One of {TAIL ~ the first and second connections} is securely fixed to {HEAD ~ its associated shaft end}, and the other forms a pivotal universal joint 
One of { TAIL ~ the first and second connections } is securely fixed to { HEAD ~ its associated shaft end } , and the other forms a pivotal universal joint
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH