Circular saw leveling and tensioning machine

Abstract

A circular saw blade straightening and tensioning machine has a set of straightening and tensioning rollers on both sides of a saw blade. The rollers are mounted on parallel shafts. Each shaft has a hub at its end, comprising a center portion horizontally eccentric with respect to the center line of the shaft, and a pair of side portions disposed on opposite sides of the center portion. Each of the side portions is horizontally eccentric with respect to the shaft center line, but in a direction opposite to that of the center portion. A roller is rotatably mounted on each of the center and side portions of the hubs. An actuator rotates each of the upper and lower shafts selectively ninety degrees in both the clockwise and counterclockwise directions. Rotation of the shafts selectively force a center roller against one surface of the saw blade while simultaneously forcing the side rollers against the other surface of the saw blade, thereby to level deformations in the blade. Rotation of the shafts in opposite directions forces the center rollers on both shafts against both surfaces of the saw blade, thereby to tension the blade. A sensor includes a movable foot pivotably mounted intermediate four fixed foot supports. The movable foot carries a gauge that measures the deviation underneath the movable foot from the plane determined by the fixed supports.

I claim:  
     
       1. A circular saw blade straightening and tensioning machine for reducing or eliminating unevenness in circular saw blades, comprising: 
       a rotatable mounting adapted to rotatably support a circular saw blade;  
       a set of straightening and tensioning rollers adapted to be disposed on both sides of the saw blade, the axis of the set being concurrent with a radius of the saw blade, the set being movable along the radius of the saw blade from the center to the periphery thereof,  
       the set comprising an upper shaft and a lower shaft, the upper and lower shafts being adapted to be disposed parallel to the upper and lower surfaces of the saw blade, respectively;  
       a hub mounted on one end of each of the upper and the lower shafts,  
       each of the hubs comprising a center portion horizontally eccentric with respect to the centerline of its respective shaft and a pair of side portions disposed on opposite sides of the center portion, each of the side portions being horizontally eccentric with respect to the centerline of its respective shaft in a direction opposite to that of the center portion;  
       a roller rotatably mounted on each of the center and side portions of each of the hubs, each roller having the same outer diameter;  
       an actuator adapted to rotate each of the upper and lower shafts selectively ninety degrees in the clockwise and counterclockwise directions,  
       rotation of the upper shaft in one of the clockwise and counterclockwise directions forcing the roller on the side portions of the hub on the upper shaft downwardly against the upper surface of the saw blade, simultaneous rotation of the lower shaft in said one direction forcing the roller on the center portion of the hub on the lower shaft upwardly against the lower surface of the saw blade, the downward movement of the rollers on the side portions of the hub on the upper shaft combining with the upward movement of the roller on the center portion of the hub on the lower shaft to force upwardly a downwardly extending unevenness in the saw blade,  
       rotation of the upper shaft in the other of the clockwise and counterclockwise directions forcing the roller on the center portion of the hub on the upper shaft downwardly against the upper surface of the saw blade, simultaneous rotation of the lower shaft in said other direction forcing the rollers on the side portions of the hub on the lower shaft upwardly against the lower surface of the saw blade, the downward movement of the roller on the center portion of the hub on the upper shaft combining with the upward movement of the rollers on the side portions of the hub on the lower shaft to force downwardly an upwardly extending unevenness in the saw blade,  
       rotation of the lower shaft in said one of the clockwise and counterclockwise directions and simultaneous rotation of the upper shaft in the other of the clockwise and counterclockwise directions forcing the roller on the center portion of the hub on the upper shaft downwardly against the upper surface of the saw blade and the roller on the center portion of the hub on the lower shaft upwardly against the lower surface of the saw blade, the downward movement of the roller on the center portion of the hub on the upper shaft combining with the upward movement of the roller on the center portion of the hub on the lower shaft to exert a compression force on the saw blade; and  
       a sensor adapted to scan one surface of the saw blade in advance of the set of rollers, said sensor being adapted to generate a signal to the rollers in the event of unevenness in the saw blade in either the upward or downward directions.  
     
     
       2. The circular saw blade straightening and tensioning machine of  claim 1 , wherein the set of rollers and the sensor are displaceable by the same distance towards the center or towards the periphery of the saw blade. 
     
     
       3. The circular saw blade straightening and tensioning machine of  claim 2 , wherein the sensor is positioned on a radius of the saw blade ninety degrees in advance of the radius of the saw blade with which the axis of the set of rollers is concurrent. 
     
     
       4. The circular saw blade straightening and tensioning machine of  claim 3 , further comprising 
       a base,  
       a threaded spindle mounted on the base,  
       a motor adapted to rotate the spindle, and  
       a first carriage adapted to mesh with the threaded spindle and to be driven therealong by the motor, the set of rollers being mounted on the first carriage, rotation of the spindle driving the first carriage to move the set of rollers along the radius of the saw blade.  
     
     
       5. The circular saw blade straightening and tensioning machine of  claim 4 , further comprising: 
       a track mounted on the base, the track making an angle of ninety degrees with respect to the axis of the threaded spindle;  
       a second carriage mounted on the track and being adapted to be driven therealong, the sensor being mounted on the second carriage; and  
       chain means connecting the first and second carriages, whereby rotation of the spindle driving the first carriage in a direction toward or away from the center of the saw blade pulls the second carriage the same distance in said direction.  
     
     
       6. The circular saw blade straightening and tensioning machine of  claim 5 , wherein the chain means comprises: 
       a first sprocket and a second sprocket coaxially mounted on the base and adapted to rotate with respect thereto;  
       a first chain attached at its ends to the first carriage, the first chain being entrained around the first sprocket to rotate the same;  
       a second chain attached at its ends to the second carriage, the second chain being entrained around the second sprocket and adapted to be rotated therewith, whereby movement of the first carriage rotates the first chain and the first sprocket to cause rotation of the second sprocket and the second chain to cause movement of the second carriage a distance equal to the movement of the first carriage.  
     
     
       7. The circular saw blade straightening and tensioning machine of  claim 4 , further comprising: 
       a first arm pivotally mounted to the first carriage, the lower shaft of the set of rollers being supported by the first arm; and  
       a second arm pivotally mounted to the first arm, the upper shaft of the set of rollers being supported by the second arm,  
       whereby the upper and lower shafts of the set of rollers can be separated to permit the circular saw blade to be placed on the rotatable mounting and between the rollers.  
     
     
       8. The circular saw blade straightening and tensioning machine of  claim 7 , further comprising: 
       a first air cylinder mounted on the first arm;  
       a first piston disposed within the first air cylinder;  
       a first piston rod attached to the first piston and extending downwardly to sit on the first carriage,  
       whereby retraction of the first piston rod permits the first arm to rotate downwardly to lower the lower shaft and the rollers mounted thereon and extension of the first piston rod rotates the first arm upwardly to raise the lower shaft and place the rollers mounted thereon adjacent the lower surface of the saw blade and in a working position.  
     
     
       9. The circular saw blade straightening and tensioning machine of  claim 8 , further comprising: 
       a generally vertical extension attached to the second arm, the extension extending above the second arm;  
       a second air cylinder mounted on the extension and depending therefrom;  
       a second piston disposed within the second air cylinder;  
       a second piston rod attached at its upper end to the second piston, the second piston rod being attached at its lower end to the second arm,  
       whereby retraction of the second piston rod rotates the second arm upwardly to raise the upper shaft and the rollers mounted thereon and extension of the second piston rod rotates the second arm downwardly to lower the upper shaft and place the rollers mounted thereon adjacent the upper surface of the saw blade and in a working position.  
     
     
       10. The circular saw blade straightening and tensioning machine of  claim 9 , further comprising: 
       means to introduce a selected amount of air pressure into the upper end of the second air cylinder upon extension of the second piston rod to limit the amount of force applicable by the actuator through the set of rollers against the upper and lower surfaces of the saw blade to said selected amount of air pressure.  
     
     
       11. The circular saw blade straightening and tensioning machine of  claim 1 , wherein the sensor comprises: 
       a frame having at least three fixed foot supports, the fixed foot supports having contact surfaces for sliding along the upper surface of the saw blade, the contact surfaces of the fixed foot supports defining a flat plane;  
       a movable foot pivotally mounted from the frame generally centrally of the fixed supports and adapted to contact the upper surface of the saw blade intermediate the fixed foot supports at a point along said radius of the saw blade; and  
       a gauge connected to the movable foot, the gauge being adapted to measure upward and downward deviation of the upper surface of the saw blade from said plane at said point along said radius and to generate a signal to the set of straightening and tensioning rollers proportional thereto.  
     
     
       12. The circular saw blade straightening and tensioning machine of  claim 11 , wherein the frame is generally rectangular, and the fixed foot supports comprise four fixed foot supports. 
     
     
       13. A circular saw blade straightening and tensioning machine for reducing or eliminating unevenness in circular saw blades, comprising: 
       a rotatable mounting adapted to rotatably support a circular saw blade;  
       a sensor adapted to move along a radius of the circular saw blade and to scan the upper surface thereof, the sensor comprising:  
       a frame having at least three fixed foot supports, the fixed foot supports having contact surfaces for sliding along the upper surface of the saw blade, the contact surfaces of the fixed foot supports defining a flat plane;  
       a movable foot pivotally mounted from the frame generally centrally of the fixed supports and adapted to contact the upper surface of the saw blade intermediate the fixed foot supports at a point along said radius of the saw blade;  
       a gauge connected to the movable foot, the gauge being adapted to measure upward and downward deviation of the upper surface of the saw blade from said plane at said point along said radius and to generate a signal proportional thereto; and  
       a set of rollers adapted to be disposed on both sides of the saw blade and to exert upward and downward pressure on said saw blade at said point responsive to said signal generated by said gauge.  
     
     
       14. The circular saw blade straightening and tensioning machine of  claim 13 , wherein the frame is generally rectangular, and the fixed foot supports comprise four flat foot supports. 
     
     
       15. A circular saw blade leveling machine for reducing or eliminating unevenness in circular saw blades, comprising: 
       
         a rotatable mounting adapted to rotatably support a circular saw blade, the saw blade having a center and first and second opposed surfaces;  
       
       
         a drive mechanism for rotating the saw blade;  
       
       
         a set of straightening rollers adapted to be disposed in proximal relationship to the first and second surfaces of the saw blade, the set being movable along a radius of the saw blade, the set including:  
       
       
         first and second shafts having respective first and second centerlines, the first and second shafts being adapted to be disposed parallel to the respective first and second opposed surfaces of the saw blade,  
       
       
         first and second hubs mounted on the respective first and second shafts, each of the first and second hubs comprising a center portion positioned between two side portions, the side portions eccentric with respect to the centerline of their respective shafts, and  
       
       
         first and second subsets of rollers, the first subset mounted for rotation about the first shaft and including a center roller rotatably mounted on the center portion of the first hub and positioned between two side rollers rotatably mounted on the side portions of the first hub, the first subset of rollers adapted to be positioned adjacent the first surface of the saw blade, the second subset of rollers mounted for rotation about the second shaft and including a center roller rotatably mounted on the center portion of the second hub and positioned between two side rollers rotatably mounted on the side portions of the second hub, the second subset of rollers adapted to be positioned adjacent the second surface of the saw blade;  
       
       
         a sensor adapted to scan one of the first and second surfaces of the saw blade and generate a sensor output signal indicative of the presence of unevenness in the saw blade; and  
       
       
         an actuator in operative association with the first and second shafts to selectively rotate the first and second shafts in response to the sensor output signal,  
       
       
         rotation of the first shaft in one of clockwise and counterclockwise directions forcing the side rollers on the first shaft against the first surface of the saw blade as the center roller on the second shaft supports the second surface of the saw blade to reduce an inwardly extending unevenness in the first surface of the saw blade, and  
       
       
         rotation of the second shaft in one of clockwise and counterclockwise directions forcing the side rollers on the second shaft against the second surface of the saw blade as the center roller on the first shaft supports the first surface of the saw blade to reduce an outwardly extending unevenness in the first surface of the saw blade. 
       
     
     
       16. The circular saw blade leveling machine of  claim 15  in which the set of rollers and the sensor are displaceable by the same distance from the center of the saw blade. 
     
     
       17. The circular saw blade leveling machine of  claim 15  in which the sensor is positioned on a radius of the saw blade ninety degrees in advance of the first and second shafts. 
     
     
       18. The circular saw blade leveling machine of  claim 15  in which the first and second opposed surfaces lie in horizontal planes. 
     
     
       19. The circular saw blade leveling machine of  claim 15 , further comprising: 
       
         a base;  
       
       
         a threaded spindle having a length and rotatably supported by the base;  
       
       
         a motor adapted to rotate the threaded spindle; and  
       
       
         a first carriage adapted to mesh with the threaded spindle and to be driven by the motor along the length of the threaded spindle, the set of rollers being mounted on the first carriage, and rotation of the threaded spindle driving the first carriage to move the set of rollers along the radius of the saw blade. 
       
     
     
       20. The circular saw blade leveling machine of  claim 20 , further comprising: 
       
         a first arm pivotally mounted to the first carriage, the second shaft of the set of rollers being supported by the first arm; and  
       
       
         a second arm pivotally mounted to the first arm, the first shaft of the set of rollers being supported by the second arm, whereby the first and second shafts of the set of rollers can be separated to permit the circular saw blade to be placed on the rotatable mounting and between the first and second shafts and thereby between the first and second subsets of rollers mounted thereon. 
       
     
     
       21. The circular saw blade leveling machine of  claim 15  in which the sensor comprises: 
       
         a frame having at least three fixed foot supports, the fixed foot supports having contact surfaces for sliding along one of the first and second surfaces of the saw blade, the contact surfaces of the fixed foot supports defining a flat plane;  
       
       
         a movable foot pivotally mounted from the frame generally centrally of the fixed supports and adapted to contact the one of the first and second surfaces of the saw blade intermediate the fixed foot supports at a point along the radius of the saw blade; and  
       
       
         a gauge connected to one of the movable foot and the frame, the gauge being adapted to measure deviation of the one of the first and second surfaces of the saw blade from the plane at the point along the radius and to generate the sensor output signal. 
       
     
     
       22. In a circular saw blade leveling machine for reducing or eliminating unevenness in circular saw blades, the machine including a rotatable support for a circular saw blade having a center and first and second opposed surfaces, a drive mechanism for rotating the saw blade, and a sensor adapted to scan one of the first and second opposed surfaces of the saw blade and generate a sensor output signal indicative of the presence of unevenness in the saw blade, a compact straightening press for eliminating deformations or unevenness in the saw blade in response to the sensor output signal, comprising: 
       
         a set of multiple straightening rollers adapted to be disposed in proximal relationship to the first and second opposed surfaces of the saw blade, the set being movable along a radius of the saw blade;  
       
       
         the set comprising first and second shafts having respective first and second centerlines, the first and second shafts being adapted to be disposed parallel to the respective first and second opposed surfaces of the saw blade;  
       
       
         the set comprising first and second subsets of rollers, the first subset of rollers mounted for rotation about the first shaft and including an interior roller positioned between two side rollers, and the first subset of rollers positioned adjacent the first surface of the saw blade, the second subset of rollers mounted for rotation about the second shaft and including an interior roller positioned between two side rollers, the second subset of rollers positioned adjacent the second surface of the saw blade;  
       
       
         the side rollers of the first subset having axes offset with respect to the centerline of the first shaft so that the side rollers are eccentric with respect to the first shaft, and the side rollers of the second subset having axes offset with respect to the centerline of the second shaft so that the side rollers are eccentric with respect to the second shaft;  
       
       
         an actuator in operative association with the first and second shafts to rotate each of the first and second shafts selectively in the clockwise and counterclockwise directions in response to the sensor output signal;  
       
       
         rotation of the first shaft in one of the clockwise and counterclockwise directions causing at least one of the side rollers of the first subset to move toward and press against a contact location on the first surface of the saw blade as the center roller of the second subset provides support against the second surface of the saw blade adjacent a location on the second surface opposite the contact location of at least one of the side rollers of the first subset to force outwardly relative to the first surface an inwardly extending unevenness in the first surface of the saw blade; and  
       
       
         rotation of the second shaft in one of the clockwise and counterclockwise directions causing at least one of the side rollers of the second subset to move toward and press against a contact location on the second surface of the saw blade as the center roller of the first subset provides support against the first surface of the saw blade adjacent a location on the first surface opposite the contact location of at least one of the side rollers of the second subset to force inwardly relative to the first surface an outwardly extending unevenness in the first surface of the saw blade. 
       
     
     
       23. The circular saw blade leveling machine of  claim 22  in which the first and second opposed surfaces lie in horizontal planes. 
     
     
       24. The circular saw blade leveling machine of  claim 22  in which the rotatable support for the saw blade includes an arbor that is operatively connected to the center of the saw blade and driven by the drive mechanism to rotate the saw blade. 
     
     
       25. A circular saw blade leveling machine comprising: 
       
         a rotatable mounting adapted to rotatably support a circular saw blade, the saw blade having a center and first and second opposed surfaces;  
       
       
         a drive mechanism for rotating the saw blade;  
       
       
         a set of straightening rollers adapted to be disposed in proximal relationship to the first and second surfaces of the saw blade, the set being movable along a radius of the saw blade, the set including:  
       
       
         first and second subsets of rollers adapted to be positioned adjacent, respectively, the first and second surfaces of the saw blade, the first subset mounted for rotation about a first shaft and including multiple first rollers, at least two of which being eccentric with respect to each other, and the second subset of rollers mounted for rotation about a second shaft and including multiple second rollers, at least two of which being eccentric with respect to each other;  
       
       
         a sensor adapted to scan one of the first and second surfaces of the saw blade and generate a sensor output signal indicative of the presence of unevenness in the saw blade; and  
       
       
         an actuator in operative association with the first and second shafts to selectively rotate the first and second shafts in response to the sensor output signal,  
       
       
         rotation of the first shaft moving one or more of the first rollers to contact the first surface of the saw blade as at least one of the second rollers contacts the second surface of the saw blade to reduce a first unevenness of the saw blade, and  
       
       
         rotation of the second shaft moving one or more of the second rollers to contact the second surface of the saw blade as at least one of the first rollers contacts the first surface of the saw blade to reduce a second unevenness of the saw blade, the first and second unevennesses including an inwardly extending unevenness and an outwardly extending unevenness of the saw blade, and selective rotation of the first and second shafts allowing reduction of the inwardly and outwardly extending unevennesses. 
       
     
     
       26. The circular saw blade leveling machine of  claim 25  in which rotation of the first and second shafts moves at least one of the first rollers to contact the first surface of the saw blade and at least one of the second rollers to contact the second surface of the saw blade to exert a compression force on the saw blade. 
     
     
       27. The circular saw blade leveling machine of  claim 25  in which the sensor is positioned on a radius of the saw blade ninety degrees in advance of the first and second shafts. 
     
     
       28. The circular saw blade leveling machine of  claim 25  in which the first and second opposed surfaces lie in horizontal planes. 
     
     
       29. The circular saw blade leveling machine of  claim 25 , further comprising: 
       
         a base;  
       
       
         a threaded spindle having a length and rotatably supported by the base;  
       
       
         a motor adapted to rotate the threaded spindle; and  
       
       
         a first carriage adapted to mesh with the threaded spindle and to be driven by the motor along the length of the threaded spindle, the set of rollers being mounted on the first carriage, and rotation of the threaded spindle driving the first carriage to move the set of rollers along the radius of the saw blade. 
       
     
     
       30. The circular saw blade leveling machine of  claim 29 , further comprising: 
       
         a first arm pivotally mounted to the first carriage, the second shaft of the set of rollers being supported by the first arm; and  
       
       
         a second arm pivotally mounted to the first arm, the first shaft of the set of rollers being supported by the second arm, whereby the first and second shafts of the set of rollers can be separated to permit the circular saw blade to be placed on the rotatable mounting and between the first and second shafts and thereby between the first and second subsets of rollers mounted thereon. 
       
     
     
       31. The circular saw blade leveling machine of  claim 25  in which the sensor comprises: 
       
         a frame having at least three fixed foot supports, the fixed foot supports having contact surfaces for sliding along one of the first and second surfaces of the saw blade, the contact surfaces of the fixed foot supports defining a flat plane; and  
       
       
         a gauge connected to the frame, the gauge being adapted to measure deviation of the one of the first and second surfaces of the saw blade from the plane and to generate the sensor output signal.