(under subclass 300) Cleaning apparatus having means specially designed to muffle the noise of the air being discharged by the air pump.
(1) Note. So-called dust traps in the form of short tubes extending into a filter bag from the pump exhaust opening act in a degree as mufflers but have not been classified in this subclass unless the muffling function has been claimed.
SEE OR SEARCH CLASS
181, Acoustics,
231, for fluid conducting or guiding mufflers, per se.
417, Pumps,
312, for pumps combined with a muffler for acting on the fluid handled by the pump.
