1851 Calculating Machine

1900 Simplex Slide Rule

Worldwide Slide Rule Patents

Starting in the 1800's, inventors began filing for patent protection for their slide rule designs. The patents listed in this gallery are specifically for those apparatus that deal with mathematical operations, for the most part with logarithmic scales. Most take the shape of common slide rules, either linear or circular, but in some case more complex inventions, which used logarithms, are included here as well as they progressed toward the automation of math calculations. I also include the TI and HP electronic slide rule calculator patents. This gallery is beginning with over 1000 patents, and still more as they are found. Please help in this endeavor if you help search the public databases in your country. Thank you. Work in Progress

In the meantime another excellent resource is Rechner Lexicon Patent Page, a German wiki site which includes all mechanical computing devices, and of course Europe's Worldwide Network of Patent Databases, espacenet.


1937 Duplex Slide Rule

1975 Electronic Slide Rule

United States (US)
716 Patents

Great Britain (GB)
145 Patents

Germany (DE)
50 Patents

Italy (IT)
1 Patents

Belgium (BE)
1 Patents

Canada (CA)
15 Patents

Japan (JP)
6 Patents

Switzerland (CH)
2 Patents

Luxembourg (LU)
1 Patents

Korea (KR)
1 Patents

France(FR)
5 Patents

Netherlands (NL)
1 Patents

China (CN)
1 Patents

Soviet Union (SU)
1 Patents

Spain (ES)
1 Patents


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