Patent ID: 6959775
Filing Date: 2005-11-01
Classification: B23B,E21B,Y10T

Abstract:
1. A drill adapted to be rotated in a predetermined direction, comprising: a shank part adapted to be received in a drill holder of a drilling machine, an opposite cutting end part defining a diametrically extending slit or slot opening at a free end of said end part, an intermediate fluted part defining a pair of co-extending helical flutes or channels, and a plate-like cutting member of hard metal, which has an outer free end surface, an opposite inner end surface, a pair of opposite broad side surfaces, a pair of transverse, narrow side surfaces, and is received in said slot so as to extend axially and radially therefrom, and which is fastened to said end part, said free end surface of the cutting member defining a pair of substantially diametrically extending main cutting edges, and each of said narrow side surfaces defining a pair of substantially axially extending side cutting edges, a leading part, in relation to said direction of rotation, of each of said broad side surfaces adjacent to a side cutting edge being exposed and defining a recess, which extends axially from the outer free end surface of the cutting member to an adjacent open end of one of said flutes or channels.