recovery of core, mainly in alternating in hardness rock. The bore bit consists of an internal cylinder element with slots in a lower part for installation of removable tool holders with inclined external surface fixed with an external cylinder element and connected with the internal cylinder element by means of thread. According to the first version the bore bit features with slots in the lower part of the internal cylinder element made on its external surface, also the slots with tool holders installed in them are made with responsive conical surfaces, the top of which is on the side opposite to a bottomhole. Notably, the internal surface of the lower part of the external cylinder element and the external surface of the tool holders contacting it are of conical shape parallel to conical surface of the internal surface of the tool holder. According to the second version the bore beat features with slots in the lower part of the internal cylinder element made on its external surface, and in front plane they have the shape of trapezoid, the smaller base of which is situated from the side of the bottomhole of a well, additionally, the tool holders installed in the slots have congruent shape.

EFFECT: upgraded engineering and economical performance of bore bit due to simplification of design.

3 cl, 4 dwg