Implements with just one hydraulic hose?

[SmallChange]

I've looked over a couple different towed implements (a wagon and a tedder) that have a single hydraulic line running up to the hitch. What is the story with that? Are they doing some action with a gravity return, like lifting or tilting the implement? Can they operate on a tractor that has pairs of hydraulic lines, just by leaving the other one of these unconnected? Seems to me the motion in one direction would require the tractor to try to drive a dead ended hose and go into relief, is that right?

 

[oldnslo]

Yes they are single acting cylinder where power up and gravity down. When you lower with standard double acting valve you forcing oil over the relief. This is usually not a problem Unless implement takes a long time to lower. Most implements it is only a few seconds. Dump wagon could be a longer time to lower depending on cylinder size and stroke.

 

[mo1]

I've looked over a couple different towed implements (a wagon and a tedder) that have a single hydraulic line running up to the hitch. What is the story with that? Are they doing some action with a gravity return, like lifting or tilting the implement? Can they operate on a tractor that has pairs of hydraulic lines, just by leaving the other one of these unconnected? Seems to me the motion in one direction would require the tractor to try to drive a dead ended hose and go into relief, is that right?

Essentially all tractor hydraulic remotes have two connectors per remote, one for extend and one for retract. You would connect a single-acting cylinder with only one line only to the "extend" connector on that hydraulic remote. Single-acting cylinders work best with hydraulic valves with a float function. Float will allow the oil in the cylinder to drain backward through the extend circuit to the oil return line without putting the pump in relief.

A large cylinder under a not very heavy load like the lift cylinder on an emptied dump trailer/wagon can take a minute or so to lower using gravity and float, this is about twice as long as using powered-down with a double-acting cylinder. A small cylinder under a fair amount of weight like the lift cylinder(s) on a drawn rotary cutter or disc mower retract about as fast in float as they do in double-acting mode, they drop almost immediately.

 

[LouNY]

A control valve with a float mode is the best to use with a single action cylinder, but as already mentioned a cheaper control valve without float will work just not as well

 

[SmallChange]

Single-acting cylinders work best with hydraulic valves with a float function.

Ah! This is the clue I didn't think of!

Thanks

 

[MHarryE]

Take a look at most tractors - lift arms on 3 point hitches are generally single acting. I remember hearing a few tractors have been made with power down 3 point but never have seen them. I have multiple pieces of equipment on my farm with single acting cylinders. If I have to connect one to my tractor QD, I use a remote with float. When I had CUT’s with no float remotes, I still could use my Haybine with a single acting, one hose cylinder just fine.

 

[Texasmark]

If you powered down a 3 pt on a 2wd tractor, expect a long stay in your current position.....rear wheels off the ground!

 

[ROUSTABOUT]

If you powered down a 3 pt on a 2wd tractor, expect a long stay in your current position.....rear wheels off the ground!

Nice when you're stuck. I've been around one. Blocks under the lift, push down, wheels come up, block under tires, sit it down and drive out. That was the first one I had ever seen.

 

[LouNY]

The IH Farmalls with their 2 point fast hitch all had down power and with the adapters in the fast hitch they could use 3 point implements. Also I believe some of the Russian tractor and a few of the Europeans could be gotten with down pressure.
The IH fast hitch was superior to the 3 point but IH kept it proprietary so it faded away, the last tractors I recall with a fast hitch were in the 56 series.

 

[mo1]

If you powered down a 3 pt on a 2wd tractor, expect a long stay in your current position.....rear wheels off the ground!

I suspect you'd stay there only as long as it took you to grab the 3 point lever and raise your implement enough to put your tires back on the ground.