The belt portion 10 is provided with a series of cogs 12 on {HEAD ~ the rear side} along {TAIL ~ the longitudinal direction} 
along
The belt portion 10 is provided with a series of cogs 12 on { HEAD ~ the rear side } along { TAIL ~ the longitudinal direction }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL