BORE-HOLE DRILLING BIT WITH REPLACEABLE SECTIONS Russian patent published in 1998 - IPC

FIELD: drilling machinery and equipment. SUBSTANCE: this relates to drilling deep bore-holes of large diameter by means of bits with replaceable rock-crushing sections. Drilling bit has body 1 which carries rock-crushing sections 2 fastened by means of locking and fastening units. Section 2 has shank with taper thread 3. Locking unit is represented by step 4 with faceted external surface on shank which is seated in faceted hole of body 1. Nut 6 of fastening unit has faceted shank 7. Thread 8 of nut 6 is of taper type. Installed in washing passages of body 1 are head-piece holders which can be turned for adjustment and dismantling. One or several head-pieces can be installed in respective head-piece holders. Head-pieces can be installed perpendicularly to work face surface or at angle to axis of drilling bit with possibility of dismantling. Aforesaid embodiment has locking unit of simple and reliable design. Fixing of rock-crushing section is more rigid and accurate with respect to drilling bit axis. EFFECT: higher efficiency. 7 dwg