When the member is in its upper position, the ring is in {HEAD ~ the path} of {TAIL ~ the air stream} emitted by the fan to produce a stream of bubbles 
When the member is in its upper position , the ring is in { HEAD ~ the path } of { TAIL ~ the air stream } emitted by the fan to produce a stream of bubbles
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH