Alps SKCC series

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Alps SKCC series
Alps SKCC series -- infobox.jpg
Manufacturer Alps Electric
Introduced 1980 or earlier
Switch type Linear
Sense method Metal leaf
Switch mount Plate mount

Alps SKCC series (formerly known as Alps vintage tee mount) is the forerunner of the Alps SKCL/SKCM series, and shares the same switchplate design. The switch uses a tee mount, while keycaps use a cruciform slot. See also the virtually identical General Instrument Series S950. Production dates back to 1980 or earlier, and appears to have run to at least 1989.

Description

Conventionally, the pins are to the side of the switch instead of the front/back.[1] However, since the keycaps support all four orientations, some keyboards have the switches rotated by 90° with the same pin orientation as SKCL/SKCM,[2] and at least one keyboard used mixed orientations.[3] Mounting holes are 14 mm square.

The series dates back at least as far as 1979. Cream switches have been found in both a Radio Shack TRS-80 Model I and an Alps AKB-3420 with ICs dating from 1979, and the grey switches have been found in a Monroe calculator with ICs dating from 1979.

Full travel measures between 3.33 and 3.47 mm, based on a selection of cream, green and tall cream switches. This would be consistent with a specification of 3.5−5% mm.

The switch bears the oval Alps logo on the bottom.

Evolution

The design of SKCC series changed with time. Manufacturing lifetime appears to have had a substantial overlap with Alps SKCL/SKCM series: SKCC has been found with black, grey, tall white and short white switchplates. This implies that SKCC series was still in production in 1989.

Changes include:

  • Addition of a chamfer to either side at the bottom; this appears to be a very early change
  • The exterior recess in the base enclosing the terminals has had both straight and semicircular ends, as well being unbroken and later divided
  • Some batches used terminal sealant, which appears to be one reason for the recess in the base
  • Newer revisions featured a ridge in the base to hold the switchplate; this was retained after the change to short switchplates, when the switchplate no longer reached down to the bottom of the switch

Disassembly

The side tabs are much harder to unlatch than SKCL/SKCM series, and noticeably thinner, and consequently face a much greater risk of snapping clean off when trying to lever them open. When opening a switch, it helps to insert a thin object underneath the tab on one side, prior to opening the tab on the other side, to stop the tab on the other side from closing again. The cocktail stick method used with Alps SKCL/SKCM series is not possible with SKCC, as the ledge that rests on the mounting plate overhangs the tabs.

Variants

Few part numbers have been recovered. To date, there is tentative evidence to suggest that subseries "A" comprises the tall momentary switches, and subseries "B" comprises the standard height momentary switches. More data is required to confirm this theory.

The height of the black and grey variants have not been measured, and are unclear.

Slider and keystem height measurements are approximate and averaged from multiple switches, rather than being taken from any specifications. The keystem height is measured from the circular base through which it protrudes to the top of the slider. The keystem height is measured in the axis relative to the keycap, not to the slider motion (only different for side-angled cream).

Name Model Type Weight Slider height Keystem height
No photograph.svg Alps SKCC Black Momentary ca. 9 mm ca. 4 mm
No photograph.svg Alps SKCC Grey Momentary ca. 9 mm ca. 4 mm
No photograph.svg Alps SKCC Tall Black Momentary
Alps SKCC Cream -- variants table.jpg Alps SKCC Cream SKCCBJ Momentary 70 gf 9.7 mm 5.0–5.3 mm
Alps SKCC Green -- variants table.jpg Alps SKCC Green SKCCBK Momentary ~60 gf 9.7 mm 5.1 mm
Alps SKCC Tall Cream -- variants table.jpg Alps SKCC Tall Cream SKCCAF Momentary 70 gf 13.4 mm 4.7 mm
Alps SKCC Lock -- variants table.jpg Alps SKCC Lock Alternate action 9.6 mm 5.1 mm
Alps SKCC Cream LED.jpg Alps SKCC Cream LED Momentary illuminated 70 gf?
Alps SKCC Side-Angled Cream -- variants table.jpg Alps SKCC Side-Angled Cream Momentary 13.0 mm 5.5 mm

Unmapped part numbers

The following part numbers are known to exist (surplus stock no longer available), but no photograph exists of them and they have not been assigned to a moniker above:

  • SKCCAC

References

  1. Mousefan — TOSHIBA PASOPIA700 '85 Retrieved 2015-07-23.
  2. KBTalking — ■鍵盤史的遺跡Apple M0110A (ALPS凸軸)■ Dated 2010-12-03. Retrieved 2015-07-23.
  3. Deskthority — IBM 5954339