It is a further object of the invention to provide a change gear system capable of preventing {HEAD ~ teeth} of {TAIL ~ a rack gear} and a pinion to be broken 
of
It is a further object of the invention to provide a change gear system capable of preventing { HEAD ~ teeth } of { TAIL ~ a rack gear } and a pinion to be broken
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH