Johnny L Dubois

US Patent:

58066080, Sep 15, 1998

Filed:

Feb 14, 1997

Appl. No.:

8/800789

Inventors:

Johnny DuBois - Holden LA

International Classification:

B23B 4516
B25D 914

US Classification:

173 90

Abstract:

An air-driven post driver that includes a hammer assembly and a post receiving assembly. The hammer assembly includes an air-driven piston hammer slidably disposed within a cylinder bore of a cylinder body having a circumferential compressed air groove of a first groove width formed into the cylinder wall that defines the cylinder bore and an upper discharge port and a lower discharge port. The piston hammer includes an upward thrusting air passageway and a downward thrusting air passageway. The upward thrusting air passageway includes a radially oriented upward intake passageway and a longitudinally oriented upward discharge passageway. The upward discharge passageway is of a length greater than one half the length of the piston hammer. The downward thrusting passageway includes a radially oriented downward intake passageway and a longitudinally oriented downward discharge passageway having a threaded downward discharge port. The downward discharge passageway is of a length greater than one-half the length of the piston hammer.