at least two support bars having bores in {HEAD ~ the center} transversely mounted on {TAIL ~ said supporting shank} 
transversely mounted on
at least two support bars having bores in { HEAD ~ the center } transversely mounted on { TAIL ~ said supporting shank }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL