In FIG 9, {HEAD ~ angular relationships} between a dust bag 34 and {TAIL ~ walls} 65, 65 of a housing 63 are achieved by creating a non rectangular housing 
between
In FIG 9 , { HEAD ~ angular relationships } between a dust bag 34 and { TAIL ~ walls } 65 , 65 of a housing 63 are achieved by creating a non rectangular housing
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH