RAFI (also Rafi) is a German electronics manufacturer specialising in human–machine interaction. RAFI was an early adopter of Hall effect keyboard technology, and likely remain the only veteran Hall effect keyboard maker, being one of the few companies to have continuously produced keyboards from the 1970s to the present day.
The company takes its name from Raimund Finsterhölzl, the first CEO of the Institute for Electrical, Optical & Mechanical Engineering, founded in 1900 in Ravensburg by Ernst Bucher. In 1908, Finsterhölzl took ownership of the company. Patents from the 1950s to the early 1970s give the company name as “Raimund Finsterhölzl Elektrotechnische Spezialfabrik”, abbreviated to “Rafi” and “RAFI”. In the late 1970s this changed to Rafi GmbH & Co, and is currently given as RAFI GmbH & Co. KG.
According to the RAFI website, the first RAFI keyboard was produced in 1970. No details on this keyboard are given, and it seems to pre-date all discovered RAFI keyboard switches. As with many keyboard manufacturers, RAFI patents exist for products yet to be discovered, or that never entered production; keyboard-related patents go back to the 1960s.
German patent 6805719U filed in November 1968 depicts a keyboard assembly design, formed from mounting bars that hold the switches. The switches are tall, with two or three terminals (two shown, but three holes in what seems to be the PCB. The design bears a strong resemblance to the mounting bar system of Micro Switch KB. No visual details are given as to the kind of switch used.
The RAFI-System 72 (RC 72) catalogue makes the following claim:
The importance attributed internationally to the development of contactless, solid state components was demonstrated by the award to RAFI of the “Munich Electronic Prize ’68” at the Electronica Exhibition.
Although the Electronica trade fair is still active, there seems to be no readily available details on that prize.
RAFI’s older contactless keyboard switches were magnetoresistive, as described in German patent 7024643U filed in July 1970 (available in English as US patent 3668596).
German patent 2256360A1 filed in November 1972 (and available in English as US patent 3882337 from November 1973) covers RC 72. The patent also depicts an automated means of partially demagnetising the switch to tune the actuation point to the correct distance; the magnet is initially over-magnetised and the strength is reduced until the actuation point is set correctly.
A few years later, around 1975, RAFI introduced the more familiar RS 74 switches, which were followed not long afterwards by RS 76.
The following products from RAFI relate to keyboards:
- Magnetoresistive keyboards and switches
RC 72 high-profile switches and keyboards:
- RC 72 C contactless Hall effect
- RC 72 M mechanical
- RC 72 L dummy switches
- RC 72 N mains power switches
RS 74 and RS 76 low-profile switches:
- RS 74 C contactless Hall effect, 2.5 mm travel
- RS 74 M mechanical, 2.5 mm travel
- RS 76 C contactless Hall effect, 4 mm travel
- RS 76 M mechanical, 4 mm travel
- Hall effect and mechanical keyboards, both off-the-shelf and bespoke
RAFI part numbers are structured (schematic), but bear no relationship to the series names. A single series may use multiple part number ranges. Older part numbers are divided into three digit groups separated by dots. Where the item’s colour is considered a variation, a fourth digit group containing the colour code is appended, separated by a slash. For example:
- 3.13001.010 (RS 76 C 0.7 N non-illuminated switch, with no colour variant code)
- 3.13001.110/0000 (RS 76 C 0.7 N illuminated switch, with no LED and 0000 “not applicable” colour variant code)
- 3.13001.110/1450 (RS 76 C 0.7 N illuminated switch, with yellow LED and 1450 colour variant code)
The format of part numbers changed at some point: the second digit group was split into two (e.g. “3.13001…” became “3.13.001…”, and the variant digit group was made mandatory (“/0000” for “not applicable” is always present). The part numbers above changed to the following:
- 3.13.001.010/0000 (non-illuminated)
- 3.13.001.110/0000 (illuminated, no LED)
- 3.13.001.110/1450 (illuminated, yellow LED)