{HEAD ~ a follower} secured to each of said racks and extending from {TAIL ~ said central opening} to one of said peripheral openings to be received within a respective groove of said sleeve upon rotation of said shaft, 
extending from
{ HEAD ~ a follower } secured to each of said racks and extending from { TAIL ~ said central opening } to one of said peripheral openings to be received within a respective groove of said sleeve upon rotation of said shaft ,
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL 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 OTH OTH OTH OTH