Detection Apparatus And Method For Saw Blade Sharpening Operations

Abstract

An apparatus for positioning a feed finger of a saw sharpening machine with a saw blade mounted in the saw sharpening machine includes a tooth detection unit which is used to detect the position of a tooth of the saw blade relative to the feed finger. The tooth detection unit comprises an object detection sensor that is mounted to the feed finger facing the tooth and is used to determine the position of the tooth and an adjacent gullet. Once the position of the tooth and gullet is determined, the feed finger is moved into the gullet and the feed finger is actuated to advance the saw blade into a position for a tooth grinding operation.

1 . A method for determining a position of a saw blade mounted in a saw sharpening machine, comprising:
 positioning an object detection sensor beside an outer edge of a saw blade such that the object detection sensor faces a row of alternating saw teeth and gullets on the outer edge of the saw blade;   moving the object detection sensor relative to the row of alternating saw teeth and gullets until the object detection sensor is in an aligned position, wherein the object detection sensor faces and detects a first tooth or a first gullet; and   determining a position of the first tooth or the first gullet from the aligned position of the object detection sensor.   
     
     
         2 . The method as claimed in  claim 1 , wherein the object detection sensor is selected from the group consisting of optical sensors, inductive sensors, and capacitive proximity sensors. 
     
     
         3 . The method as claimed in  claim 2 , wherein the object detection sensor is an optical sensor selected from the group consisting of photoelectric sensors, fiber optic sensors, and laser sensors. 
     
     
         4 . The method as claimed in  claim 3 , wherein the optical sensor is a reflective type and comprises an emitter and an adjacent detector; and
 wherein both face the saw blade.   
     
     
         5 . The method as claimed in  claim 1 , wherein the object detection sensor is affixed to a feed finger of the saw sharpening machine at a known location relative to a feed fingertip of the feed finger; and
 wherein the method further comprises:
 moving the feed finger until the object detection sensor is in the aligned position with the first tooth or first gullet; 
 determining the position of a feed fingertip of the feed finger relative to a target gullet of the saw blade, wherein the location of the target gullet relative to the first gullet or the first tooth is known and the location of the feed fingertip relative to the object detection sensor is known; and 
 moving the feed finger until the feed fingertip is aligned with the target gullet. 
   
     
     
         6 . The method as claimed in  claim 5 , wherein the step of moving the feed finger comprises:
 advancing the feed finger in a direction parallel to the saw blade such that the object detection sensor moves past an expected location of the first gullet and the first tooth;   reading the object detection sensor and retracting the feed finger in a direction parallel to the saw blade and until the objection detection sensor does not detect a signal above a detection threshold; and   stop retracting the feed finger and indicate that the object detection sensor is in the aligned position.   
     
     
         7 . The method as claimed in  claim 6  further comprising after the feed fingertip is aligned with the target gullet:
 inserting the feed fingertip into the target gullet; 
 advancing the feed finger to move the saw blade; 
 withdrawing the feed fingertip out of the target gullet; and 
 retracting the feed finger into a home position. 
 
     
     
         8 . The method as claimed in  claim 1  further comprising:
 positioning a saw blade data reader in proximity to an electronically readable data source on the saw blade; and 
 reading data stored on the data source. 
 
     
     
         9 . The method as claimed in claimed  8 , wherein the saw blade data reader is a bar code scanner and the electronically readable data source is a bar code. 
     
     
         10 . The method as claimed in  claim 9 , wherein the data stored on the bar code includes information about the saw blade; and
 wherein the method further comprises decoding the data and executing a computer aided manufacturing program to perform a saw grinding operation on the saw blade using the decoded information.   
     
     
         11 . An apparatus for determining a position of a saw blade mounted in a saw sharpening machine comprising:
 an object detection sensor located beside an outer edge of the saw blade such that the object detection sensor faces a row of alternating saw teeth and gullets on the outer edge of the saw blade;   one or more motors coupled to the object detection sensor such that actuation of the one or more motors moves the object detection sensor relative to the saw blade; and   a processor and a memory having encoded thereon program code executable by the processor to:
 operate the one or more motors to move the object detection sensor relative to the row of alternating saw teeth and gullets until the object detection sensor is in an aligned position, wherein the object detection sensor faces and detects a first tooth or a first gullet; and 
 determine a position of the first tooth or the first gullet from the aligned position of the object detection sensor. 
   
     
     
         12 . The apparatus as claimed in  claim 11 , wherein the object detection sensor is selected from the group consisting of optical sensors, inductive sensors, and capacitive proximity sensors. 
     
     
         13 . The apparatus as claimed in  claim 11 , wherein the object detection sensor is an optical sensor selected from the group consisting of photoelectric sensors, fiber optic sensors, and laser sensors. 
     
     
         14 . The apparatus as claimed in  claim 13 , wherein the optical sensor is a reflective type and comprises an emitter and an adjacent detector; and
 wherein both face the saw blade.   
     
     
         15 . The apparatus as claimed in  claim 11 , wherein the one or more motors comprises one or more feed finger motors coupled to a feed finger of the saw sharpening machine;
 wherein the object detection sensor is affixed to the feed finger at a known location relative to a feed fingertip of the feed finger; and   wherein the program code is further executable by the process to:
 operate the one or more feed finger motors to move the feed finger relative to the row of alternating saw teeth and gullets until the object detection sensor is in the aligned position; and 
 determine the position of the feed fingertip relative to a target gullet; 
 wherein the position of the target gullet and the first tooth or the first gullet is known. 
   
     
     
         16 . The apparatus as claimed in  claim 15 , wherein the program code is further executable by the processor to:
 operate the one or more feed finger motors to advance the feed finger in a direction parallel to the saw blade such that the object detection sensor moves past an expected location of the first gullet and the first tooth, and retract the feed finger in a direction parallel to the saw blade by an increment that is less than the present amount;   read the object detection sensor and retract the feed finger in a direction parallel to the saw blade and until the objection detection sensor does not detect a signal above a detection threshold; and   stop retracting the feed finger and indicate that the object detection sensor is in the aligned position.   
     
     
         17 . The apparatus as claimed in  claim 16 , wherein after the program code has been executed and indicates that the object detection sensor is in the aligned position; and
 wherein the program code is further executable by the processor to:
 operate the one or more feed finger motors to move the feed finger until the feed fingertip is aligned with the target gullet; 
 insert the feed fingertip into the target gullet; 
 advance the feed finger to move the saw blade; 
 withdraw the feed fingertip out of the target gullet; and 
 retract the feed finger into a home position. 
   
     
     
         18 . The apparatus as claimed in  claim 11  further comprising a bar code scanner positioned to face a bar code on the saw blade, and operable to read data stored on the bar code. 
     
     
         19 . The apparatus as claimed in  claim 18 , wherein the data stored on the bar code includes information about the saw blade; and
 wherein the program code is further executable to decode the data and execute a computer aided manufacturing program to perform a saw grinding operation on the saw blade using the decoded information.   
     
     
         20 . The apparatus as claimed in  claim 15  further comprising an air jet assembly comprising:
 an air jet nozzle mounted on the feed finger and facing the object detection sensor; and 
 a pressurized air source fluidly coupled to the air jet nozzle.