Larry D Franklin

US Patent:

7357606, Apr 15, 2008

Filed:

Feb 3, 2006

Appl. No.:

11/357461

Inventors:

Donald R. Pettit - Houston TX, US
Ronald K. Penner - Hampton VA, US
Larry D. Franklin - Hampton VA, US
Charles J. Camarda - League City TX, US

Assignee:

United States of America as represented by the Administrator of the National Aeronautics and Space Administration - Washington DC

International Classification:

B23G 5/20
B23B 51/08

US Classification:

408222, 408 1 R, 408225, 470199

Abstract:

Methods and tool for simultaneously forming a bore in a work piece and forming a series of threads in said bore. In an embodiment, the tool has a predetermined axial length, a proximal end, and a distal end, said tool comprising: a shank located at said proximal end; a pilot drill portion located at said distal end; and a mill portion intermediately disposed between said shank and said pilot drill portion. The mill portion is comprised of at least two drill-tap sections of predetermined axial lengths and at least one transition section of predetermined axial length, wherein each of said at least one transition section is sandwiched between a distinct set of two of said at least two drill-tap sections. The at least two drill-tap sections are formed of one or more drill-tap cutting teeth spirally increasing along said at least two drill-tap sections, wherein said tool is self-advanced in said work piece along said formed threads, and wherein said tool simultaneously forms said bore and said series of threads along a substantially similar longitudinal axis.