Hydraulic Side Tilt For 3PH--Single or Double Acting?

[npalen]

Quite a few cylinders that are marketed as SA are constructed as DA cylinders with a breather in one port.

But true SA cylinders like I am referring to are found on things like snowplow angle or lift c

The OPs problem would be without the ground limiting travel the cylinder will just extend on it's own and it would never hold adjustment. It needs to be a hard connection limited in both directions. Otherwise when he lifts the three point the side with the single acting cylinder will just drop as far as the length of the ram will allow.

I don't think so.

 

[jdmeth]

I'm just looking for a reason why a single acting cylinder with a double acting valve (single hose) wouldn't work.
It would give a larger selection of cylinders to choose from.

Works just fine. I had a front 3 point hitch I bolted to my 120 hp four wheel drive JD 4250. I ran one hose to it. The lift cylinders rod end ports had a fitting with an air filter in it. Raising the lift forced air out and filtered air would be sucked back in when I lowered the lift. This also allowed the attached implement to float up, air would be forced out and a vacuum pulled on the pressure side. Worked great.

Of course the cylinders were mounted to the base and lifted by extension, like the boom on a backhoe. Using them mounted to lift arms would not work, gravity would just pull the rod out. To work you would have to use a double acting cylinder with the hose plumbed into the rod end and a filter fitted to the piston end.

 

[DSteiner]

Your current vertical lift arms are fixed with an adjustment on one or both. This keeps things on an even keel side to side. A single action cylinder will destroy that ability. For example you want a rear blade to cut deeper on one side in relation to the other.

 

[npalen]

I agree with your thinking as a single acting cylinder would allow that side of the 3PH to float upward without necessarily affecting the other "rigid" side. Yes, that would destroy the desired tilt that had previously been set by retracting or extending the SA cylinder.

There might be a case or two where it is desired to let the SA side float independently when working with existing road crown, for example, but that would probably be an exception.