Patent ID: 7198434

Claim:
A displacement-type auger bit for drilling a borehole, which bit comprises: a stem with lower and upper sections and a longitudinally-extending, rotational axis; said lower and upper sections terminating at lower and upper stem ends respectively; a cutting tool mounted on said lower stem end and adapted for cutting through a subsurface material in connection with drilling a borehole; said stem lower section having a downwardly-tapered configuration; said stem upper section having an upwardly-tapered configuration; a coupling mounted on said stem upper end and adapted for coupling to a grout pipe; flighting including a flighting tower section mounted on said stem lower section and generally helical in a first direction and a fighting upper section mounted on said stem upper section and generally helical in the opposite direction; a soil path generally defined by said stem and said flighting; and anti-wear protrusions comprising multiple longitudinally-extending teeth formed along said stem and extending between respective turns of said flighting and adapted for trapping soil on said stem.