When {TAIL ~ top plate} 10 is lowered by {HEAD ~ displacement} of cylinder 62, fluid extension ducts 182 compress springs 186 and thereby maintain the seal 
When { TAIL ~ top plate } 10 is lowered by { HEAD ~ displacement } of cylinder 62 , fluid extension ducts 182 compress springs 186 and thereby maintain the seal
OTH TAIL TAIL TAIL TAIL TAIL TAIL 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