(Photograph courtesy of Dick Hack.)

Coin slot faceplate in National piano #7352. Across the top are eight separate coin slots interspersed with letters spelling out the word "Program." Below each of the coin slots is a push button that, when pushed, causes a correctly sized coin to be released and then dropped into the appropriate channel in the wooden coin transfer connector situated below. This connector, in turn, channels the falling coin into the correct coin chute at the back side of the coin switch mechanism. Below the push buttons is the text:

"Play Nickel In One Or More Slots
Push Button Each Nickel"

In the lower portion of the faceplate is the tune title strip display window, with a numbered tune title strip for each of the eight coin slots. The key-lock restricts access to the title strips. To select a tune, take note of the tune title strip's numbered position, and then drop a coin into the corresponding coin slot. The largest coin that can be inserted is a nickel. Anything smaller will be rejected, ding a small bell, and then promptly be delivered to the coin return tray.

(Photograph courtesy of Dick Hack.)

Coin size detector mechanism behind the coin slot faceplate in National piano #7352. When a coin is inserted into any of the eight slots it first takes a short but zigzag trip that terminates with the coin falling into a little die-cast coin trap, which allows any coin smaller than a nickel to fall through. These undersized and rejected coins fall into a metal catch-all chute that rolls the coin into a little bell, and then delivers it to the coin return tray. In this photograph the metal chute for rejected coins is missing, although the shiny glow of the coin reject bell is partially visible at bottom left.

Each of the little die-cast coin traps have a spring loaded L-shaped lever with a large flattened area that projects to the rear of the trap. The upper part of the lever sticks up and has a little compression spring behind it. The lower horizontal leg of the lever is not visible here, because it is hidden inside the die-casting. Its purpose is to narrow the slot going from top to bottom through the trap, so that undersized coins fall through the trap, but properly sized nickels stay trapped—until an action occurs that causes the nickel to fall into the wooden transfer connector that is below and a little to the rear. Each of the little coin traps are connected to their own lever that is actuated by the push button below the associated coin slot. When the push button is pressed inward, the associated coin trap at the bottom end of the lever swings back and away from the faceplate, and lines up over the wooden transfer connector waiting patiently below. At about the same time, the little lever sticking up on the backside of the coin trap bumps up against the stationary metal bar fixed behind the zigzag coin chutes, rotating the lever slightly, which then allows the trapped nickel to fall out of the trap and into the transfer connector.

(Photograph courtesy of Dick Hack.)

Coin trap actuating levers between the zigzag coin chutes in National piano #7352. Each of the little die-cast coin traps (dangling near the bottom of the photograph) are screwed to a long lever that has a bearing swivel point near the top of the associated zigzag coin chute to its right. Down the lever from the pivot bearing is a small L-shaped metal bracket that extends to the right and over the corresponding push button. A hole in the bracket fits over a rounded nub on the back end of the push button. When the button is pushed the connected coin trap swings backward away from the faceplate. When the spring loaded lever sticking up on the rear of the coin trap contacts the stationary bar the trapped coin is released, it falling out of the trap and into the wooden transfer connector below.

(Photograph courtesy of Dick Hack.)

Close-up of a die-cast coin trap in National piano #7352. Here the foremost coin trap is shown pushed to the rear and to the point whereby the upward projecting lever on the back side of the trap is just barely making contact with the stationary bar. Although touching the bar, the L-shaped lever has not yet been shoved forward, so as to rotate the lever and release the coin trapped within the coin trap casting. As the L-shaped lever rotates it effectively makes the bottom of the slot opening wider, thereby allowing a coin previously trapped to fall free. The large fin or flattened area projecting to the rear of the lever was probably used by a route operator to manually clear and/or release a coin stuck in a coin trap,

(Photograph courtesy of Bob Gilson.)

An overall view behind the coin slot faceplate in National piano #348. At top are the zigzag coin chutes with the little die-cast coin traps dangling directly underneath the chute exit slots. Below the coin traps, and at a steep angle, is the reject coin collector chute, which rolls the coins into the little bell, ringing it, with the coin then bouncing off and falling through a slot in the piano case front panel and into the coin return tray. To quell any questions about the obvious, wide vertical channel below the coin slot faceplate, and cut into the backside of the piano's upper front panel, this relief cut provides space for a chain sprocket and the chain that provides motive power to a retrofitted dog race diorama.

(Photograph courtesy of Bob Gilson.)

Close-up of the coin reject bell setup in National piano #348. The shiny little bell is at left. The reject coin collector chute funnels wayward coins toward the bell. After striking and ringing the bell the coin bounces back a bit and falls into a spacious slot in the piano's front panel, which deposits the coin into the return tray mounted on the front side of the panel.

(Photograph courtesy of Bob Gilson.)

Close-up of the coin return tray in National piano #348. The coin return tray is nothing more than a little metal dish attached with a pair of wood screws to the front side of the piano's upper front panel. The cutout in the rear flattened part of the tray is aligned with the coin chute cut into the front panel. The coin reject bell (mounted on the backside) is above and to the right of the coin return tray.