We have VERY large sash windows and the meeting rails are 2200mm off the floor. They're a pain to operate even for me. Now that's not a serious problem in the main part of the house because the windows don't get opened that much, but the bathroom windows do.

Having completely refurbed it I'm about to refit the large bathroom window and plan to seal the bottom sash closed, because who wants passers-by to see into their bathroom? but leave the top sash operating, using a similar idea to the old Cambridge fastener which operated on a series of pulleys.

My idea is simpler. Run a looped cord through a pulley located in the head of the sash frame and run it to an eye on the glazing bar of the top sash where the cord will be fixed, down to another eye on the bottom sash through which the cord will run free, allowing you to open or shut the window with the cord.

Anyone aware of any convenient joining thingy that would make a neater job than just melting the ends of a length of nylon sash cord together?

(I saw something almost identical, well the traces of such a system, on an extremely old sash window I once worked on, but that worked with a single cord because the window had no balance weights, the bottom sash was fixed and, because there was no parting bead, the top sash ran against it. The cord carried the whole weight of the top sash once its catch was released. Must have been fun if you lost your grip!)

Figure of eight knot, works for me when climbing, told a couple of stop knots work too.

Picking up on Colin's idea how about ferrule crimps, the sort used for wire rope. They are usually used for crimping two ropes side by side but end crimping may be a possibility with a longer crimp. Alternatively, possibly use rope instead of woven cord and then you could do an "end splice".

Mike

Ha ha. Mike, you're as industrial as Steamy!

Had considered an end splice, but I simply don't have the skill to make a good enough job of it, certainly not good enough to have any kind of guarantee that it wouldn't come apart with dire consequences when SWMBO's using it.

I rather like Cwatter's idea of a shrink-sleeve because it will assume the outline of the cord's weave.

Thanks for all the entries though.

Don't know where you can get those safe-break couplings now, Will. Ebay certainly doesn't have any and googling for them just pulls up items for safe caravanning!

Ha ha. Never, ever, had to measure the stuff so wouldn't know off the top of my head.

OK, just climbed up to the window in here. It's standard pre-stretched nylon sash cord @ 6mm.

What have you discovered?

I lost the ebay link , it was this kind of thing but cant remember exactly who it was I got them from http://www.ebay.co.uk/sch/i.html?_kw=blind+chain+break+connector

No good for 6mm cord tho!

There is a lot of tips on the ROSPA website about toddler deaths and window cords, http://www.rospa.com/about/currentcampaigns/blindcords/

Contrary to my other post, they dont recommend cutting cord loops
"It is hoped that a voluntary agreement among manufacturers and retailers will eventually see an end to looped blind cords altogether. In the meantime it is essential that they are fitted with some form of safety device such as a chain/cord-break connector, chain/cord tidy or cleat."
"RoSPA does not recommend that cords are cut, even as a short-term solution. It is advisable that any action taken on the blind cord is a permanent one which will take the cord out of reach of children. "

Not quite what your after, but they may know:
http://www.savacable.com/pages/prod_02_04.html

Found it Joiner; two types 12.7mm and 9.5mm in clear, both with a 3:1 max shrink ratio. I can't vouch for the strength when under tension, so you may have to double up on the join. Whisper me your address and I'll mail you a bit of each to play around with.

Mike

My pleasure, done!

You could make a large grommet.
A grommet is formed by carefully unlaying a length of traditional 3-strand rope and then re-laying one of the strands into a continuous ring, tucking the ends in as in a splice.

To avoid waste you could use all three strands, staggering the ends around the circumference of the final loop.
There would be no ends, no join, just continuous rope.

You could just use a small rotary hand winch. Takes all the strain, even tension.

Joiner, Your say:-
run it to an eye on the glazing bar of the top sash where the cord will be fixed,

Could you not fix the join in the cord to the glazing bar with a cover piece of brass tube? it would look like a continuous loop and the join would be covered?

Posted By: Joiner(Can't find the brass 'eye'.)

I realised that this is sorted, and I can't point to a brass 'eye', but maybe a brass sash handle would have been enough for the fanlight hook hook to pull/push?

http://www.screwfix.com/p/sash-handle-polished-brass-pack-of-5/54422

I've never used one with a sash, but I have found them handy for lots of other little jobs that need a small handle.

Joiner when you said:
"Went into the local small hardware shop, the type where you expect to see Ronnie Barker behind the counter,"
I fully expected the "Four candles" sketch