Saw blade for cutting fiber cement

Abstract

An improved circular saw blade designed for cutting fiber cement workpieces, which are becoming more and more prevalent on the construction site, includes a PCD/carbide tip mounted in the rim of a saw blade at six, rather than the usual four locations, equally spaced around the blade. The tips are mounted adjacent a relatively large-diameter, semi-circular gullet, which itself is preceded by a chip and dust minimizer. The minimizer includes several alternating hills and valleys formed in the rim of the saw blade, each hill and valley having the same radius, producing a sinuous array essentially centered on the rim of the blade. It has been discovered that such a dust and chip minimizer reduces the level of dust and chips produced by the blade and clears the same from the kerf generated in the blade-workpiece interface. Ideally, all of the parameters and relief angles for the surfaces on the saw blade tip can be generated by cutting an array of such tips from a large-diameter blank of PCD fused to a layer of tungsten carbide, and by mounting the tips onto the blade in such an orientation as to present, preferably, a negative hook or rake angle to the workpiece.

1 - 20 . (canceled)  
   
   
       21 . A process for making a saw blade tip, comprising: 
 cutting an array of tips from a PCD blank;    the PCD blank having a PCD layer pre-joined to a carbide layer;    each tip having two diverging radially-relieved side surfaces; and wherein    the array is formed by a plurality of adjacent tips oriented such that one of said relieved side surfaces of one tip is adjacent the opposite relieved side surface of another tip.    
   
   
       22 . The process claimed in  claim 21 , wherein the base of one tip is adjacent the top of another tip.  
   
   
       23 . A process for making a saw blade, comprising: 
 cutting all of the relief surfaces into a PCD blank to form a saw blade tip; and    mounting a plurality of said cut tips on rim shoulders adjacent a corresponding plurality of gullets formed in the rim of a circular saw blade, the tips being mounted at a negative rake angle.    
   
   
       24 . A circular saw blade formed by the process claimed in  claim 23 , and further comprising: 
 a dished area formed in said shoulder to underlie a corner of said tip.    
   
   
       25 . A circular saw blade formed by the process claimed in  claim 23 , further comprising a chip and dust minimizer formed at a plurality of sites in said rim of said saw blade.  
   
   
       26 . The circular saw blade claimed in  claim 25 , further comprising a plurality of gullets formed in the rim of said circular saw blade, each chip minimizer being formed in front of each said gullet in the direction of rotation of the saw blade.  
   
   
       27 . The circular saw blade claimed in  claim 25 , wherein at least one gullet is annular and having a constant radius.  
   
   
       28 . The circular saw blade claimed in  claim 27 , wherein said at least one gullet is substantially defined in profile by a semicircle, the center of the semicircle being located radially inwardly of the perimeter of the saw blade.