Thales Model A
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This is the Thales model A. It is a small calculator using a standard Odhner pinwheel design. It was first made in 1911, and as this particular machine has the fairly low serial number 3834 it was probably made no more than two or three years later.
The calculator is mounted on a wooden base, and comes with a curved wooden cover that can be locked onto the base. The lock of this case has been replaced by the previous owner. The machine is in good working condition, but is missing the bell on the left side of the carriage, and the small locking bar that is used to keep the carriage fixed during transport.
The machine is quite simple, without the various safety mechanisms that later versions have. It has a 9-digit input, without display register. The carriage contains a 13-digit main register, and an 8-digit revolution counter without a carry mechanism.
Here are some pictures of the mechanism. The mechanism is very simple, with very few safety mechanisms or interlocks. Many parts are stamped with the digits 34, the last two digits of the serial number 3834. In later versions of the model A the carriage would have a spring to allow it to shift easily in one direction, but it is unclear whether this early model once had such a spring or if it was introduced later.
Here is a video where I demonstrate how to use the Thales model A.
In this video I explain the pinwheel mechanism of the Thales A.
The Thales KA has a 9-digit register at the front. It has an 8-column full keyboard on top. The keys are tilted buttons, hinged at the left and sticking up on the right. When you press a button, it is pushed down flat, and it will also force all the buttons of the smaller digits lower down the same column to be pushed in as well. There is a pushbar to the left of the keyboard with which you can reset the keys so that they all stick up again, which is useful for correcting a mistake.
On the right side of the machine is a large lever. Pushing down this lever will cause the entered number to be added to the register. It normally also resets the keyboard so that you can enter the next number to be added.
There is a small switch to the right of the keyboard. Flipping this switch changes the machine to subtraction mode, which means that pushing down the large lever will subtract the entered number from the register. There is another switch at the top right of the machine, the Repeat switch. This controls whether the keyboard is automatically reset after each addition or subtraction. Not resetting allows you to add/subtract the same number several times in quick succession, thereby multiplying it by a small number. It is not possible to do full multiplication because there is no provision for shifting the input or register relative to each other.
The small lever on the left hand side clears the register. Earlier versions of the KA had a clearing wheel at the front right instead. They also had the option of attaching the large lever to the left hand side, and optionally had a 2-digit counter at the back which counted the number of additions/subtractions made.
My Thales KA has serial number 39507 which makes it one of the later ones, probably about 1960-1961. It does however still have a metal case, whereas even later versions used a grey plastic case.
This machine has an unusual mechanism. When the large lever is pushed down, the whole register is moved backwards, passing underneath the keyboard to the back. Releasing the lever returns the register to the front to become visible again. Every key has a small pin attached. Pushing down a key causes its pin to move into the path of the corresponding wheel of the register. If you press for example a 7, then all the keys 1 to 7 in that column are flipped, which puts 7 pins into the path of that register wheel so that 7 will be added to the wheel when it passes underneath. When the register moves forward again it does so a few millimeters further down so that it bypasses the pins. On that return stroke the carries are performed instead by pins that have been flipped up from below.
When the switch for subtraction is set, the whole keyboard is move slightly to the left. This causes the pins of the unpressed keys to lie in the register's path instead. This therefore adds the complement of the entered digits. There are also 9 pins in the column to the left of the keyboard to handle the ninth register wheel, and one extra pin in the first column to make it the tens complement.
When I got my machine, the Repeat switch did not work, and was such that it is always on. The keyboard had to be reset manually every time. It turned out that the machine had been taken apart and reassembled incorrectly. The switch connects via some rods to an axle at the front, and that axle was in an incorrect orientation so that it was unable to engage with the keyboard properly. Simply removing the axle at the rear of the keyboard allowed me to remove the keyboard and then reassemble it correctly.
The instructions are on a small sheet of paper (149mm×210mm).
It had a one-year guarantee (149mm×207mm).
Here is a video where I demonstrate my Thales KA.
