The cranks confine the motion of each of {TAIL ~ the transmission rings} to a non rotary, {HEAD ~ planetary motion} 
The cranks confine the motion of each of { TAIL ~ the transmission rings } to a non rotary , { HEAD ~ planetary motion }
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD