DRILLING ASSEMBLY Russian patent published in 2016 - IPC E21B10/40 E21B10/64 E21B7/20 E21B17/46 

FIELD: mining.

SUBSTANCE: invention relates to a drill assembly for making a well in soil or rock. Drill assembly comprises a pilot bit drilling middle part of well and a ring bit drilling outer circle of well. When drilling, ring bit is adjusted around pilot bit and rotary movement and drilling impacts are directed from pilot bit to ring bit (1) with help of irregularly shaped holes and components, installed between bits and conveying power, wherein ring bit can be removed around pilot bit and can be installed to it. coupling ring, which can be locked to ring bit, is installed around ring bit in order to join a casing pipe, which can be pulled into drilled well with help of said mentioned coupling ring. Drill bit comprises at least two annular grooves on outer circumference, in said annular grooves there are parts mounted with possibility of rotation and movement in desired range in axial direction of drilling, said parts being involved in fixing, such as snap rings and disposed on inner surface of coupling ring, wherein coupling ring is installed around periphery of drill bit in such a way that parts involved in reciprocating movement, locking coupling ring and drill bit, at least two are located on different sides of line when device is assembled, and said line extends substantially through middle point of surface, transmitting rotation of drill bit.

EFFECT: technical result is reducing length of drill bit and increasing drilling speed.

7 cl, 4 dwg