Alps SKFR/SKFS series
|This article requires additional photographic illustration — internals of black variant needed|
|Switch type||Tactile, linear|
|Sense method||Metal leaf|
|Total travel||3.5 mm|
|Switch mount||PCB mount|
Alps SKFR/SKFS is a series of low-profile PCB-mount switches from Alps. Despite their diminutive size, they retain full 3.5 mm travel.
Unlike many other Alps switches, the keycap mount is not the common Alps mount.
Even though it also has four pins and is low-profile, it is neither pin-compatible or keycap compatible with the Alps SKFL switch.
The switches are branded "ALPS" on the top, in a lower weight of type than of other Alps switches.
No patent has been confirmed for this switch, but US patent US4935591—filed in 1988—bears a resemblance.
A number of variants exist. Most of the part numbers are taken from the 1994 Alps catalogue, courtesy of Sandy. Part number SKFRAK has been sighted on the Web, but no details of any kind are known. A switch exists that resembles SKFR but with a taller slider that accepts regular Alps keycaps; this switch has been found only in 1995, and were this to be SKFRAK, the date may explain its omission from the 1994 catalogue.
The following photos depict a Sager NP-925 laptop keyboard:
SKFS White uses an innovative design wherein a click leaf is placed in front of a chamber whose front wall is open. The stationary sides of the leaf fit into a grooves at the side of the switch, and the movable centre section backs onto the open chamber. As such, when the click leaf is released, it has nothing to strike, and produces no click sound. The result is greater tactility than if a typical tactile leaf were used, but at a cost of requiring some empty space within the switch.
NOS switch from AliExpress.
Apple Adjustable Keyboard
Opened, showing the contact mechanism, tactile leaf and jumper
SKFS Yellow is a reduced-depth switch. In a 1996 example, the Alps GlidePoint Keypad took advantage of this characteristic to provide a key with an integrated LED, which suggests that possibly by 1996 the LED versions of SKFS Black, listed in the 1994 Alps catalogue, were no longer sold.
- Apple Adjustable Keyboard (SKFS White)
- Sager NP-925 laptop keyboard (SKFR Black)
- Alps GlidePoint Keypad (SKFS White, SKFR Yellow)
A nearly-identical switch exists, that has two distinct differences to SKFR:
- The reach of the slider is greater, in a manner very similar to the robust version of Cherry ML
- The slider accepts standard Alps mount keycaps
The series identity of this taller version is not known. Nothing matching this description was included in the 1994 Alps catalogue, but it has been found in keyboards from ca. 1991–1992 and from 1995. Alps part number SKFRAK0001 was previously listed on the Web as a surplus part without any details; neither Google nor Bing search is aware of any supplier currently listing this part.
The keyboards that are known to use this switch are:
- Datacomp DCK84/85 (1995, and ca. 1991–2)
- Macway TP-997KB-J (case 1993, IC 1995, used for a single key)
- Geekhack — Default:ALPS switches (archive) Archived 2014-01-12. Retrieved 2015-07-22.
- KBtalKing — ■鍵盤史的遺跡DataComp DCK85CH61(ALPS角軸)■
- tttっちゃtttttったりttttったいね — Macway TP-997KB-J ALPS白軸後期
- KBTalking — Apple Adjustable Keyboard M1242 鍵盤拆解紀錄 Posted 2009-04-18. Retrieved 2015-07-22.
- Sandy — apple_adjustable
- MouseFan — AppleAdjustableKeyboard M1242 Retrieved 2015-07-22.
- Telcontar.net — Alps GlidePoint Keypad for Macintosh
- Telcontar.net — Macway TP-997KB-J