{TAIL ~ angular position} determining {HEAD ~ means} connected to said engaging means for rotation therewith and for providing an indication of the angular position of said engaging means; and 
{ TAIL ~ angular position } determining { HEAD ~ means } connected to said engaging means for rotation therewith and for providing an indication of the angular position of said engaging means ; and
TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH