Mechanical Details of Seeburg Pipe Chests

(Photograph courtesy of Art Reblitz)

Early style single-rank pipe chest from Seeburg F #54,160 (Haddorff, made in 1913) with the toe board removed, showing the valves inside. The small springs on the valve stems hold the valves shut when they are off. The pneumatic fingers are not connected to the stems. The slender wood screw going through the little fork at the top end of each finger allows fine adjustment of lost motion between the finger and stem. When the pneumatic closes, the leather pad on the finger pushes on the valve stem and also seals the hole around the stem, preventing any leakage from occurring while the pipe is playing.

(Photograph courtesy of Art Reblitz)

Interior of two-rank pipe chest in Seeburg G #58,571 (Haddorff, 1914). In this later design, the valve stems are pressed into the pneumatic fingers so they don’t need springs or internal stem guides.

(Photograph courtesy of Art Reblitz)

Another interior view of the two-rank chest shown immediately above. Some examples had wire hinge springs in the pneumatics to assist holding the valve shut, but many had no springs, relying instead on the small pneumatics’ natural tendency to spring open when at rest.

(Photograph courtesy of Don Teach)

Reverse pipe chest pneumatics in a rare transitional style H orchestrion, #74,785, made in 1917. Because the finger overhangs the hinge end of the pneumatic, the pneumatic must have suction in order to keep the pipe from playing. Releasing the suction allows the spring in the pneumatic to open it and the valve, causing the pipe to play. The valve system that controls these pneumatics, allowing the pipes to play solos without playing the piano, remains undocumented.

(Photograph courtesy of Art Reblitz)

Early style pressure-operated pipe chest vent pneumatic in Seeburg G #8,905, made in 1914. When the roll turns on a rank of pipes, pressure in the pipe chest blows the vent pneumatic open, and the valve mounted on the hinge-end finger closes a small hole in the pipe chest, preventing air from leaking out. It is shown here in the “on” position.

(Photograph courtesy of Art Reblitz)

Early vent pneumatic in the “off” (or vented) position. When the roll turns the pipes off, the immediate slight pressure drop inside the chest allows the pneumatic spring to close it, opening the dump valve and releasing the remaining residual pressure from the chest.

(Photograph courtesy of Art Reblitz)

Late style vacuum-operated pipe chest vent pneumatics in Seeburg G #94,919 made in 1921. In this later style, suction from the “pipes on” pneumatic collapses the vent pneumatic, now with a finger on its open end, closing the hole in the chest. While the early pressure-operated style works well when the cloth is new, it depends on its hinge spring being adjusted perfectly to work right. The suction in the late style is more powerful than the pressure is in the early one, providing more positive closure of the valve, even when the cloth gets old and a little stiff.