Link Coin Slot Mechanisms

(Photograph courtesy of Rusty King)

Early Link vertical coin accumulator mechanism with electrical contacts and coin eject pneumatic located at the bottom. The tall, upright nickel accumulator is a nicely crafted brass casting that can hold up to 20 nickels. When a coin is dropped into the slot it falls through the accumulator and lodges against the stationary electrical contacts situated at its bottom. This then trips the motor switch and as the vacuum level in the system rises the coin drop pneumatic pushes the coin off of the electrical contacts and into a sheet metal chute that is a direct route to the coin collection box. Should there be more than one coin dropped into the coin accumulator the nickel drop pneumatic linkage prevents additional coins from touching the electrical contacts until after the motor stops and the vacuum level bleeds off to normal atmospheric pressure, whereupon the coin drop pneumatic relaxes and allows the next coin in line to fall onto the electrical contacts.

(Photograph courtesy of Rusty King)

The electrically triggered motor switch in housed in a sturdy cast iron housing located to the immediate left of the motor. When a coin falls onto the electrical contacts in the coin accumulator mechanism (not shown in this picture) it energizes the pair of electromagnets at the top of the switch unit, which in turn releases a mechanical latch holding the motor switch open. With the switch closed and the motor operational, when the coin trip perforation passes over the tracker bar the large pneumatic at the right side of the switch enclosure pulls the motor switch open, whereby it is then held open by means of a mechanical latch--until triggered again by a coin falling onto the coin accumulator electrical contacts.

(Photograph courtesy of Rusty King)

Close-up of the coin drop electrical contacts and associated "accumulator" chute in Link keyboard orchestrion #2264. Here a coin is shown resting on the two large contact points. These contacts are wired in series with the trip electromagnet located in a separate switch box (see next image pane below). The contact/trip circuit is then in turn wired in parallel with the motor electrical switch, so that when the motor is switched on there is no electrical current flowing through the coin, contacts, or trip magnet. With the motor running the increasing vacuum level collapses the small pneumatic behind the coin contacts, whereupon a lever pushes the coin forward and free of the contacts while at the same time blocking any additional coins in the chute from falling onto the electrical contacts. This coin "pusher" and chute blocking lever retracts after the tune ends and the motor is shut off, and when any residual vacuum within the system normalizes. At this point another coin, if any, can then drop onto the contacts, tripping the motor switch and repeating the aforementioned process.

(Photograph courtesy of Rusty King)

This close-up image of an old, rather grimy and orphaned early style Link electromagnetically triggered motor switch clearly shows the overall layout of the device. The electromagnet is at the top and consists of a pair of coils wired in series. These are momentarily energized when a coin falls onto the coin accumulator's electrical contacts (see the previous image pane above), whereupon the motor switch closes, which in effect then removes the electromagnet's coils from the circuit, thus preventing overheating and/or burnout. The vertically oriented knife switch is spring loaded, but is held open by a mechanical latch. When the electromagnet is energized the latch is released and the motor switch snaps closed. The large pneumatic at the right pulls the knife switch open, whereupon the switch latch keeps it open.

(Photograph courtesy of Rusty King)

A late ratchet style coin accumulator and switch mechanism installed in a Link model 2EX. This device is much more compact and much simpler than the earlier multi-component arrangement. When a coin is dropped into the slot it falls through the accumulator and hits a small lever which trips a (one tune count) latch on the ratchet wheel, allowing it to rotate counterclockwise one tooth (or one tune count). The ratchet wheel can be incremented multiple times (adding additional tune counts) by either a coin drop or by the electromagnet (connected to external wall boxes.) Once the ratchet wheel is initially tripped the motor switch closes. A hook attached to the pneumatic at right rotates the ratchet wheel one click clockwise, subtracting one tune count, or if no additional tune counts are available the motor contacts are pulled open.

(Photograph courtesy of Dana Johnson)

Link cast iron wall box of a design that was probably in vogue when the Link Piano Company began business in 1913. When a coin was dropped into the slot at the top of the unit (just above the crank and below the "Drop Nickel" sign) it fell into a pocket attached to the small crank handle. If the coin was undersized it would fall through the pocket and out into the coin box without any further action. A nickel sized coin, however, could not fall through and when the handle was rotated 1/2 turn the top nickel visible in the little glass window was pushed down by a cam action and the nickel in the crank pocket would fall into its place, the latest nickel then visible as the top coin in the window. When the coins (visible in the window) were pushed down the bottom nickel, which was held snugly in the coin chute by a spring loaded pawl, would be ejected, whereupon it would fall upon a little weight balanced finger that, when depressed, closed an electrical contact. The idea of the coin viewing window was to allow anyone to see whether or not a slug (a nickel sized metal punching) had been nefariously inserted, essentially keeping patrons honest through threat of peer embarrassment.

(Photograph courtesy of Dana Johnson)

Link cast iron wall box of a later design, estimated circa 1920. The more complicated earlier designs had given way to a much more simplistic, plain looking design by the 1920s. Here there is a simple nickel drop slot at the top.

(Photograph courtesy of Dana Johnson)

Interior of the Link cast iron wall box, circa 1920. When the nickel drops it encounters the first zig-zag, where its speed is reduced as it rolls past a coin sizing slot in the backside of the coin chute. The simple flat spring pushes any undersized coins out through the sizing slot without any further action. But if the coin makes its way past the sizing slot it continues on into the next zig-zag where it finally comes to a stop and falls into the cast bronze weight balanced finger. When this finger is rotated due to the weight of the coin the balancing weight (at its left) makes contact with a brass strip, thereby closing the electrical contact.