SPIRAL BLADE BIT, CONTAINING THIS BIT SYSTEM FOR ROCK CASING, METHOD FOR CUTTING SPIRAL GROOVE IN INTERNAL SURFACE OF GUIDE BOREHOLE AND METHOD OF GUIDE BOREHOLE REAMING BY MEANS OF SAID BIT, SYSTEM FOR CASING ROCK WITH ANCHOR BOLT Russian patent published in 2009 - IPC E21D21/00 E21B10/44 

FIELD: mining.

SUBSTANCE: here disclosed group of inventions refers to mining and can be implemented for casing of mine workings. Casing of a mine working consists in boring a guide borehole, in cutting a spiral groove in an internal surface of the guide borehole by rotating a spiral blade bit in the direction corresponding to a constant angular pitch, thus arranging a casing facility/anchor in the borehole, strengthening rock of mine working. Also the spiral blade bit corresponds to a shaft with plurality of cutting blades possessing axial length and assembled with a constant angular pitch. Notably, axial length of each cutting blade exceeds axial length of cutting blades situated nearer to the end of the bit shaft. The bit shaft can be made in form of links laid one upon another, each containing at least two cutting blades. Further, each cutting blade ends with a bit edge designed to cut a spiral groove in rock. The system for rock casing consists of the spiral blade bit, of the casing facility/anchor and of fastening means. Also cement grout can be used as fastening means.

EFFECT: upgraded efficiency and reliability of casing mine workings with bolting.

29 cl, 2 tbl, 32 dwg