Denes_Papp
162
An elegant solution #3
The Breguet rotor wrench arrived and finally I was able to to get close to the coupling wheel in question.
From the beginning I was suspicious that the coupling wheel is more elaborate then it looks.
My suspicions were correct!
It is actually two wheels stacked and sharing the same pivot. The top wheel meshes with the chronograph driving wheel and the lower meshes/engages with the chronograph seconds wheel.
In addition the two wheels have differing number of teeth. Top 60 teeth and bottom wheel 80 teeth.
This arrangement rewrites the traditional horizontal coupling arrangement by separating the driving wheel and the chronograph seconds wheel by a flexible wheel arrangement. Also with having different number of teeth I assume the coupling to the second wheel much more smoother.
In order to fit this arrangement to the existing Cal. 582 design the chronograph driving wheel was raised about 0.5mm, it meshes with the top LIGA wheel that has 60 teeth and the bottom 80 teeth wheel meshes with the chronograph seconds wheel. This arrangement allows the wheels connected and flexible.
I do not have hands to this movement, but I am looking for it. So currently I can not check how much this actually translates in actual smoothness of starting of the chronograph hand.
Denes
An elegant solution #3
The Breguet rotor wrench arrived and finally I was able to to get close to the coupling wheel in question. From the beginning I was suspicious that the coupling wheel is more elaborate then it looks. My suspicions were correct! It is actually two wheels s...
This is also how oscillating pinions work, two different sets of teeth
It's also (rarely) done on normal lateral coupling system, like some of VC's ...
The real mystery
What I really do not understand this arrangement being a really radical solution. In order to accomplish the stacked wheel coupling, they had to redesign several parts of the chronograph mechanism. Not only the coupling wheel bridge, also the coupling yok...
a completely new concept to me - thanks for going the distance and sharing.
I'm kinda curious, what is a watch chop shop? Hard to imagine that gutting a Breguet for the gold in the case would be the best value....unless it's stolen, I guess..