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