Patent CA-2163472-A1 (CA)
Title: Dual rotary cutter blade sharpener
Inventor: TERRIS ALTA FAYE
IPC: B24B3/46
Filed: 1995-11-22
Abstract: This invention is a tool designed to sharpen rotary cutter blades used for cutting fabrics.  In the first or preferred embodiment, when a dulled blade is placed over a threaded shank, an inside-threaded  clamp  is  screwed  down  upon  the  blade, pressing it tightly against a platform from which the shank rises, and holding the blade from turning.          When an upper casing containing an inside angled abrasive  strip  is  lowered  over  the  clamp  until contact  is  made  against  the  blade  surface,  the abrasive  strip is  brought into contact with the blade edge.  When the upper casing is rotated around the  tightened clamp,  the abrasive acts  upon the blade edge and thereby sharpens the edge.  Removing the upper casing and clamp, the blade is then turned over,  replaced  on  the  platform  and  the  process repeated, thereby sharpening both sides of the blade edge.  A first alternate embodiment of this rotary cutter blade sharpening tool has two part, an outer casing and an inner casing, which form a circular box when assembled.   Inside the inner casing is a keyed hub platform upon which a dulled blade is placed, the hub key protruding up through one of the several blade slots formed around the blade center-ing hole, the key thereby restraining movement of the blade rotationally.   When the outer casing if placed over and around the inner casing an abrasive strip  affixed  at a certain  angle on a platform inside the outer casing then comes into contact with the blade edge, and when the outer casing is rotated around  the  inner  casing  in  clockwise  and  anti-clockwise motions, the abrasive strip thereby acts on the blade edge, sharpening said edge to a uniform sharpness.   The box can then be opened, the blade turned upside-down, replaced on the platform inside the  lower casing and the process  repeated,  thus sharpening both sides of the blade edge.    A second alternate or most preferred embodiment of  this  hand-held  apparatus  for  sharpening  the circular cutting blade of a rotary cutter tool is disclosed.    The  most  preferred  embodiment  is generally comprised of a blade holder for holding the cutting blade stationary and a ring member with an abrasive strip which fits around the blade holder such that the abrasive strip contacts the edge of the  cutting  blade.    The  blade  holder  comprises detachable  male  and  female  members  having  base portions for securing the cutting blade and handle portions mounted on the base portions for rotating the blade holder relative to the ring member.  The male member includes a means for fastening the male member to the female member mounted on the base portion which can be a screw or a shank portion.          The female member includes a cavity in the base portion for receiving the fastening means.  The ring member  has  two  radial  sides  with  an  angulated portion on each side and an abrasive strip fixedly attached to each angulated portion,  one abrasive strip having a finer abrasive than the other strip.          In operation, the cutting blade is positioned on the base portion of the male member.  The female member is then positioned on the cutting blade such that the fastening means engages the cavity in the female member.   The ring member is positioned around the base portion of the  female member such that the coarser abrasive  strip contacts  the  edge of  the cutting blade.  The blade holder is rotated relative to  the  ring  member,  rubbing  the  cutting  blade against the abrasive strip.  The ring member is then inverted and the  finer abrasive  strip is  rubbed against  the  cutting  blade.    The  procedure  is repeated for the opposite side of the cutting blade.