GUN DRILL Russian patent published in 2009 - IPC B23B51/00 

FIELD: mechanical engineering and metal working.

SUBSTANCE: proposed drill comprises replaceable cutting head attached onto the stem. Cutting head consists of cutting and jointing parts. The latter comprises bearing surface directed axially backward and locking surface representing, preferably, a truncated cone surface with diametre decreasing axially inward and towards cutting part. Stem comprises jointing part formed nearby its front and including bearing surface directed axially forward and locking surface representing, mainly, a truncated cone surface with diametre decreasing axially inward and towards front end. Cutting head locking surface passes from periphery from side surface of cutting head chip groove, opposite the direction of rotation, and is located on central angle making over 180° along periphery. Stem locking surface passes along periphery from side surface of chip groove, opposite the direction of rotation, to side surface (50, 250), and located on central angle making over 180° along periphery. When fixed, cutting head jointing part and that of stem are coaxially locked. Note here that cutting head bearing surface interacts with stem bearing surface, while peripheral surfaces of cutting head and stem and those of their chip grooves are mutually aligned counter direction of rotation.

EFFECT: fast and simple tool replacement.

27 cl, 22 dwg