anyone familiar with these? I've never seen one in person.

Have a post on tractor talk too.

karl f

These work by pulling upward on the towed implement, which in turn pushes down on the rear tires of the tractor, boosting traction.

In practice, it worked but it was hard on the implement. Get a little too aggressive with the weight transfer, and you end up with a bent tongue on the implement.

Most implements of the time were not designed for the stresses of the weight transfer hitch.

It never really caught on, obviously.

somebody on my tractor talk post called it a
"widow maker." I can see that reputation being
earned in transport, panic, fatigue or in the
hands of an inexperienced/unadaptable operator.
Plus you can turn sharper and hook a tongue on a
tire...
On the USA farmalls with 2 identical levers doing
3 things (postion, draft, plus flow control
(action control zone)one could get mixed up
easily. Especially if you are accustomed to the
plow and 90% of other implements using the
position control lever for lifting at headlands.
Throw in a little fatigue at tillage time and bad
things will happen. stop screws might help limit
your actions with the levers but anything can
happen. Not attacking farmall's hitch design
either as other designs and makes also are not
exempt from design limitations, complications or
operator error. I happen to like the farmall draft
system controls.

This particular hitch design would especially be
unstable in transport since the average 3 point
hitch does not have down pressure and there is no
vertical travel limiter in the design of the
weight transfer attachment.

It's an interesting piece of engineering
curiosity, but I guess I talked myself out of
advocating its use

karl f