A pneumatic percussion mechanism for a hand-held power tool includes a
percussion piston (23) displaceable in a guide tube (21) for applying
impacts to an anvil (24), a driving member (22) reciprocating in the
guide tube (21) for driving the percussion piston, and an air spring (25)
for transmitting a driving torque from the driving member (22) to the
percussion piston (23) and directly switchable on and off by the anvil
(24).