Patent ID: 7862267
Filing Date: 2011-01-04
Classification: B23Q,Y10T

Abstract:
1. A rotary cutting machine comprises: a machine body including a rotatable arbor having a central axis of rotation and adapted to hold a rotary cutting tool, said rotary cutting tool being rotated with said arbor about said central axis of rotation, wherein said arbor comprises: a proximal rotary shaft mounted to said machine body for rotation about said central axis of rotation and drivingly connected to a motor; an intermediate rotary shaft telescopically connected to said proximal rotary shaft and movable between an extended position wherein said proximal rotary shaft and said intermediate rotary shaft are axially overlapped with one another by a relatively short axial length and a retracted position wherein said proximal rotary shaft and said intermediate rotary shaft are axially overlapped with one another by a relatively long axial length, said intermediate rotary shaft being rotated with said proximal rotary shaft; a distal rotary shaft having a leading end, said distal rotary shaft being telescopically connected to said intermediate rotary shaft and moved between an extended position wherein said intermediate rotary shaft and said distal rotary shaft are axially overlapped with one another by a relatively short axial length and a retracted position wherein said intermediate rotary shaft and said distal rotary shaft are axially overlapped with one another by a relatively long axial length, said distal rotary shaft being rotated with said intermediate rotary shaft, said rotary cutting tool being secured to said leading end of said distal rotary shaft; a cylindrical holder for rotatably supporting said distal rotary shaft, said cylindrical holder being mounted to said machine body so that said cylindrical holder is axially movable with said distal rotary shaft; and a cylindrical guide axially movably mounted to said machine body and adapted to axially movably hold and rotationally secure said cylindrical holder; said rotary cutting machine further comprising a feed mechanism including: a first pinion rotatably mounted to said machine body; a first rack formed on an outer peripheral surface of said cylindrical holder and extending parallel to said central axis of rotation; a second rack formed on an outer peripheral surface of said cylindrical guide and extending parallel to said central axis of rotation, said second rack being meshed with said first pinion; a third rack formed on said machine body and extending parallel to said first rack; and a second pinion rotatably mounted to said cylindrical guide and meshed with said first and third racks, said cylindrical guide being axially displaced upon rotation of said first pinion to cause said second pinion to be moved along said third rack so that through said first rack, said distal rotary shaft and said intermediate rotary shaft are moved between said respective extended and retracted positions.