The biasing member applies {HEAD ~ force} to {TAIL ~ the stopper} for pulling in the stopper into the receiving portion 
to
The biasing member applies { HEAD ~ force } to { TAIL ~ the stopper } for pulling in the stopper into the receiving portion
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH