The support frame 12 comprises {TAIL ~ a pair} of side rails 20 and 22 which are welded to two lateral section members 24 and 26 in {HEAD ~ a rectangular shape} 
The support frame 12 comprises { TAIL ~ a pair } of side rails 20 and 22 which are welded to two lateral section members 24 and 26 in { HEAD ~ a rectangular shape }
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD