Kris Cox

US Patent:

41250575, Nov 14, 1978

Filed:

Mar 31, 1976

Appl. No.:

5/672294

Inventors:

Kris E. Cox - Gardena CA

International Classification:

B23C 332

US Classification:

90 1158

Abstract:

Motor driven milling and boring machine used primarily for forming screw threads of any selected pitch, external to cylindrical or conic projection or within similar-shaped bore of workpiece, particularly workpieces such as are too large or irregular-shaped to be themselves rotated. A tubular housing, upstanding or tiltably disposable, journals a longitudinally displaceable and rotatable hanger which in turn axially journals a power-driven spindle having a selectively offset-positionable stub portion, terminally carrying a thus radially extensible drive segment which distally positions a rotary milling cutter. A second or planetary tracking motor jointly operates a pair of selectively coupled ring gears of the housing, which in conjunction with a master nut fixed along the housing axis, move the hanger respectively annularly and axially so that the distal cutter may follow a helical path, the pitch of which path is determined by the chosen velocity ratio give the two ring gears. A particular velocity ratio results from the choice of gearing assembled in a detachable twin-segment gear train cassette insertable between the pair of ring gears. While remaining in place, the gear train may be disengaged from one drive component of the hanger to enable arcuate resetting for production of multi-start threads, or alternately to provide annular or linear movement of the cutter.