Chain Saw Sharpener

Abstract

A chain saw sharpening device having a generally U-shaped frame defined by an upper web and first and second parallel side walls for overlying the chain and the guide bar of the chain saw. The frame includes an open area near the center of the upper web defining a sharpening area. Clamping screws are associated with the frame to secure the frame to the cutting bar and an additional clamping screw is associated with the frame for engaging the link of the tooth to be sharpened in order to fix its position with respect to the sharpening area of the frame. A rotary burr having an abradant surface is receivable in either of two diagonally disposed, independently removable bore guides for sharpening left-hand and right-hand cutting teeth.

1 . A device for sharpening the cutting teeth of a chain saw while the chain is in place on the guide bar of the chain saw, the device comprising:
 a frame having an upper web and first and second parallel side walls for overlying the chain and guide bar of the chain saw;   an open area adjacent the center of the upper web defining a sharpening area;   clamp means associated with the first side wall to secure the frame to the guide bar;   second clamp means associated with the side wall for lightly engaging the chain saw tooth to be sharpened in order to fix its position with respect to the sharpening area;   a tooth stop pawl for adjusting the position of the tooth within the sharpening area, the tooth stop pawl being mounted in a sliding block received in a keyway in the upper web of the frame, the keyway being aligned with the guide bar of the chain saw and permitting only a single degree of freedom in the direction of the guide bar;   a pawl member pivotally attached to the sliding block extending into the open sharpening area;   an adjustment bolt associated with the tooth stop pawl and rotatably captured with respect to the frame for adjusting the position of the sliding block along the length of the keyway; and   two independently removable guide means having bores for receiving therein a rotary burr for sharpening the teeth of the chain saw.   
   
   
       2 . The device of  claim 1  wherein the guide mean bores are disposed at an angle from a center axis for the guide means. 
   
   
       3 . The device of  claim 2  wherein the angle ranges from about 1° to about 10°. 
   
   
       4 . The device of  claim 2  wherein the angle is about 5°. 
   
   
       5 . The device of  claim 4 , wherein the device is configured to sharpen a tooth having a cutting surface of about 25° in when the guide means is in a first position and configured to sharpen a tooth having a cutting angle of about 35° when the guide means is rotated about its center axis 180°. 
   
   
       6 . The device of  claim 1 , wherein the device is configured to sharpen a tooth having a cutting surface of about 25° in when the guide means is in a first position and configured to sharpen a tooth having a cutting angle of about 35° when the guide means is rotated about its center axis 180°. 
   
   
       7 . A device for sharpening the cutting teeth of a chain saw while the chain is in place on the guide bar of the chain saw, the device comprising:
 a frame having an upper web and first and second parallel side walls for overlying the chain and guide bar of the chain saw;   an open area adjacent the center of the upper web defining a sharpening area;   a first and second bore disposed diagonally in the side second wall; and   independently removable guide means received in the bores, the guide means having a bore configured to receive a rotary burr for sharpening the teeth of the chain saw.   
   
   
       8 . The device of  claim 7  wherein the center axis of the first and second bores crosses the center line of the sharpening area at an angle in the range from about 20° to about 40°. 
   
   
       9 . The device of  claim 7  wherein the center axis of the first and second bores crosses the center line of the sharpening area at an angle of about 30°. 
   
   
       10 . The device of  claim 9 , wherein the guide mean bore is disposed at an angle from a center axis of the guide means. 
   
   
       11 . The device of  claim 10  wherein the angle ranges from about 1° to about 10°. 
   
   
       12 . The device of  claim 11  wherein the angle is about 5°. 
   
   
       13 . The device of  claim 12 , wherein the device is configured to sharpen a tooth having a cutting surface of about 25° in when the guide means is in a first position and configured to sharpen a tooth having a cutting angle of about 35° when the guide means is rotated about its center axis 180°. 
   
   
       14 . The device of  claim 9  wherein the guide means comprise a first and second pair of guide means, the first set having bores coaxial to the center axis of the guide means and the second pair having bores disposed at an angle of about 5° from the center axis of the guide means. 
   
   
       15 . The device of  claim 7 , wherein the first and second bores taper a larger diameter adjacent the outside of the second wall to a smaller diameter adjacent the sharpening area. 
   
   
       16 . The device of  claim 15 , wherein the guide means have a substantially conical form. 
   
   
       17 . A device for sharpening the cutting teeth of a chain saw while the chain is in place on the guide bar of the chain saw, the device comprising:
 a frame having an upper web and first and second parallel side walls for overlying the chain and guide bar of the chain saw;   an open area adjacent the center of the upper web defining a sharpening area; clamp means associated with the first side wall to secure the frame to the guide bar;   second clamp means associated with the side wall for lightly engaging the chain saw tooth to be sharpened in order to fix its position with respect to the sharpening area;   a tooth stop pawl for adjusting the position of the tooth within the sharpening area, the tooth stop pawl being mounted in a sliding block received in a keyway in the upper web of the frame, the keyway being aligned with the guide bar of the chain saw and permitting only a single degree of freedom in the direction of the guide bar;   a pawl member pivotally attached to the sliding block extending into the open sharpening area; an adjustment bolt associated with the tooth stop pawl and rotatably captured with respect to the frame for adjusting the position of the sliding block along the length of the keyway; and   a first and second bore disposed diagonally in the second side wall, independently removable guide means received in the bores, the guide means having a bores configured to receive a rotary burr for sharpening the teeth of the chain saw.   
   
   
       18 . The device of  claim 17  wherein the center axis of the first and second bores crosses the center line of the sharpening area at an angle of about 30° and the guide mean bore is disposed at an angle of about 5° from a center axis of the guide means. 
   
   
       19 . Device of  claim 17  wherein web, first and second parallel side walls, and key way are formed in an extrusion process. 
   
   
       20 . The device of  claim 17  wherein sliding block comprises a semicircular threaded channel on a bottom side, the threaded channel configured to receive therein a screw for advancing and retracting tooth stop pawl.