Swinging drawbar

Suburban boy wants to know what the purpose is for the swinging drawbar? Examples of what you would hook up with the tongue off center?

The actual truth is that it is designed to pull from a position in front of the center of the rear tires. This allows the tractor to pull from a position during a corner that is off set toward the corner direction. This aids in causing the front wheels to actually make the corner (the rear tires are off set to the left from the pull in a right hand corner, pulling the tractor right)
Rollers, spike and spring tooth drags, field cultivators and disk harrows are all suited to making turns while still in the soil working.
Swinging in this way makes turning much easier.
it also limits the snagging of wide link type drawbar systems from encountering the rear tire and removing the operator from earth.
If the draw bar is pinned to the loop, the pull point in fact is forced to the side away from the turn, and the steering "pushes" (a nascar term) dramatically.
The hitch on a plow should be adjusted to allow a center pull on the tractor. (that is the reason for all the bolt holes in the drawbar setup on trailer plows.) If it pulls off center, the tractor is difficut to keep in the furrow. It should be neutral.
Never use a swinging drawbar (unless pinned stationary) with trailers or other free pulling devices. Always pin the drawbar when pulling the disk Wheels down blades up. I hope this helps. Jim

As Jim said the main purpose (as far as I'm concerned) is to make turning easier. Back in the 50's we had no hydraulically controlled trailing implements. A couple of them were next to impossible to turn without the swinging part of the drawbar because there was no way to release the load.

You also might use it to tow a baler or other offset implement down the road and through gates and such. You'd anchor the drawbar off to the side to make the combination narrower by a foot or so.
Zach