FIGS 2 and 4 show the arm pivoted to {TAIL ~ two positions} on {HEAD ~ opposite sides} of the intermediate position of FIG 3 which correspond to the shortening of one of the two cords 57 and the lengthening of the other 
FIGS 2 and 4 show the arm pivoted to { TAIL ~ two positions } on { HEAD ~ opposite sides } of the intermediate position of FIG 3 which correspond to the shortening of one of the two cords 57 and the lengthening of the other
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD 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