Patent

Patent:DE521877 01.08.1929 Bergmann, Jean (P) : Taste für Rechen-, Schreib-, und ähnliche -Maschinen
Patent:GB191119394 18.01.1912 Metall, Ind Schoenebeck A G (P) : Method of Fixing Celluloid Key Rings on to the Metal Keys of Typewriting, Calculating and other Key-board Machines
Patent:GB730883 01.06.1955 RIV (P) Officine Di Villar Perosa : Process for manufacturing keys provided with figures, letters or other symbols, for registering and calculating machines typewriters and the
Patent:NL6700334 17.07.1967 NV Philips' Gloeilampenfabrieken : Druktoetseenheid
Patent:US2615547 17.01.2011 Grobl, J. E. (P) : Keyboard Key
Patent:US2615548 17.01.2011 Hopkins, G. W. (P) et al : Keyboard Key
Patent:US2615549 17.01.2011 Marlow, C. K. (P) : Keyboard Key
Patent:US982416 17.01.2011 Felt, Dorr E. (P) : Key for Keyboard Calculating Machine
Patent:US982417 17.01.2011 Felt, Dorr E. (P) : Key for Keyboard Machine

Rechnerlexikon