History of the Rheinmetall company

With a production of one million mechanical calculators, the Sömmerda, Thüringen, Germany based manufacturer is one of the biggest manufacturers. The high quality leibnitz wheels machines known under the market names Rheinmetall, Supermetall and Soemtron are produced from 1889 until the mid seventies of the previous century.
In 1918 they labored 48 000 employees in the ammunition / military field . After the first world war, forced by the treaty of Versailles, they changed to office machines, with 1500 employees.
In Mr. Berk (worked for Ludwich Spies company in Gasshütte, Sachsen) set up in 1920 the calculator division and made his first concep in 1921 named Saldo. The Dusseldorf headquarters rejected the the design and in 1922 the first series approval was given and the R4 series were produced. In 1923 the complete tens carry mechanism was redesigned and patented by mr. Berk. Their Leibnitz wheel machines have clever designs, such as double served wheels, meaning one wheel turning two gears / digits. This made de display windows compact and on relative short distance from each other, what directly improved the readability. The adding machines have a specialty as well. They distinguish in the way they display negative numbers. It was common to represent 100-110 as -99990. Rheinmetall displayed the negative number, in the way we are now used to, as 100-110= -10 and are printed in red. This made these Rheinmetall adding machines verry popular.
In 1925 a key engineer mr. August Kottman, who started low in the organization, managed to get more influence on the design principles. He became head of construction and in 1941 Director of the Calculation machines Department and was loved by the workforce and the company headquarters. He was strong in favor of using electrical motors to increase the calculation speed. In 1926 the first electrical driven machines was released in the automatic division. By that time mr. Berk was forced to leave Rheinmetall, and it seems under financially bad conditions for him.
In 1933 the first series of the elektrical forced calulators (for the four basic calculations) named KEW; KEL and KELR were relased. The W stands for movable carriage, the L has a electrical reset for the registers as well and the R has a back set posibility of the serult to the calculation input. They are followed by the super automates SAL, SASL and SAR.

After WW II mr Kottmann was forced to change to a lower position as first Constructor. The company was forced to produce only for Russia and 3/4 of the factory was dismantled and shipped to Russia as well. Part of the management had to work in Russia for a number of years.
Curt Herzstark was surviving Buchenwalt and became Rheinmetall's technical director. During his years in concentration camp he designed the "Curta I". After a short time in office he escaped to western Germany
During the DDR times the company became state owned and got the new name "VEB Mechanik Büromaschinenwerk Rheinmetall Sömmerda". 80% of the workers were layed off.
April 1, 1969 the VEB became part of the new established Kombinats Zentronik. Others where Buchungsmaschinenwerk in Karl-Marx-Stadt, das Optima-Büromaschinenwerk in Erfurt and the VEB Maschinelles Rechnen Meiningen/Zella-Mehlis (the former Mercedes-Büromaschinenwerk, later Cellatron). In 1978 was the BWS Sömmerda fused with the Kombinat Robotron with the headquarters in Dresden. The full name was :"VEB Robotron Büromaschinenwerk Sömmerda" and they should make personal computers. The competition off the west PC's was so strong that they closed the company in december 1991.

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