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Semi-Automatic Piston Valve Diagram

Posted: Wed Mar 11, 2009 5:23 pm
by burgerace69
I've been thinking about how I could make a portable, powerful, and most importantly, efficient cannon. I think I may have developed something after some long hours in math class.

Referring to the Diagram:
Granted, I'm sure we all know what numbers 1 through 3 are, but just to clarify: 1 is an air reserve including a schradder valve, 2 is an exhaust valve for the main piston valve, and 3 is, of course, a co-axle piston valve. Number 4 is a secondary semi-automatic piston valve that I've developed. This consists of three parts: part A is a thin tube (ie: rubber charcoal lighter gas hose) that connects the exhaust of the secondary piston valve to the active air reservoir located around the barrel, part B is a very weak spring in order to overcome equilibrium air pressures, and part C is the small piston, which purpose serves as a plug to the large air reserve.

As far as how it works, just try to imagine the course of air flow and the changes it will make on the mechanisms inside as the gun fills, pressures equalize, the gun shoots, and the gun refills. It would be wordy and arbitrary for me to try to explain it in full detail to you.

I would appreciate any constructive criticism, thoughts, or feedback on this design. If you have any questions, please ask. Thanks for taking a look.

Re: Semi-Automatic Piston Valve Diagram

Posted: Thu Mar 12, 2009 12:46 am
by jackssmirkingrevenge
burgerace69 wrote:I think I may have developed something after some long hours in math class.
That's how I used to spend the hours :roll: :D

As to your design, interesting. If I understood correctly, when you fire the piston the chamber empties, allowing the second piston to move back until the chamber refills and pressure equalises, closing it again.

I'm wondering though, is it worth the excess complication? I don't know how much air you'll actually save.

Posted: Thu Mar 12, 2009 9:48 pm
by psycix
I see one thing that can go wrong:
On firing, the second piston will snap back and 1 will be emptied.

Actually, when the 1st piston can pass air into the chamber, the tube A is not even needed. The tube will just cause to leak air through the barrel before the piston seals.

Posted: Thu Mar 19, 2009 11:48 am
by burgerace69
I guess i probably didn't set the proportions correctly at all. the semi auto portion is smaller than cpvc and the blue part (1) is much larger in respect to the piston coaxial tank(which will be relatively small- probably for shooting air soft or paint balls). i plan to use some golden rods from ace hardware, which fit perfectly inside of each other, that are about a 1/4" in diameter. I've actually made a piston like this one before for a breech loading system and it worked way better than i even expected. I'll have to build it to see if it works-ill try that this summer and upload my pics.