Jaeger-LeCoultre

stromer
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Let me try again

Hi Stefan, hi Stefan's son!

D..., I always mix up the "Insert" button and the "Igame uploader" link.............. Sorry for the first post.
So here we go again:

Basically I know of three reasons to put two (or more) barrels into a watch:

1. You want to drive different things in the watch independently like in a DuoMètre, a Minute repeater or something similar.

In this case the crown wheel (red) would drive the click wheels (blue) together or independently (like in a DuoMètre, where turning the crown in one direction winds one barrel and turning it in the other direction winds the other) and thus wind the barrels (orange). Both barrels would then run independently turning their loads (green)


2. You want a lot of torque for driving something big.

In this case the crown wheel would turn both click wheels in parallel winding both barrels at the same time. The two barrels then operate in parallel, joining their torque to drive the load (green) together. This will increase the torque, not the power reserve as both barrels are operating all the time at the full speed required by the load. It is comparable to operating two batteries in parallel.


3. You want a long power reserve (as in your Reverso Grande GMT)

In this case the crown wheel operates on the left click wheel only. As soon as the main spring in left barrel is wound tighter than the one in the right barrel, the barrel will start to turn in the same direction as the click wheel. So in this moment the left click wheel/barrel combination starts behaving a little like a single gear wheel. (We are still winding the watch.) Because the left barrel it is connected with the right click wheel by an intermediate gear the red crown wheel is now driving the right click wheel (blue) also and thereby winding the second barrel (orange).

During normal watch operation the right barrel will have the task of driving the load (green). The left barrel assumes the task of turning the click wheel of the right barrel and thereby helping to drive to right barrel. Sounds funny? Let's assume that both barrels have the same specifications: Then the rotation of the right barrel will be driven in equal parts by two sources:

• The left barrel drives the right click wheel through the intermediate gear.
• The main spring within the right barrel turns the barrel agains the right click wheel.

A more space economic way to implement the serial double barrel scheme is to leave out the intermediate gear and turn the right barrel upside down. But the principle remains the same;