Patent ID: 7464773

Claim:
A lubricating nutating single cone drill bit comprising: a bit shank having a drill string connection on a proximal end and an axially skewed journal on a distal end; at least one bearing rotatably retaining a cutter body on the axially skewed journal; a plurality of cutter elements affixed to a distal end of the cutter body so that a tip of each cutter element is forward an intersection of a central axis of the bit shank and an axis of rotation of the cutter body and a first radial distance to the tip of each cutter element from the axis of rotation of the cutter body is longer than a second radial distance to said tip of each cutter element from the central axis of the bit shank, upon contact with a borehole floor; a lubricant chamber in the bit shank in communication with a first fluid inlet port on an exterior of the bit shank and at least one bearing; a plunger in the lubricant chamber inhibiting the ingress of an annulus fluid; a first fluid outlet port on a distal end of the journal extending through an opening in the cutter body and in communication with a fluid passage the bit shank in, the fluid passage thereby in communication with a second fluid inlet port in the proximal end of the bit shank; and, a second fluid outlet port on the exterior of the bit shank in communication with the fluid passage.