Pneumatic Auto Possibility

[Atlantis]

In this design, there is a piston with a kind of pin valve, when it is pushed in air can flow through it. Normally the piston keeps the air in the chamber, when you open the valve some of the chamber's air goes into the area behind the piston and pushes it forwards, once it pushes it past the tee all the air from the chamber dumps behind the piston and it slams forward, when the pin/bolt hits the wall, the piston keeps going but the bolt begins to open, this vents all the air into the barrel. Once the gun is fired the piston moves back under spring pressure and seals off the chamber again. Then the process repeats. A continuos air supply would be hooked up on the far end of the chamber. The piston is kind of like reverse venting, you pump air IN to move the piston, since nothing is dumped to atmo, no air is wasted. The idea is kind of hard to explain, the picture will help clear things up, I need to figure out how to animate. Any suggestions or ideas would be greatly appreciated.

[rna_duelers]

Bit of machining and lathe work,but if you do make it i see a porblem wiht getting a spring strong enough for the job you want with out hampering the power.

[Atlantis]

The spring would only have to push the piston back, since the air supply is far away from the piston it takes a second for the air to reach and push against it.

[boilingleadbath]

Looks like it'd work fairly well, and would only require 3 O-rings.

[Atlantis]

Cool, can somebody test this for me please. I still haven't built my first pneumatic. Ironic. I'm hoping to build one soon, maybe a burst disk. I'm also thinking about making a piston valve, maybe 2".

[Rambo]

You better make a burst disc hybrid

[jrrdw]

I think this is a workable idea, the air hole in your "pin" would have to be the same size as the barrel or you will lack in power. You will probly have to build a catch in your trigger or your constent air feed will cause the "pinned piston" to flutter back and forth uncontrolable causeing it to be fully automatic. I think that would tear it up quickly if high presure is used. So build it very strong! VERY GOOD THINKING, I'M IMPRESSED WITH THIS IDEA!!!! One of the best i've seen lately, and i'm not easy to impress with mechnical ideas! Very good thinking!

[Atlantis]

Thanks for the compliments. I think I came up with another idea, I'll post it later If I can draw it up. It's a simpler version of this.