{TAIL ~ a plurality} of independently mounted rollers fixably and detachably mounted to said first members of {HEAD ~ said frame} such that said rollers vertically extend above said frame; and, 
{ TAIL ~ a plurality } of independently mounted rollers fixably and detachably mounted to said first members of { HEAD ~ said frame } such that said rollers vertically extend above said frame ; and ,
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH