Apparatus for producing improved cutting edges

Abstract

An apparatus is provided for forming cutting edges including a grinding stage. The grinding stage includes abrading wheels with a strip receiving end configured to receive a strip with a first profile along a path P and a strip exiting end. Axes of the abrading wheels are oriented at a tilt angle relative to the path P. Lands are provided on each abrading wheel with an abrasive surface that varies from fine to coarse in a direction from the strip receiving end to the strip exiting end. The lands are arranged in a spiral helix such that the helix is a right-handed thread on one wheel and a left-handed thread on the other wheel. An improvement is also provided for a system for removing material from a strip of metal incident on the system along a path P.

What is claimed is: 
     
         1 . An apparatus for providing cutting edges, comprising:
 a grinding stage comprising a pair of abrading wheels, wherein each abrading wheel defines a strip receiving end configured to receive a strip with a first profile along a path P and a strip exiting end that is opposite to the strip receiving end, wherein the grinding stage is oriented at a tilt angle between a plane defined by axes of the abrading wheels and the path P of the strip incident on the strip receiving end; and   a plurality of lands on each abrading wheel of said pair of abrading wheels, wherein each of said lands comprises an abrasive surface that varies from a fine abrasion to a coarse abrasion in a direction from said strip receiving end to said strip exiting end such that the lands are configured to remove metal from the first profile to form a second profile.   
     
     
         2 . The apparatus of  claim 1  further comprising a first grinding stage configured to remove metal from the strip incident on the first grinding stage along the path P to form the first profile and wherein the grinding stage is a second grinding stage. 
     
     
         3 . The apparatus of  claim 1  wherein said tilt angle is oriented such that the axes are more proximate to the path P at the strip exiting end than the strip receiving end. 
     
     
         4 . The apparatus of  claim 1  wherein the tilt angle is selected such that a contact angle between a first direction orthogonal to the path P and a second direction between a tip of the strip and a center of rotation of the pair of abrading wheels diminishes in said direction from said strip receiving end to said strip exiting end. 
     
     
         5 . The apparatus of  claim 1 , wherein said lands are arranged in a spiral helix such that the helix is a right-handed thread on one abrading wheel of the pair of abrading wheels, and a left-handed thread on the other abrading wheel of the pair of abrading wheels. 
     
     
         6 . The apparatus of  claim 1 , wherein a value of the tilt angle is selected in a range from about 0.3 degrees to about 10 degrees. 
     
     
         7 . The apparatus of  claim 1 ,
 wherein the abrasive surface comprises a plurality of sections between the strip receiving end and the strip exiting end;   wherein a first section of the plurality of sections adjacent the strip receiving end comprises a fine abrasive surface configured to contact a tip of the first profile; and   wherein a second section of the plurality of sections adjacent the strip exiting end comprises a coarse abrasive surface configured to contact a distance back from the tip of the first profile.   
     
     
         8 . The apparatus of  claim 7 , wherein the coarse abrasive surface is more coarse than the fine abrasive surface and wherein the apparatus further includes a third section of the plurality of sections between the first section and the second section and wherein the third section comprises an abrasive surface that is more coarse than the fine abrasive surface of the first section and less coarse than the coarse abrasive surface of the second section. 
     
     
         9 . The apparatus of  claim 1 ,
 wherein said tilt angle is oriented such that the axes are more proximate to the path P at the strip exiting end than the strip receiving end; and   wherein the tilt angle is selected such that a contact angle between a first direction that is orthogonal to the path P and a second direction between a tip of the strip and a center of rotation of the pair of abrading wheels diminishes in said direction from said strip receiving end to said strip exiting end.   
     
     
         10 . An apparatus for providing cutting edges comprising:
 a grinding stage including a pair of abrading wheels that extend from a strip receiving end to a strip exiting end;   wherein the pair of abrading wheels each comprise an abrasive surface that is configured to remove material from a strip of metal incident on the strip receiving end along a path P; and   wherein the abrasive surface varies from a fine abrasion to a coarse abrasion in a direction from the strip receiving end to the strip exiting end.   
     
