Alps SKFF series

From Deskthority wiki
Jump to navigation Jump to search

This article is a stub. You can help Deskthority by expanding it.

Template icon--Illustration.png This article requires photographic illustration
Alps SKFF series
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.


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.


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.


Type Notes
No photograph.svg Alps SKFF White
No photograph.svg Alps SKFF LED
No photograph.svg Alps SKFF Bar Angled White
No photograph.svg Alps SKFF Double Action Black Second stage spring is external
No photograph.svg Alps SKFF Double Action White Second stage spring assumed to be internal



  1. Deskthority — Canon AP400
  2. Deskthority — Facit 8111-2 Typewriter