Patent 5066172 Issued on November 19, 1991. Estimated Expiration Date: July 31, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
The countersink tool assembly of the present invention is rotatably driven by a conventional drill apparatus and includes an insert having a central aperture and two diametrically opposed ears which extend into the central aperture. A multi-fluted countersink tool is concentrically mounted within the aperture such that the diametrically opposed ears extend into the flutes of the countersink tool at a desired axial location. The ears are adapted to engage and follow the contour of the curved outer wall surface which concentrically surrounds the hole. As such, the countersink tool assembly translates rectilinearly with respect to corresponding changes in the curved contour of the outer wall surface.