Cutting bit and compact

Abstract

A replaceable cutting bit for insertion in a bit holder. The cutting bit includes a carbide ballistic compact having polycrystalline diamond layer brazed into a cavity defined in a protective ring. The cutting bit further includes a steel base having a hexagonal portion adapted for engagement with a wrench of other tool. The steel base defines a cavity into which a first hardened washer coated with abrasion resistant material is provided. The cutting bit further includes a second hardened washer coated with abrasion resistant material that is adapted to rotate relative to the first washer when the cutting bit is in operation in a bit holder.

What is claimed is: 
     
         1 . A cutting bit comprising:
 a base protective ring having a top portion and a bottom portion;   a top protective ring coupled to the top portion of the base protective ring;   a compact provided in a cavity of the top protective ring; and   a cutting bit holding assembly coupled to the bottom portion of the base protective ring, the cutting bit holding assembly comprising a baseplate provided around a top portion of a central shaft, with a cavity defined in a bottom portion of the baseplate;   a first washer provided in the cavity and around the top portion of the central shaft; and   a second washer provided around the central shaft;   wherein the second washer is rotatable or spinnable relative to the first washer.   
     
     
         2 . The cutting bit of  claim 1 , wherein the second washer is rotatable or spinnable relative to the first washer when the cutting bit holding assembly is coupled to a cutting bit holder. 
     
     
         3 . The cutting bit of  claim 1 , wherein the compact is made of a polycrystalline diamond layer affixed to a high cobalt matrix straight grade tungsten carbide. 
     
     
         4 . The cutting bit of  claim 1 , wherein the top protective ring and base protective ring are each made at least partially of tungsten carbide. 
     
     
         5 . The cutting bit of  claim 4 , wherein the compact, top protective ring, base protective ring are coupled together by brazing. 
     
     
         6 . The cutting bit of  claim 1 , wherein the compact is ballistic shaped. 
     
     
         7 . The cutting bit of  claim 1 , wherein baseplate includes a bottom portion having a geometric shape configured for engagement with a wrench. 
     
     
         8 . The cutting bit of  claim 1 , wherein the geometric shape is an polygonal shape. 
     
     
         9 . The cutting bit of  claim 1 , further comprising a fastener provided around a bottom portion of the central shaft. 
     
     
         10 . The cutting bit of  claim 9 , further comprising a spring clip provided around the central shaft between the fastener and the fastener and the baseplate. 
     
     
         11 . The cutting hit of  claim 1 , wherein the central shaft comprises a top section and a bottom section. 
     
     
         12 . The cutting bit of  claim 11 , wherein the top section of the central shaft is made, coated or hardened at least partially with tungsten carbide. 
     
     
         13 . A cutting bit comprising:
 a top protective ring coupled the top portion of a rumbler shank; and   a compact provided in a cavity of the top protective ring;   wherein the rumbler shank comprises a holding assembly having a central shaft and a baseplate.   
     
     
         14 . The cutting bit of  claim 13 , further comprising a ballistic nut having external threading, the ballistic nut being threaded into a threaded internal borehole defined in the bottom of the central shaft. 
     
     
         15 . The cutting bit of  claim 13 , wherein the ballistic nut is tapered. 
     
     
         16 . The cutting hit of  claim 13 , wherein the ballistic nut expands at least one relief slot defined in central shaft as the ballistic nut is threaded into the central shaft.