US Patent 9951851 Multi ratio drive

A multi ratio drive including a first drive chain having a first drive chain engaged state and a first drive chain disengaged state; and a second drive chain having a second drive chain engaged state and a second drive chain disengaged state. The first drive chain drives the axle with a first gear ratio between the drive shaft and the axle when the first drive chain is in the first drive chain engaged state and the second drive chain is in the second drive chain disengaged state; the second drive chain drives the axle with a second gear ratio between the drive shaft and the axle when the second drive chain is in the second drive chain engaged state and the first drive chain is in the first drive chain disengaged state; and the first gear ratio is different from the second gear ratio.