e through a first filter and a second filter to purify exhaust gas with at least one of the filters and to regenerate at least one of the filters with exhaust gas; valve includes a body and a flow inhibitorUS20040045124 *2 Nov 200111 Mar 2004Tommy LindquistVaccum cleanerUS2005024110229 Apr 20053 Nov 2005Castronovo Charles AVaccum cleaners especially quiet vacuum cleaners, pumps, and enginesUS20080