FIG 15 is a perspective view of {HEAD ~ a series} of {TAIL ~ spring elements} in a stacked arrangement 
of
FIG 15 is a perspective view of { HEAD ~ a series } of { TAIL ~ spring elements } in a stacked arrangement
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH