DRILLING BIT AND METHOD OF FASTENING OF ITS INSERTS Russian patent published in 2015 - IPC E21B10/46 E21B10/56 

FIELD: mining.

SUBSTANCE: drilling bit contains the housing with holes where hard-alloy inserts with cylindrical shanks are fixed. Sidewalls of holes in the housing and shanks of inserts are implemented with the ring grooves displaced in the vertical plane from bottom of holes and end face of shanks and forming together the toroidal cavity for placement of fixing bushings of material with shape memory, and in the starting position the outer diameter of fixing bushings is not greater than diameter of holes in the housing, and in the working position it is greater. The method of fastening of inserts of the drilling bit includes fixing of inserts in bit housing holes, and before installation of inserts in the housing holes on their shanks in ring grooves the fixing bushings from material with shape memory are installed, they are placed in holes of the housing and fixed there, then the fixing bushings are brought into the working position by expansion of their radial sizes and making a sinusoidal form in the plan view.

EFFECT: simplification of bit manufacturing techniques and method of fastening of inserts in housing holes.

3 cl, 2 dwg