Molding concrete pipe sections - GIF

[BuffaloJohn]

But you can see in the video that the cylinder is not twisting. And even if it was, a piston rod is free to spin inside a hydraulic cylinder. So you can spin a base or mount all day long and it won't spin the piston rod. I'm not even sure how you would construct a hydraulic cylinder such that it could apply any appreciable torque to the piston rod. They have to be able to spin inside the bore of the cylinder.

The cylinder has a piston and the piston is twisting, I didn't write it well enough, sorry.

Imagine a hydralic cylinder that has the piston sticking out both ends of the cylinder. If the piston extends through a gland on the non-visible side, it can be twisted. The piston is held in place by the glands on either end and the piston that slides inside the cylinder. The cylinder itself doesn't need to spin, and if it did, it wouldn't spin the load. That is why you need to spin just the piston shaft. And, you could apply a decent torque to the shaft to spin it.

It is a specialty application, but with proper design on both ends, it would work like this.

Is there another way to do it? Perhaps. You might, but I don't see any other bits to rotate the lowered head assembly. My explaination is fairly simple and would work.

There is a cut in the video (around the 4-5 second mark), you can see the stack of rings in the loader have a "jump". But that does not effect the simple explaination as far as I can tell...