Method and apparatus for sharpening curved blades

A sharpener for blades comprising first and second wheels each having an arcuate blade-sharpening surface and rotatable in the same direction on a common axis,

• two stationary blade guides, each located adjacent to a different one of said surfaces, and
• a movable support for a blade, said support comprising a blade holder and pivotally interconnected first and second links,
• the first link pivotably supported at a location fixed with respect to the blade guides and midway between the two wheels,
• the second link supporting the blade holder adjacent a distal end of the second link, the two links together supporting the blade holder for movement in first directions toward and away from either blade-sharpening surface, in second directions transverse to the first directions, and in third directions transverse to the first and second directions, wherein the blade holder is movable simultaneously in two of said three directions during sharpening of a blade held by said blade holder,
• said blade holder being pivotably supported on the second link,
• the links and pivots being located and arranged to support the blade holder adjacent either blade guide for movement in three substantially mutually perpendicular directions relative to either blade guide and blade-sharpening surface.

A method of sharpening an elongated curved blade defining a blade edge lying in a plane comprising:

• moving a sharpening surface along a predetermined path of travel, said surface having a width substantially less than the extent of said blade;
• stationing a blade engaging guide adjacent said path of travel;
• fixedly supporting said blade on a blade support with said blade edge projecting away from said support and with said plane extending tangentially with respect to said sharpening surface;
• resiliently urging said blade into engagement with said guide;
• engaging said blade edge with said sharpening surface adjacent said guide so that said blade edge plane is to tangential to said sharpening surface and said blade curve is engaged with the guide;
• shifting said blade support to move said blade edge across said sharpening surface and shifting said blade support in a second direction parallel to the plane of said blade edge while maintaining said blade in engagement with said guide and said surface.