Rocking back and forth of the turnable member acts through the clutch teeth and {HEAD ~ sprags} to turn {TAIL ~ the intermediate member} 
to turn
Rocking back and forth of the turnable member acts through the clutch teeth and { HEAD ~ sprags } to turn { TAIL ~ the intermediate member }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL