Saw chain sharpening method and apparatus

A sharpener for a chain saw including a saw bar around which a saw chain is driven, said saw chain including links provided with cutter teeth having top sharpenable surfaces and side sharpenable surfaces and movable along a predetermined path, said sharpener comprising:

• an attachment for application to a curved end of said saw bar adjacent a curved portion of the path of the cutter teeth of the saw chain, said attachment including a flexible abrasive member, and locating means mounted relative to said predetermined path for positioning said flexible abrasive member adjacent said path, said member having an abrasive surface disposed thereby generally along said path and facing the top sharpenable surfaces of said cutter teeth,
• said flexible abrasive member being flexed to bear against said top surfaces of said cutter teeth while being otherwise unrestrained in an area of contact with the cutter teeth top surfaces, said flexible abrasive member being flexed to curve around at least part of the curved portion of the path of the cutter teeth of said saw chain,
• wherein said attachment is further provided with side sharpening elements disposed adjacent sides of said saw chain to sharpen said side sharpenable surfaces of said cutter teeth.

A sharpener for a saw having a plurality of cutter teeth provided with top sharpenable surfaces and movable along a predetermined path, said sharpener comprising:

• locating means mounted relative to said predetermined path and a flexible strip of abrasive material positioned thereby adjacent said path, said strip having an abrasive surface disposed generally along said path and facing the top sharpenable surfaces of said cutter teeth to have an area of contact with the top surfaces of said cutter teeth moving along said path,
• strip support means on said locating means supporting said strip of abrasive material adjacent the opposite ends of sida area of contact, said strip being free of support between said strip support means whereby it may flex relative to the top surfaces of said cutter teeth toward and away from said path in said area of contact with said cutter teeth top surfaces so that said strip can assume the contour of the path of the cutter teeth top surfaces in said area of contact.

A sharpener for a saw having a plurality of cutter teeth provided with top sharpenable surfaces and outwardly disposed side sharpenable surfaces and movable along a predetermined path, said sharpener comprising:

• locating means mounted relative to said predetermined path and a flexible strip of abrasive material positioned thereby adjacent said path, said strip having an abrasive surface disposed generally along said path and facing the top sharpenable surfaces of said cutter teeth to have an area of contact with the top surfaces of said cutter teeth moving along said path,
• said strip of abrasive material being supported by said locating means to impart flexure to said strip relative to the top surfaces of said cutter teeth, said strip being unrestrained in an area of contact with the cutter teeth top surfaces except for the said flexure thereof,
• wherein said locating means is substantially U-shaped having opposed legs for positioning on respective sides of a saw structure and is provided with side sharpening elements at said legs for contacting and sharpening said outwardly disposed side sharpenable surfaces on the cutter teeth.

A sharpener for a chain saw, said chain saw including a saw bar with a curved end, a saw chain entrained around the edge of said saw bar, and driving means for driving said chain around said bar, said saw chain having cutters with top sharpenable surfaces and outer side sharpenable surfaces, said sharpener comprising:

• an attachment removably engageable with said saw bar, said attachment having end means for sharpening said top sharpenable surfaces as said chain is driven around said bar, and said attachment having side sharpening means for sharpening said outer side sharpenable surfaces,
• said side sharpening means facing inwardly at the edge of the saw bar toward the side sharpenable surfaces of a saw chain located therebetween and having abrasive surfaces for contacting said side sharpenable surfaces,
• said attachment including means for yieldably urging said side sharpening means toward said side sharpenable surfaces of said saw chain.

A sharpener for a saw device having a plurality of cutter teeth with outer side sharpenable surfaces which are movable along a predetermined path, said sharpener comprising:

• side sharpening elements for sharpening said outer side sharpenable surfaces of said cutter teeth,
• means for mounting said side sharpening elements at each side of said path and facing toward side sharpenable surfaces of the cutter teeth moving along said path, said side sharpening elements having inwardly, substantially planar abrasive surfaces for contacting said side sharpenable surfaces,
• and means for yieldably urging said side elements toward the side sharpenable surfaces of said cutter teeth.

A sharpener for a chain saw, said chain saw including a saw bar with a curved end, a saw chain entrained around the edge of said saw bar, and driving means for driving said chain around said bar, said sharpener comprising:

• an attachment removably engageable with said saw bar for receiving a strip of flexible abrasive material having an abrasive surface disposed by said attachment in generally parallel relation to the path of said chain and facing the top surfaces of cutters forming part of said saw chain,
• said attachment including strip supporting means for flexing said strip for causing the abrasive surface thereof to be urged radially inwardly of said saw bar in contacting relation with the top surfaces of said cutters of said chain, said strip being longitudinally restrained and supported upstream along said strip from an area of chain contact by said strip, said strip being unrestrained longitudinally forwardly along the path of chain travel from said contact area, the strip immediately adjacent the top surfaces of said cutters being free to flex radially toward the top surfaces of said cutters.

A sharpener for cutters movable in one direction in an arcuate path on a saw, said sharpener comprising means for mounting an elongate flexible abrasive strip adjacent the arcuate path of the cutters to engage and sharpen top, radially outwardly facing surfaces of the cutters at a contact region, said mounting means including means upstream from said contact region for restraining the strip against longitudinal movement in the direction of movement of a cutter, a pair of strip support members spaced apart upstream and downstream, respectively, along said path from said contact region and so positioned that a straight line connecting said support members defines a chord of said arcuate path to cause a portion of a strip extending therebetween and supported thereby to be urged into contact with said cutters at said contact region, there being no other support of said flexible strip between said members whereby said flexible strip is free to move toward and away from said path in the region of contact so that said strip can assume the contour of the path of said cutters in said region of contact.

A sharpener for cutters movable in one direction in an arcuate path on a saw, said sharpener comprising means for mounting an elongate flexible abrasive strip adjacent the arcuate path of the cutters to engage and sharpen top, radially outwardly facing surfaces of the cutters at a contact region, said mounting means including means upstream from said contact region for restraining the strip against longitudinal movement in the direction of movement of a cutter, a pair of strip support members spaced apart upstream and downstream, respectively along said path from said contact region and so positioned that a straight line connecting said support members defines a chord of said arcuate path to cause a portion of a strip extending therebetween and supported thereby to be urged into contact with said cutters at said contact region, said strip being otherwise unrestrained in the region of contact, and said strip being free of longitudinal restraint downstream in said path from said contact region.

A sharpener for cutters movable along a path in a saw, said cutters having laterally outwardly facing side sharpenable surfaces, said sharpener comprising:

• a mounting frame having a pair of laterally spaced portions defining a path through which cutters may pass,
• a pair of side sharpening surfaces mounted on said frame on opposite sides of said path to engage side sharpenable surfaces of said cutters moved through said path, and
• and biasing means yieldably urging said side sharpening surfaces inwardly toward said path to produce positive engagement of said side sharpening surfaces with side sharpenable surfaces of cutters moved along said path.

The method of sharpening cutter teeth having outer side sharpenable surfaces on side plates, and rearwardly and downwardly sloping surfaces on top plates, said method comprising:

• moving said cutter teeth along a predetermined path,
• disposing abrasive surfaces against the outer side sharpenable surfaces of said cutter teeth moving along said path,
• and canting said abrasive surfaces inwardly toward the bottom of said side sharpenable surfaces to provide said cutter teeth with vertical and horizontal side plate clearance angles.