{HEAD ~ The spring} 13 has {TAIL ~ one end} mounted in the blind hole 102, and an opposite end connected to one end of the toothed arch block 12 
has
{ HEAD ~ The spring } 13 has { TAIL ~ one end } mounted in the blind hole 102 , and an opposite end connected to one end of the toothed arch block 12
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL 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 OTH