Patent ID: 8726763

Claim:
A gearbox comprising: a first gear pair including an input gear and an output gear meshed to define a first gear ratio; a second gear pair including an input gear and an output gear meshed to define a second gear ratio; a third gear pair including an input gear and an output gear meshed to define a third gear ratio; a fourth gear pair including an input gear and an output gear meshed to define a fourth gear ratio; a fifth gear pair including an input gear and an output gear meshed to define a fifth gear ratio; a sixth gear pair including an input gear and an output gear meshed to define a sixth gear ratio; an input shaft rotatable about an axis of rotation for driving a selected one of the first gear pair and the second gear pair; a first output shaft for being driven by output of a selected one of the first gear pair and the second gear pair; a second output shaft for being driven by output of a selected one of the third gear pair and the fourth gear pair; a third output shaft for being driven by output of a selected one of the fifth gear pair and the sixth gear pair; a first selector arranged between the first gear pair and the second gear pair, the first selector being movable to select either of the first and second gear pairs by engagement therewith; a second selector arranged between the third gear pair and the fourth gear pair, the second selector being movable to select either of the third and fourth gear pairs by engagement therewith; and a third selector arranged between the fifth gear pair and the sixth gear pair, the third selector being movable to select either of the fifth and sixth gear pairs by engagement therewith; wherein a ratio of rotational speed between the input shaft and the third output shaft is a product of at least three gear ratios respectively selected by the first selector, the second selector, and the third selector; wherein the first gear pair, the second gear pair, the third gear pair, the fourth gear pair, the fifth gear pair, and the sixth gear pair output in a single direction and have a binary relationship such that a total number of gear ratios from gear pairs in the single direction is represented by 2 n/2 , where n equals a total number of the gear pairs in the single direction.