{HEAD ~ A change gear system} comprises {TAIL ~ a driven case}, a driving shaft and shifting means for shifting the drive shaft, and three sliding frames are provided in alignment in the driven case 
comprises
{ HEAD ~ A change gear system } comprises { TAIL ~ a driven case } , a driving shaft and shifting means for shifting the drive shaft , and three sliding frames are provided in alignment in the driven case
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL 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 OTH OTH