     
         11 . The apparatus of  claim 10 , further comprising:
 a first grinding stage configured to remove metal from the strip incident on the first grinding stage along the path P to form a first profile; and   wherein the grinding stage is a second grinding stage, wherein the strip receiving end faces the first grinding stage and wherein the abrasive surface is configured to remove material from the first profile to form a second profile.   
     
     
         12 . The apparatus of  claim 10 , further comprising:
 a tilt angle formed between a plane defined by axes of the abrading wheels and the path P of the strip; and   wherein said tilt angle is oriented such that the axes are more proximate to the path P at the strip exiting end than the strip receiving end.   
     
     
         13 . The apparatus of  claim 12 , wherein a value of the tilt angle is selected in a range from about 0.3 degrees to about 10 degrees. 
     
     
         14 . The apparatus of  claim 11 , further comprising a plurality of lands on each abrading wheel of said pair of abrading wheels, wherein each of said lands comprises the abrasive surface such that the lands are configured to remove metal from the first profile to form the second profile. 
     
     
         15 . The apparatus of  claim 14 , wherein said lands on each abrading wheel of said pair of abrading wheels are arranged in a spiral helix with the spiral helix having a right-handed thread on one abrading wheel of the pair of abrading wheels, and a left-handed thread on the other abrading wheel of the pair of abrading wheels. 
     
     
         16 . The apparatus of  claim 12  wherein the tilt angle is selected such that a contact angle between a first direction orthogonal to the path P and a second direction between a tip of the strip and a center of rotation of the pair of abrading wheels diminishes in said direction from said strip receiving end to said strip exiting end. 
     
     
         17 . The apparatus of  claim 10 ,
 wherein the abrasive surface comprises a plurality of sections between the strip receiving end and the strip exiting end;   wherein a first section of the plurality of sections adjacent the strip receiving end comprises a fine abrasive surface configured to contact a tip of the first profile; and   wherein a second section of the plurality of sections adjacent the strip exiting end comprises a coarse abrasive surface configured to contact a distance back from the tip of the first profile.   
     
     
         18 . The apparatus of  claim 17 , wherein the coarse abrasive surface is more coarse than the fine abrasive surface and wherein the apparatus further includes a third section of the plurality of sections between the first section and the second section and wherein the third section comprises an abrasive surface that is more coarse than the fine abrasive surface of the first section and less coarse than the coarse abrasive surface of the second section. 
     
     
         19 . An improvement for a system for removing material from a strip of metal incident on the system along a path P, wherein the system includes a grinding stage with a plurality of abrading wheels having an abrasive surface that varies from a coarse abrasion to a fine abrasion in a direction from a strip receiving end to a strip exiting end of the grinding stage, wherein the improvement comprises:
 an intermediate stage positioned after the grinding stage wherein the intermediate stage includes an abrasive surface that varies in a reverse direction to the abrasive surface of the grinding stage, from a fine abrasion to a coarse abrasion in a direction from a strip receiving end to a strip exiting end of the intermediate stage.   
     
     
         20 . A system for removing material from a strip of metal incident on the system along a path P, wherein the system includes:
 a finishing stage with a plurality of abrading wheels having axes that extend from a strip receiving end to a strip exiting end of the finishing stage and are oriented at a first orientation relative to the path P, wherein the abrading wheels include a plurality of lands arranged in a spiral helix such that the helix is a right-handed thread on one abrading wheel of the pair of abrading wheels, and a left-handed thread on the other abrading wheel of the pair of abrading wheels, wherein a start of the helix at the strip receiving end of the abrading wheel contacts a tip of the strip in a direction from the tip of the strip to a body of the strip; and an intermediate stage positioned before the finishing stage, wherein the intermediate stage includes;
 a plurality of abrading wheels having axes that extend from a strip receiving end to a strip exiting end of the intermediate stage, wherein the axes are oriented at the same first orientation of the axes of the finishing stage relative to the path P, and 
 a plurality of lands arranged in a spiral helix having a same orientation as the spiral helix of the finishing stage relative to the axes of the intermediate stage.