{TAIL ~ The adjustable ring} 1 additionally comprising means for biasing said linkage means in a predetermined position to normally maintain said adjustable ring in {HEAD ~ a contracted condition} 
{ TAIL ~ The adjustable ring } 1 additionally comprising means for biasing said linkage means in a predetermined position to normally maintain said adjustable ring in { HEAD ~ a contracted condition }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD