A toothed arch block is mounted within the box end is and forced by the spring into engagement with the ratchet wheel to limit rotary motion of the ratchet wheel inside {HEAD ~ the box end} to {TAIL ~ one direction} 
to
A toothed arch block is mounted within the box end is and forced by the spring into engagement with the ratchet wheel to limit rotary motion of the ratchet wheel inside { HEAD ~ the box end } to { TAIL ~ one direction }
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 OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL