Bit sharpening apparatus and method of using

• US 20090124170A1
• Filed: 10/02/2008
• Published: 05/14/2009
• Est. Priority Date: 12/04/2004
• Status: Active Grant

• Current Assignee: Charles M. Thomas
• Original Assignee: Charles M. Thomas
• Inventors: Thomas, Charles M.
• Granted Patent: US 7,946,905 B2
• Time in Patent Office: Days
• US Class Current: 451/11
• CPC Class Codes: B24B 3/10 of routers or engraving needles
• CPC Class Codes: B24B 3/38 for planing wood, e.g. cutter blades

Abstract

Disclosed in the present application is a sharpening apparatus and method for sharpening a cutting bit. The apparatus comprises a sharpening member and a laser for accurately positioning the cutting bit surface to be sharpened with respect to the sharpening member. The apparatus and method are particularly useful for sharpening a router or shaper bit.

Also disclosed is a sharpening apparatus for a cutting bit having a flat face comprising grinding wheel having a shaft and a flat annular grinding surface perpendicular to said shaft; a bit holder adapted to hold said cutting bit and to orient the bit flat face into a plane that is parallel to the plane of the grinding wheel grinding surface; a carriage supporting the bit holder; advancing means for advancing said carriage in a motion parallel to the grinding wheel shaft so that the bit is against the grinding wheel grinding surface; means for side-to-side movement of said carriage in a motion perpendicular to the grinding wheel shaft; said advancing means further comprising a gear train for further advancing the bit flat face against the grinding wheel grinding surface in small increments to remove small layers of material from said bit cutting face during said side-to-side movement.

Claims

1. A sharpening apparatus for sharpening a cutting bit comprising a sharpening member and a laser for accurately positioning the cutting bit surface to be sharpened with respect to said sharpening member.

2. The sharpening apparatus of claim 1 comprising a target at the point of origin of the laser beam, said laser beam being reflected onto said target.

3. The sharpening apparatus of claim 2 further comprising a reflecting surface attachable to the cutting bit surface to be sharpened, the laser beam being directed onto said reflecting surface, said target comprising cross hairs for both vertical and horizontal adjustment of the cutting bit surface to be sharpened.

4. A sharpening apparatus for a cutting bit having a flat face comprising;

a. a grinding wheel having a shaft and a flat annular grinding surface perpendicular to said shaft;

b. a bit holder adaptable to hold said cutting bit and to orient the bit flat face into a plane that is parallel to the plane of the grinding wheel grinding surface;

c. a carriage supporting the bit holder;

d. advancing means for advancing said carriage in a motion parallel to the grinding wheel shaft so that the bit is against the grinding wheel grinding surface;

e. means for side-to-side movement of said carriage in a motion perpendicular to the grinding wheel shaft;

f. said advancing means comprising a gear train for further advancing the bit flat face against the grinding wheel grinding surface in small increments to remove small layers of material from said bit cutting face during said side-to-side movement.

5. The sharpening apparatus of claim 4 wherein said advancing means is adaptable to withdraw the cutting bit flat face away from the grinding wheel grinding face in a motion that is parallel to the grinding wheel shaft.

6. The sharpening apparatus of claim 4 wherein said bit holder comprises a tool holder, the bit being rotatable in the tool holder to position the bit flat face in a plane that has the same orientation with respect to the vertical as the grinding surface of the grinding wheel, and a tool post supporting the tool holder, the tool post being rotatable about an axis parallel to the grinding surface of the grinding wheel to position the bit flat face in a plane that is parallel to the grinding surface of the grinding wheel.

7. The sharpening apparatus of claim 6 comprising a laser and target therefore, the laser and target being positioned for accurate rotation of the bit in the tool holder and accurate rotation of the tool post.

8. A sharpening apparatus of claim 7 wherein said bit is a router or shaper bit having a plurality of blades, each blade having a carbide flat face, said grinding wheel comprising an annular fine grit diamond grinding surface.

9. A method for sharpening a cutting bit using a sharpening apparatus comprising the step of using a laser beam to accurately position the cutting bit surface to be sharpened with respect to said sharpening apparatus.

10. The method of claim 9 comprising the steps of reflecting the laser beam onto a target and accurately adjusting the position of the cutting bit surface to be sharpened both vertically and horizontally using the laser beam.

11. The method of claim 10 wherein said bit is a router or shaper bit having a plurality of blades, each blade having a carbide flat face, using a grinding wheel having an annular flat grinding surface, comprising the steps of;

a. positioning the bit in a tool holder and adjusting the bit, using said laser beam and target therefore, so that the bit flat face is in a plane that has the same orientation with respect to the vertical as the plane of the grinding surface of the grinding wheel;

b. rotating the tool holder about an axis that is parallel to the grinding surface of the grinding wheel to position the bit flat face, using said laser beam and target therefore, in a plane that is parallel to the grinding surface of the grinding wheel.

12. The method of claim 11 further comprising the step of withdrawing the bit from engagement with the grinding surface of the grinding wheel following sharpening in a motion that is perpendicular to the plane of the grinding surface of the grinding wheel.