A muffler for quieting the operation of a pneumatic tool. In one embodiment the
muffler (630) is disposed within a volume defined by a peripheral wall (612)
that receives an exhaust stream. An upper plate (631) having several open
tubes (632) is disposed in the volume. Each tube is has an intermediate
blocking plate (634). A plurality of sound-deadening panels (636)
is disposed below the upper plate. The panels have apertures that slidably engage
the tubes. A lower plate (650) is disposed below the tubes. The lower plate
includes a plurality of apertures (657). One or more diffuser panels (652,
654) is disposed beneath the lower plate. An external exhaust vent (670)
closes the volume. In operation, the exhaust enters the volume, is directed through
the tubes, then into the sound-deadening panels, back into the tubes, and through
the diffuser panels.
