Patent ID: 6935636
Filing Date: 2005-08-30
Classification: B23B,D01H,Y10T

Abstract:
1. An apparatus comprising: a rotatable tool coupled to a support body, said support body being composed of first material; a drive shaft, composed of a second material that is harder than said first material, detachably mounted to said rotatable tool, such that the rotatable tool is drivable in a working direction; said support body comprising a cylindrical inlet opening defined by at least three eccentric segments arranged to project radially inwardly and symmetrically distributed on a circumference of said cylindrical inlet, wherein radii of each of said at least three eccentric segments decrease in the working direction from a largest cylindrical diameter of said inlet opening to an end of said eccentric segment; said drive shaft comprising an immersion area structured and arranged for insertion into said central inlet opening, said immersion area comprising at least three longitudinal ribs arranged to project radially outwardly and symmetrically distributed on a circumference of said immersion area; said longitudinal ribs comprising thread-cutting segments, wherein, after inserting said immersion area into said cylindrical inlet, said longitudinal ribs are rotated relative to said support body, whereby said thread-cutting segments at least partially cut threads into said at least three eccentric segments to couple said drive shaft to said support body.