I was watching the course on the Hermle chiming clock. I understand well how the hooks stop the snail, how the self-correcting works, but what is not explained is what is keeping the snail from continuing to spin when the clock is placed in warning mode. The snail spins just a little and then stops, but nothing in the course about what is stopping it and exactly and how it is being kept there until the lever drops. Just says the lever drops and the snail spins. Where is the warning mode locking and keeping it from spinning until the lever drops?
The warn locking action takes place between the plates when the lifting lever rises up on the cam lobe. You will see two flags on the lifting lever that reach into the movement through a slot in the plate. I think the upper flag is the one that will intercept a wheel pin, stopping the wheel until the lifting lever drops off of the cam lobe. I don’t have a movement in front of me but pretty sure that’s what’s going on. Common warn function though.
Take a look at Video Part 3 in the Hermle Course from about 7:16 up through about 10 mins. and you’ll see the flag on the lifting lever. You’ll need a movement in hand to see the actual pin intercept but again normal warn function if I remember correctly.