Patent attributes
A power take-off (PTO) transmission unit transfers power between an input shaft and an output shaft. A gear set selectively couples the input shaft to the output shaft. A shift device includes a shift rail with ends forming inner pistons within chambers. The shift rail is configured to translate between first, second, and third positions based on the pressures of the chambers. Inner pistons nest within the outer pistons in the chambers. A shift fork and shift collar translate with the shift rail to, in the first position, engage the gear set such that power is transferred at a first speed ratio; in the second position, engage the gear set such that power is transferred at a second speed ratio; and in the third position, engage the gear set to provide a neutral mode in which the output shaft is free to rotate relative to the input shaft.