Patent ID: 7188682

Claim:
A drill bit, comprising: a drill bit body forming an interior plenum, a pin end suitable for connection to a drill pipe with an internal passageway therethrough, and a cutting end suitable to cut a borehole; a multi-stage diffuser nozzle assembly attached to said drill bit body and in fluid communication with said interior plenum, said multi-stage diffuser nozzle assembly comprising, a flow restrictor component in fluid communication with said interior plenum, said flow restrictor component having at least one internal passage to carry fluid, said interior passage having a throat with an effective cross-sectional area A 0E ; a fluidic distributor component distinct from said flow restrictor component, said fluidic distributor component having a fluid entrance side connected to a fluid exit side, said fluid entrance side being in fluid communication with said interior passage of said flow restrictor and said fluid exit side having at least a first fluid exit port, wherein said fluid exit side connects to at least one distributor throat residing inside said fluidic distributor component, said at least one distributor throat having a total effective cross-sectional area A 1E , A 1E being greater than A 0E , and wherein said at least one distributor throat occupies a location of minimum cross-sectional area in said fluidic distributor component; and an axis through said fluidic distributor component wherein a first fluid exit port on said fluid exit side of said fluidic distributor component is disposed to direct said fluid generally along a line that is non-collinear with said axis.