Patent ID: 6637521
Filing Date: 2003-10-28
Classification: E21B,Y10T

Abstract:
An earth borer, comprising a thin-walled tubular shaft (4) having smooth inner and outer surfaces; a shank (2) provided at one end of the tubular shaft (4); a drilling head (5) provided at another, opposite end of the tubular shaft, projecting radially beyond the tubular shaft (4), and having at least one cutter (6, 6a, 6b, 6c, 6d) extending, at least partially, radially inward and at least one internal groove (7, 7a, 7b) associated with the at least one cutter (6a, 6b, 6c, 6d), and a releasable tubular connection member (8) for drivingly connecting the shank (2) with the tubular shaft (4) for joint rotation with each other, wherein the drilling head (5) has a rim (12) for fixedly circumferentially connecting the drilling head (5) with the tubular shaft (4), and wherein the cutter (6) tapers towards a tip point lying on a borer axis (A) and diametrically spans the head rim (12).