Anatomy of a WurliTzer Theatre Pipe Organ
This is looking from the bottom.
Air enters through the hole at the top left into the small chamber in the body.
The valves fit into the round hole and seal against the white leather, which has felt underneath
it to reduce noise. The valve rod goes through the small hole in the top board. It is the movement
of the top board that moves the valve. When the top board is forced down by the springs exerting
more downwards force that the air pressure inside the regulator the valves are pushed down to open
the flow of air from the small chamber into the top of the regulator. As the air pressure rises
so does the top of the regulator against the springs. When the air pressure reaches to the level
that pushes the top up far enough the valves are pulled up against the leather seal which prevents
further movement of air and further rise in the pressure.
Air in the top of the regulator flows through the rectangular hole into the large chamber and
out of the small hole on the right end to the console, or other device.
Whan air is drawn off the regulator the pressure, and hence the top of the regulator, drops causing
the valves to be opened and more air admitted to compensate for the air drawn off.