Variable wear pad for crossflow drag bit

Claim 1

A diamond studded insert drag bit apparatus having a multiplicity of individual diamond insert cutter blanks inserted in the face of said bit, said bit forming at least one hydraulic passage that communicates between the face of the bit and an interior chamber formed by said bit, said bit comprising: a substantially cylindrical drag bit body having a relatively flat first face end and a second pin end, and at least one wear pad having a support base at one end and a wear surface at an opposite end, said pad being attached to said first face end of said drag bit body at said support base of said wear pad, said wear pad is attached to said first face end of said drag bit body by at least one bolt recessed within said wear pad, said wear pad being positioned adjacent said multiplicity of diamond inserts, said wear surface extends beyond said first face end of said drag bit, the diamond cutting tips of said diamond insert cutter blanks extend partially beyond the wear surface of said pad, said pad forms at least one hydraulic passage between said first face end of said drag bit and a borehole bottom to direct hydraulic fluid exiting said at least one hydraulic passage over said adjacent multiplicity of diamond inserts to cool and clean said inserts and to remove detritus material from said borehole bottom, said wear pad assumes the shape of said borehole bottom to affect a hydraulic seal between said borehole bottom and said face of said drag bit.