The arch block 12 is a biased or forced by {HEAD ~ the spring} 13 into engagement with the ratchet wheel 11 to limit rotary motion of {TAIL ~ the ratchet} wheel 11 to one direction 
The arch block 12 is a biased or forced by { HEAD ~ the spring } 13 into engagement with the ratchet wheel 11 to limit rotary motion of { TAIL ~ the ratchet } wheel 11 to one direction
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH