SKCC double action [SKCCKB]

User avatar
zrrion

20 Sep 2019, 08:06

I pulled this out of a Cannon AP350X and I do not see them on the wiki. I can say, without any hyperbole, that these are my new favorite switch.

Image

First off, here is what I know or suspect about the switch:

1) These are in fact alps switches. They have an alps logo on the bottom and the PCB is also clearly branded ALPS.

2) These switches are double actuation switches. They have a second contact assembly embedded in the bottom of the switch that is actuated by a peg in the slider pressing down when firmly bottoming out. This peg pokes through the spring and makes it very easy to keep the spring in place when taking the switch apart.

3) They feel like a heavier SKCC switch. I do not have the tools to compare them with SKCC cream, but considering they are heavier than the greens used for the rest of the board, I suspect they may be similar in weighting.

and here I go with wild speculation
4) They are likely newer than SKCC but older than SKCM. I say this for a few reasons. The slider inside the switch is symmetrical and shaped more similarly to SKCM than SKCC. The other big thing that makes them feel newer than SKCC is that the top housing is symmetrical in a similar way to SKCM brown. It would not surprise me if ALPS initially tried to put two vertical switchplates in this switch but determined that there was no way to get a contact leaf on a vertical switchplate to actuate reliably on a hard bottom out and they ended up using a horizontal contact assembly molded into the bottom of the switch instead. The horizontal switchplate actually clicks when it is actuated so it is reasonable to assume that ALPS wanted the second actuation to be noticeable. It is likely that in the process of messing around with contact leaf shapes in an attempt to make the second actuation noticeable they likely happened on a leaf shape similar to brown alps and when making SKCM switches they included a second dummy assembly as a way to increase tactility and later a simplified leaf with all designs after brown alps. If all this is true it would mean that SKCL green and SKCM brown are for sure the oldest switches of that line.

5) The stabilized caps that use this switch (minus the space bar) use wire stabilizers that are almost identical to those used with SKCM switches, even though the caps support a rod-stye stabilizer in the same way SKCC does.

6) I don't think the switches I have are the standard switch type of the family they belong to. The blue marking on the top of the slider reminds me an awful lot of striped amber, and since these are pretty heavy, there likely exists an unmarked variety that is lighter.

7) These aren't different enough from SKCC for a single actuation switch to make sense, they are to different from SKCM to fit in with those switches either, and a few keyboards that use double actuation switches along side SKCC seem to use SKFF. SKFF had to have ceased production by the time these were brought out, but there isn't a lot of demand for this type of switch for it to be made without a specific client asking for it. I suspect that these were designed and made by ALPS for a specific client and weren't produced much outside of what that client needed. ALPS likely used this as an opportunity to get a client to basically pay for RND on their next proper switch design and the things ALPS learned when designing this switch likely lead directly to what ALPS did with the SKCL/SKCM line, including the switch to wire stabilizers on all keys.

If anyone has any information on these at all, a part number or anything they were used in besides the cannon typewriter would be huge. If you have a supplier that can get me like a thousand or so of these for sure hit me up.
Last edited by zrrion on 15 Jan 2022, 09:24, edited 1 time in total.

User avatar
zrrion

20 Sep 2019, 08:18

And this post is for pictures:

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The switch for the enter key, notice the wire stabilizer even though the [plate has a cutout that would work for a rod stabilizer

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The backspace cap with modern style stabilizers

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more wire stabilizer

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switch side

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switch side

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switch bottom

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The switch as disassembled as I am willing to take it. I don't have spares to sacrifice for a more complete tear-down

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The bottom contact plate, or what is visible of it with out taking it apart in ways that I do not think are reversible

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top housing

Feel free to use any of this on the wiki if someone decides to make a page for the switch. IDK what to even call them as a temp. name so I am hesitant to make a page for them.
EDIT: And here's an SKCC green LED switch to close with.
Image
Last edited by zrrion on 04 Mar 2021, 03:27, edited 2 times in total.

User avatar
ZedTheMan

20 Sep 2019, 08:45

Oh, I had found these just a few weeks ago, was talking about them on the discord. I personally call them Coral Blue #2 Semi-Gloss Alps Switch, due to the blue paint matching very closely to that color from the SpongeBob skit.

Great pictures, you are braver than I to have disassembled one!

Found mine in an AP350X as well. I hope some more info comes up on these oddities.

User avatar
Chyros

20 Sep 2019, 09:41

Most interesting, thanks for the write-up! Perhaps a model name starting with SKC and ending with a letter between C and L?

User avatar
CountNoctua

20 Sep 2019, 10:03

Chyros wrote:
20 Sep 2019, 09:41
Most interesting, thanks for the write-up! Perhaps a model name starting with SKC and ending with a letter between C and L?
SKCE?

"E" can also represent "electric blue".

HC514

20 Sep 2019, 11:22

This switch is already documented, actually. It's SKFF Double Action. HaaTa covered a later variant in this thread.

User avatar
Chyros

20 Sep 2019, 11:29

HC514 wrote:
20 Sep 2019, 11:22
This switch is already documented, actually. It's SKFF Double Action. HaaTa covered a later variant in this thread.
I don't think that's correct. This switch uses a C contact plate; SKFF's is completely different.

HC514

20 Sep 2019, 11:43

Yeah. Given the "special order" look of this thing then, maybe it was a temporary solution from before or after the availability of the SKFF equivalent., or maybe Canon requested a less clicky double action switch.

Edit: Regarding the model code, do note that SKCC is a family that comprises at least two distinct designs (momentary and latching). This is still similar enough to SKCC that it could be a kind of "SKCC Double Action" with a code like SKCCxx.

User avatar
SneakyRobb
THINK

20 Sep 2019, 19:08

Hi,
This reminds me of this patent I came across previously. Specifically the lower contact part. Where there are 4 legs in addition to the switchplate legs.

Not sure if this is helpful.
JPS58150232U.pdf
(226.81 KiB) Downloaded 188 times

User avatar
zrrion

20 Sep 2019, 19:31

That looks like it is the patent for this switch, like its a dead ringer. I'm not exactly able to read it though, which is a shame.

User avatar
SneakyRobb
THINK

20 Sep 2019, 19:36

The housing is not exactly the same, and it lacks the metal part on the top... but it does have that bottom part.

Not sure how it works though.

I also found this german version. Maybe someone can run it through a translator
DE3308989A1.pdf
(609.66 KiB) Downloaded 183 times

User avatar
SneakyRobb
THINK

20 Sep 2019, 20:07

Hi,

I think this should be the text.....

Spoiler:
Alps Electric Co., Ltd. - 3 lo. March, 1983
1

-7 Yukigaya Otsuka-Cho G-SW-1429 IG / Wo
Ota-Ku, Tokyo 145, Japan VNR Io2 741
Push switch
(Priority of Japanese Application No. 46644/82 of 31.
March 1982)
The invention relates to a push-button switch according to the preamble of claim 1.
The input and keyboards of computers and word organized registers and memories have a plurality of keyswitches. Here are once included push-button, which occupy the "on" position only when the button is depressed, but also operating in two-stage pushbutton, z. B. Tastabstandselemente, in word-organized memories and registers, which serve to move a position indicator on a Braun tube (screen) by the distance of a letter when the probe is exerted only a small force. However, these Tastabstandselemente allow a greater number of incremental distances to bridge when a relatively larger pressure force is applied to him. In general, push-buttons of this type are designed to have two contact mechanisms, referred to as the first and second contact mechanisms, housed in a switch housing and actuatable by a shaft-type actuator which is displaced in the vertical direction.
The first contact mechanism is actuated by the movement of the first stage when the button is depressed and the first stroke moves the shaft only a smaller predetermined distance. The second contact mechanism is actuated by the second stroke when the shaft is displaced by a longer displacement. becomes.
However, these switches are in need of improvement insofar as misalignments occur during the operation, since the force of the actuating movements for the first and the second stroke not
'5 are clearly distinguishable from each other. This is once due to the fact that the force exerted by the operator is different for each setting movement and secondly, that there are often cases in which the push-button is inserted too deeply during the first working stroke due to the individual sense of touch. In the latter case, therefore, the second contact mechanism (faulty) is operated instead of the first contact mechanism. Known switches are still disadvantageous in that their construction is still relatively complicated, are therefore expensive and their assembly is difficult.
· ' ■
The invention has for its object to provide a push-button switch for two different travel paths, in which the distinction between the pressure forces between the first travel and the second travel is more accurate and a special feel (click feeling) occurs when operating the second travel, so that erroneous settings are avoided , At the same time, the design should be simplified and the manufacturing costs are reduced.
This object is achieved by the features characterized in the patent claim1. Advantageous embodiments are shown in the subclaims.
There are thus two switching elements in the housing, in which the first switching element by the first stroke or Travel of the shaft is actuated. This is the smaller travel. The other switching element is by the second stroke or Travel of the shaft actuated. This is the larger travel, this is the hood-like movable contact piece is actuated. Since now such a force rests on the shaft which prevents its movement during the second travel, only a relatively small pressure causes only one switching element, namely the first-stage shifting element, to shift to the "on" position.
on the other hand, on the other hand, the other switching element, namely that of the second stage, is placed in the "off" position. On the other hand, the second-stage switching element is set to the "on" position by applying such a compressive force, which is now distinguishable from the force needed to actuate the first switching element to the "on" position. On the other hand, since the hood-shaped movable contact piece is reversed at the time in an advantageous manner, the click feeling is improved: it is possible to sensitively initiate the switching position for the first switching element and that for the second switching element by the pressure difference between them when the pressing force is applied also differ by the click-like feeling. Furthermore, it is advantageous that the switching movements can be carried out reliably, the reliability is increased. The push button switch is simpler in design and can be manufactured at a lower cost.
Embodiments of the invention are illustrated in the drawings and will be explained in more detail below. Show it:
Pig. 1 is a perspective view of the key switch
Pig. FIG. 2 is an exploded view of the key switch of FIG. 1. FIG
Pig. 3 is an exploded view of the switching element of the first stage 3o
Fig. 4 is a part of the working process to form the fixed contact
Figs. 5 (A), 5 (B) and 5 (C) are views for explaining the operation of the key switch.
According to FIG. 1, an upper housing 1 has a through opening 1a in the upper wall. From this opening la protrudes a shaft 2 and serves as the actuator for actuating the
Contact mechanisms. A lower case 10o has a bottom plate and vertically projecting side walls which are fitted into the side walls of the upper case 1. In Figure 1, the actual push button is not shown. The details of the push-button initially go from Figure 2. The Tastknopf3 has on its lower wall an opening for insertion of the upper end wall of the shaft 2 (opening not shown). The upper wall of the touch button 3 has a book bar or a symbol. Opposite side walls of the upper housing 1 have grooves Ib, while the end walls offset thereto have projections Ic. The shaft 2 is provided with a pin-shaped pressure piece 2a at the bottom, the GehäusIo facing the end. In this area there is a return spring 4, while laterally to the head 2b of the shaft 2 there is a leaf spring 5 with a holding part 5a of a nose 5b and one or more fingers 5c. A first switching element 6 is shown in perspective in FIG.
It has a setting part 6a made of synthetic resin, which is provided in the middle with a pressing part 6b, which is actuated by the shaft 2. Further, retaining projections (not shown) are provided at the rear lower end of the pressing member 6b. A metal-made movable contact 6c is provided with its frame 6ca and a terminal 6cd formed integrally therewith. The frame 6ca is provided with a thin metal plate 6cc. A resin-made partition 6d has a circular window 6da in the center of the panel. A fixed contact 6e has a contact piece 6ea in the middle and a terminal 6eb at the lower end of the latter.
These components are assembled as layers into one part. The retaining projections formed at the lower end of the actuator 6a are inserted into small holes respectively provided at the lower end of the movable contact 6c, the partition plate 6d and the fixed contact, and these retaining projections are detuned to form the first retaining member 6 from its component parts. A resin plate 7 is provided with small holes formed at both ends and a tube 7b in the middle. In the center of the tube 7b, a through opening 7c is formed.
• " * *■
A cup-shaped or hood-shaped movable contact piece 9 of elastic material, in particular of phosphor bronze is ■ provided in the housing. There is a circular depression 10a 'for supporting the movable contact piece 9 in the inner middle portion of the lower case 10o. Furthermore, latching parts lob, preferably in the form of brackets or arms, are present around the lower housing Io with the upper housing 1 to: connect; also holding pieces loc to the push button according to the invention to the chassis or the like. to fix. These components are arranged in opposing positions on the circumference of the lower housing Io, respectively. Further, a through-hole iodine is provided to receive each terminal of the first switching element 6. There is a mounting projection loe, see. Fig. 2, available. Furthermore, a fixed central contact j 11a with terminals 11b, and edge contacts 12a, 12a with an-! whose connection terminals 12b, 12b are connected, which are embedded in this recess 10a, and together with the movable contact piece 9, a second switching element 8 of the second stage
form. ;
A contact plate 13> cf. Fig. 4, is punched out and is shown in the position in which it is in the lower housing; Io is embedded to form the fixed contacts 11a, 12a and 12a. The terminals 11b and 12b are formed by cutting and bending down the end portions of the contact plate 13.
The push-button switch is mounted as follows: First, the movable contact piece 9 is inserted into the recess hole of the lower case 10 and brought into contact contact with the edge contacts 12a. The holding plate 7 is inserted into the lower case 10, the mounting bosses 10e are inserted through the small holes 7a, and then the ends of the mounting bosses 10e are fixed to fix them. Then, the first switching element 6 is inserted into the lower case Io. In this case, the terminals 6cb, 6eb of the switching element 6 project outwardly beyond the through holes Iod of the lower case 10a. The holding part 5a of the leaf spring
5 is at the upper end of the Sohaltelementes 6 for the purpose of assembly; arranged. Then, the return spring 4 is inserted into the tube 7 b of the holding plate 7. After the pressure piece 2a; 5 of the shaft 2 in the upper end of the return spring 4 inserted! is set, the upper housing 1 is placed on the latter, then the upper end of the shaft 2 projects beyond the opening of the upper housing 1 to the outside. Further, when the upper case 1 is inserted, the projections Ic of this case come into engagement with the holes in the detents Lob I of the lower case 10, so that the upper and lower housings are united. Further, the push button 3 to the upper; End of the shaft 2 is fixed and the key switch is ready to contribute. This state is now shown in Figure 5A in an I 15 side section, the switch is completely monitiert.
The key switch operates as follows: The state in Figure 5A shows that all switching elements imi 2o state are "off". When, in this start or rest state, the shaft 2 is now depressed, the shaft head 2b of the shaft 2 pushes the leaf spring (clamping plate) 5 * with the finger or fingers 5c so that the pressing part 6b of the first-stage switching element 6 is in the direction of the figure after 25 goes right. Consequently, the fixed contact 6e and the movable contact 6c of the switching element 6 come into contact with each other with the result that the switching element 6 is in the "on" state. If the shaft 2 is depressed further, its pressure piece 2 a comes into contact with the movable contact piece 9, and if now the operator continues to press down the shaft 2 further
But now that his fingers are subjected to a relatively strong tension due to the elastic force of the movable contact piece 9, the operator hesitates
; 35 Lower the shaft 2 further. Therefore, here is a kind stop in the adjusting movement, cf. Fig. 5B. When the operator's fingers are lifted off the shaft 2, the latter moves upwards under load of the return spring 4 and causes the first shift element 6 to move in the direction of the load.
stand "off" comes, so that the first switching stroke is completed, Fig. 5A. Will now the operator in the second Sehalthub (second switching position) change, he presses again on the shaft 2 according to state Fig. 5 which takes place against the elastic force of the movable contact piece 9, but with the result that the movable contact piece 9 now tilts, i. with respect to its convex surface, reversing and allowing the stem 2 to be further pressed down and moved to the position Fig. 5C to come. Consequently, the movable contact piece 9 is brought into contact contact with the central fixed contact 11a and the second switching element 8 comes to the "on" state. When the operator removes his fingers from the stem 2, the stem 2 moves, both under
effect of the return spring 4 and the movable contact piece 9, upwards, with the result that the second Schaltjelement8 goes into the "off" state. In a preferred; Embodiment, the compressive force values for the first shift position and that for the second shift position about 6o g or 5oo g.
blank page

User avatar
CountNoctua

20 Sep 2019, 20:45

Is that last bit saying it takes 60g of force for the second actuation?

User avatar
zrrion

20 Sep 2019, 21:20

It looks like it is 60 for the first and 500(!) for the second. Idk if that second number is accurate, but it doesn't list tolerances so who knows. The 60gbsounds right though.

User avatar
SneakyRobb
THINK

20 Sep 2019, 21:29

Hi,

The second actuation force could very well be correct. (edit)
http://www.firstpr.com.au/rwi/tr-808/TR ... e-card.jpg

if you see the switch type in the second column just about half way down 10904 "KHF" switches

The second actuation force can get quite high

User avatar
SneakyRobb
THINK

22 Sep 2019, 23:18

Hi, are you able to take the bottom part apart?

User avatar
zrrion

22 Sep 2019, 23:53

probably, but it looks like it is held together with plastic rivets and if I took it apart it would likely destroy the switch. If I aver get ahold of some damaged ones or if I find a large supply or something I will take apart the bottom contact and see what is inside of it.

User avatar
SneakyRobb
THINK

23 Sep 2019, 16:35

Hi

Ah yes makes sense you mentioned. Obviously you should keep it together then.
I hope to find one of these switches then to disassemble. That lower contact mechanism is neat.

There are quite a few patents from alps in the 70s and 80s time frame where they have large variation in sensing method, springs etc before they really close in on the SKCM format.

The earliest patent ive seen for the alps contact foil mechanism "sandwhich" is 1976 if I recall correctly.

I think we have many more years of unusual and strange alps switches turning up.

User avatar
zrrion

26 Aug 2020, 20:23

Bit of a bump, but a while back I got ahold of the older version of this typewriter that used SKFF and the similarities between this and the double action SKFF are interesting. The slider shape and mount (at least what is outside of the switch) are very similar and the inside of SKFF does house 2 verticval contact assemblies. ALPS likely tried that with this switch but decided on the embedded blister switch on the bottom for unknown reasons. At this point I feel that this switch was made for Cannon specifically so that they could continue using the same designs that relied on double actuation switches in their newer typewriters, and the same may also be true for the double action switches found in other Cannon typewriters. Apple used some SKFF double action alongside tall SKCC so I feel like if these switches were a normal thing for ALPS to produce we would have seen them used by Apple. I'm also pretty sure the reason APPLE uses tall SKCC is so that they match in height with SKFF, there would be no reason for tall SKCC to exist if there was a double action switch from the start of the SKCC line's production, further supporting the idea that Cannon requested these specifically.

I still don't have any leads on other sources for these switches or any concrete info at all really. I'm hesitant to call them SKCC double action as they don't appear to have been developed at the same time as standard SKCC but unless I somehow get some concrete information on them that says otherwise I guess that is as good a designation as any.

EDIT: I remembered this while looking at this thread and remembered we actually know what the 2 letter code for double action switches is so I've edited the OP's title to reflect that knowledge. These are SKCC series double action switches, which makes them SKCCKB.

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