Patent ID: 7918288

Claim:
A core drill bit, comprising: a shank portion having a first end for attaching to a drill string component, an opposing second end, and a central axis extending therethrough, said shank portion defining an interior space about said central axis for receiving a core sample; a cylindrical cutting portion having a first end, an opposing second end, an inner surface, and an outer surface, wherein said first end is secured to and extends away from said second end of said shank portion, wherein said second end of said shank portion has a diameter that is smaller than the diameter of said first end of said cylindrical cutting portion, and wherein said opposing second end defines a cutting face; one or more enclosed slots extending from said inner surface to said outer surface, said one or more enclosed slots being positioned in said annular cutting portion a first distance from said cutting face; one or more additional enclosed slots extending from said inner surface to said outer surface, said one or more additional enclosed slots being positioned in said annular cutting portion a second distance from said cutting face, wherein said second distance is greater than said first distance; and at least one flute extending at least partially into said cylindrical cutting portion.