It’s technically an auto UNlock, so you don’t slap the door open pneumatic switch and just stress the hell out of the door and it’s hinges. The way it will work is air goes to unlocker ram first, once it engages the latch and releases, air switch allows air to flow to opening side of double acting ram for the door hinge actuator.
The door must “bump” open first to open the valve for the pressurized air to physically reach the door swing ram.
On closing, the latch is open, and captures the pin.
If you open the door manually from the outside or the inside by pulling the lever, the valve is just sort of floats, acting as if you flipped the “emergency release” switch above the door in an unmodified bluebird bifold pneumatic door.
At some point in the future I may replace the double circuit pneumatic switch on the dash with an electronic one, so I can push a keyfob button to open and close the bus door.
Don’t have any more pics right now, not done. Note that the door handle does NOT have a lock built into it. I have a flush mount 5 pin mortise lock on the outside, which is attached to an additional dead bolt in the door frame.
The dead bolt and mortise lock are attached via linkage to the bear claw lock so it’s a double lock setup. (bear claw won’t release unless it’s unlocked too)
If the cylinder lock and deadbolt are engaged, then the pneumatic unlock actuator will fire but not unlock, and it won’t pop the door, and then the air for the opener ram will just make an angry loud hissing sound because it’s vented through the air switch.
I suppose I could put some party whistles, a wig wag, or maybe some streamers on the air outlet. Maybe an inflatable balloon with the words “unlock me printed on it”. (I mostly kidding)
Here’s a parts list.
Momentary pneumatic pin switch with spring return I already had. Air routes out one port or the other. Unlocker ram plumbed to the normally closed position. When door is closed on pin switch, it’s open, allowing air to open ram and prevent from getting to door actuator. Once door opens via mechanical release, pin switch routes air to door hinge actuator ram.