{TAIL ~ The member} may be directed to sweep the excess material away through a successive number of {HEAD ~ sweeps}, which may vary for each cross section, at least a velocity which may vary for each sweep 
{ TAIL ~ The member } may be directed to sweep the excess material away through a successive number of { HEAD ~ sweeps } , which may vary for each cross section , at least a velocity which may vary for each sweep
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH