Patent ID: 7510023

Claim:
An impact assembly for a power tool having a chamber and a handle and a rotary driver being mounted in the chamber near the handle and having a driving shaft, the impact assembly comprising a hammer frame being mounted in the chamber and being connected to the rotary driver and having a front wall; a rear wall; a mounting recess being formed in the hammer frame between the walls and having two opposite inner sides; and a through hole being formed centrally in the front wall of the hammer frame; at least one hammer being mounted pivotally in the mounting recess of the hammer frame between the walls and each one of the at least one hammer having a center; an external surface; an engaging hole being defined through the center of the hammer and having an inner surface; a loosening protrusion being formed on the inner surface of the engaging hole in the hammer; and a tightening protrusion being formed on the inner surface of the engaging hole, being smaller than the loosening protrusion; two hammer pins being mounted in the hammer frame to pivotally connect the at least one hammer to the hammer frame; and an output axle being mounted in the hammer frame and the engaging hole in the each one of the at least one hammer and protruding out through the through hole and having an external surface; a hammer end; an outer end; and at least one anvil being formed on the external surface of the output axle near the hammer end and selectively abutting the loosening and tightening protrusions.