Alps SKFF series
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| Manufacturer | Alps Electric |
|---|---|
| Inventor | Katsuyuki Matsuo |
| Switch type | Clicky |
| Sense method | Metal leaf |
| Keycap mount | Generic cruciform |
| Patents |
US4186290 (1978) US4249055 (1979) |
Alps SKFF series, or Alps vertical plate spring, is a switch that shares characteristics of both Alps SKCP series and Alps SKCC series. It is designed from the outset to support double action.
Contents
Nomenclature
The Canon AP400 typewriter in which it was discovered bears the Alps keyboard codes 12KF006C and KFFBA010; from this, (S)KFF was deduced. The Apple III service manual was subsequently found to cite these switches as "KFF". However, they remain listed here as SKFF until Alps's apparent inconsistent naming is better understood.
Description
Alps vertical plate spring switches differ from plate spring by having the plate spring assembly mounted vertically down the side of the switch. This change results in the switch being significantly more complicated than the original plate spring switch. The repositioning of the plate spring assembly allows for two separate plate spring assemblies to be fitted side by side, with a staged actuation to provide a double action response to the host.
The switch is clicky, and the click sound created by inversion of the plate spring is specifically mentioned in both US patents.
The ziggurat design of the slider is very similar to that of the Alps SKCC series switch.
The switch exists in single action and double action variants, and supports a spring-mounted LED just as with SKCC series.
Typically, the keystem is a small and cruciform. It has also been found with a tall, angled bar keystem assumed to be compatible with that of Alps SKCC Side-Angled Cream, both of which are from Swedish-made Facit typewriters.
Variants
| Type | Notes | |
|---|---|---|
|
Alps SKFF White | |
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Alps SKFF LED | |
|
Alps SKFF Bar Angled White | |
 |
Alps SKFF Double Action Black | Second stage spring is external |
|
Alps SKFF Double Action White | Second stage spring assumed to be internal |
Keyboards
- Apple III keyboards (double-action white and black)
Typewriters / Word Processors
- Some Canon AP400 typewriters (momentary, double-action black, illuminated; 1982 example)[1]
- Facit 1880 (bar angled white)
- Facit 8111-2 (bar angled white; cross mount illuminated)[2]
- Sharp ZX-400 (white; some illuminated, double-action black on spacebar, enter, backspace and other keys)
- Sharp ZX-510 (white; some illuminated, double-action black on spacebar)
- Silver Reed EX 77[3]
References
- ↑ Deskthority — Canon AP400
- ↑ Deskthority — Facit 8111-2 Typewriter
- ↑ YouTube Alps SKFF / Vertical Plate Spring Switch Sound Test | Silver Reed EX 77 Typewriter | ASMR Uploaded 01-17-2022.
