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