wherein said {HEAD ~ outer teeth gears} include a plurality of {TAIL ~ outer teeth}, each of said outer teeth being crowned 
wherein said { HEAD ~ outer teeth gears } include a plurality of { TAIL ~ outer teeth } , each of said outer teeth being crowned
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH