Diaphragm Cylinder

[CanuckMiner]

We have some old details (from "before my time") that use (Norgren) Martonair diaphragm cylinders (also referred to as pot cylinders) to open a latch mechanism. To my knowledge, Norgren no longer makes these and so I am searching for a suitable replacement.

The cylinder I am looking for will have a short stroke (say 2 or 3 inch) with a spring return. A face/flange mounting arrangement would be best. I'm guessing that bore dia. would be around 3 or 4 inches (can't tell from the old details that were prepared on "hand CAD"). Compressed air at 90psig is the medium.

Can anyone point me to a suitable replacement? I have been googling for nearly two hours with no luck. I have also hunted through my catalogues for other cylinder manufacturers (Parker, Miller, Nopak), again with no luck.

Cheers,
CanuckMiner

 

[unclesyd]

There are a lot pneumatic valve operators that will handle your requirements. They go from the sophisticated to simple. We use these to operate all sorts of devices.

Try a search on pneumatic valve operators.

 

[ruble3]

try

http://www.controlair.com

?

 

[ruble3]

sorry-

http://www.controlair.com

 

[quark]

Bore dia. of 2 to 3" seems to be pretty big. You can try your luck with

http://www.festo.com

or

http://www.smcusa.com

for compact cylinders.

Regards,

 

[MintJulep]

Is there some reason that a diaphragm actuator must be used? (or is that the nature of your problem? It's always been one.)

In addition to all of the normal cylinder suppliers listed, take a look a Firestone, Lord and Sumitomo who all make air springs. I think they also have rolling seal type cylinders that might be a suitable replacment.

 

[btrueblood]

Marsh-Bellofram (

http://www.marshbellofram.com

) manufactures a line of pneumatic diaphragm cylinders, spring return, multiple sizes/strokes. Controlair.com also has similar. Google and Thomas Register searches for "diaphragm cylinder" and similar phrases found these. There were some others, but never heard back from them on email queries. The guys at Bellofram were pretty helpful.

If you come across any other manufacturers who make a liquid-tight version, double- or single-acting, please post back here!

For what its worth, diaphragm air cylinders have a very low break-away and running friction loss compared to any other type of actuator. They also can be useful to prevent leakage of the driver fluid (wiping seals tend to "weep" a little fluid on every stroke), and are more capable of resisting wear due to environmental dust/debris contamination since the seal doesn't wipe. Hmm...that sounds bad the way it's worded.

 

[CanuckMiner]

Thank you to all who have responded.

unclesyd, If I understand what you are suggesting, I'm not sure it would work. I need linear actuation, while the valve actuators I am familiar with are rotary actuators.

ruble3, I will hunt around at the link you provided.

quark, I am guessing at the bore size as it not specified on our old drawings. It may be much smaller. I will search these links as well.

MintJulep, It doesn't have to be a diaphragm actuator, but it would help if it fit into the same spatial envelope (or thereabouts).

In my office, we have a (good) habit of re-using old details, often in a rush without checking whether the components are still available (bad habit). What has happened in the past is that the contractor in the field (construction job)replaces these out of date items and doesn't tell us so that we here in the office naively copy the design yet again. While checking a drawing being prepared by my colleague, I came across one component I knew was out of date, so thought I would investigate the others. Little did I realize the jackpot that I would find with several components to update. :-(

Thanks again for your responses.

Cheers,
CanuckMiner

 

[FredGarvin]

You may want to take a look at Bimba's Flat (called Space Saving Cylinders)cylinders. They also do a lot of custom work. I'm sure you could find something thru them.

http://www.bimba.com/products/products.htm

 

[Compositepro]

Rolling diaphagm air cylinders are usually only used where they are specifically needed for their very low stiction. Some applications are for applying force to dancer arms or brake pads in tension control loops. Using common piston type cylinders will severely degrade the performance of the system. Bellofram and Controlair make them, as noted above. I've seen a lot of very poorly peforming tension control loops caused by designers not paying attention to details like the amount of friction in bearings and air cylinders.

 

[daveb9]

Have you tried using a car break cylinder here is a link to Haldex

http://www.brake-eu.haldex.com/html/frameset.php3

you could also try Bendix and Wabco

Dave

 

[brents]

I do a lot of custom work for people, when it comes to pneumatics and hydraulics..I'm not sure exactly what you need, but if you run out of options, then let me know if I can help...

I am a machinist/design engineer...

Brent