US Patent 10024103 Down-the-hole drill hammer having a roller ramp clutch

A down-the-hole drill hammer is provided that includes a housing, a drill bit, a piston, a roller ramp clutch and a coupler. The DHD is configured to have a bit-piston-clutch-casing torque circuit which concurrently rotates the piston and drill bit. The drill bit is positioned proximate a distal end of the housing. The piston is configured to reciprocally move within the housing along an axial direction. The piston includes a helical spline and an axial spline on a surface of the piston. The roller ramp clutch circumscribes and engages the piston. The coupler circumscribes and engages the piston and drill bit.