DRILLING BIT Russian patent published in 2013 - IPC E21B10/18 

FIELD: mining.

SUBSTANCE: drilling bit comprises a body with mills mounted on its journals and a blow channel, in which a check valve is installed, comprising a protective jacket rigidly fixed to a body and a stop element placed in its cavity. The check valve is installed along the bit axis, the protective jacket is made with through slots by number of mills directed into the mill-to-mill space, and the stop element is made in the form of a tension spring with a guide cone, at the same time the upper end of the tension spring is rigidly connected with the protective jacket, and the lower one - with the guide cone. The diameter of tension spring turns in the middle part and on end sections may differ.

EFFECT: simplified design, efficient cleaning of a bottomhole from sludge, increased efficiency of bit operation.

2 cl, 4 dwg