{HEAD ~ An apparatus} 11, wherein said suction duct is closed by {TAIL ~ pivotable flaps} 
{ HEAD ~ An apparatus } 11 , wherein said suction duct is closed by { TAIL ~ pivotable flaps }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL