Alps common mount low profile

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Alps common mount low profile

Manufacturer	Alps Electric
Switch type	Linear, Tactile
Sense method	Metal leaf
Keycap mount	Alps mount
Switch mount	PCB mount
Patents	US 4760225 (1987) US 5004880 (1990)

Alps common mount low profile (or Alps octagonal for short) is a provisional name for a low-profile PCB mount switch from Alps. SKFM/SKFN series is likely to be the official designation.

Nomenclature

Keyboard assembly KFFMBB0034 has white switches.<ref name="dropbox" /> Assuming these are linear, this would give SKFM series for linear switches. Since the preceding series name (SKFL) is already taken, then the second series within the pair (for tactile switches) would be SKFN. SKFNAA is a known Alps model number, of which no details are known.<ref name="Tyro-SKFNAA" /> Tentatively, it appears that these switches should be classified as Alps SKFM/SKFN series.

Description

This switch uses the common Alps mount, unlike Alps SKFR/SKFS series which has a unique mount.<ref name="rzw" /> The slider design is similar to that of Alps SKCL/SKCM series, but reduced in front-to-back depth to fit inside the switch's small shell. The contact mechanism is very similar to that of Alps SKFL; the latter is cited as prior art in the patent.

Where SKFR/SKFS series has a black slider for linear and a colourless slider for tactile, the colours are reversed with common mount low profile: black for tactile as with SKCM series, and colourless for linear.

The only branding is a minute Alps logo in the centre of the base, visible only by desoldering the switch.<ref name="rzw" />

The switch features an integrated jumper. The tactile version has a click leaf and likely arranges this in the same way as SKFR/SKFS.<ref name="tactile" /> The patent for the leaf (which curiously shows the base as rectangular instead of octagonal) describes the switch as "click-type", but a clicky version has yet to be encountered.

Variants

	Slider	Type
	Colourless	Linear
	Colourless	Linear, with LED support
	Black	Tactile

Keyboards

• Acer 6083 (Black slider)
• IBM 5535-M18 Multistation keyboard<ref name="ibm5535"/>
• IBM 5556-P01 (not clear if some, or all; LED variant without LEDs)<ref name="MouseFan-5556-001" />
• Leading Edge DC-8212<ref name="leading"/>
• Nixdorf 8810 M15 / M20
• Toshiba T1200 (White slider)<ref>Deskthority — Toshiba T1200</ref>
• Toshiba T1600 (White slider)<ref>Deskthority — https://deskthority.net/viewtopic.php?f=2&t=23803&p=463314#p463314]</ref>
• Toshiba T5200/100 (White slider)<ref>Deskthority — Toshiba T3100 & T5200</ref>
• Zenith TurbosPORT 386

Keypads

• Toshiba UE0254P02 (Standard variant)<ref name="MouseFan-UE0254P02" />
• Zenith ZA-180-89 (LED variant)
• Zenith ZA-3034-NP

Gallery

Linear

• 
  Top
• 
  Partially disassembled, with keycap
• 
  Slider and return spring
• 
  Contact mechanism
• 
  Toshiba T1200, linear

Tactile

• 
  Switch with black slider in an Acer 6083
• 
  Switch with black slider in an Acer 6083
• 
  Switch with black slider in an Acer 6083

LED variant

• 
  Top
• 
  Contact mechanism
• 
  Return spring and slider
• 
  Slider
• 
  Upper shell viewed from below, showing LED recess

References

<references> <ref name="rzw">ちゃたりたいね — ZENITH ZA-180-89 ALPS導電ゴム枕</ref> <ref name="MouseFan-5556-001">MouseFan — IBM 5556 P/N5962851</ref> <ref name="MouseFan-UE0254P02">MouseFan — Toshiba UE0254P02</ref> <ref name="tactile">Deskthority — Best Tactile Switch?</ref> <ref name="dropbox">Dropbox — alps-low-profile ^{[Volatile reference]}</ref> <ref name="Tyro-SKFNAA">Tyro teQ Inc. — SKFNAA ALPS | 在庫通販 ^{[Volatile reference]}</ref> <ref name="leading">Imgur — [1] Uploaded 2022-04-20.</ref> <ref name="ibm5535">YouTube — IBM 5535 Keyboard Module Typing Demo Uploaded 2021-07-04.</ref> </references>