Tapered bushing for bit removal

Abstract

A tapered bushing includes a conical inner surface defining a conical axis, and a radial direction. The tapered bushing further includes an outer surface of revolution, and defines a minimum radial wall thickness that ranges from 3.0 mm to 15.0 mm measured from the conical inner surface to the outer surface of revolution. Also, the conical inner surface defines a draft angle that ranges from 2.0 degrees to 30.0 degrees.

What is claimed is: 
     
         1 . A tapered bushing comprising:
 a conical inner surface defining a conical axis, and a radial direction; and   an outer surface of revolution;   wherein the tapered bushing defines a minimum radial wall thickness that ranges from 3.0 mm to 15.0 mm measured from the conical inner surface to the outer surface of revolution, and the conical inner surface defines a draft angle that ranges from 2.0 degrees to 30.0 degrees.   
     
     
         2 . The tapered bushing of  claim 1 , wherein the outer surface of revolution is cylindrical. 
     
     
         3 . The tapered bushing of  claim 2 , wherein the tapered bushing defines an outer diameter and an axial height, and a ratio of the axial height to the outer diameter ranges from 0.95 to 1.2. 
     
     
         4 . The tapered bushing of  claim 1 , wherein the tapered bushing comprises at least one of the following materials: steel, and brass. 
     
     
         5 . The tapered bushing of  claim 1 , wherein the tapered bushing has at least one of the following coatings: electroless nickel, silicon carbide, titanium nitride, and tungsten carbide. 
     
     
         6 . The tapered bushing of  claim 2 , wherein the conical inner surface defines a minimum diameter that ranges from 30.0 mm to 60.0 mm, and the tapered bushing has a consistent cross-section in any plane including the radial direction and the conical axis.