A helical spring is received in, and actually extends into, a blind hole in each stem, and the inner end of the spring rests on {HEAD ~ the retaining ring} at the projection urging {TAIL ~ the blades} outward 
A helical spring is received in , and actually extends into , a blind hole in each stem , and the inner end of the spring rests on { HEAD ~ the retaining ring } at the projection urging { TAIL ~ the blades } outward
OTH OTH OTH OTH OTH OTH OTH OTH 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 OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH