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Walther

Walther RMKZ
   Video
Walther WSR-160
   Video
History
Models
Books and Manuals
Promotional material
Articles and Advertisements
Patents
Links

Walther RMKZ

The Walther RMKZ is a calculator based on the classic Odhner pinwheel calculator design. My machine is in fairly good working condition. It does however have some damage, namely the part of the body holding the crank handle has cracked and one of the input display digit wheels is damaged slightly. The latter is purely cosmetic damage, the former does not interfere with the working of the machine.

At some point, possibly in the 1950s, it has been refurbished, and its original black paint was changed to a metallic hammer grey enamel. This enamel is chipped at the left edge of the carriage, but otherwise looks very good.

Its serial number is 10,890. Until about 1933 the input display registers of the RMK and RMKZ were in a module attached on top of the machine. In 1936 the serial numbers were above 20,000 (I think the numbering was restarted from that point). So my machine is therefore probably from between 1933 and 1936.

The rear panel has stamped in it the writing "CARL WALTHER, Abt. Rechenmaschinen, ZELLA-MEHLIS Thün".

Video

In this video I demonstrate how to do addition, subtraction, multiplication, and division.

Walther WSR-160

The Walther WSR-160 is the last model pinwheel calculator that Walther made. It was in production from about 1956 until 1968 or possibly 1971. It was also sold using other brand names, for example in Great Britain it was called the Muldivo Mentor. My machine is in working condition, although one of the input pins is hard to move.

Compared to the RMKZ there are several improvements in its design:

• The controls of the machine are all on the right hand side, so it can be operated using only one hand.
• The input pins remain stationary when the crank is turned.
• The clearing lever on the carriage by default clears both registers in the carriage (the revolution counter and the output register). To clear only one of the registers, move the sliding switch at the front right of the carriage to the left or right before using the clearing lever. The switch returns to the middle automatically when the clearing lever is used, or when the tiny metal latch at the front of the carriage is pushed upwards.
• The carriage can automatically move left to the units position when the clearing lever is used. This behaviour can be enabled or disabled with the switch on the carriage underneath the clearing lever.
• It has a back transfer mechanism, i.e. the value in the output register can be transferred to the input pins. Pull down the red lever next to the input register, which then remains locked down. This clears the input, and prepares the transfer mechanism. If you then clear the output register, its value gets transferred to the input. If the transfer lever has been pressed down accidentally, it can be released using the small white button behind and below the crank.
• The carriage can easily be removed for cleaning and oiling by pulling the metal latch that is accessible through a hole in the base plate on the underside of the machine.

Its serial number is 194,935 which means it was probably made in around 1967. The label in the back says Walther Büromaschinen G.m.b.H., Niederstotzingen/Wttbg., with the model and serial number. The serial number can also be found on the carriage.

Video

In this video I demonstrate how it works, including two methods of division.

History

Carl Walther GmbH is a German company better known for making weapons such as the Walther PPK that James Bond is so fond of. Carl Walther founded his company in 1886, making hunting rifles and selling them in his gunshop in Zella-Mehlis. From 1908 the company started making pistols instead of rifles. Carl died in 1915, and from then on the company was run by one of his sons, Fritz Walther.

The treaty of Versailles at the end of World War I severely restricted arms manufacturing and trade, so Walther had to diversify. In 1924 they started producing calculators. This came about in cooperation with Mercedes, who had a factory in Suhl just a few kilometres away from Zella Mehlis. Mercedes made pinwheel calculators under the Melitta brand, but wanted to focus their production on the Mercedes-Euklid type of machine. Walther then took over the production of the Melitta calculators, and were allowed to sell them under the Walther brand name, too. Soon they started developing them further, including electrically driven models. In 1931 they also manufactured the Tasma, an adding-listing machine with a full keyboard which had until then been made by Thales, though it seems this was never sold under the Walther brand name.

The Walther factory was destroyed in the second world war, no doubt due to its arms manufacturing activities. Zella-Mehlis was in the Soviet-occupied region of Germany, and Fritz Walther decided it was better to rebuild the company and factory in the Allied-occupied region. He and some of his engineers settled in Heidenhelm, where they set up a basic workshop. In about 1947 they were ready to set up a factory to manufacture calculators in the nearby town of Gerstetten and then another in Niederstotzingen. A few years later in 1953 the company had grown enough to restart the arms manufacturing in a new factory Ulm, at which point the calculator business was split off as a separate company, Walther Büromaschinen GmbH.

From 1952 they also started making electrically driven, 10-key adding-listing machines, such as the Walther SR-12. This machine was also sold in the USA by Felt & Tarrant under the name Comptograph 202. Fritz Walther died in December 1966, and was succeeded by his son Karl-Heinz Walther. By the late 1960s the WSR-160 was the only remaining pinwheel model still in production, but its end date is somewhat uncertain (some sources say 1968, others 1971). The other desk calculators became more electronic, and remained in production until the mid 1970s. The Walther Büromaschinen company went public and then became Walther Electronic AG, and later specialised in scanning and sorting machines under the name Walther Data GmbH.

Models

The data for the table below is mostly taken from the two sites Rechnerlexikon and Rechenmaschinen Illustrated. Unfortunately, their information sometimes contradicts each other, and then I have chosen whichever data seems more plausible.

Walther made many models of pinwheel calculators, and this list is possably not complete. The letters in the model name have the following meanings:
M - has a larger input register (10 instead of 6 digits).
K - has a display showing the input number
Z - has a carry mechanism in the revolution counter and a subtraction switch.
D - has automatic division
E - electrically powered
W - back transfer mechanism (copies accumulator into input).

Books and Manuals

Montage-Anleitung für Walther Rechenmaschinen Mod. WSR 110/160    (PDF, 8.85 MB or archive.org)
Metallwarenfabrik J. A. Heinrich Dankers
1960
18 page booklet
148mm × 205mm × 1mm

This booklet shows how to fully disassemble the Walther WSR 110/160, so that all the parts can be thoroughly cleaned.

Promotional material

Walther SR12 leaflet
1952-1962
3-part folded leaflet
Folded 107mm × 103m, unfolded 295mm × 103mm

This is a leaflet for the Walther SR12 adding machine, though it also mentions simpler hand-driven model S9.

Walther WSR leaflet
1952-1957
2-part folded leaflet
Folded 211mm × 151m, unfolded 422mm × 151mm

This is a leaflet for the Walther WSR 11 and WSR 16 pinwheel calculators.

Walther magnifying glass

This is a small magnifying glass inside a leather cover. The cover has the Walther logo embossed on one side, and a pictre of the model EMKD on the other.

Walther ashtray

This is a plastic ashtray, with the Walther logo in the centre.

Walther matchbooks

This is a set of 10 identical matchbooks with wooden matches. It has the Walther logo, the motto "Wir machen Rechnen einfach" (We make calculation easy), and the text "WALTHER liefert Rechenmaschinen, Addiermaschinen, Multiplikationsautomaten, Organisationsmachinen, Datenerfassungsgeräte." (Walther supplies calculators, adding machines, multiplication machines, organisation machines, data collection devices).

Articles and Advertisements

Here are some advertisements I found in online archives of magazines and newspapers.

Here are some articles I found in online archives.

Patents

Here are just a few of the relevant patents.

Links

• Walther, the company's website contains a page with history of the company.
• Wikipedia entry for the Carl Walther, the founder of the Walther company.
• Rechnerlexikon has a page about Walther and separate pages for many models auch as the RMKZ 16, WSR 160, and others. The Walther material page includes lists of serial numbers.
• Rechenmaschinen Illustrated has pictures and details of many Walther models.
• John Wolff's Web Museum has a page about Walther.
• Rechenkasten has various pages about Walther, though mostly about the electronic calculators.
• Detlev Bölter has in his collection an EMKD and RKZ.
• Rechnen ohne Strom has several Walther pinwheel machines.
• XNumber has the article The Walther Company, Historic Recollections by Ray Mackay.
• Christian-M. Hamann has an RK, a WSR-160, as well as a Diwa-32.
• Vintage Calculators has a Muldivo Mentor with a nice explanation of the stationary input pins.
• Cris vande Velde has a several Walther machines, such as RMK, EMKD, SMKZ, DMKZ, and WSR-110/160.

© Copyright 2015-2024 Jaap Scherphuis, mechcalc a t jaapsch d o t net.