Jaap's Mechanical Calculators Page

Addo

Addo Model 2 Addo-X 341 Addo-X 351



Addo Model 2
   Video
Addo-X 341
   Video
Addo-X 351
History
Models
Manuals
Promotional material
Articles
Advertisements
Patents
Links

Addo Model 2

The Addo Model 2 is an adding machine somewhat reminiscent of the Rapid Computer or Comptator. The machine has 9 sliding rods, which allow you to enter any number of up to 9 digits. Further forward is a window with a 9-digit register. The front plate is painted black, and has the text "Aktiebolaget Addo, Malmö, Patent, Mod. 2" in gold letters. It is mounted on a wedge-shaped wooden base that has a compartment for a stylus.

Each sliding rod has notches marked 1 to 9. For each digit of the number you want to enter, you put the stylus in the notch of the correct value, and slide it downwards as far as possible. When all the digits have been entered, the number can be read back in the lowest row of notches. Each rod has a little knob at the top allowing you to make corrections by pulling it back up.

To add the entered number to the register, pull the lever on the right towards you and then allow it to return to its original position. This action resets the input rods, and finalizes the addition by performing any carry operations that were necessary (the digit values were already added when the number was entered).

The smaller lever resets the register to zero. Unfortunately this lever can only be used while the addition lever is also pulled forward. This makes the machine rather awkward to use.

Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2

It has serial number 2041, which is stamped into the far side. This is the lowest serial number that I have found anywhere online, so it was probably made in 1920 or 1921, the start of its production run. The numbering may have started at 2000. Later machines have a register with some sets of red number wheels to mark off the groups of three digits. Still later machines are mounted on a metal base instead of a wooden one.
Most adding machines of a similar type perform carries simultaneously, which can make it hard to enter a number when multiple carries occur. In the Addo 2 the carries are performed ripple fashion, triggered by a rotating drum with a helical arrangement of pins.

Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2
Addo Model 2

The rubber feet have deteriorated, becoming squashed, hard and brittle, but they remain fairly intact. The rubber spacers between the base and the machine were mostly broken so I have replaced them.


Video




Addo-X 341E

The Addo-X 341E is an electrically driven adding machine. The keyboard has a 10-key number pad with function keys arranged symmetrically around it. There are several variants with regards to the paper feeding mechanism, the most common of which is a simple paper roll. The version here has a wide typewriter style carriage for paper sheets, but also has a spool attached for paper rolls.

The machine allows an input of 10-digit numbers, and has an 11-digit register that handles negative values. To the right of the keyboard is a large plus button which will cause the current input to be printed and added to the main register, after which the input is cleared. The large minus button to the left of the keyboard does the same except that it subtracts and prints the number with a minus sign after it.

The two red buttons at the top right are the Sub-Total and Total buttons. These print the current value of the register in red with a square or asterisk symbol after it. If the (sub)total is negative, there is a A printed after it as well, meaning Credit. In the Total was requested, the register is cleared.

The two red buttons at the top left are used in multiplication, or rather, repeated addition. These two buttons act the same as the minus and plus buttons, except that the input is not cleared. Holding the button down with therefore add/subtract the input repeatedly until the button is released. There is a small switch to the left of these buttons, and if the switch is in the upper position then the Step-O-Matic is activated. This will append a zero to the input whenever one of the multiply buttons is released. An experienced operator can use this to speed up multiplications.

There is a Non-Add button located away from the symmetrical keyboard, and pressing this will print and clear the input without affecting the current totals register, wihch is useful for order numbers or dates.

Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341

It has serial number 615,026. The paper feeding mechanism is easily removed by taking out four screws. In that respect it has a similarly modular design as the Burroughs Portable.

Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341
Addo-X 341

Video

A short demonstration of the machine.




Addo-X 351

The Addo-X 351 adding machine is the successor to the model 341 above. It has the exact same functionality, but has a somewhat improved mechanism and an entirely new case. The buttons are the same, with one extra button that opens the top of the case to give access to the ink ribbon.

Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351

It has serial number 426,251. The case is extremely easy to remove. Press the button to flip open the top section. Next to each ink ribbon spool is a small clip, and after they have been pushed aside, the whole upper case can be lifted off.

Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351
Addo-X 351

History

Aktiebolaget Addo was founded in Malmö in 1918 by Hugo Agrell. He had been a salesman, mostly of American and German calculators. When the first world war made the import of these machines more difficult, he had the idea to make Swedish adding machines. His cousin Oscar Printz was a mechanical engineer, and together they started the Addo company. At first they made machines similar to the Comptator, but then improved on it and added a printing mechanism. From about 1927 they made full keyboard adding listing machines of their own design, and from about 1935 they made machines with 10-key numeric input, named Addo-X.

In 1966 Addo was bought by Facit-Odhner. Facit was slow to merge with Addo, so the two production lines ran simutaneously for a while, essentially competing with each other. This became more problematic when cheap electronics rapidly changed the market for calculators. Addo/Facit was unable to adapt quickly enough, and in 1973 was sold off to Electrolux. Production of the last Addo adding machines ended a year later.

Models

Only models made by Addo will be listed here. Not included are the adding machines made by the daughter company Dixma from 1939 onwards. These were sold under the brand name DIXI and had a Dalton-style keyboard. Also not listed here are the Multo pinwheel calculators.

Addo adders 1918-1926

Addo started out making a relatively simple adder that was similar to the Comptator, an adder based on the Rapid Computer. The first four Addo models were based on this, all using sliders that the user moves with a stylus.

ModelYearDigitsDescription
Addo 11918-1920?9Like Comptator, metallic.
Addo 21920-192610On a wooden or later metal base; black finish.
Addo 31920?-192610As Addo 2, but for British currency.
Addo 41924-192610As Addo 2, with printing mechanism.
Addo 51924-192610As Addo 3, with printing mechanism. It is not clear if any were made.

Below is a list of the serial numbers for models 2-4 that I have found online, with descriptions.

Serial NumberDescription
2041Wooden base, black number wheels, main lever attached with screw
2499, 2508, ????Wooden base, black and red number wheels, main lever attached with nut
2772, 2797, 3164, 3656, 4176, ????Metal base painted black, silver and copper rods
3606 3875Model 4 (printing), wood paint finish

Addo machines, 1926-1936/1958*

From about 1927 Addo made full keyboard adding machines, using model numbers starting from 6. Most were available in both manual and electric versions, the latter having an E appended to the model name. The upper case was made from Trolit, a plastic similar to Bakelite, but slightly more brittle.

ModelDigitsDescription
Addo 69×9
Addo 79×10
Addo 88×8
Addo 99×9British currency, up to £999,999 19s 11d.
Addo 109×10British currency
Addo 2069×9Like Addo 6 but with extra memory register. Probably first made in about 1940
Addo 2079×10Like Addo 7 but with extra memory register. Probably first made in about 1940
Addo 3079×10Like Addo 7 but can handle negative totals. Probably first made in about 1940

*) Production of these models was greatly reduced when the new 10-key machines were introduced in 1936. Nevertheless they continued to be produced and improved, taking on some characteristics of the later series. The casing was changed to metal, the keys changed from round to square. By the 1940s extra functionality from the later machines was incorporated, and these were given model numbers with 200 (extra register) or 300 (negative totals) added to the base model number. The main reason for the long production of these models is that the full keyboard is more easily adapted for use with British currency and other non-decimal calculations. These later productions mostly took place in Britain.

Addo-X series 20, 1936-1950

All later models used a 10-key numerical keyboard and these were named Addo-X, where presumably the X is the Roman numeral for 10. These variants were given base model numbers starting at 20. Again there were also versions with an electric motor which had an E appended to their model name. In around 1940 variants with negative totals functionality were introduced.

ModelDigitsDescription
Addo-X 209×9
Addo-X 2110×11
Addo-X 228×8
Addo-X 239×10
Addo-X 309×9These seem to be simplified versions of the series 20 that have no subtraction.
Addo-X 347×7
Addo-X 32110×11Like Addo-X 21 but can handle negative totals

Addo-X series 40, 1950-1962

In around 1950 the series 40 was introduced. This had a different styling, with a metallic green or grey case instead of black. The keyboard was symmetrically arranged (at least on the electric models), with a large subtraction key on the left of the number keys mirroring the large addition key on the right. There was not just a repeat addition key for multiplication but also a repeat subtraction key. Also new was the Step-O-Matic functionality, which could automatically append a zero when a repeat addition/subtraction key was released, making multiplications faster.

Once again the last digit of the model number indicates the register capacity, and extra functionality was indicated by prefixing one or two digits to the base model number. Most of them are listed in the table below. The various paper feed mechanisms that could be attached were denoted by appending a hyphen and two-digit number to the model.

ModelDigitsDescription
Addo-X 409×9These are the base models, which have a register that cannot handle negative totals, and often manual rather than electric
Addo-X 4110×11
Addo-X 428×8
Addo-X 24110×11This has an extra totaliser register for adding together the totals from the main register. Neither register handles negative totals.
Addo-X 2428×8
Addo-X 34110×11The main register can handle negative totals, with an indicator window above the 9-key that shows the sign.
Addo-X 3458×9
Addo-X 44110×11This has an independent extra register. Neither register handles negative totals.
Addo-X 54110×11This has an extra totaliser register for adding together the totals from the main register. Both registers handle negative totals.
Addo-X 74110×11This has an independent extra register. Both registers handle negative totals.
Addo-X 234110×11As 341 but with multiplier keys implementing shortcut multiplication.
Addo-X 334110×11As 341 but with multiplier keys, moving decimal point
Addo-X 354110×11As 541 but with multiplier keys, moving decimal point
Addo-X 434110×11As 341 but with automatic division
Addo-X 454110×11As 541 but with automatic division

There are also versions with larger model numbers, e.g. 5341, 7341, 8341, but these are more bookkeeping machines than mere adding machines. The last one is even a combination of a 341 adding machine with a complete typewriter. Models 47 and 347 are designed for calculating with British currency.

Addo-X series 50, 1962-1974

In around 1962 all the machines were redesigned to become the series 50. The light grey plastic case was desiged to be very easy to remove. Functionally this series was very similar to the series 40. The most common models are listed below. All these models were electrically driven, though one manual model was still available which was given the anachronistic model number 331.

ModelDigitsDescription
Addo-X 1528×8Base electric model, register without negative totals.
Addo-X 1549×10Base electric model, register with negative totals.
Addo-X 35110×11Negative totals, step-o-matic,
Addo-X 35312×13
Addo-X 3558×9
Addo-X 65312×13Extra totaliser with negative totals.
Addo-X 235312×13Negative totals, multiplier keys
Addo-X 335312×13
Addo-X 365312×13Extra totals register with negative totals, multiplier keys.
Addo-X 435312×13
Addo-X 465312×13Extra totals register with negative totals, multiplier keys, Automatic division

Model 356 was designed for calculating with British currency.
During this time Addo was also making data processing machines, producing variants of the adding machines as data capture devices, which then stored the input on punched paper tape or punch cards.


Manuals

Wie Man Rechnet Gebrauchsanweisung fur die ADDO-X Serie 40     (PDF, 8.35 MB or archive.org)
ADDO, Malmö, Schweden
1955
15 page stapled booklet
147mm × 209mm

This is the German manual for the Addo-X models series 40. The back page lists all the models 40E, 41E, 42E, 345E, 341E, 40, 41, 42, 341, and 241E. It briefly describes addition, subtraction, negative totals, multiplication, with calculation exercises.

Wie man rechnet
Wie man rechnet
Wie man rechnet
Wie man rechnet
Wie man rechnet

ADDO-X Gebrauchsanweisung     (PDF, 3.49 MB or archive.org)
ADDO, Malmö, Sweden
1957?
6 page trifold leaflet
149mm × 212mm folded, 444mm × 212mm unfolded

This is the German instruction leaflet for the Addo-X models 40E, 41E and 341E. It has no copyright date, but these models were introduced in 1950, and the code on the last page suggests it was printed in 1957.

Addo-X 40E 41E 341E manual
Addo-X 40E 41E 341E manual
Addo-X 40E 41E 341E manual
Addo-X 40E 41E 341E manual
Addo-X 40E 41E 341E manual

Addo-X model 154     (PDF, 7.12 MB or archive.org)
ADDO, Malmö, Sweden
1962?
20 page stapled booklet
150mm × 211mm

This is the Dutch instruction manual for the Addo-X model 154. It has no copyright date, but this model was introduced in 1962.

Addo-X 154 Manual
Addo-X 154 Manual
Addo-X 154 Manual
Addo-X 154 Manual
Addo-X 154 Manual
Addo-X 154 Manual

Handleiding voor de Addo-X schrijvende rekenmachines modellen 3653 en 3353.     (PDF, 9.18 MB or archive.org)
ADDO, Malmö, Sweden
1965-1970?
30 page stapled booklet
150mm × 211mm

This is the Dutch instruction manual for the Addo models 3653 and 3353. It has no copyright date, but this model was in production from 1965 till 1970. The style of the manual, in particular the yellow sidebar with the illustrations, seems to have been influenced by the Facit manuals so presumably this was made after Facit acquired Addo in 1966.

Addo-X 3653 Manual
Addo-X 3653 Manual
Addo-X 3653 Manual
Addo-X 3653 Manual
Addo-X 3653 Manual
Addo-X 3653 Manual
Addo-X 3653 Manual
Addo-X 3653 Manual

Addo serviceboek 40-serie
A.B. Addo
1958-1962
Binder with many pages divided in 35 sections
265mm × 316mm × 60mm

This is the Dutch version of the service manual for the series 40 Addo-X machines. The pages are all dated, starting from September 1958. As improvements and other changes were made to the machines, new pages were printed and inserted which were added to or replaced the existing pages to keep the manual up to date.

Addo-X 40 Service Manual
Addo-X 40 Service Manual
Addo-X 40 Service Manual
Addo-X 40 Service Manual
Addo-X 40 Service Manual
Addo-X 40 Service Manual
Addo-X 40 Service Manual
Addo-X 40 Service Manual
Addo-X 40 Service Manual
Addo-X 40 Service Manual

Spare parts catalogue Addo-X models 353, 351, 355.
A.B. Addo
1961-1962
SA 104
15 page softcover book
213mm × 298mm

This is the 1961 spare parts catalogue for models 351, 353, and 355. It shows exploded diagrams of the various sections of the adding machine, with all parts numbers. The book as originally printed was only for model 353, but modified afterwards with additional information about models 351 and 355. A loose supplemental page was inserted for models 152 and 154, which is dated 1962.

Parts listing 1961
Parts listing 1961
Parts listing 1961
Parts listing 1961
Parts listing 1961
Parts listing 1961

Spare parts catalogue Addo-X models 152, 154, 351, 353, 355, and 2353.
A.B. Addo
1963
SA 164
32 page softcover book
213mm × 298mm

This is the 1963 spare parts catalogue for models 152, 154, 351, 353, 355, and 2353. It shows exploded diagrams of the various sections of the adding machine on the right hand page, with all corresponding parts numbers on the left hand page. This is the updated version of the 1961 parts catalogue above.

Parts listing 1961
Parts listing 1961
Parts listing 1961
Parts listing 1961
Parts listing 1961
Parts listing 1961

Promotional material

Addo-X, die Addiermaschine unserer Zeit
A.B. Addo, Schuster & Walther
1950?
One-sided flyer
202mm × 294mm

This German advertising flyer describes the Addo-X Series 40. At the bottom the address of a Walther & Schuster branch in Nürnberg has been added.

Addo-X Series 40 Flyer
Addo-X Series 40 Flyer

Articles

Here are various articles about Addo and its adding machines.

1921 Orga-Handbuch
1925 Ernst Martin
1930 Organisations-Lexikon
1941-10-18 International Commerce
1941-12 Office Appliances
1949 Efficiency op kantoor - addo
1949-12 Administrative Management
1953-08 Administrative Management
1954-08 Administrative Management
1954-10-16 The Economist
1957-08 Administrative Management
1958-09 Office Appliances
1958-11 The Office
1959-02 Office Appliances
1959-09 The Office
1959-10 Office Products Dealer
1960-02 Best's Review
1960-04 Business Education World 1
1960-04 Business Education World 2
1960-04 The Office
1961-03 Business Education World
1961-06 Industrial Design
1961-08 Office Products
1962-03 Business Education World
1962-04 The Office
1963-03 Business Education World
1963-08 The Office
1964-03 Business Education World
1965 Business Week
1965-03 Business Education World
1965-10-16 National Post (Toronto Ontario)
1966-03 Business Education World
1967-03 Business Education World 3
1968-03 Business Education World 2
1969-09 International Business Equipment
1969-11-14 The Kingston Daily Freeman (Kingston New York)
1970-12 The Office
1973-03 Case and Comment

Advertisements

Here are various ads for Addo adding machines and calculators.

Addo 1919-1936

1919-12-05 Morgenavisen (Norway)
1927-10-19 Bergens tidende (Norway)
1928-08-24 Uusi Aura (Finland)
1928-12-28 Aftenposten (Norway)
1932-02-20 Kansan Työ (Finland)
1932-12-15 Uusi Aura (Finland)
1932-12-24 Karjala (Finland)
1932-12-24 Uusi Suomi (Finland)
1933-01-01 Karjala (Finland)
1933-12-24 Helsingin Sanomat (Finland)
1933-12-28 Hufvudstadsbladet (Finland)
1934-10-07 Suomen Sosialidemokraatti (Finland)
1934-12-01 Maaseudun Tulevaisuus (Finland)
1935-02-28 Karjala (Finland)
1936-01-05 Uusi Suomi (Finland)
1936-03-01 Pohjois Pohja (Finland)
1936-05-03 Uusi Suomi (Finland)
1936-06-03 Pohjolan Sanomat (Finland)
1949-05 Business
1949-06 Business
1949-12 Business
1950-03-11 The Economist

Addo-X series 20: 1936-1950

1936-12-10 Savon Suunta (Finland)
1936-12-31 Uusi Suomi (Finland)
1937-12-13 Hufvudstadsbladet (Finland)
1937-12-14 Kajaani (Finland)
1937-12-17 Hufvudstadsbladet (Finland)
1938-02-05 Sisä Suomi (Finland)
1938-04-07 Hufvudstadsbladet (Finland)
1938-04-20 Uusi Häme (Finland)
1938-10-31 Ajan Suunta (Finland)
1938-10-31 Hufvudstadsbladet (Finland)
1939-02-27 Hufvudstadsbladet (Finland)
1939-04-13 Turun Sanomat (Finland)
1939-05-26 Centraal blad voor Israelieten in Nederland
1939-07-29 The Vancouver (British Columbia Canada)
1939-11-12 De Maasbode
1940-06-03 Times Colonist (Victoria British Columbia Canada)
1941-12 Office Appliances 2
1946-04-21 Hufvudstadsbladet (Finland)
1949-05 Office Appliances
1949-08 Office Appliances
1949-09-01 Times Colonist (Victoria British Columbia Canada)
1950-04-25 The Montreal Daily Star (Montreal Quebec Canada)

Addo-X series 40: 1950-1964

1950-11 Office Appliances
1950-12 Office Appliances
1951-12 The Office
1952-09-30 The Vancouver News Herald (British Columbia Canada)
1952-11 The Office
1952-11-11 The Gazette (Montreal Quebec Canada)
1952-12-16 The Gazette (Montreal Quebec Canada)
1953-03 The Office
1953-05 The Office
1953-08 Business Management
1953-08 The Office
1953-10 Business Management
1953-11 Business Management
1953-12 Business Management
1954-01 The Office
1954-03 The Office
1954-05 The Office
1954-07 Business Management
1954-07-20 The Cincinnati Enquirer (Ohio)
1954-07-29 Daily Kennebec Journal (Augusta Maine)
1954-09-14 Arizona Daily Star (Tucson Arizona)
1954-10 Business Management
1954-10-05 The Gazette (Montreal Quebec Canada)
1955-03 The Independent Banker
1955-04-09 Algemeen Handelsblad
1955-04-16 Het vaderland
1955-10-26 The Gazette (Montreal Quebec Canada)
1955-11-12 Algemeen Handelsblad
1956-02 Administrative Management
1956-03-13 The Times (Munster Indiana)
1956-05 Business Management
1956-12-08 Algemeen Handelsblad
1957-01 Administrative Management
1957-05 The Office
1957-12 Office Appliances
1957-12 The Office
1957-12-18 The Nottingham Evening Post (UK)
1958-01 Display World
1958-01 Office Products Dealer
1958-01 The Journal of Accountancy
1958-12 The Office
1959-02 Office Appliances 2
1959-03 The American-Scandinavian Review
1959-06 Office Products Dealer
1959-09-29 Algemeen Handelsblad
1960-02 Nation's Business
1960-02 Office Appliances
1960-03 International Management Digest
1960-03-04 Electronics
1960-04 The Office 2
1960-05 Office Products Dealer
1960-06 International Management Digest
1960-08 Administrative Management
1960-08 International Management Digest
1960-08 Nation's Business
1960-09 International Management Digest
1960-09 The American-Scandinavian Review
1960-10 International Management Digest
1960-11 International Management Digest
1961-02 International Management Digest
1961-03 Administrative Management 1
1961-03 Administrative Management 2
1961-06 Office Products
1962-02 Business Management
1962-09 Business Management
1962-11 Business Management
1964-04 Business Automation
1964-10-10 National Post (Toronto Ontario)

Addo-X series 50: 1965-1973

1965-02-22 The Sydney Morning Herald (NSW)
1965-06 Administrative Management
1966-05 International Business Equipment
1966-12 International business automation
1967-04 The Office
1968-10 Administrative Management
1969-05 The Office
1970-02 Business South Africa
1970-11 Business Automation
1971-03 Administrative Management
1972-06 The Office
1972-11-27 The Burlington Free Press (Vermont)
1973-01 The Office
1973-03 The Office
1995 Josef Mueller-Brockmann, designer

Patents

Here are some of the patents or the Addo.

Addo 1-5
PatentFiling datePublish dateNameDescription
CH 78,43707-11-191716-07-1918Oscar Adolf Kristian PrintzAddo 1
See also: DE 313,835, DK 23,853 C, GB 112,455
SE 46,172 C130-04-191706-12-1919O. A. K. PrintzPrinting mechanism
See also: CH 79,357, DK 24,208 C, FR 489,771, GB 119,818
SE 54,147 C103-03-192028-03-1920Aktiebolaget Addo; O. A. K. PrintzAddo 2
 
Addo series 40+
PatentFiling datePublish dateNameDescription
CH 196,00916-03-193728-02-1938Aktiebolaget AddoRepeated addition mechanism
DE 913,83011-01-195221-06-1954Aktiebolaget Addo; Rolf Bertil AndrénRepeated addition mechanism
GB 756,77209-04-195412-09-1956Aktiebolaget AddoAdding machine improvements
DE 960,77108-01-195328-03-1957Aktiebolaget Addo; Thure Bernhard BogertPrinter carriage control
See also: CH 311,851
DE 1,097,18621-03-195612-01-1961Aktiebolaget Addo; Gösta Roland Holmström; Ove Gustaf KlingströmShockabsorber for input mechanism
See also: US 2,985,363
DE 1,145,39421-08-195614-03-1963Aktiebolaget Addo; John LydforsPrinting of multiplier digits
See also: US 3,016,188
DE 1,196,88329-11-195515-07-1965Aktiebolaget Addo; John LydforsMultiplier keys

Links


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