The output from Oak Industries included printed circuit boards, discrete keyboard and calculator switches and full membrane keyboard assemblies. The Oak logo can be found on the PCBs of a number of keyboards, including those of most BBC Microcomputers; this is somewhat misleading as it can lead people to think that Oak made the entire keyboard. (Another PCB manufacturer whose PCBs are branded is Sung Wei, who made many PCBs for Datacomp.)
Oak keyboards and keyboard switches have been produced under a number of Oak brands:
- Series 400 was covered under the Oak Manufacturing Co. brand in their Electronic Engineers Master 1971–2 advertisement; Oak Manufacturing Co. was listed as a division of Oak Electro/Netics Corp.
- In their Electronic Engineers Master 1973–4 advertisement, the brand name had changed to Oak Industries Inc. Switch Division. As with the 1971–2 advertisement, Series 400 was depicted but not named. Series 475 was advertised by Oak Industries Inc. Switch Division in 1977, as was Series 415 in 1978.
- Full Travel Membrane was advertised by Oak Technology Inc, Switch Division in 1980, but in 1983 the relevant brand was Oak Switch Systems Inc. In a separate 1983 advertisement, Oak Switch Systems Inc. is said to be an Oak Technology Inc. company.
- In 1985, the Keyboard Products Division of Oak Switch Systems Inc. was named.
Oak are now Oak-Mitsui. However, the switch division is now owned by Electroswitch. The FTM patent, and the N-key rollover patent for FTM, filed in 1980 and 1981 respectively, passed to Zenith Electronics Corporation in 1989, suggesting that Zenith took over the keyboard division.
TG3 bought Oak’s “switch line” in the early 1990s and continued production until the tooling reached end of life, possibly into the 2000s or 2010s (TG3 did not indicate this clearly). TG3 were not specific about which products they acquired, although they did provide scans of FTM literature.
- Full-Travel Membrane (the most common by far)
- Series 400 tall mechanical switches
- Series 415 extremely low-profile mechanical switches for calculators
- Series 475 reduced-height mechanical switches
The following patents are not specific to any switch series; switch patents are documented under the individual switch series pages.
|Apparatus for the sublimation printing of keyboard caps