Pull cord reposition

[securespark]

I like putting the MK unscrewable doobries at the top. Then when the cords are filthy, you can unscrew the whole cord and acorn and put them in a bowl of bleach water to get them clean again.

 

[JohnW2]

Well surely the cheaper version would not include the plastic insulator,....

The plastic thing replaced the the previous brass thing. Since the brass thing was obviously not an insulator, the original idea can't have been anything to do with insulation and may well have been there for the reason that I and morqthana have suggested (ease of replacement) - and that original idea may simply have persisted when a cheaper material (which happened to be an insulator) became available?

to maximise profit make the pull switches sealed units so total replacement is required when the string needs replacement - just like so many other components these days.

Sadly, that is only too common these days - but it was much less of a way of thinking all those decades ago!

 

[SUNRAY]

The plastic thing replaced the the previous brass thing. Since the brass thing was obviously not an insulator, the original idea can't have been anything to do with insulation and may well have been there for the reason that I and morqthana have suggested (ease of replacement)

Which I have already mentioned.

For what it's worth the early pull switches in their early designs were made in a way that the cover was easily unscrewable and the replacement string easily EXTREMELY EASILY knotted to the lever, in fact it was easier than the fiddly little plastic insulators, we see now. Or some models/makes had a length of metal chain and the string tied to it.

Then someone came up with the idea of an external join rather than remove the switch cover and a 2 part brass fitting was used.

 

[morqthana]

Who said anything about distilled water?

You did:

Water vapour will condense/settle in/on the nylon cord.

Where is this ficticious distilled water coming from?

Please don't try to persuade us the moisture in the bathroom miraculously goes through some form of distillation process while you have your shower.

It's not a miracle, it's chemistry.

In addition to the damp atmosphere; the bathroom is full of contaminants: Hairspray, deodorants, antiperspirant, towel fluff, dead skin just for starters and according to you; the strings get so dirty they have to be replaced on a regular basis.

The cords get dirty at the bottom, where people touch them. And a lot of the "contaminants" you mention are insulators.

So now let's get all of that crap clinging to your switch string and inside your switch wet...

So you're suggesting that there's so much water inside the switch that current will flow to the cord (which is not in contact with any electrical parts), and then down the cord to a person, and that enough current would flow to be dangerous.

Sorry, but a polite word for that is "nonsense".

For what it's worth the early pull switches in their early designs were made in a way that the cover was easily unscrewable and the replacement string easily EXTREMELY EASILY knotted to the lever, in fact it was easier than the fiddly little plastic insulators, we see now. Or some models/makes had a length of metal chain and the string tied to it.

Then someone came up with the idea of an external join rather than remove the switch cover and a 2 part brass fitting was used.

And that idea was so that people didn't have to open up the switch to replace the cord. That was the safety measure - removing the need for people to fiddle around in close proximity to live terminals, and I'm with JohnW2 - the change from brass to plastic was to save money, not because they decided there needed to be an insulator in the cord.

 

[Harry Bloomfield]

Wrong, lets install a plastic insulator... the single chamber was so small the 2 bits of string were in solid contact so MKII version was 2 chambers, no more shocks.

I'm sadly old enough to remember these progressions and also one of my duties on BT included a safety project restoring pull switches back to original (we used thousands of them in exchanges) where string would break and be casually repaired with random string, waxed lacing twine or wire and some equally random knot, usually directly onto the string above the insulator.

Mmm, now you mention all those..!

Except I cannot agree with your idea of the nylon string becoming conductive, due to condensation. Condensation, requires a notable difference in temperature to occur - nylon will quite rapidly acquire the temperature of it's surrounding air, it has near zero thermal mass. A plastic moulding costs just a fraction of the cost of the brass item, a bit of nylon string, a fraction of the cost of a metal chain.

 

[Mottie]

OK. I was trying to avoid conductivity on the cord. That was part of the reason I went with the cable clip instead of the eyelet screw.

NutJobs fault for this thread going on and on and on…

 

[DiyNutJob]

I like putting the MK unscrewable doobries at the top. Then when the cords are filthy, you can unscrew the whole cord and acorn

What exactly is an MK unscrewable doobries? This kind of heavy duty modding is the perfect excuse for the insurer to not pay when your house burns down.

 

[securespark]

What?

It's less of a "mod" than that which you are doing.

Get real man and give your head a wobble.

 

[JohnW2]

Which I have already mentioned.

You have, hence my point/question ....

... you appear to acknowledge that they came up with the idea of an (initially brass) 'external join' in the cord to facilitate its's replacement (and length adjustment'), without the need to fiddle about inside the switch. So why do you seem so sure that when cheaper materials came along (which happened to be electrically insulating) the reason for the join suddenly changed from the prior one to 'insulation'?

 

[securespark]

The afore-mentioned MK ones were even easier. They had the screw on/ screw off detachable part.

 

[Mottie]

detachable part.

Doobries. Please use the correct terminology.

 

[securespark]

Doobries. Please use the correct terminology.

I doff my cap to you, Squire, and apologise profusely.

 

[DiyNutJob]

The afore-mentioned MK ones were even easier. They had the screw on/ screw off detachable part.

So MK unscrewable doobries can be unscrewed? I misunderstand that it cannot be screwed, therefore there wouldn't be a need for unscrewing something that isn't screwed..

 

[securespark]

Well, some things can be screwed up that are not intended to be unscrewed... They are tamper proof.

 

[JohnW2]

It's not a miracle, it's chemistry.

Given that it's the weekend and that this thread is already way off the OP's question ....

... that raises an interesting, almost semantic, question. Whilst it is Tue that Chemistry and chemists make a lot of use of distillation, I think I would describe is as Physics, rather than Chemistry - although I accept that the two disciples ultyimately converge, anyway.

Anyway, in terms of the point we've both made, it is certainly true that Sunray was the first one to mention (the concept of) distillation, even though he didn't seem to realise that he had