초록 ▼

A sharpening apparatus having at least one guide slot, a drive pulley drivingly coupled to a frame and at least one idler pulley rotatably coupled to a support member. The support member is pivotably coupled to the frame. The apparatus includes an endless abrading belt rotatable in a path over the d

A sharpening apparatus having at least one guide slot, a drive pulley drivingly coupled to a frame and at least one idler pulley rotatably coupled to a support member. The support member is pivotably coupled to the frame. The apparatus includes an endless abrading belt rotatable in a path over the drive pulley and the at least one idler pulley and a biasing member coupled to the frame for biasing the support member toward an engaged position. Pivotal movement of the support member adjusts tension in the belt. A tool is traversed into the guide slot for sharpening a cutting edge thereof. The belt and support member respond to application and release of a force applied to the belt by the cutting edge to decrease and increase, respectively, belt speed to preclude overheating of the cutting edge and damage to the belt and cutting edge.

대표청구항 ▼

What is claimed is: 1. An apparatus for sharpening a cutting tool having a cutting edge, said apparatus comprising: a frame having at least one guide slot; a motor having a drive shaft, said motor coupled to said frame, said drive shaft defining a drive pulley rotational axis; a drive pulley couple

What is claimed is: 1. An apparatus for sharpening a cutting tool having a cutting edge, said apparatus comprising: a frame having at least one guide slot; a motor having a drive shaft, said motor coupled to said frame, said drive shaft defining a drive pulley rotational axis; a drive pulley coupled to said drive shaft and rotating about said drive pulley rotational axis when said motor is activated; at least one idler pulley rotating about an idler pulley rotational axis; a support member pivotably coupled to said frame and pivoting about a support member rotational axis between an engaged position and a disengaged position, wherein said idler pulley rotational axis is fixed relative to said support member; an endless belt having an abrading surface, said endless belt trained in a path over said drive pulley and said at least one idler pulley, said endless belt rotating along said path in response to rotation of said drive pulley; and a biasing member coupled to said frame and biasing said support member toward said engaged position; wherein when said cutting edge traverses said at least one guide slot in a direction toward said endless belt, said cutting edge engages said abrading surface imparting a force on said belt to sharpen said cutting edge; wherein when said force is at and below a first threshold, said support member is in said engaged position and said belt rotates along said path at a first rotational speed; and wherein when said force increases from said first threshold toward a second threshold, said support member and biasing member respond to said force to pivot said support member from said engaged position toward said disengaged position and decrease tension in said belt such that said belt rotates along said path at a second rotational speed that is reduced from said first rotational speed. 2. The apparatus of claim 1, wherein when said force increases to said second threshold, said support member and biasing member respond to said increased force to pivot said support member into said disengaged position and release substantially all tension in said belt causing said belt to stop travel along said path. 3. The apparatus of claim 1, comprising: a detent member for releasably securing said support member in said disengaged position wherein the belt tension is released. 4. The apparatus of claim 1, wherein when said cutting edge traverses said guide slot in a direction away from said endless belt, said force decreases and said support member and biasing member respond to said decreasing force to pivot said support member toward said engaged position and increase tension in said belt such that said belt rotates along said path toward said first rotational speed. 5. The apparatus of claim 1, wherein said drive pulley rotational axis is positioned between said idler pulley rotational axis and said support member rotational axis. 6. The apparatus of claim 1, further comprising: a linkage having a first end and a second end; said first end being secured to said support member; and said second end being accessible by an operator for causing rotation of said support member about said support member rotational axis. 7. The apparatus of claim 1, comprising: a plate extending from said support member; said plate having a bearing surface disposed substantially parallel to and adjacent a driving surface of said belt, said driving surface opposite said abrading surface; and wherein said force is impaired on said belt, said bearing surface supports said driving surface. 8. The apparatus of claim 1, comprising: at lest one switch for opening and closing an electrical circuit, said at least one switch having an operable portion; said motor and said at least one switch being in electrical communication with said electrical circuit; and wherein rotation of said support member to said disengaged position causes a portion of said support member to engage said operable portion of said at least one switch to open said electrical circuit disconnecting power to said motor. 9. The apparatus of claim 1, comprising: at least one switch for opening and closing an electrical circuit, said at least one switch having an operable portion; said motor and said at least one switch being in electrical communication with said electrical circuit; and wherein rotation of said support member to said engaged position causes a portion of said support member to disengage said operable portion of said at least one switch to close said electrical circuit connecting power to said motor. 10. The apparatus of claim 9, comprising: a battery in electrical communication with said electrical circuit for providing electrical power to said circuit. 11. The apparatus of claim 1, comprising: a cover hingedly cooperating with said frame to house at least said belt, said support member, said drive pulley, and said idler pulley; said cover having a substantially concave inside surface defining an abutment surface thereon; and wherein when in said engaged position and said cover is rotated towards an open direction, said abutment surface interferes with a portion of said idler pulley thereby precluding further opening of said cover. 12. The apparatus of claim 1, comprising: a cover hingedly cooperating with said frame to house at least said belt, said support member, said drive pulley, and said idler pulley; said cover having a substantially concave inside surface defining an abutment surface thereon; and wherein when in said disengaged position and said cover is rotated towards an open direction, said abutment surface clears said idler pulley enabling further opening of said cover. 13. The apparatus of claim 1, comprising: said at least one guide slot including at least one guide surface for limiting angular rotation of said cutting edge relative to the belt. 14. The apparatus of claim 1, comprising: belt tracking means disposed on at least one of said drive pulley and said idler pulley for maintaining alignment of said belt on said drive pulley and said idler pulley. 15. The apparatus of claim 14, wherein said belt tracking means comprises at least one flange disposed on an outer edge of at least one of said idler pulley and said drive pulley. 16. The apparatus of claim 14, wherein said belt tracking means comprises: a first flange disposed on an outer edge of at least one of said idler pulley and said drive pulley; and a second flange disposed on an inner edge of at least one of said idler pulley and said drive pulley; wherein said first and second flanges are disposed on opposing ones of said idler and drive pulleys. 17. A method for sharpening a cutting edge of a cutting tool, the method comprising steps of: providing an endless belt rotating in a path about a plurality of pulleys, at least one of the pulleys affixed to a support member pivoting about a rotational axis between an engaged position and a disengaged position; engaging the belt with the cutting edge to impart a force on the belt and sharpen the cutting edge; wherein when the force is at and below a first threshold, the support member is in the engaged position and the endless belt rotates at a first rotational speed; increasing the force above the first threshold toward a second threshold; and in response to the increased force, rotating the support member from the engaged position toward the disengaged position and decreasing a tension in the belt such that the belt rotates at a second rotational speed that is less than the first rotational speed. 18. The method of claim 17, further including: wherein when the force is at and above the second threshold, rotating the support member into the disengaged position, releasing substantially all tension in the endless belt such that the belt stops travel along the path. 19. The method of claim 17, further including: wherein when the force is decreasing from and below the second threshold, rotating the support member toward the engaged position, increasing tension in the belt and increasing rotation of the belt along the path toward the first rotational speed. 20. The method of claim 17, further comprising: selectively engaging the belt with the cutting edge to impart intermittently increasing and decreasing force on the belt; in response to the intermittently increasing force, rotating the support member from the engaged position toward the disengaged position and decreasing a tension in the belt such that the belt rotates from the first to the second rotational speed; and in response to the intermittently decreasing force, rotating the support member from the disengaged position toward the engaged position and increasing a tension in the belt such that the belt rotates from the second to the first rotational speed.