Tool holder and gun drill or reamer

摘要

A tool holder for a gun drill or reamer has internal and external cylindrical rear end pilot portions and a radial pilot flange for precisely connecting coaxially with a rotatable and axially moveable power source. A sleeve confined coaxially within the internal cylindrical portion has an axially extending flat spline surface for effecting driving engagement with a mating flat of a tool shank. A contractible conical split collet at the forward end of the holder coaxially clamps the tool shank when moved axially to a clamping position by means of a non-rotatable nut secured to the collet for cocking out of axial alignment therewith to assure precise coaxial clamping of the tool shaft. The nut is in screw threaded engagement with a rotatable and non-axially moveable collar provided with beveled gear teeth for rotation by a Jacobs type tool.