# Jaap's Mechanical Calculators Page

The Dial-Admatic is simple dial adder which literally has telephone dials for inputting the numbers. Supermarkets could attach these to the shopping cart handlebar, allowing the shopper to keep track of their total spending. It should not be confused with the Dial-a-Matic, a stylus-operated dial adder.

The adder has a four digit register, made of four large number wheels. The top edge of these number wheels poke out the top of the machine, displaying one digit each. Only the three right-most wheels have a dial on the front, marked Dollars, Dimes, and Cents. The shopper simply dials in the prices of the items bought, and the register shows the running total, up to a maximum of \$99.99. It has no reset mechanism, so the wheels must be reset individually, starting from the right. The left-most wheel can be turned by hand too, even though it does not have a dial.

There are transparent plastic covers to the left and along the bottom of the dials, and behind those the supermarket could place ads, or display current special deals. It seems to have the serial number 2534, visible in ink behind the left plastic cover.

The rear of the machine bears the text "Dial-Admatic, Inc.  Minot, No. Dak.    Pat. Pend.". It was invented by Samuel M. Librande, also of Minot, North Dakota, and he filed for a patent in May 1964 which was granted February 1966. It was used in a few supermarket chains from the end of 1964, but seems to have been very short-lived.

The mechanism is relatively simple. The carry mechanism between two adjacent wheels consists of a sliding bar with hooks at both ends, and which gets pulled to the right when a carry occurs. The hook on the right rides along a cam wheel, and only gets caught when the disc moves from 9 to 0. The hook on the left end then pulls that number wheel one step forward.

This machine is very rare as they were never directly sold to consumers, and were usually disposed of when the supermarkets stopped using them.

## Video

Here is a series of ads from a supermarket chain in Manitoba that trialled the Dial-Admatic.

Here are a few articles about the Dial-Admatic being introduced in some supermarkets.

## Patents

PatentFiling datePublish dateNameDescription
US 3,236,44615-05-196422-02-1966Samuel M. LibrandeSupermarket Adding Machine