Patent ID: 7641579

Claim:
An eccentric gear mechanism, comprising an input drive having a centric portion rotated about an axis and an eccentric portion; a movable inner ring gear having outer circumferential gear teeth and an outer ring gear having inner circumferential teeth partially engaged with said outer circumferential gear teeth of said inner ring gear, so that when said centric portion and said eccentric portion of said input drive turn in one direction against said movable inner ring gear to apply a turning force to said movable inner ring gear in an opposite direction, said inner ring gear moves against said outer ring gear and applies a turning force to said outer ring gear in said one direction and transfers said given turning force applied on said outer ring gear outwardly, wherein said outer ring gear only circumferentially surrounds said inner ring gear and has an axial dimension which corresponds to an axial dimension of said inner ring gear so that said outer ring gear does not extend axially outwardly beyond said inner ring gear.