Patent ID: 8302708

Claim:
A drill wrench assembly for a rotary drilling apparatus, the drill wrench assembly comprising: a forward end; a rearward end longitudinally distant from the forward end; an internal driver for driving a drill steel, the internal driver being rotatable about a longitudinal axis and shaped to fit in an internal-drive recess defined within an end of the drill steel; an external support member configured to at least partially surround at least a portion of the drill steel when the internal driver is inserted in the internal-drive recess of the drill steel, the external support member including: a first longitudinal section defining a first recess, the first longitudinal section extending longitudinally away from the forward end, a second longitudinal section defining a second recess, the second longitudinal section extending longitudinally away from the first longitudinal section, the second recess having a different cross-sectional shape and smaller cross-sectional size than the first longitudinal section, a third longitudinal section defining a third recess, the third longitudinal section surrounding the internal driver and extending longitudinally away from the second longitudinal section; wherein, when the internal driver is inserted in the internal-drive recess and rotated about the longitudinal axis, the internal driver is configured to drive the drill steel by engaging at least one surface within the end of the drill steel that defines at least a portion of the internal-drive recess, and wherein the drill wrench assembly comprises a shank extending generally parallel to the longitudinal axis, the shank of the drill wrench being configured to fit within a coupling recess of a chuck.