Kluge EHD - after skipping a sheet, platen still under impression

I’m not certain this applies to your EHD press, but this is from a Kluge Operating Manual. If it makes sense for you, you are welcome.

“Throw-off — proper lubrication is important to any machine which is precision built … if the throw-off fails to operate, then carefully check the entire throw-off system to determine whether all bearings and moving parts are properly lubricated. If any of the bearings or moving parts are sticking the throw-off will not operate.
Your Kluge Press was carefully tested at the factory before it was shipped to you, however, if the £eerier fails to throw-off prop­erly, all that may be needed to correct the condition is to check the throw-off counterweights which are located at the bottom, right side of the press, below the feeding arm post. If the press fails to throw-off, move the weights out toward the end of the rocker arm … if the throw-off fails to come in, move the weights in toward the center of the rocker arm. LOOK EVERYWHERE ELSE, however, BEFORE MOVING THESE WEIGHTS … air leaks, proper lubrication, and so forth.
The throw-off is operated by suction and when the feeding arm picks up the sheet a suction is created in the feeding arm post which raises a piston at the bottom of the post. If no suction is created it is evident that there is an air leak and, as a consequence, the press will not print. For this reason, it is advisable to check the air system regularly for possible air leaks.
As your press is used over a period of time the throw-off may not operate efficiently because oil has been allowed to accumulate with the dirt and congeal in the plunger. If this is so, then remove the hose which connects the feeding arm post with the feeding arm and shoot kerosene into the feeding arm post. This kerosene will run down the post and into the plunger and as a result dean the plunger. It must be remembered that kerosene is the agent to be used for this cleaning operation.”

John Henry
Cedar Creek Press

Those instructions above are for the older 12x18 presses. they are not usable on your press, there is a plunger mechanism at the other end of the assy in your pic. make sure that plunger is clean and DRY. A dry lube such as Tri-flow is ok there but NO OIL. There is a hose that runs to the plunger block. make sure there is no oil in it. It sounds like you have an electric vacuum pump. There should be valves on it that you can adjust for less vacuum. Make sure your special feed valve is aligned properly.

Thank you @jhenry, its something different, my press does not has “the weight”.

@ericm Thank you very much! There is no oil in the hoses. Plunger opens fast and smooth immediately after air pump is off. And the plunger opens very slowly (sometimes even not opens) when suckers are open and air flows trough the hoses and the plunger.
- I will try to decrease vacuum pressure on the pump (hope will find out how to do that)
- Will disassemble and clean the plunger.

What is the “special feed valve”? That one which is marked on the attached photo?

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I have cleaned the plunger, it was just little oil inside. I have opened arm suction valve (check out the photo) on the pump to have little leak of the vacuum. I didn’t found any other valve to adjust the vacuum on the pump. Seems that everything started to work properly. THANK YOU @ericm!

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Yes! those are the valves. adjust them as you need to for each job. Hard to tell which is which, from the pic, but one goes to the feed systerm, and other goes to the delivery.

The “Special feed” valve is right next to the pluger you cleaned. you pull the bottom of the 3 control cables to “feed without impression”. make sure it is aligned so that when the control is pushed in, you cannot put a small drilll bit into the hole that is drilled in it. look closely, you will see it.

Ok, Thank you @ericm!