SpudFiles

Looking around and came across patent drawings for the K1. Looked like a toolies piston held by a sear... which caught my interest and spurred further digging.

Found a tear down video and actually started chuckling when the fellow showed the firing valve.

While I'm mot 100% certain, it looks to be eerily similar to JSR's "hammer piston"....with some of the discussion taken into account as well.....

http://www.spudfiles.com/pneumatic-cann ... r%20piston

Patent; https://www.google.com/patents/EP2455699A1

Tear down video;

Spudgun "tech" in an airgun....or airgun "tech" in a spudgun...interesting stuff either way. 8)

The working principle of the hammer-less mechanism is as follows:
After the trigger is pulled to release the sear, air pressure pushes the piston backward. Driven by the piston, the air valve opens the air passage and the pellet is propelled out. Then the air passage is cut off by an adjustable shut-off valve. After that, the air pressure pushing the piston backward disappears, and the piston returns to its original position under the force of the spring, thus achieving automatic cocking.

Interesting indeed, nice find!

Funny how I'm reading this right after making a thread asking about mechanically actuated launchers. In my thread I've put up a concept sketch where the chamber pressure is what's opening the valve and after pressure's gone a spring returns the piston to close the valve.

I recently started looking at this mechanism again and it really is quite interesting.

This is the manufacturer's animation:



I made my own simplified animation of how I understand it works:



A two-part piston held by a sear seals the breech.

When the sear is tripped by the trigger, the piston can move back allowing air to flow out.

If that was the end of it then the entire chamber would be dumped.

However the is a second valve that separates the de factor firing chamber from the main reservoir.

This is normally held open by a spring but the air flow forces it closed, choking the flow.

This allows the pressure to drop in the firing chamber, and the piston can re-close and be caught by the sear.

The firing chamber then pressurizes again and as the firing chamber and reservoir equalize, the flow choking valve opens again.

The cycle can then be repeated.

Another clever thing is that the drop in pressure is linked to a piston that indexes the rotating magazine.

It really is something I had been playing with more than a decade ago:



That didn't work very well, the stroke of genius is the addition of the choking valve to enable the piston to cycle.