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