Gouging cutter structure and drill bit made therewith

Abstract

A gouging cutter, includes a cutting element having a cutting end and a mounting feature displaced from the cutting end a cutter body affixable to a drill bit body. The cutter body has a corresponding mounting feature arranged to cooperate with the mounting feature on the cutting element to retain the cutting element to the cutter body so as to enable rotation of the cutting element therein. A drill bit may include a bit body having features to enable connection to a drill string and at least one of the foregoing gouging cutters mounted to the bit body.

What is claimed is: 
     
         1 . A gouging cutter, comprising:
 a cutting element having a cutting end and a mounting feature displaced from the cutting end; and   a cutter mount body affixable to a drill bit body and having a corresponding mounting feature arranged to cooperate with the mounting feature on the cutting element to retain the cutting element to the cutter mount body so as to enable rotation of the cutting element with respect thereto.   
     
     
         2 . The gouging cutter of  claim 1  wherein the cutting element comprises at least one of tungsten carbide, cubic boron nitride and polycrystalline diamond. 
     
     
         3 . The gouging cutter of  claim 1  wherein the cutter body comprises steel. 
     
     
         4 . The gouging cutter of  claim 1  wherein the cutter body is rotatably mounted in a corresponding pocket in a bit body. 
     
     
         5 . The gouging cutter of  claim 1  wherein the cutting end is substantially conical. 
     
     
         6 . The gouging cutter of  claim 1  wherein the mounting feature on the cutting element comprises the cutting element having a cutting end, a main diameter portion having a selected outer diameter and an inner end having a selected outer diameter larger than the outer diameter of the main portion, the cutter mount body having an internal diameter selected to enable movement therein of the inner end of the cutting element, and a retainer having an internal opening selected to enable movement therethrough of the main portion and a mounting surface having an external diameter selected to substantially match an internal diameter of the cutter mount body. 
     
     
         7 . The gouging cutter of  claim 1  wherein the mounting feature on the cutting element comprises a first groove formed on an inner surface of an opening in a longitudinal end of the cutting element opposed to the cutting end, the groove cooperating with a second groove formed on an end of the cutter mount body shaped to fit within the opening, and a locking element disposed in the first groove and the second groove. 
     
     
         8 . The gouging cutter of  claim 7  wherein the cutting element comprises a separate cutting element affixed to a rotating cutter body. 
     
     
         9 . The gouging cutter of  claim 7  wherein the locking element comprises ball bearings. 
     
     
         10 . The gouging cutter of  claim 9  wherein the ball bearings are insertable into the first groove and the second groove through a fill port extending radially through the first groove. 
     
     
         11 . The gouging cutter of  claim 9  wherein the ball bearings are releasably retained the first groove and the second groove by a retaining sleeve having a groove on an internal surface thereof. 
     
     
         12 . The gouging cutter of  claim 7  wherein the locking element comprises a snap ring. 
     
     
         13 . The gouging cutter of  claim 7  wherein the locking element comprises a set screw. 
     
     
         14 . The gouging cutter of  claim 1  wherein a ratio of an overall length of the gouging cutter to an overall diameter of the gouging cutter is at most 2.5. 
     
     
         15 . A drill bit, comprising:
 a bit body having features thereon to enable connection to a drill string; and   at least one feature for retaining at least one gouging cutting element, the at least one gouging cutting element comprising, a cutter element having a cutting end and a mounting feature displaced from the cutting end and a cutter mount body affixable to or integrally formed with a drill bit body and having a corresponding mounting feature arranged to cooperate with the mounting feature on the cutting element to retain the cutter element to the cutter mount body so as to enable rotation of the cutter element with respect thereto.   
     
     
         16 . The bit of  claim 15  wherein the cutter element of the at least one gouging cutting element comprises at least one of tungsten carbide, cubic boron nitride and polycrystalline diamond. 
     
     
         17 . The bit of  claim 15  wherein the cutter mount body comprises steel. 
     
     
         18 . The bit of  claim 15  wherein the gouging cutter mount body is permanently affixable to a corresponding pocket in a the body. 
     
     
         19 . The bit of  claim 15  wherein the mounting feature on the cutter element comprises the cutter element having a cutting end, a main diameter portion having a selected outer diameter and an inner end having a selected outer diameter larger than the outer diameter of the main portion, the cutter mount body having an internal diameter selected to enable movement therethrough of the inner end of the cutter element, and a retainer having an internal opening selected to movement therethrough of the main portion and a mounting surface having an external diameter selected to enable movement therein of the cutter mount body. 
     
     
         20 . The bit of  claim 15  wherein the mounting feature on the cutter element comprises a first groove formed on an inner surface of an opening in a longitudinal end of the cutting element opposed to the cutting end, the groove cooperating with a second groove formed on an end of the cutter mount body shaped to fit within the opening, and a locking element disposed in the first groove and the second groove. 
     
     
         21 . The bit of  claim 20  wherein the locking element comprises ball bearings. 
     
     
         22 . The bit of  claim 21  wherein the ball bearings are insertable into the first groove and the second groove through a fill port extending radially through the first groove. 
     
     
         23 . The bit of  claim 21  wherein the ball bearings are releasably retained the first groove and the second groove by a retaining sleeve having a groove on an internal surface thereof. 
     
     
         24 . The bit of  claim 20  wherein the locking element comprises a snap ring. 
     
     
         25 . The bit of  claim 15  wherein the cutting surface is substantially conical. 
     
     
         26 . The bit of  claim 15  wherein the bit body comprises a plurality of blades and the at least one gouging cutter is mounted at least one of, rotationally ahead of the plurality of blades and on one of the plurality of blades. 
     
     
         27 . The bit of  claim 15  further comprising at least one shear cutter affixed to the bit body. 
     
     
         28 . The bit of  claim 15  wherein the at least one feature comprises a pocket. 
     
     
         29 . The bit of  claim 15  wherein a ratio of an overall length of the at least one gouging cutting element to an overall diameter of the at least one gouging cutting element is at most 2.5.