Patent attributes
A reversible PTO shaft having opposite splined ends whose numbers of teeth are different from each other is inserted at one of the splined ends into an output sleeve and not-relatively rotatably connected to the output sleeve. For constituting at a position out of the PTO transmission system an actuator for changing the rotary speed of the output sleeve and holding the output sleeve changed in rotary speed simultaneously to the reversing of PTO shaft, a second collar connected to a shifter collar for changing the rotary speed of output sleeve so as to be slidable integrally with the shifter collar is disposed on an inner end of the output sleeve. When the splined end of PTO shaft having the greater number of teeth is inserted into the output sleeve, a sensor having a cam surface is moved by an end surface of the PTO shaft so as to make a pin project from the output sleeve, thereby holding the second collar at its low speed position. A power take-off assembly which sets the output sleeve into either a low speed mode or a high speed mode simultaneously to the reversing of the PTO shaft is also disclosed.