Star Adding Machine
Video
History
Manuals
Newspaper and Magazine Advertisements
Patents
Links
This Star Adding Machine was made by the Todd Protectograph Company. It has serial number 71,052, and was made in about 1923.
It has a 7 digit register. Below the register is a row of co-axial paddlewheels which are used for entering numbers. To enter a digit, put your finger on the paddle-wheel for that location on the paddle that is marked with the digit you want to enter, and pull your finger downwards until it hits the ledge at the front of the machine. As the paddle-wheel turns, the number wheel of the register above it is turned too, adding the selected digit. In the front ledge is a button that puts a brake on the turning number wheel so that the number wheel will not overshoot however fast you pull down on the paddle wheel. The paddle wheel springs back to its starting position when you release it. The register carries automatically using a spring-loaded mechanism.
The paddle wheels are also marked with complementary digits in a smaller font, and these allow you to do subtraction. To subtract a number, simply enter it using these complementary digits, including any leading zeroes. The row of red buttons at the top of the machine suppress any carry to the associated register number wheel, and are used to obviate the need to enter most leading zeroes during subtraction. Note that the right-most carry suppression button is useless since nothing carries into the units digit.
The bottom plate of the case can easily be removed. The rest of the casing is more tricky to remove because the paddles of the input wheels are wider than the slots in the casing, and so all the input wheels have to be pushed all the way down and held there simultaneously.
Below is a video I made that demonstrates the Star Adding Machine.
This machine was originally made by the Accounting Machine Corporation, and named
the AMCO Adding Machine. The company had its factory in Grand Rapids, Michigan, and
their main office in New York. The AMCO Adding Machine was designed and patented
by Fred Doerr of Grand Rapids in 1917, was put in production that year, and was
produced until 1922. The manufacturing and sales rights were then bought by the Todd
Protectograph Company (Rochester, New York), and produced in various versions until 1928
using the names Star Adding Machine and Todd Visible Adding Machine.
The table below lists the versions and their distinguishing characteristics.
| Years | Name | Description |
|---|---|---|
| 1918-1922 | AMCO Adding Machine | Made by the Accounting Machine Corporation (AMCO).
Two sizes - 7 or 9 digits. |
| 1922-1923 | Star Adding Machine | Made by Todd Protectograph Company. Identical to the AMCO, apart from the label.
Two sizes - 7 or 9 digits. |
| 1923-1924 | Star Adding Machine | In about April 1923 a carrying handle was added. This handle could also be folded down onto the input wheels and locked in place so as to keep the register's state safe from changes. The handle bears the text "MACHINE IN USE - DO NOT OPERATE". The right-most carry suppression button unlocks the handle. |
| 1924-1926 | Star Adding Machine | The machine now simply has a lockable cover with a key, and a separate carrying handle.
9 digit register only. |
| 1926-1928 | Todd Visible Adding Machine | This version has an input register displaying the entered number.
9 digit register only. |
Instructions for Operating The Star Desk Adding Machine
Todd Protectograph Co., Inc., Rochester, New York
1923-1924
Form 15501-A
8 page stapled leaflet
101mm × 171mm
This is the instruction leaflet for the Star Desk Adding Machine, in particular the version from 1923-1924 which has a carrying handle that can fold down to lock the input wheels.
Here are some articles and advertisements I found in online archives. First those relating to AMCO.
The following articles and ads relate to the Todd Protectograph Company, the Star Adding Machine, and the Todd Visible Adding Machine.
Here are the patents related to the AMCO/Star/Todd Visible Adding Machine.
| Patent | Filing date | Published date | Name | Description |
|---|---|---|---|---|
| US 1,398,068 | 16-03-1917 | 22-11-1921 | Fred H. Doerr | Computing Machine |
| US 1,517,412 | 28-08-1920 | 02-12-1924 | Fred H. Doerr, Todd Protectograph Company, Inc. | Zero-setting Mechanism |
| US 1,560,381 | 12-11-1923 | 03-11-1925 | Alton L. Gray, Todd Company, Inc. | Locking Mechanism |
| US 1,787,259 | 15-01-1927 | 30-12-1930 | Walter B. Payne, Raymond E. Bohrer, William Fuhlborn, Todd Company Inc. | Input register |
|
AMCO also made an adding-listing machine, named the Century Adding Machine, but it must have been unsuccessful as I have not found any proof of its physical existence. Its patents were sold to the Bleick syndicate, presumably in 1922, and it is unclear if this machine re-emerged under a different name. Below are the patents for this machine. | ||||
| Patent | Filing date | Published date | Name | Description |
| US 1,556,756 | 17-11-1919 | 13-10-1925 | Edgar Maynard Camp; Bleick Syndicate | Adding Machine |
| US 1,358,427 | 10-12-1919 | 09-11-1920 | Andrew Ekman; Accounting Machine Company | Carry mechanism |
| US 1,522,874 | 14-11-1921 | 13-01-1925 | Andrew Ekman; Bleick Syndicate | Ribbon mechanism |
| US 1,591,664 | 14-11-1921 | 06-07-1926 | Andrew Ekman; Bleick Syndicate | Adding machine |
| US 1,625,801 | 14-11-1921 | 26-04-1927 | Andrew Ekman; Bleick Syndicate | Dash pot |
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