PERCUSSION HAMMER BIT

摘要

A drill bit for use with a percussion drilling apparatus can include an elongated body with a first end, a second end, and a longitudinal surface extending between the first and second ends. A plurality of splines extends along the longitudinal surface of the drill bit internally, and at least one of the splines has an apex, a root, and a planar surface between the apex and root. The planar surface can be oriented at an angle to a plane extending from a center of the drill bit to a midpoint of the apex. The internal splines of the hammer bit correspond to external splines in a hammer casing.

主权项

1. A downhole percussion hammer assembly, comprising:
a hammer bit having internal splines; a generally cylindrical hammer casing having external splines corresponding to the splines of the hammer bit; a bit retention mechanism external to the hammer casing, and connected to the hammer bit internally; a locking device located externally to the hammer casing, and internally to the hammer bit; a friction reducing agent between the hammer casing splines for reducing friction between the hammer casing splines and the bit splines; a piston for delivering percussive force to the hammer bit; a top sub assembly comprising a top cylinder having an air distributor for timing air flow to upper and lower air chambers of the percussion hammer assembly, wherein the top sub assembly is secured to the hammer casing.