Abstract: A bit assembly is for a percussive drill that includes a casing with an interior chamber and includes a bit connectable with the casing and having a longitudinal bore and an axis through the bore. The bore has a retainer portion with one or more generally conical inner surfaces extending circumferentially about and facing generally toward the axis. A generally cylindrical valve has a longitudinal passage with an inlet fluidly connectable with the casing chamber and an outlet fluidly connectable with the bit central bore and an axis through the passage. An engagement portion with at least one generally conical outer surface extends circumferentially about and faces generally away from the valve axis. The valve engagement portion is disposable within the bit bore retainer portion such that the valve conical outer surface is disposed within and against the bit conical inner surface to retain the valve coupled with the bit.

Abstract: An earth bit includes a cone rotatably mounted to a shaft with a hub unit and thrust roller bearings. The hub unit is moveable between mounted and unmounted positions on the shaft, as a single unit, in a repeatable manner. The hub unit includes a pair of roller bearings positioned between inner and outer races. The outer race includes a recess extending around its outer periphery. A sealing structure is slidingly engaged with the recess to provide a seal between the cone and shaft.

Abstract: A device is for channeling solids and fluids within a reverse circulating, fluid operated drill that has first and second ends, an axis extending between the ends, a casing and a piston. The casing has a bore extending between the drill ends and drive and valve chambers defined within the bore, the piston being movably disposed within the bore. The channeling device includes an elongated body disposeable within the casing bore so as to extend along the casing axis and through the piston. The body has a longitudinal axis, a first end locatable proximal to the drill first end, and a second end spaced from the first end and locatable proximal to the drill second end. A material transport passages extends axially between the two body ends and provides a path for moving solid materials through the drill. A fluid passage is configured to couple the valve and drive chambers.