As illustrated in FIGS 2 and 3, {HEAD ~ the third roller} 20 includes a third circular disc portion 20A and {TAIL ~ a third small circular disc portion} 20B continuous with the third circular disc portion 20A and having a diameter smaller than that of the third circular disc portion 20A 
As illustrated in FIGS 2 and 3 , { HEAD ~ the third roller } 20 includes a third circular disc portion 20A and { TAIL ~ a third small circular disc portion } 20B continuous with the third circular disc portion 20A and having a diameter smaller than that of the third circular disc portion 20A
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH