The assembly continues by reviewing the chronograph runners on which the second and minute hands will be mounted. This is the top of the central seconds runner where the heart is fitted. This is fine as are the pivots.
A detail of the teeth on this wheel, again these are fine.
And on the underside is the cam that will operate the minute counter.
That cam interacts with the runner intermediate wheel and it will turn one tooth every minute in a single step. All teeth and both pivots are fine.
Which will in turn, move the minute runner, on which the minute counter hand is mounted, once every minute in a single step. Both pivots and the teeth are fine on this wheel as well.
On the upper side, this also has a reset heart.
Here are the three parts, plus a tension spring for the seconds runner, mounted on the bridge.
This is the minute jumper and the right hand side will work with the wheel teeth of the minute runner.
And it is mounted on a post on the underside of the chronograph bridge – the spring tension here is important.
And fitted and the spring has clipped onto the flat side of the minute jumper boss.
The jewels and bush in the chronograph bridge are reviewed and these are clean and undamaged.
The chronograph bridge is fitted to the movement to support the pivots of these wheels.