Blind pulley chord mechanism

Hi All,

I went to rotate one my blinds last night (just before bed d'oh!) and the blind chord that you use to rotate the horizontal blind slats from open to closed has stopped working. (Just so I'm clear - this isn't the mechanism that you use to lift the entire blind up).

I pulled the mechanism out to see if I could get it to work... but I think the chord pulley gear mechanism must be knackered - it works fine without any load on the pulley mechanism but doesn't work when the blind is hanging up in the window and has weight on it.

I've had a quick look on-line to see if there's an obvious replacement - however I'm not really sure what these things are called or where to find them?

The mechanism in the blind looks like this:



and removed from the blind looks like this:



Could anyone help on where to get a replacement??

TY,

Z