Drilling Tool

Abstract

Methods of forming a drill bit or boring tool having a cutting edge that includes a pair of generally smooth curvilinear shaped portions that are positioned near the radial outer portions of the cutting edge and connected to one another by a pair of generally linear portions that traverse a longitudinal centerline of the tool.

What is claimed is: 
     
         1 . A method of forming a boring tool comprising:
 providing an elongate body that extends along a longitudinal axis, the elongate body having a first end configured to cooperate with a drive tool and a cutting point formed at a second end of the elongate body opposite the first end;   forming a first linear portion and a second linear portion along a distal edge of the cutting point, the first linear portion and the second linear portion being on opposite sides of the longitudinal axis; and   forming a first curvilinear contour and a second curvilinear contour in the distal edge of the cutting point, each curvilinear contour being offset in a radial direction from the longitudinal axis of the elongate body and located radially outboard of a respective first linear portion and the second linear portion, such that an only non-tangential discontinuity of the cutting point is defined by a transition between the first linear portion and the second linear portion at an intersection of the longitudinal axis.   
     
     
         2 . The method of  claim 1  further comprising twisting the elongate body to form a helix that extends along the elongate body and is defined by at least two lands. 
     
     
         3 . The method of  claim 2  further comprising forming at least one groove in a radially outward facing surface between each of the at least two lands. 
     
     
         4 . The method of  claim 1  further comprising treating the cutting point for wear resistance after forming the at least one curvilinear contour. 
     
     
         5 . The method of  claim 4  wherein the treating is further defined as at least one of a honing operation, a shot peening process, a heat treating process, a quenching process, a coating process. 
     
     
         6 . The method of  claim 4  wherein the treating is further defined as a coating process that includes applying at least one of a diamond based material, a diamond like coating (DLC), and a PVD coating to at least the cutting point of the boring tool. 
     
     
         7 . A method of forming a boring tool, the method comprising:
 providing an elongate body that extends along a longitudinal axis that extends from a first end that is configured to cooperate with a drive tool to a second end that is opposite the first end;   forming a cutting edge that is defined by the second end of the elongate body; and   shaping the cutting edge to include a first linear portion and a second linear portion that extend in opposite outward radial directions relative to the longitudinal axis of the elongate body and a first curvilinear contour and a second curvilinear contour that are oriented radially outward of a respective one of the first linear portion and the second linear portion such that each curvilinear contour is offset in a radial direction from the longitudinal axis of the elongate body and located radially outboard of a respective first linear portion and the second linear portion and each of the first curvilinear portion and the second curvilinear portion have a similar shape relative to rotation of elongate body about the longitudinal axis.   
     
     
         8 . The method of  claim 7  further comprising forming at least two lands and at least two flutes that extend in a direction generally aligned with the longitudinal axis along at least a portion of the elongate body. 
     
     
         9 . The method of  claim 8  further comprising forming the at least two lands and at least two flutes to extend along the elongate body in at least one of a helical pattern and in a straight manner. 
     
     
         10 . The method of  claim 7  further comprising treating the cutting point for wear resistance after shaping of the first linear portion, the second linear portion, the first curvilinear contour, and the second curvilinear contour. 
     
     
         11 . The method of  claim 10  wherein the treating is further defined as at least one of a honing operation, a shot peening process, a heat treating process, a quenching process, a coating process. 
     
     
         12 . The method of  claim 10  wherein the treating is further defined as a coating process that includes applying at least one of a diamond based material, a diamond like coating (DLC), and a PVD coating to at least the cutting point of the boring tool. 
     
     
         13 . The method of  claim 7  wherein shaping the cutting edge further comprises tapering each of the first curvilinear contour and the second curvilinear contour in a direction toward the first end of the elongate body as the respective curvilinear contour progresses toward a radial edge of the elongate body. 
     
     
         14 . The method of  claim 7  further comprising shaping each of the first curvilinear contour and the second curvilinear contour to include a plurality of deviations and shaping a respective deviation that is nearer the longitudinal axis to extend in a direction that is more aligned with the longitudinal axis than another deviation associated with the respective curvilinear contour that is nearer a circumferential edge of the elongate body. 
     
     
         15 . The method of  claim 7  further comprising forming a step at a radially outboard surface proximate the second end of the elongate body. 
     
     
         16 . The method of  claim 15  further comprising offsetting the step toward the first end relative to the cutting edge of the elongate body.