The pinwheel calculator as we know it was invented by Willgodt Theophil Odhner in around 1871. He was Swedish, but was working in Russia at the time for Ludvig Nobel, an oil magnate. Pinwheels had been used before in various forms, but never in large numbers because the precise engineering needed for manufacturing it is difficult. At almost the same time as Odhner in Russia, Frank Baldwin in the USA developed his own pinwheel calculator, but had difficulty selling it. Odhner made a few machines for Nobel, but it wasn't until 1890 that he had an improved design that was easier to make, and had set up a workshop in St. Petersburg to start producing them. The next year he also opened a production plant in Germany, but soon found it too difficult to oversee two such widely separated locations, and in 1892 the German plant was sold to Grimme, Natalis & Co, together with all its equipment, designs and patent licenses to manufacture the Odhner calculator for the German, Belgian and Swiss market.
The company Grimme, Natalis & Co was set up in November 1871 by Carl Grimme and Kaufmann A. Natalis. They were both sewing machine manufacturers who had decided to join forces. They also made other metal household apparatus, like ovens and heaters. In 1892 they began making pinwheel calculators in their plant in Braunschweig (Brunswick) using the brand name Brunsviga, which is the latin name for the town. Their first models, models A and B, were exact copies of the Odhner design, but with different numbers of digits. Soon their main engineer and co-director Franz Trinks devised several improvements (such as safety interlocks) and new designs. It took many years for the market for calculators to develop, but through extensive advertising using the slogan "Gehirn von Stahl" (Brains of Steel), demand grew. Eventually the demand for calculators even began to outgrow that of sewing machines.
While Brunsviga was the first Odhner clone, others would follow, especially after Odhner's patents expired. For example Triumph, Thales, Walther, Facit, Felix, Tiger, and many others. Willgodt Odhner died in 1905, and his sons took over the company. In the Russian revolution the Odhner company was confiscated, so the Odhner brothers returned to Sweden and started anew with the Original-Odhner company. In Russia the confiscated assets were used to produce the Felix brand of pinwheel calculators.
Meanwhile in Germany, Grimme Natalis & Co released a new series of models in 1925, the "Nova" series, which shared many interchangable parts for ease of production and repair. In 1927 the company incorporated the brand name into its company name, changing it to "Brunsviga-Maschinenwerke Grimme, Natalis & Co ", because by then it was producing calculators almost exclusively.
Competition between calculator companies was fierce, and in 1957 Brunsviga was bought by Olympia-Werke, a company that spun off from AEG and which made mostly typewriters. So from then on Brunsviga was once again merely a brand name. By 1963 the only mechanical calculator model they still produced was the Olympia-Brunsviga 13 RM, and in 1969 the last plant that still produced this machine, located in Spain, stopped too.
The "Nova" series of models is the culmination of almost all of Franz Trink's developments. The Nova II was the most popular, and a little over 10,000 Nova II machines were produced from 1925 till 1934. The Nova I had fewer digits, and the Nova III had an extra revolution counter without a carry mechanism. Franz Trinks retired soon after this, and the Brunsviga pinwheel machines remained essentially unchanged until the 1950s. It has many clever features:
One of the few innovations not used in the Nova are longer stationary input pins. Some earlier models had input pins that did not rotate with the pinwheels when the crank was turned, which allowed them to be longer and more comfortable to use. This mechanism must have been considered too expensive or complicated to continue with.
My machine has serial number 6T 2O 864. Note that is the letter O. The first thousand had the numbers 6T 2N xxx, the next thousand 6T 2O xxx, then 6T 2P xxx, after which they switched to a fully numerical format of 103,000 onwards.
The paint on the top cover is crackled, and flaking off quite badly. Mechanically it is in reasonable condition. It mostly works fine, if a little stiffly, except that clearing the input sometimes leaves one of the digits set to 1. The back transfer also sometimes doesn't quite fully push the input pins to the correct position.
Below is a video I made that demonstrates the Brunsviga Nova II.
Unlike all other calculators that Brunsviga developed, the Brunsviga 10 has a stepped drum mechanism. It is relatively light and compact, and was apparently cheaper to manufacture. It has a smaller capacity, so it was clearly aimed at the low end of the market. It was made from 1932 until about 1952, with a break during the Second World War. The serial number on my machine is 160,469, which dates it to around 1938.
