{HEAD ~ The general structure} of {TAIL ~ the flexible coupling} may be identical to that of the flexible coupling illustrated in FIG 7 except for the tooth shape 
{ HEAD ~ The general structure } of { TAIL ~ the flexible coupling } may be identical to that of the flexible coupling illustrated in FIG 7 except for the tooth shape
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH