said sleeve is formed with {HEAD ~ entrances} to {TAIL ~ said at least one shaft} at opposite narrow ends of said sleeve, 
said sleeve is formed with { HEAD ~ entrances } to { TAIL ~ said at least one shaft } at opposite narrow ends of said sleeve ,
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH