Patent ID: 6048141
Filing Date: 2000-04-11
Classification: B23B,B27F,B27G,Y10T

Abstract:
A tool for enlarging the size of an existing bore to a selected enlarged size comprising:a spade bit including a bit having, at the from thereof, a central tapered piercing spike and blades on either side of said spike sized to define the enlarged bore,a guide having a cylindrical body sized so that the guide can be rotated in the existing bore,said guide including a slot for receiving said piercing spike and a portion of the blades on either side of said piercing spike, said slot having inwardly converging walls so that said blade portions will become wedged within said slot when the bit is pushed into the slot, andsaid guide including a cylindrical central sleeve having an axially extending hole selectively sized for receiving and centering said piercing spike,whereby the tools can be secured to a power drill and the guide inserted into the original hole to guide the spade bit as it enlarges the hole.