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