Enhanced non-planar drill insert

Abstract

A cutting element, or insert, is provided for use with drills used in the drilling and boring of subterranean formations. This new insert has improved wear characteristics while maximizing the manufacturability and cost effectiveness of the insert. This invention accomplishes these objectives by employing a superabrasive diamond layer of increased depth and by making use of diamond layer surface shape that is generally convex.

I claim:  
     
         1 . A cutting element insert for use on a bit for drilling subterranean formations, comprising: 
 (A) a substrate having a top surface; and    (B) a layer of superabrasive material, having an interface surface, bonded to said top surface of said substrate and an external contact surface, wherein said layer of superabrasive material completely covers said top surface of said substrate and wherein said external contact surface is of a generally hemispherical shape.    
     
     
         2 . A cutting element insert as recited in    claim 1   , wherein said substrate is a carbide selected from the group consisting of tungsten carbide, niobium carbide, zirconium carbide, hafnium carbide, vanadium carbide, tantalum carbide, and titanium carbide.  
     
     
         3 . A cutting element insert as recited in    claim 1   , wherein said layer of superabrasive material is composed of polycrystalline diamond.  
     
     
         4 . A cutting element insert as recited in    claim 1   , wherein said layer of superabrasive material further comprises: a cutting surface and a center axis.  
     
     
         5 . A cutting element insert as recited in    claim 1   , wherein said layer of superabrasive material is between 0.040 inches and 2.0 inches in thickness.  
     
     
         6 . A cutting element insert as recited in    claim 1   , wherein said substrate is composed of cemented tungsten carbide.  
     
     
         7 . A cutting element insert as recited in    claim 1   , wherein said layer of superabrasive material is bonded to said substrate by ultra-high pressure sintering.  
     
     
         8 . A cutting element insert as recited in    claim 1   , wherein said layer of superabrasive material is bonded to said substrate by pressing.  
     
     
         9 . A cutting element insert as recited in    claim 1   , wherein said layer of superabrasive material is bonded to said substrate by brazing.  
     
     
         10 . A cutting element insert as recited in    claim 1   , wherein said layer of superabrasive material is composed of cubic boron nitride.  
     
     
         11 . A cutting element insert for use on a bit for drilling subterranean formations, comprising: 
 (A) a substrate having a top surface; and    (B) a layer of superabrasive material, having an interface surface, bonded to said top surface of said substrate and an external contact surface, wherein said layer of superabrasive material completely covers said top surface of said substrate and wherein said external contact surface is of a generally conical shape.    
     
     
         12 . A cutting element insert as recited in    claim 11   , wherein said substrate is a carbide selected from the group consisting of tungsten carbide, niobium carbide, zirconium carbide, hafnium carbide, vanadium carbide, tantalum carbide, and titanium carbide.  
     
     
         13 . A cutting element insert as recited in    claim 11   , wherein said layer of superabrasive material is composed of polycrystalline diamond.  
     
     
         14 . A cutting element insert as recited in    claim 11   , wherein said layer of superabrsive material further comprises: a cutting surface and a center axis.  
     
     
         15 . A cutting element insert as recited in    claim 11   , wherein said layer of superabrasive material is between 0.040 inches and 2.0 inches in thickness.  
     
     
         16 . A cutting element insert as recited in    claim 11   , wherein said substrate is composed of cemented tungsten carbide.  
     
     
         17 . A cutting element insert as recited in    claim 11   , wherein said layer of superabrasive material is bonded to said substrate by sintering.  
     
     
         18 . A cutting element insert as recited in    claim 11   , wherein said layer of superabrasive material is bonded to said substrate by pressing.  
     
     
         19 . A cutting element insert as recited in    claim 11   , wherein said layer of superabrasive material is bonded to said substrate by brazing.  
     
     
         20 . A cutting element insert as recited in    claim 11   , wherein said layer of superabrasive material is composed of cubic boron nitride.