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