While the final design of the Piano Lodeon was different, the Patent from June 9, 1953 explains the basic operation. To view/download the patent, CLICK HERE.

Referring to the first graphic above, note the area in 'White' and the three areas in 'Blue'. When there are no perforations (on the music roll) passing over the trackerbar, there is an equal amount of vacuum pressure on both sides of the Striker Vane. Referring to the second graphic, the previous fact is true because of a small hole in the Striker Vane called the 'Bleed'. As a perforation passes over the trackerbar, a small gust of air (at atmospheric pressure -which is higher than the vacuum pressure) 'blows' on the Valve Vane, which causes it to teeter downward and open. This, in turn, allows a large gust of air (at atmospheric pressure) to 'blow' on the Striker Vane, which teeters downward and plays a note on the piano.

Once the perforation in the roll passes, the Valve Vane teeters upwards and closes off the atmospheric air pressure. This happens because the Valve Vane is very slightly heavier on the atmosphere side than on the vacuum side. Then, since there is now an equal amount of vaccum pressure on both sides of the Striker Vane, it teeters back upwards because it is heavier on the atmosphere side than on the vacuum side.

EDITORS NOTE: The correct size tubing for the trackerbar is 1/4" ID (#8) player piano tubing -click here. You will need 20 feet of tubing.

Also, Player-Care is now selling the drive belt for the device -click here