The case is painted black, like all Brunsviga's of the time. It has a stand that folds out and lifts up the rear of the machine, tilting it towards the user. The stand is released and locked in place by a small metal catch on either side near the bottom.
There is a crank on the right hand side, angled forwards towards the operator and slightly upwards to compensate for the tilt when the stand is used. The crank can be turned clockwise for addition, and anti-clockwise for subtraction.
The 10-digit register sits in a carriage that is in the middle of the machine. On the right there is a clearing handle. Shifting the carriage to the right is done simply by pulling it rightwards using the fixed knob on top. It is springloaded, and pressing the metal lever near the crank shifts the carriage leftwards by one digit. There is an identical left-shift lever on the left side of the machine as well. There is a stationary metal plate covering the left end of the carriage which keeps the mechanism enclosed even when the carriage is at its furthest point. When the register overflows or underflows, a bell is struck.
At the back is a 5-digit counter. It has the same kind of mechanism as the Nova series. On the left is a clearing handle. When it is clear, a green indicator is visible to the left of the counter. In this state the direction of the next turn of the crank determines whether the counter keeps track of additions or of subtractions. If the crank is turned anti-clockwise for subtraction, the windows of the counter shift to the left, revealing a set of red complementary digits, and the counter is adjusted to show the that one subtraction has been performed. Below the counter is an indicator showing the currently active digit corresponding to the location of the carriage.
At the front of the machine is the input register. It has 6 movable pins, each in a slot with the digits 0 to 9 next to them. There is a row of windows which display the current input number directly, making it easier to check it is correct. Unlike most pinwheel machines, the input pins remain stationary when the crank is turned. At the front right is a button which clears the input.
The Brunsviga 10 uses a stepped drum mechanism. Like the drums of the Monroe calculator they are split into two parts, but unlike the Monroe they are actually arranged on two axles. One axle contains drums that can move the number wheels anything from 0 to 4 steps, depending on how much they have been shifted. The other axle contains the carry mechanism and another set of drums that turn the number wheels either 0 or 5 steps. The two axles move in concert and the drums for each wheel are arranged so that they act one after the other.
The input pins are part of large input wheels, and these wheels have a cam profile on either side. These profiles push aside levers by an exact amount depending on the input setting, and those levers are connected through shafts to similar levers that push aside the stepped drums the correct amount.
It was developed by Richard Haase who was working for Grimme Natalis, and patented by him in 1932. There have been some small changes in the design of the Brunsviga 10 during its production run. Until about 1935 they did not have the cover over the left part of the register, so the mechanism was exposed when the carriage was shifted. Almost 10,000 were made before the last years of the war interrupted production. When production restarted a few years after the war, they were slightly updated by being painted green instead of black, and they had no input clearing button, and no extra carriage shift lever on the left side.
The serial numbers used on the Brunsviga 10 were not a single consecutive set. The numbering was shared between all models, and in 1932 when this model started production they were at about 136,000, and in 1943 when production was paused they were at about 192,000. I presume number ranges of size 500 or 1000 were assigned to each model, with a new range assigned whenever the previous was used up. This means that the serial numbers give a good estimate of the total number of machines that Brunsviga produced, but they say little about any particular model. There may also be large gaps in the serial numbers which were used by other more popular models. When production restarted a few years after WW2 the serial numbers were about 230,000, and when it ended in 1952 the numbers were about 248,000.
In 1952 it was redesigned and this version was first named the B10 and then renamed the Nova 10. It had a more rounded green case, and internally the mechanism was changed to put all the stepped drums on a single axle. At the same time an electrically driven version was made which had one digit more capacity on all the registers, and it was called the model 11E. A few years later the model 11S was made too, which was a version of the electric model 11E with a full-sized keyboard.
Here is a video where I demonstrate the Brunsviga 10.
Here is a video showing the mechanism of the Brunsviga 10.
The Brunsviga 11E is a further development of the Brunsviga 10. It was made from about 1952 until at least 1959. The serial number on my machine is 11-16,672, which dates it to 1957.
The case is painted a metallic silvery gold and it has red keys. It has an 11-digit register to match its increased model number. The counter has 6 digits, and there are 7 digits of input set using a set of input pins. It is electrically driven, using the motor to perform the addition or subtraction, as well as to clear the register or counter. Shifting the carriage to the right is still manual however, though it moves left by a spring. There is a latch on the right hand side of the carriage that locks the carriage in place for transport.
The counter has the same mechanism as the Nova series for counting positive numbers in white, negative numbers in red, with the choice depending on the first operation after clearing the counter. There is a red underline marker under the current digit of the counter, where the current digit depends on the location of the carriage.
At the front-right of the machine is the input register. It has 7 movable pins, each in a slot with the digits 0 to 9 next to them. There is a row of windows which display the current input number directly, making it easier to check it is correct. Unlike most pinwheel machines, the input pins remain stationary when the crank is turned. At the front left are the various control buttons. The buttons marked I, II, and III will clear the input, counter, and register respectively. The left-arrow button shifts the carriage to the left, and the + and - buttons perform an addition or subtraction.
The selection switch next to the buttons has three options:
The Brunsviga 11E the same stepped drum mechanism as the Brunsviga 10, so see above for a more in depth description. It has a small electric motor at the back that is connected to the mechanism through a drive belt. There is no reversing gear, but for subtraction the polarity is switched so that the motor drives in reverse.
Here is a video where I demonstrate the Brunsviga 11E.
The Brunsviga 90 TA is full keyboard adding machine. The keyboard has 8 columns
of keys, where each column has nine keys numbered from 1 to 9. Below the
keyboard is an 8-digit input register which shows the number entered on
the keys. Above the keyboard is a 9-digit results register. The register
has a sliding window to allow negative numbers to be displayed through the
use of complementary digits.
Attached to the right side of the machine is a large lever which is pushed down and released to perform any one of the three operations adding, subtracting or clearing the register. There are four control keys at the right of the keyboard. The usage of these keys is explained later.
It has serial number 22-05788. About 8000 of these machines were made and sold between 1956 and 1959. Towards the end they mostly produced a variant called the 90 T, which was identical except that it did not have the input register. Presumably this was to reduce costs. The Brunsviga ADSUM was another variant designed for British currency.
The mechanism uses toothed racks. Pushing the lever downwards lifts the register up away from a set of toothed racks, and these racks are pulled forward. They move until they hit a blockage determined by the input key settings. When the lever is released, the register descends onto the racks, and the racks are returned to their original position, turning the register's number wheels in the process. Switching between addition and subtraction is done by shifting the whole register sideways, which connects the number wheels to the racks without the use of an intermediate wheel, making them turn in the opposite direction.
|Entering a number:||Enter the number on the keyboard, pressing one key in each column that has a non-zero digit. For example, to enter 104, press the 4 key in the rightmost column and the 1 key in the third column from the right. You can clear the entered number by pressing C.|
|Addition:||Enter the number to add on the keyboard. Press down and release the lever.|
|Subtraction:||Enter the number to subtract on the keyboard, and also press the minus button. Press down and release the lever.|
|Negative Results:||If the register underflows because the result is a negative number, then shift the register's sliding window to the left. The register now displays the complementary digits with a green background. If the last digit is not a zero, then the displayed number is the correct negative result. If the last digit is zero, which is shown with a red dot in its centre, that zero should really be thought of as a ten. To get the actual negative number, that ten should be mentally carried over to the tens digit. For example, if the register displays in green the number 699 then it means -699, but if it displays a green number 690, then it really means the number -700.|
Press the * button, then press down and release the lever.
IMPORTANT NOTE: If the last operation was a subtraction, then the * button cannot be pressed down. If this happens, then push and release the lever (effectively adding a zero). You can then clear the register normally.
Enter the number and press the R button. Repeatedly push the lever as many times as
you want to add the number. Press the C key to clear the input.
Repeated subtraction is possible, but you have to press the minus and the R buttons simultaneously to get them to stay pushed in.
This machine was not actually developed by Brunsviga but originally produced by Komet. The company Komet Rechenmaschinen GmbH was founded on June 1951 by Hugo Schumann in Frankfurt, and produced four calculator models. These machines were probably all manufactured in the machine workshop run by Siegfried Link in Griesheim, near Darmstadt. The first model in production was the Komet SK. It was a licensed copy of the Resulta BS7 (except that it had 8 digits) and was their cheapest and most successful model. Similarly, the Komet R8 was a copy of the Resulta AS7. The third model was the Komet TA 8/9, designed by Siegried Link. It came to market in 1953. The last model was the Komet DM 10, which was a large calculator with a full keyboard and a carriage, somewhat similar to a Monroe.
The Komet company went bankrupt in November 1955, less than four and a half years after it was founded. It is probable that the development and production of model DM 10 was too expensive and ambitious for this small young company. About 16,000 model SK were sold, about 1,000 of the model TA 8/9, but it is unclear if the model DM 10 even reached the market. Brunsviga bought all rights to the model TA 8/9, and all remaining stock was rebadged and sold as the Brunsviga Jedermann. They then continued production of the model, which was dubbed the Brunsviga 90 TA, and later also a variant without the input register display called the Brunsviga 90 T.
It is quite likely that Siegfried Link's company was responsible for manufacturing the Brunsviga 90 TA and 90 T, just like it was for the Komet TA 8/9. This lasted until about 1958, when production of this model ended. Note that Siegfried Link's company survived this setback, as it could fall back on making the Komet SK, now renamed the Link SK. They managed to diversify into making parts for other industries, for example for cars and bicycles.
Below is a video I made that demonstrates the Brunsviga 90 TA.
In 1957, Brunsviga was bought by Olympia-Werke, a company that spun off from AEG and which made mostly typewriters, but also some pinwheel calculators. In the 1960s, Olympia gradually stopped producing most mechanical calculator models, moving to electric and electronic ones. The mechanical model that continued the longest was the Olympia-Brunsviga 13 RM. It is a fairly standard pinwheel machine, with back transfer. They were mostly manufactured in Spain, and the ones sold in Spain itself used the brand name Minerva. Other than the name, the Minerva is identical to the Olympia-Brunsviga 13 RM.
It uses a standard pinwheel design, clearly from the Olympia stable rather than the Brunsviga. It has its 8-digit revolution counter in the carriage, to the left of the 13-digit results register. The add/subtract switch is shifted to a neutral position when the counter is cleared, and the direction of the next turn of the crank shifts it to the correct state. To do a back transfer, first clear the input, push down the back-transfer button which is located to the right of the register, and then clear the register.
This Minerva has serial number 30091, and is in reasonable condition. It works correctly, except that the back-transfer mechanism does not always quite push the input pins back to their correct places.
After removing the four rubber feet the bottom plate comes free. This gives access to the screws on the sides that keep the top part of the casing in place.
This is a coin or medal made of a light metal, possibly a zinc alloy. One side
bears the image of a Brunsviga pinwheel calculator, with the text
"Grimme Natalis & Co., Brunsviga, Braunschweig".
The other side has a perpetual calendar for the years 1908 to 1928. A thin plate covers most of this side of the coin except for two windows. When you rotate the coin so that the year in the top window lines up with the month on the front plate, the other window shows the correct days of the week for the calendar for that month and year.
It has some instructions in German: "Man setze gewuenschten Monat unter Jahr. Unterstrichene Jan & Feb dienen nur fuer Schaltjahre."
Geschichtliche Daten aus der Entwicklung der Rechenmaschine von Pacal bis zur Nova-Brunsviga (PDF, 26.3 MB or archive.org)
Dr. Ing. eh. Franz Trinks
170mm × 230mm × 2mm
This German booklet gives a short history of the development of mechanical calculators, ending with a description of the full range of Brunsviga-Nova calculators that were available. It was written by Franz Trinks, who was the main engineer who designed the Nova series. A year after its publication in 1926 it was reproduced in the Grimme-Natalis company magazine, Braunschweiger GNC-Monatsschrift #14.
Différents Modèles Nova-Brunsviga
212mm × 281mm
This French leaflet has pictures of the models Nova I, Nova IVa, Nova 13, and Nova Duplex, and also briefly describes the Nova II and Nova IV.
148mm × 210mm
This French leaflet shows and describes the models Nova II and Nova IVa. The models Nova III and Nova IV are briefly mentioned.
148mm × 210mm
This French leaflet shows and describes the models Nova 13, Nova 13Z, Nova 13ZG, and Nova 13ZK, where the latter two are on an additional page pasted in the middle. Also listed are the Nova II, Nova III, Nova IV, Nova IVa, and Dupla.
Tabelle der reziproken Werte von 1-1000 für BRUNSVIGA-Rechenmaschinen und BRUNSVIGA-Addiermaschinen
98mm × 210mm
This is a table of reciprocals from 1/1 to 1/1000. The front has pictures of the models 11 E, G 111 E, and 13 RK.
Here are a various advertisements relating to Grimme Natalis & Co, their Brunsviga calculators, and to Olympia.
Here are some articles related to Grimme, Natalis & Co., and Brunsviga calculators.
Die Rechenmaschine Brunsviga
Modern Instruments and Methods of Calculation, a Handbook of the Napier Tricentenary Exhibition
The Calculating Machines
(1925, Ernst Martin)
Elementary Mathematics from an Advanced Standpoint
(1932, Felix Klein)
Here is a large selection of patents relating to Brunsviga's pinwheel machines leading up to the Nova series. Most are by Franz Trinks.
|Patent||Filing date||Published date||Name||Description|
|DE 124,578||07-07-1900||21-10-1901||Franz Trinks||Lock crank/input when clearing|
See also AT 9,031 B, GB 1900/19,762
|DE 126,743||26-06-1900||08-01-1902||Franz Trinks||Lock input when crank turns|
See also AT 9,034 B, GB 1900/19,762
|FR 344,541||07-09-1904||07-11-1904||Franz Trinks||Input register|
|AT 30,756 B||16-11-1905||25-11-1907||Franz Trinks||Lock input when shifting carriage|
|AT 30,763 B||16-11-1905||25-11-1907||Franz Trinks||Overshoot prevention|
|DE 185,005||07-11-1905||16-05-1907||Franz Trinks||Lock input through pin at crank handle|
|AT 32,602 B||19-10-1906||10-04-1908||Franz Trinks||Independent input pins|
See also FR 6,833 E, GB 1906/23,659
|FR 362,969||21-04-1906||18-07-1906||Franz Trinks||Carry mechanism lever|
|US 843,506||06-03-1906||05-02-1907||Franz Trinks||Input lever arrangement|
|DE 203,659||26-10-1907||29-10-1908||Franz Trinks||Counter with complemetary digits|
See also AT 39,207 B, CH 45,340, DK 12,416 C, FR 395,531, GB 1908/22,435, US 935,565
|US 975,180||13-06-1907||08-11-1910||Franz Trinks||Fixed counter|
|AT 43,003 B||29-03-1909||11-07-1910||Grimme, Natalis & Co.||Carriage shift by button press|
See also CH 50,241, FR 409,262, US 967,821
|AT 43,677 B||29-03-1909||25-08-1910||Franz Trinks||Back transfer|
|DE 224,131||25-07-1908||12-07-1910||Grimme, Natalis & Co.||Register locking mechanism|
See also AT 47,275 B, CH 49,626, DK 13,282 C, US 953,622
|DK 13,284 C||10-07-1909||30-05-1910||Grimme, Natalis & Co.||Carriage shift mechanism|
See also CH 49,628, FR13873E, FR 406,992, US 946,367
|AT 59,385 B||24-04-1912||26-05-1913||Franz Trinks||Block input when clearing register|
See also CH 59,698, FR 443,343, GB 1912/10,604, US 1,040,059
|AT 61,307 B||12-10-1912||25-09-1913||Franz Trinks||Input display register|
See also CH 61,229, FR 449,723, GB 1912/24,275
|AT 63,783 B||02-01-1913||10-03-1914||Franz Trinks||Ratcheted clearance mechanism|
See also CH 62,620, FR 452,838
|AT 66,728 B||18-10-1913||25-09-1914||Franz Trinks||Carry mechanism|
See also CH 66,344, FR 463,789, GB 1913/25,754
|AT 66,729 B||22-12-1913||25-09-1914||Franz Trinks||Carry mechanism|
See also CH 67,131, FR 466,956, GB 1914/00,037, US 1,098,193, US 1,100,631
|AT 68,733 B||16-03-1914||25-05-1915||Franz Trinks||Carry mechanism improvement|
See also CH 68,850, FR 470,156, GB 1914/07,963, US 1,134,780
|AT 68,992 B||27-03-1914||10-06-1915||Franz Trinks||Optionally copied input|
See also CH 71,871, GB 1914/08,867, US 1,118,829
|FR 467,396||17-01-1914||10-06-1914||Carl Rasmussen; Grimme, Natalis & Co.||Carry mechanism|
|AT 72,870 B||06-08-1915||27-12-1916||Franz Trinks||Lock crank when pins not aligned|
See also CH 71,476, FR 520,006, GB 147,114, US 1,220,029
|CH 72,515||29-11-1915||02-06-1916||Grimme, Natalis & Co.||Lock crank when pins not aligned|
See also US 1,194,900
|CH 72,990||27-11-1915||01-08-1916||Grimme, Natalis & Co.||Pin alignment|
|CH 72,991||27-11-1915||17-07-1916||Franz Trinks||Lock crank when pins not aligned?|
|CH 91,917||16-06-1920||01-12-1921||Franz Trinks||Mechanism for shifting window on counter|
|DE 321,611 C||23-04-1919||09-06-1920||Franz Trinks||Counter register with complementary digits and sliding window|
See also SU 10,427
|DE 325,901 C||18-04-1919||09-01-1922||Franz Trinks||Counter register with complementary digits and sliding window|
See also AT 86,598 B, CH 90,733, DE 325,902 C, DE 325,903 C, SU 10,427,US 1,445,461
|AT 90,434 B||10-12-1920||27-12-1922||Franz Trinks||Fixed counter above input |
See also CH 91,167, FR 528,855, GB 157,898
|DE 354,897 C||21-06-1921||20-06-1922||Grimme, Natalis & Co.||Mechanism for shifting window on counter|
|DE 359,634 C||18-12-1921||25-09-1922||Grimme, Natalis & Co.||Input alignment mechanism|
|DE 377,424 C||15-09-1922||18-06-1923||Grimme, Natalis & Co.||Lock for transport|
|DE 378,838 C||01-11-1922||06-08-1923||Grimme, Natalis & Co.||?? shifting mechanism|
|DE 383,722 C||31-10-1922||17-10-1923||Grimme, Natalis & Co.||?? Register clearing mechanism disengages clicking mechanism|
|DE 384,531 C||22-08-1922||03-11-1923||Grimme, Natalis & Co.||Input clearing mechanism|
|DE 386,578 C||21-11-1922||21-12-1923||Grimme, Natalis & Co.||Number wheel|
|DE 390,460 C||29-03-1923||19-02-1924||Franz Trinks||Warning bell on counter with sliding window|
See also AT 99,483 B, CH 108,102, DK 34,004 C, FR 577,413, GB 213,549
|DE 393,955 C||20-06-1923||11-04-1924||Franz Trinks||Carriage shifting mechanism|
|DE 396,316 C||21-03-1922||02-07-1924||Grimme, Natalis & Co.||Input clearing disengages clicking mechanism|
|CH 107,414||09-02-1924||16-10-1924||Grimme, Natalis & Co.||Pinwheel|
See also DK 33,854 C, FR 577,245, GB 212,540
|AT 99,766 B||07-02-1924||25-04-1925||Franz Trinks||Warning bell on counter with sliding window|
See also CH 108,220, DK 34,136 C, FR28776E, GB 212,561
|AT 101,809 B||20-09-1924||25-11-1925||Grimme, Natalis & Co.||Crank handle cradle lock|
See also CH 110,312, DK 35,306 C, FR 586,482, GB 224,212
|CH 110,311||03-09-1924||01-06-1925||Grimme, Natalis & Co.||Carriage shift mechanism|
See also DK 34,566 C, GB 223,895, SU 5,719
|GB 212,548||03-03-1924||22-01-1925||Grimme, Natalis & Co.||Shifting carriage rack|
|GB 223,894||08-10-1924||11-06-1925||Grimme, Natalis & Co.||Number wheel|
|GB 224,211||04-10-1924||12-03-1925||Grimme, Natalis & Co.||Single tooth drive|
|CH 113,198||23-03-1925||02-01-1926||Grimme, Natalis & Co.||Clearing indicator|
See also GB 233,672
|DE 401,412 C||02-03-1924||04-09-1924||Grimme, Natalis & Co.||decimal point indicators|
|DE 404,370 C||17-04-1924||18-10-1924||Grimme, Natalis & Co.||carry mechanism|
See also DE 412,945 C, FR 595,063, GB 232,577
|DE 404,887 C||14-05-1924||25-10-1924||Grimme, Natalis & Co.||Clearing mechanism|
See also CH 112,987, DK 35,289 C, GB 234,061
|DE 405,482 C||17-04-1924||06-11-1924||Grimme, Natalis & Co.||carry mechanism|
See also GB 232,567
|DE 408,461 C||11-04-1924||29-01-1925||Grimme, Natalis & Co.||Guard against crank reversal|
|DE 409,297 C||22-06-1924||05-02-1925||Grimme, Natalis & Co.||Lock input|
|DE 411,403 C||12-10-1924||20-03-1925||Grimme, Natalis & Co.||Decimal point indicator|
|DE 412,373 C||02-10-1924||21-04-1925||Grimme, Natalis & Co.||Lock input|
|DE 415,284 C||18-04-1924||12-02-1928||Grimme, Natalis & Co.||pins in two sections|
|DE 416,830 C||24-12-1924||27-07-1925||Grimme, Natalis & Co.||Carry mechanism|
|DE 419,313 C||20-12-1924||08-10-1925||Grimme, Natalis & Co.||Simplified number wheel construction|
See also AT 102,415 B, CH 113,197, DK 35,372 C, GB 229,301
|DE 426,140 C||20-12-1924||09-03-1926||Grimme, Natalis & Co.||Improved pinwheel|
See also AT 102,414 B, CH 112,632, DK 35,119 C, FR 596,069, GB 228,902
|DE 414,135 C||21-09-1923||17-02-1926||Grimme, Natalis & Co.||Calculation mechanism timing|
See also CH 118,488, DK 35,686 C, SU 7,077
|DE 416,040 C||15-01-1925||07-07-1925||Grimme, Natalis & Co.||Carriage alignment during back transfer|
See also GB 230,828
|DE 416,828 C||04-02-1925||27-07-1925||Grimme, Natalis & Co.||Turn direction indicator|
|DE 417,288 C||05-02-1925||10-08-1925||Grimme, Natalis & Co.||Backtransfer interlock|
See also CH 118,033, DK 36,935 C, FR 610,268
|DE 417,396 C||04-02-1925||14-08-1925||Grimme, Natalis & Co.||Backtransfer|
See also CH 118,489, DK 36,934 C, FR 610,247, SU 7,076
|DE 418,746 C||27-02-1925||21-09-1925||Grimme, Natalis & Co.||Backtransfer interlock|
See also CH 118,490, DK 36,936 C, FR 610,269, SU 8,380
|DE 418,749 C||20-02-1925||21-09-1925||Grimme, Natalis & Co.||Clearing mechanism for register|
See also CH 117,597, DK 36,643 C
|DE 437,284 C||30-04-1926||18-11-1926||Grimme, Natalis & Co.||Crank cradle pincer|
|Here are the patents related to the Brunsviga 10 and its descendants.|
|Patent||Filing date||Published date||Name||Description|
|DE 554,277 C||07-03-1931||16-06-1932||Grimme, Natalis & Co.||Brunsviga 10|
|DE 565,704 C||04-09-1931||24-11-1932||Grimme, Natalis & Co.||Input mechanism|
|DE 576,881 C||02-10-1931||04-05-1933||Grimme, Natalis & Co.||Carry mechanism|
|DE 578,683 C||04-09-1931||17-06-1933||Grimme, Natalis & Co.||Keyboard and back transfer|
|US 2,042,986||08-06-1932||02-06-1936||Richard Haase; Grimme, Natalis & Co.||Brunsviga 10, single axle|
|US 2,545,550||14-09-1949||20-03-1951||Kurt Jordan; Brunsviga Maschinenwerke||Improved input clearing mechanism|
|US 2,648,498||14-09-1949||11-04-1953||Kurt Jordan; Brunsviga Maschinenwerke||Improved drum axle construction|
|Here are the few design patents related to the Brunsviga TA, by Siegfried link.|
|Patent||Filing date||Published date||Name||Description|
|DE 1,709,046 U||26-07-1955||27-09-1955||Siegfried Link||Green complement numbers|
|DE 1,709,047 U||30-07-1955||27-09-1955||Siegfried Link||Input register|
Rechnerlexikon has pages for the models
90 TA, and
13 RM. The page for
Komet links to a good
article about Komet.
Rechenmaschinen-Illustrated has one page with many Brunsviga pinwheel models, one with the Brunsviga 10 and later models, and one with Brunsviga adding machines such as the 90 T. It also has a page about Komet with a rare DM 10.
Rechnen Ohne Strom is an interesting site that has a page about Brunsviga/Olympia, and a page with toothed rack machines including the 90 TA.
John Wolff has a page about Brunsviga models including the 10.
The Odhner Calculator, Memorial site has information about the early pinwheel machines by Odhner.
Cris Vande Velde has many Brunsviga models including Brunsviga 10, and a section about a Brunsviga Exposition.
Arithmeum has information about the Brunsviga 10.
Vintage Calculators Web Museum has pictures of the Brunsviga 10 and its mechanism.
© Copyright 2019-2021 Jaap Scherphuis, mechcalc a t jaapsch d o t net.