450 Slide-out FIX

[davidbrady]

Hi Ross,

It's hard to visualize without a diagram, but I'm thinking that restricting the flow on port 1 works because this allows the flow on the exhaust ports to dominate.

Port 4 get's a steady flow, albeit restricted, which allows the pin to stay locked during bus transit. When the switch is thrown to retract the pins, port 4 still gets a steady flow but now port 2 is fed from port 1 pressurizing the cylinders to unlock. During the pin unlock phase port 4 is exhausted to port 5 and port 1 is directed to port 2. If the exhaust port dominates, meaning that it's flow is much greater than the source supplying port 4, then the locking pin moves as port 2 is pressurized. Confusing, I know, but I can see how restricting flow of the source at port 1 such that it's significantly less than the flow at the exhaust ports (which are vented to atmosphere) would allow the pins to retract even if a steady air supply is being directed to port 4. Whew!

If we had a diagram it'd be fun to try to improve on the design.

Thanks for the idea. I need to do something similar with my entryway stairwell cover. It behaves much like your locking pins except it doesn't have a continuous air feed on port 4 keeping the platform closed. This is a problem because my kids like to stand on the platform and lean against the dash. Without a steady air feed the platform opens with their foot pressure. I need to fix it!