Claims
- 1. A sheet material cutting apparatus comprising:a support frame having a work supporting surface; a cutting head coupled to said support frame adjacent to said work supporting surface and including a rotatable knife frame having a presser foot movably coupled thereto for movement between a working position and a non-working position relative to said knife frame, said knife frame being rotatable relative to said support frame; an elongated blade having cutting surfaces defining a vertically extending cutting edge and coupled to said knife frame for reciprocation relative to said knife frame to cut sheet material supported on said work supporting surface; a primary sharpener coupled to said knife frame and selectively engageable with the elongated blade for removing material therefrom during a primary sharpening operation; and a secondary sharpener coupled to said presser foot and fixed in a generally vertical direction with respect to said presser foot for movement therewith in said generally vertical direction, said secondary sharpener including a sharpening surface movable in a generally horizontal direction with respect to said presser foot for movement relative to said presser foot in said generally horizontal direction to selectively engage said blade during a secondary sharpening operation, and wherein the secondary sharpener further includes a biasing member coupled to said sharpening surface and biasing said sharpening surface away from said blade, whereby the secondary sharpener can be spaced from the blade when said presser foot is in the working position.
- 2. A sheet material cutting apparatus as defined by claim 1, comprising: said secondary sharpener being generally vertically movable with respect to said primary sharpener.
- 3. A sheet material cutting apparatus as defined by claim 1, wherein:said cutting edge is defined by two intersecting cutting surfaces; said primary sharpener is engageable with at least one of said cutting surfaces; and said secondary sharpener is engageable with both of said two cutting surfaces.
- 4. A sheet material cutting apparatus as defined by claim 3, wherein said secondary sharpener is defined in part by a monolithic sharpening member having said sharpening surface thereon, and said sharpening surface comprises a V-shaped notch of a shape complementary to said cutting edge of said blade.
- 5. A sheet material cutting apparatus as defined by claim 1, further comprising a controller wherein the primary sharpener is in communication with the controller and includes at least one abrasive grinding wheel coupled to said knife frame adjacent to said cutting edge, said abrasive grinding wheel being selectively engageable with said cutting edge during reciprocation of said blade for removing material therefrom, and sharpening said cutting edge in response to commands issued from the controller.
- 6. A sheet material cutting apparatus as defined by claim 1, wherein said secondary sharpener further comprises:a sharpening member having said sharpening surface thereon and slideably coupled to said presser foot adjacent to said cutting edge; actuating means for moving said sharpening member into sharpening engagement with said blade such that said sharpening surface engages at least a portion of at least one of said cutting surfaces when said presser foot is in said non-working position.
- 7. A sheet material cutting apparatus as defined by claim 6, wherein said actuating means includes a solenoid.
- 8. A sheet material cutting apparatus as defined by claim 6, said actuating means includes a pneumatic cylinder.
- 9. A sheet material cutting apparatus as defined by claim 6, wherein said actuating means includes a hydraulic cylinder.
- 10. A sheet material cutting apparatus as defined by claim 1, wherein said secondary sharpener includes a sharpening member having said sharpening surface thereon and further includes at least one guide member coupled to said presser foot, said sharpening member being slidably engaged with said guide member for movement between a sharpening and a non-sharpening position.
- 11. A sheet material cutting apparatus as defined by claim 10, wherein said guide member further includes a rod and said sharpening member defines an aperture extending therethrough, said aperture slidably receiving said rod; and wherein said biasing member is a spring slidably positioned over said rod and between said sharpening member and said presser foot for urging said sharpening member away from said cutting edge during a cutting operation.
- 12. The sheet material cutting apparatus of claim 1 wherein said secondary sharpener does not rotate relative to said blade when engaged with at least one of said cutting surfaces.
- 13. The sheet material cutting apparatus of claim 1 wherein said secondary sharpener remains stationary relative to said knife frame when engaged with at least one of said cutting surfaces that defines a leading edge of said elongated blade.
CROSS REFERENCE TO RELATED APPLICATION
This application is a divisional of U.S. patent application Ser. No. 09/007,412 entitled DUAL SHARPENER APPARATUS FOR MAINTAINING THE SHARPNESS OF THE CUTTING EDGE ON BLADES USED TO CUT SHEET-TYPE WORK MATERIALS, filed on Jan. 15, 1998, now abandoned.
US Referenced Citations (12)