Hour does not increase on Solari Udine School Clock

[Joker223]

Hello there,
I hope you can help me! I'm new to this forum so bear with me if I am in the wrong section or something...
My school wanted to dump their old clocks its a Solari Udine Cifra 6 (receiver) (serial is 15099 patent number is723779-9505B/67).
Seeing the piece of art it is I saved it from being dumped and took it home.
It does not have an active clock mechanism itself to keep track of the time, rather it gets a 12V inverted pulse every minuted that will make it progress by one minute.
I build an H-Bridge to replace the original timekeeper that I was missing.
That so far seems to work fine. Whenever I send a -12V/12V pulse the flywheel-thing turns and progresses by one minute.
My issue is, that after a full hour the hour-page will not turn. Even after looking at it for hours I cannot figure out how the original mechanism was intended to increase the hour wheel.
I can observe a bar being pushed away by the minute wheel, which unlocks the hour wheel and makes it spinnable. But there is no mechanism to be found to push the hour forward
(except for the manual one which works fine...)
I really want to bring the device back to life and would appreciate some help of any kind!
Best regards

Dennis

ps. In the attached video I speed up my pulse signal for presentation purposes:

[Mackey]

Moved this topic to the appropriate area (but that's not a big deal).
Have you made any progress. I haven't had a Cifra 6 in my hands. But I'd bet there's a spring missing somewhere. It seems that I recall a mechanism that as the minutes turned it drew back an arm that was released under spring pressure and pushed the hour wheel forward. But I honestly have no idea. Do you have a picture of the hour side of the mechanism?

[themightycuin]

Hi Dennis - I've resolved this issue on a cifra 6 I purchased off eBay - there is a ratchet and pinion which pulls the hours forard on the hour, but the pawl is made of acrylic so the springiness goes and it doesn't re-engage with the gear any more. I fixed it by gluing a piece of elastic band from the back end acrylic pawl to the spring return peg above it. It doesn't need to be particularly tight, just enough to overcome the resistance of the pivot itself. Worked like a charm - just waiting for a 24V driver myself to get mine fully up and running.