Some "live" pto tractors have a two stage clutch, where the first stage is the pto and then using more pedal gets the drive clutch.
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Power Take-Off (PTO) Types
There are three basic types of PTO control on a farm tractor:
Transmission
The simpliest, and earliest, form of PTO is the
transmissionPTO. The PTO shaft is directly connected to the tractor's transmission.The PTO is only working when the tractor's clutch is relased, so if you take the tractor out of gear while slowingdown the PTO will stop working. This is a disadvantage in applicationssuch as mowing.
An
overrunning clutch is often needed with a transmission PTO.Without it, the driven equipment (such as mower blades) will put aforce on the PTO shaft, and then the transmssion, due to inertia. The equipmentwill "drive" the tractor, and you will still move after using the tractor's transmission clutch. An overrunning clutch prevents this fromhappening by allowing the PTO shaft to freely spin in one direction. In more recent models, this is built into the tractor. Inolder tractors, it is an extra piece of equipment mounted on the PTOshaft.
Live (two-stage clutch)
A
live PTO works with the use of a two-stageclutch. Pressing the clutch half-way will disengage the transmissionwhile pressing it fully will disengage the transmission and the PTO.This allows the operator to slow down or change gears while the PTO isstill operating.
Independent
An
independent PTO means that the PTO shaft iscontrolled with a separate clutch. As with a live PTO, this allows forfull control over the tractor while separately controlling the PTO.There are two major types of independent PTO; mechanical andhydraulic. A mechanical-independent PTO uses a separate on-offselector, in addition to the PTO control lever. Often the tractor mustbe stopped or off to change this selector position. Ahydraulic-independent PTO uses a single selector.
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