Cutting bit for mining and excavating tools

Abstract

A wear-resistant cutting bit for use on a mining or excavating cutting tool is disclosed. The cutting bit utilizes a hardened insert having a narrow base attached to the remainder of the cutting bit. An extended collar of the hardened insert projects from the cutting bit and ends with a generally conical section. The extended collar and narrow base of the hardened insert enable the cutting bits of the present invention to be more wear-resistant and cost-effective than other cutting bits used on mining and excavating equipment.

1 . An insert for a cutting bit comprising:
 a generally conical portion;   an extended collar adjacent and rearward of the generally conical portion, the extended collar portion having a diameter and an axial length;   a tapered transition segment adjacent the extended collar; and   a reduced diameter base adjacent the tapered transition segment.   
   
   
       2 . The insert for a cutting bit of  claim 1 , wherein the reduced diameter base has a diameter which is about 35% to about 85% of the diameter of the extended collar. 
   
   
       3 . The insert for a cutting bit of  claim 1 , wherein the reduced diameter base has a diameter which is about 70% of the diameter of the extended collar. 
   
   
       4 . The insert for a cutting bit of  claim 1 , wherein the hardened bit is made from cemented tungsten carbide. 
   
   
       5 . The insert for a cutting bit of  claim 1 , wherein the extended collar has a diameter of about 15 mm to about 35 mm. 
   
   
       6 . The insert for a cutting bit of  claim 1 , wherein the extended collar has a diameter of about 25 mm. 
   
   
       7 . The insert for a cutting bit of  claim 1 , wherein the extended collar has an axial length of about 5 mm to about 35 mm. 
   
   
       8 . The insert for a cutting bit of  claim 1 , wherein the extended collar has an axial length of about 10 mm. 
   
   
       9 . A cutting bit comprising:
 a forward portion and a shank oriented about a longitudinal axis, the forward portion having a socket;   a hardened insert affixed to the socket of the forward portion, the hardened insert comprising a generally conical portion adjacent an extended collar adjacent and transition segment adjacent a reduced diameter base,   wherein the reduced diameter base and transition section fit into the socket of the forward portion.   
   
   
       10 . The a cutting bit of  claim 9 , wherein the reduced diameter base has a diameter which is about 35% to about 85% of the diameter of the extended collar. 
   
   
       11 . The cutting bit of  claim 9 , wherein the reduced diameter base has a diameter which is about 70% of the diameter of the extended collar. 
   
   
       12 . The cutting bit of  claim 9 , wherein the hardened bit is made from cemented tungsten carbide. 
   
   
       13 . The cutting bit of  claim 9 , wherein the extended collar has a diameter of about 15 mm to about 35 mm. 
   
   
       14 . The cutting bit of  claim 9 , wherein the extended collar has a diameter of about 25 mm. 
   
   
       15 . The cutting bit of  claim 9 , wherein the extended collar has an axial length of about 5 mm to about 35 mm. 
   
   
       16 . The cutting bit of  claim 9 , wherein the extended collar has an axial length of about 10 mm. 
   
   
       17 . The cutting bit of  claim 9 , wherein the hardened insert is affixed to the socket by brazing. 
   
   
       18 . The cutting bit of  claim 9 , further comprising a wear-resistant sheath affixed to the forward portion.