Editing Alps SKFR/SKFS series

{{TODO photo|more=true|reason=internals of black variant needed}}

{{infobox dswitch
| image name        = Alps SKFR-SKFS.jpg
| manufacturer      = [[Alps Electric]]
| inventor          = 
| switch type       = Tactile, linear
| contact mechanism = [[Metal leaf]]
| travel            = 3.5 mm
| product code      = 
| family            = 
| keycap mount      = Unique
| switch mount      = [[PCB mount]]
| lifetime          = 
| force graph       = 
| peak force        = 
}}

'''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.<ref name="gh-Alps" />

==Description==
Unlike many other Alps switches, the keycap mount is not the common [[Keycap mount#Alps mount|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.

The switches are 10.3 mm tall and include an integrated [[jumper]].<ref name="gh-Alps" />

No patent has been confirmed for this switch, but [http://www.google.com/patents/US4935591 US patent US4935591]—filed in 1988—bears a resemblance.

==Variants==
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.

{| class="wikitable variants-table"
!                                  !! Moniker        !! Model   !! Type   !! Features    !! Sighted
|-
| [[File:Alps SKFRAC.jpg|175px]]   || SKFR Black     || SKFRAC || Linear  ||             || Yes
|-
| [[File:Alps SKFRAD.jpg|175px]]   || SKFR Yellow    || SKFRAD || Linear  || Short depth || Yes
|-
| [[File:No photograph.svg|175px]] || ?              || SKFRAK || Linear  ||             || Uncertain
|-
| [[File:No photograph.svg|175px]] || SKFR Black LED || SKFRFA || Linear  || Red LED     || No
|-
| [[File:No photograph.svg|175px]] || SKFR Black LED || SKFRFB || Linear  || Green LED   || No
|-
| [[File:No photograph.svg|175px]] || SKFR Black LED || SKFRFC || Linear  || Amber LED   || No
|-
| [[File:Alps SKFSAA.jpg|175px]]   || SKFS White     || SKFSAA || Tactile ||             || Yes
|}

===SKFR Black===
This is the linear version. An LED version exists, but this has yet to be sighted. Since there is no LED capacity in the design of SKFR Black, the LED version must take a different form.<ref name="KBT-taller" /><ref name="rzwv-taller" />

The following photos depict a [[Sager NP-925]] laptop keyboard:

<gallery widths=250 heights=187>
File:Alps low-profile black 1.jpg                       | A look at the switch
File:Alps low-profile black 2.jpg                       | Closeup
File:Alps low-profile PCB layout.jpg                    | PCB layout, with four pins per switch
</gallery>

===SKFS White===
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 parts====
NOS switch from AliExpress.

<gallery widths=250 heights=187>
File:Alps SKFSAA -- opened.jpg                          | Opened
File:Alps SKFSAA -- tactile leaf in-place.jpg           | Tactile leaf in place
File:Alps SKFSAA -- tactile leaf from behind 1.jpg      | Tactile leaf from behind, showing that it backs against an open chamber and cannot make a click sound
File:Alps SKFSAA -- tactile leaf from behind 2.jpg      | Alternate shot of the leaf from behind under different illumination
File:Alps SKFSAA -- disassembled, back views.jpg        | Fully disassembled
</gallery>

====Apple Adjustable Keyboard====
<gallery widths=250 heights=187>
File:Alps low profile -- white -- top.jpg               | Top
File:Alps low profile -- white -- opened, top.jpg       | Opened, showing the contact mechanism, tactile leaf and [[jumper]]
File:Alps low profile -- white -- contact mechanism.jpg | Contact mechanism
File:Alps low profile -- white -- parts.jpg             | Parts
File:Alps low profile -- white -- tactile leaf.jpg      | Tactile leaf
File:Alps low profile -- white -- slider.jpg            | Slider
</gallery>

===SKFS Yellow===
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.

<gallery widths=250 heights=187>
File:Alps SKFRAD.jpg           | Top
File:Alps SKFRAD -- rear.jpg   | Rear, showing external jumper
File:Alps SKFRAD -- bottom.jpg | Bottom
File:Alps SKFRAD -- opened.jpg | Opened
</gallery>

==Keyboards==
*[[Apple Adjustable Keyboard]] (SKFS White)<ref name="KBT-White" /><ref name="Sandy-Adj" /><ref name="MouseFan-Adj" />
*[[Sager NP-925]] laptop keyboard (SKFR Black)
*Alps GlidePoint Keypad (SKFS White, SKFR Yellow)<ref name="TDN-GlidePoint" />

==Tall version==
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.

<gallery widths=250 heights=177>
File:Datacomp DCK85 -- switches detail.jpg               | Switches
File:Alps like-SKFR-but-taller -- disassembly.jpg        | Disassembly
File:Alps like-SKFR-but-taller -- profile comparison.jpg | Profile comparison with SKBM and MX
</gallery>

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)<ref>Telcontar.net — [http://telcontar.net/KBK/Keycombo/keyboard.php?id=158  Macway TP-997KB-J]</ref>

==References==
<references>
<ref name="Sandy-Adj">Sandy — [http://sandy55.fc2web.com/keyboard/apple_adjustable_e.html apple_adjustable]</ref>
<ref name="KBT-White">KBTalking — [http://kbtalking.cool3c.com/article/7533 Apple Adjustable Keyboard M1242 鍵盤拆解紀錄] Posted 2009-04-18. Retrieved 2015-07-22.</ref>
<ref name="MouseFan-Adj">MouseFan — [http://mousefan.telcontar.net/image/adjustable.htm AppleAdjustableKeyboard M1242] Retrieved 2015-07-22.</ref>
<ref name="gh-Alps">Geekhack — [http://archive.today/45sFi Default:ALPS switches] (archive) Archived 2014-01-12. Retrieved 2015-07-22.</ref>
<ref name="TDN-GlidePoint">Telcontar.net — [http://telcontar.net/KBK/KCref/Alps_GlidePoint_keypad_0/ Alps GlidePoint Keypad for Macintosh]</ref>
<ref name="KBT-taller">KBtalKing — [https://kbtalking.cool3c.com/article/15958 ■鍵盤史的遺跡DataComp DCK85CH61(ALPS角軸)■]</ref>
<ref name="rzwv-taller">tttっちゃtttttったりttttったいね — [http://kbd.rzw.jp/alps/macway_tp-997kb-j/ Macway TP-997KB-J ALPS白軸後期]</ref>
</references>

[[Category:Alps switches]]
[[Category:Metal contact switches]]
[[Category:Linear switches]]
[[Category:Tactile switches]]
[[Category:List of all keyboard switches]]