In rest position, i.e., when the pump does not operate, {HEAD ~ the bellows} 11 takes {TAIL ~ an expanded position} and the bellows 12 a non expanded position 
takes
In rest position , i.e. , when the pump does not operate , { HEAD ~ the bellows } 11 takes { TAIL ~ an expanded position } and the bellows 12 a non expanded position
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH