In Minute Repeater: Minute Transmission Wheel...
Yes. Isobars, was too quick to respond - initially stating this component was found in the "Perpetual Calendar". In fact, this is a critical component in the "Minute Repeater" - just as he later posted.
I am no expert here - and don't have a Minute Repeater - just trying to spark some discussion. I would normally let this thread run its course for at least a day before jumping in - but since there was some confusion around the "Perpetual Calendar" - I did not want us to get off track.
Forgive my 'layman' explanation. I don't guarantee this is 100% accurate - but that is why I posted this - perhaps there are others with more subjective expertise.
The Minute Transmission Wheel helps "figure out" how many minutes to chime. As you know, the minute repeater chimes the hours, quarter-hours, and minutes. The Minute Transmission Wheel "tells" the minute snail how far to go - and helps stop the "minute snail rack" which counts the chimes. You can see this wheel outlined in the "Portuguese Minute Repeater Skeleton" here.
Additionally, there is a link to a YouTube video of this watch - where you can see the "minute snail rack" - which is a large component - swinging down under the bridges when the minutes are being chimed.
Minute Repeater Video

