{HEAD ~ each} of {TAIL ~ said sockets} has a cam member contained in the other of said pair of holes, and 
of
{ HEAD ~ each } of { TAIL ~ said sockets } has a cam member contained in the other of said pair of holes , and
HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH