EDGELESS DRILL BIT Russian patent published in 2003 - IPC

FIELD: equipment for blasthole drilling in rocks, particularly, drill bits applicable in rock drilling. SUBSTANCE: edgeless drill bit is provided with cylindrical-spherical hard-alloy inserts and has conical joint with drill rod. Cylindrical-spherical inserts are installed with angle of inclination of geometrical axes to axis of drill bit equaling taper angle of drill bit joint with drill rod. Inclination of insert axes is opposite in direction of drill bit rotation of insert axes is opposite in direction of drill bit rotation and mutual location of neighboring inserts provides for formation of distinct wings of drill bit. Location of inserts in form of wings facilitates shearing of rocks. Inclination of inserts creates distribution of forces promoting better fastening of drill bit to provide for high reliability of conical fastening of drill bit and to utilize the impact energy for rock cutting by shearing with provision of two types of rock cutting by puncturing holes and shearing of sectors. EFFECT: higher operate reliability of drill bit. 5 dwg