In 1911 Max Müller acquired the failing calculator company "Haberer & Co" (Ludwig Haberer), based in Landau, Germany, and together with Emil Schubert used it to found the new company Thaleswerk, Rechenmaschinen-Spezialwerk GmbH. Emil Schubert, who had worked at Triumphator, became the chief engineer and Max Müller was the salesman. Thales released two simple pinwheel calculator models, A and B, which differed only in the number of digits in the registers.
In 1913 the company moved 40km South to Rastatt, a town next to the Rhine where the river forms the border with France. This allowed them to expand production to models C and D, which were similar to A and B but with a carry mechanism in the counter register. They later made variants of these machines with extra functionality, such as an input display register, back transfer, or a second register. There was also a version with fewer digits (model M), a version with more digits (G), and a double machine called GEO for calculations with coordinates.
An adding-listing machine was developed by Arthur Kaddatz in 1924, manufactured by Thaleswerke. It is possible that Thaleswerke was essentially hired to produce this machine under license, as it was never branded as a Thales machine but sold under the name Tasma. In about 1930 manufacturing of the Tasma was moved to Walther instead.
In 1936 Emil Schubert was forced to leave the company due to the rise of Nazi fascism. He managed to found his own company, Schubert & Co KG, in Rastatt a year later.
Thales continued making these pinwheel models after the war. In around 1953, Thales came out with a completely different design. This was not a pinwheel calculator, but a simple adding machine of a unique design. It was called the model KA, where KA stands for Klein-Addiermashine, small adding machine. It was produced until around 1963. A version was made for handling British currency which was sold under the name Figaro, there was an improved model called the KR which allowed for multiplication too, and even variants that were driven by an electric motor, either with the motor bolted onto the back or with it built in. From 1961 till 1965 Thales made a listing adder called the model 149.
The pinwheel models that Thales produced are listed in this table:
|A, AE, AR, AER
|From about 1930 changed to 10×8×13
|C, CE, CR, CER (1938), CES
|D, DE, DR, DER
|M, MZ, ME, MEZ, MER
|Later changed to 6×6×10
The letters in the model name variants have the following meanings:
|Input display register
|Carry in counter
|Implicit in models C, D
|Model C only?
In the UK and France these pinwheel machines were rebranded as Muldivo.
Gebrauchs-Anweisung für die "Thales" Rechenmaschine (PDF, 7.78 MB or archive.org)
24 page booklet
131mm × 196mm
This is the German manual for the model A. The drawing shows the earliest version of the machine which has wingnuts for clearing the registers. In 1920 these were replaced by small cranks, so this booklet was printed between 1911 and 1920.
Instructions pour l'emploi de la machine à calculer universelle "Thalès" (PDF, 13.7 MB or archive.org)
48 page booklet
151mm × 210mm
This is the French manual for the model AE. The drawing shows the version of the machine which has small cranks for clearing the registers, but the pictures of other models at the back of the booklet includes some with the next version, wingnuts that need only a half turn. This suggests that this booklet was printed in about 1930. Inside the back cover is a fold-out page with a labelled diagram of the machine.
In online archives of newspapers and magazines I have found a few advertisements and articles for Thales calculators.
Emil Schubert has many patents for the pinwheel machines he developed at Thaleswerke.
|Automatic reversal of direction
|Input display register. See also: GB 278,642.
|Input clearing mechanism
|Separate summation register (Model CES)
|Separate summation register (Model CES)
Here is the patent for the Tasma adding-listing machine.
|Firma Thaleswerk m.b.H (Arthur Kaddatz)
|Tasma adding-listing machine See also: US 1,593,799.
I have not found the original patent for the Thales KA, only a later one that describes the changes needed for non-decimal calculations such as British currency (sold as Figaro). It mentions the application number of the original patent, but this is crossed out so it may be that the application was unsuccessful.
|DE 1,802,903 U
|Thaleswerk G.m.b.H Rechenmaschinenfabrik
|Thales KA for non-decimal calculations
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