Coinola Box Pump
for both Vacuum and Pressure

(Photograph courtesy of Art Reblitz)

Coinola pianos with pipes typically have a box pump with sheet metal attached to the front and back, forming an enclosure to capture the air that is exhausted through the external flap valves of the vacuum bellows. This supplies the pipe chest with pressurized air to play the pipes. This picture shows the combination pump in Coinola CO orchestrion #175859.