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