Melville Clark Patents for
the Solo Apollo Player Piano

The Patent examples shown below probably do not come close to representing all of the many and perhaps sometimes trivial permutations tested over the years by the Melville Clark Piano Company. Nonetheless, these patents do represent foundational ideas, at least some of which surly found their way into actual production, and proved themselves commercially viable. It is unknown if all of the design configurations illustrated were used, some appearing to be much more practical and easier to service than others.

In the Patent text for the Solo Apollo, the two valve chests and their associated motor pneumatics are referred to as the Primary action and the Melody action, but in actual practice, at least in later years, the Primary action was generally referred to as the Accompaniment action, while the Melody action was normally referred to as the Solo action.

One of the often advertised features of the Apollo Player Piano was this: The downward touch of the piano key in front of the fulcrum is the same as in manual playing, which secures real human expression. How this claim was reconciled with some of the designs shown below is unknown.

Melville Clark Interior Piano Player Patent US 1,009,828.

Public domain US Patent Application.

Melville Clark Interior Piano Player Patent US 1,009,828 filed on April 8, 1909, and Patent granted on November 28, 1911. In this drawing the spoolbox is at top, with tracker bar tubing flowing downward to the single but compartmentalized valve chest. The control valves for the principal (accompaniment) motor pneumatics are at left side, and the control valves for the melody (solo) chest are on the right side. Channel boards conduct air to the appropriate set of motor pneumatics. The principal (accompaniment) action forward facing motor pneumatics (at left) push down on the keys just behind the fallboard. The solo melody upward facing pneumatics (at right) lift the back end of the keys by means of a crank, the lower end of which rests under the horizontal extension of a metal hook.
Melville Clark Interior Piano Player Patent US 1,011,920.

Public domain US Patent Application.

Melville Clark Interior Piano Player Patent US 1,011,920 filed on April 12, 1909, and Patent granted on December 19, 1911. In this drawing the spoolbox is at top, with tracker bar tubing routed downward to the two separate valve chests. In this drawing the principal (accompaniment) chest is suspended below the keybed, with the melody (solo) chest above and just below the spoolbox. The valves for the lower principal (accompaniment) forward facing motor pneumatics are to the right (or rear side) of that chest. The pneumatics pull down metal rods attached to the underside of the piano keys by means of a metal clip, The upper melody (solo) upward facing pneumatics (at upper right) lift the back end of the keys by means of a crank, the lower end of which rests under the horizontal extension of a metal hook. The valves for the melody (solo) action are to the left (or front side) of the melody (solo) motor pneumatics.
Melville Clark Interior Piano Player Patent US 1,014,810.

Public domain US Patent Application.

Melville Clark Interior Piano Player Patent US 1,014,810 filed on April 13, 1909, and Patent granted on January 16, 1912. The spoolbox is at top, with tracker bar tubing threaded downward and distributed appropriately between the two separate valve chests. Here the principal (accompaniment) chest is mounted above the keybed, with the melody (solo) chest suspended below the keybed. The valves for the lower principal (accompaniment) forward facing motor pneumatics are to the right (or rear side) of this chest. The pneumatics push down on the piano keys, The melody (solo) rearward facing pneumatics (at lower right) push up on the back end of the keys. The valves for the melody (solo) action are to the left (or front side) of the melody (solo( motor pneumatics.
Melville Clark Interior Piano Player Patent US 1,160,260.

Public domain US Patent Application.

Melville Clark Interior Piano Player Patent US 1,160,260 filed on July 28, 1915, and Patent granted on November 16, 1915. At drawing top is a single but divided valve chest, the front half for the principal (accompaniment) action and the rear portion (at right) for the melody (solo) action. Channel boards conduct air to the appropriate set of motor pneumatics. The principal (accompaniment) action forward facing motor pneumatics (at left) push down on a long lever that extends under the entire chest assembly, the other end of which pushes up on a flange affixed to the a piano action sticker. Similarly, the melody (solo) rearward facing pneumatics (at right) push up, by means of a metal rod, against an upper flange milled as part of a piano action sticker.
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