Pocket Protecting Retainable Cutter Bit

Abstract

Pocket protecting retainable cutter bits used on various mining, excavating, and foundation drilling tools and equipment are disclosed. The invention includes a combination of one or more free spinning wear rings axially mounted in recessed portions of the cutter bit shank and a groove and snap ring retainer. The wear rings are tapered on at least one end to assist in installation and designed to compress as the cutter bits are installed into cutter bit pockets. These wear rings are designed to protect the inside surface of the pocket by acting as a barrier between the spinning cutter bit and the stationary inside surface of the pocket. The cutter bit shank is longer than the cutter bit pocket and when installed passes through the pocket and extends past the axial length of the pocket. A flange is included with the cutter bit to protect the outer surface of the pocket.

1 . A cutter bit comprising
 a relieved shank surface, a retaining shoulder, and a split wear ring, where the split wear ring is axially mounted to and substantially surrounds the relieved shank surface, where the split wear ring has a resting outer diameter, where the retaining shoulder has an outer diameter, where the resting outer diameter of the split wear ring is greater than the outer diameter of the retaining shoulder.   
   
   
       2 . The cutter bit of  claim 1 , further comprising a snap ring shaft and a snap ring groove, where the snap ring shaft has an outer diameter, where the outer diameter of the snap ring shaft is less than the outer diameter of the retaining shoulder. 
   
   
       3 . The cutter bit of  claim 1 , further comprising a flange. 
   
   
       4 . The cutter bit of  claim 3 , where the flange has an outer diameter, where the outer diameter of the flange is greater than the resting outer diameter of the split wear ring. 
   
   
       5 . The cutter bit of  claim 1 , where the split wear ring comprises a tapered edge, where the tapered edge is adjacent to the retaining shoulder. 
   
   
       6 . The cutter bit of  claim 1 , additionally comprising an additional split wear ring. 
   
   
       7 . A cutter bit system comprising a cutting bit and a pocket,
 where the cutter bit comprises a relieved shank surface, a retaining shoulder, and a split wear ring, where the split wear ring is axially mounted to and substantially surrounds the relieved shank surface, where the split wear ring has a resting outer diameter, where the retaining shoulder has an outer diameter, where the resting outer diameter of the split wear ring is greater than the outer diameter of the retaining shoulder, where the split wear ring can be compressed thereby reducing its outer diameter,   where the pocket has an inner surface, where the inner surface of the pocket has a first inner diameter that is greater than the outer diameter of the retaining shoulder of the cutter bit and less than the resting outer diameter of the split wear ring.   
   
   
       8 . The cutter bit system of  claim 7 , where the cutter bit relieved shank surface, retaining shoulder, and split wear ring are secured within the inner surface of the pocket. 
   
   
       9 . The cutter bit system of  claim 7 , where the cutter bit further comprises a snap ring shaft and a snap ring groove, where the snap ring shaft has an outer diameter, and where the inner surface of the pocket has a second inner diameter that is less than the first inner diameter, where the second inner diameter is greater than the outer diameter of the snap ring shaft. 
   
   
       10 . The cutter bit system of  claim 9 , where the cutter bit further comprises a snap ring, where the snap ring secures the cutter bit to the pocket. 
   
   
       11 . The cutter bit system of  claim 7 , where the cutter bit further comprises a flange, where the flange has an outer diameter, where the outer diameter of the flange is greater than the resting outer diameter of the split wear ring. 
   
   
       12 . The cutter bit system of  claim 11 , where the outer diameter of the flange is greater than the first inner diameter of the pocket. 
   
   
       13 . The cutter bit system of  claim 7 , where the split wear ring comprises a tapered edge, where the tapered edge is adjacent to the retaining shoulder. 
   
   
       14 . A method of using a cutter bit comprising the steps of
 obtaining a cutter bit, where the cutter bit comprises a relieved shank surface, a retaining shoulder, a flange, and a split wear ring, where the split wear ring is axially mounted to and substantially surrounds the relieved shank surface, where the split wear ring has a resting outer diameter, where the retaining shoulder has an outer diameter, where the resting outer diameter of the split wear ring is greater than the outer diameter of the retaining shoulder, where the split wear ring can be compressed thereby reducing its outer diameter, where the flange has an outer diameter,   inserting the relieved shank surface, retaining shoulder, and split wear ring of the cutter bit into a pocket, where the pocket is secured to a host tool,   securing the cutter bit to the pocket,   using the host tool with the pocket and cutter bit to dislodge and/or break apart material   where the pocket has an inner surface, where the inner surface of the pocket has a first inner diameter that is greater than the outer diameter of the retaining shoulder of the cutter bit and less than the resting outer diameter of the split wear ring, where the outer diameter of the flange is greater than the first inner diameter of the pocket.   
   
   
       15 . The method of  claim 14 , where the insertion of the cutter bit into the pocket causes the split wear ring to compress. 
   
   
       16 . The method of  claim 14 , where the split wear ring has an inner diameter, where the relieved shank surface has an outer diameter, where the inner diameter of the split wear ring after insertion into the pocket is greater than the outer diameter of the relieved shank surface. 
   
   
       17 . The method of  claim 14 , where the cutter bit rotates relative to the pocket during use, and where the relieved shank surface rotates relative to the split wear ring, thereby reducing the wearing of the inner surface of the pocket from the rotation of the cutter bit. 
   
   
       18 . The method of  claim 14 , where the cutter bit further comprises a snap ring shaft and a snap ring groove, where the snap ring groove in conjunction with a snap ring secures the cutter bit to the pocket. 
   
   
       19 . The method of  claim 14 , where the split wear ring comprises a tapered edge, where the tapered edge is adjacent to the retaining shoulder, where the tapered edge aids in the insertion of the split wear ring into the pocket. 
   
   
       20 . The method of  claim 14 , further comprising the step of removing the cutter bit from the pocket.