A friend has a problem with one of his conservatory blinds - it won't stay up!
The cord lock consists of a brass toothed roller which is in a slot and this jams the cord. It usually jams one and lets the other slip. I noticed the other blinds in the conservatory are the same basic design - but the roller is sectioned into about 6 thin discs - so it has a better chance of gripping each cord.
If anyone understands what I mean then do you know a source of spares? The whole thing is in a transparent housing which slots into the metal channel.
As my friend is over 60 miles away, I would like to try and obtain a part and then go over with it.