Each recess includes a hole in an inner bottom thereof so that the two pawls are pivotably inserted in {HEAD ~ the two holes} by {TAIL ~ their respective shafts} 
by
Each recess includes a hole in an inner bottom thereof so that the two pawls are pivotably inserted in { HEAD ~ the two holes } by { TAIL ~ their respective shafts }
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 TAIL