Clever way of childproofing electrical outlets - Page 1
Forum section: electronics / general

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 07, 2021, 06:29:07 pm
content: Well at least until they learn about rotation...https://www.ebay.ca/itm/293113379855

author: jmelson
author_rank: Super Contributor
timestamp: June 07, 2021, 08:59:05 pm
content: Check the photo of the back of the package. This is before ZIP codes, so must be before 1963 or so.Note the units won't work with 3-prong outlets or plugs, as the hot and neutral slots are not centered in the cover plate pattern. These are almost certainly being sold as a collectible from yesteryear, not something for current use.Jon

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 07, 2021, 09:27:13 pm
content: Yes, I know... it screams the 1960s. But why did the concept fail? Must be easy to break or something.I mean we went for decades with those plastic outlet covers, only recently did I start seeing the ones with the built-in shutters.Having some sort of built-in external barrier seems reasonable, yet I've never seen it done.

author: Cerebus
author_rank: Super Contributor
timestamp: June 07, 2021, 10:09:55 pm
content: Quote from: Alex Eisenhut on June 07, 2021, 09:27:13 pmReally, only recently? Shuttered sockets (with the shutters operated by the earth pin) have been the norm here in the UK since BS 1363 was initially introduced in 1947.

author: edpalmer42
author_rank: Super Contributor
timestamp: June 07, 2021, 10:11:21 pm
content: Yikes!I looked up one of the patents listed. The application date was 1946. It was issued in 1950!Damn! That's older than me!https://patents.google.com/patent/US2498642A/en

author: Stray Electron
author_rank: Super Contributor
timestamp: June 07, 2021, 10:20:36 pm
content: Quote from: jmelson on June 07, 2021, 08:59:05 pmIt's older than that. I remember them from when I was a kid and I'm sure that that was from sometime in the 1950s. The three prong plugs didn't start making an appearance until about 1970 of so so I doubt that that is what killed off the shuttered outlets. I think that that was probably due to added cost of the shuttered outlet. Product safety didn't really become a "thing" in the US until about 1966 or 1967, particularly after the release of Ralph Nader's "Unsafe at Any Speed". After that Congress created all sorts of safety and public health agencies such as the EPA, CPSC and others.

author: nightfire
author_rank: Frequent Contributor
timestamp: June 07, 2021, 10:22:31 pm
content: Probably due to costs- those bulky units will cost probably some $$$ to produce.Maybe also operation is difficult after some time after ageing, so acceptance is low.Important thing: Unless you are in europe, where you have a symmetrical Schuko system, that depicted outlet will only accept two-pin plugs.Speaking for germany: in the 50ies this also was no big concern, as you mostly had only grounded outlets in the kitchen of a house (because of the bigger kitchen machines that required grounding due to lack of distance), in the rest of the house you had the concept of "isolated rooms".This meant that you had no central heating with metal pipes running through a room, and the wall outlet was a so called "Schweineschäuzchen (pigs nose)".Flooring was wooden, and regulations required a distance of (i think) more than 3 Meters between wall outlets.There you had simply L and N, and NO ground.Later then you had the concept of a PEN (combined PE and N), and since may 1973 only the modern 3-wire system is allowed due to VDE regulations.(My uncle built his house in 1956 and had it wired that way- one year later they installed central heating and forgot to switch the power outlets to proper Schuko with grounding)

author: themadhippy
author_rank: Super Contributor
timestamp: June 08, 2021, 12:19:18 am
content: Quoteand not long after the safety dogooders without a clue started flogging plug in covers that managed to make a perfectly safe socket into something unsafe

author: dmills
author_rank: Super Contributor
timestamp: June 08, 2021, 10:00:07 am
content: Quote from: themadhippy on June 08, 2021, 12:19:18 amI actually had an OFSTED (Education) inspector tell me a venue I worked at should be using those because we had some children's stuff going on.I got an extension lead and demonstrated why the things were an insane idea, which caused her head to explode, because they had been written into some standard for early years childcare!We were (for the fixed installation) using MK gear so you actually need all three pins in contact to open the shutters, but yea, them things be mad.

author: Cerebus
author_rank: Super Contributor
timestamp: June 08, 2021, 11:51:02 am
content: Quote from: themadhippy on June 08, 2021, 12:19:18 amI think the first time I saw the "safety" covers was in the 70s.To be fair, in the 60s and 70s there were sockets on the market that weren't as good as they should have been, on which with a little determined poking you could push the shutters aside by poking at the shutter in front of the live or neutral with something pointy*. However, the standard was revised to require a positive interlock with the earth pin so now the shutters won't open without the earth pin in place whereas before frequently (but not always) all that held the shutters in place was a spring and they were merely pushed aside by the earth pin. Ithinkthe requirement for a positive interlock was made in the same revision of BS1363 in 1984 as the introduction of insulated sleeving at the base of the live and neutral pins, but don't quote me on that.*Back before fitting moulded plugs to all new appliances was law, it was common for things to come with bare wire ends on the mains lead and you were left to fit your own plug. More than once I saw some genius wrap the bare ends onto wooden matches, often leaving the ignitor compound in place, and push them into a wall socket after finagling the shutters open. The culprit was usually in the building trade, the appliance was usually a hand-held power tool of some sort, and the earth wire didn't qualify for the matchstick treatment because they needed the shutters to close to hold the matches in place and so had to have the earth pin position unoccupied.Once upon a time, if I hadn't seen it for myself I'd have had difficulty believing that someone could bequiteso stupid. Nowadays, with years of experience of humanity behind me, I have no such problems believing that such idiots exist.