Richard Habring on Chronograph Minute Counters

Hi Fred,

Thanks for your kind words and your kind understanding! I’ll try to make the answer as short as possible: Actually we even offer both versions:

A classical semi-instant (paused) minute counter (in subcounter) in our Doppel-Felix; Doppel 3; Chrono-Felix, and a continuous minute counter (from the center) in our Doppel 3.1.

My explanation for the existence and usability of both includes not only the technical solution in the background, but as well the position of the minute counter in the movement.

Usually (the classical solution) a minute counter is positioned in a subcounter the diameter of which is limited. While the reading of a total of 30 or 45 mins. is convenient, the reading of 60 mins. turns out to be difficult when the counter is only about 10mm in diameter.

The optimal reading of minute counters is proven to be in the movement center, concentric to regular hour and minute hands. But this concentricity requires (design wise) a 60 minute interval, otherwise the design of the watch/dial gets crowded.

While 30 and 45 minute counters are usually driven directly by the mentioned spring on the chrono seconds wheel, the driving of a 60 minute counter turns out to be a little more difficult.

Here is the example of our chrono in the non-pusher-version (COS) with 30-mins. counter. [For those unfamiliar with Habring’s work, COS refers to Crown Operated System, in which all chronograph functions are accessed though the crown. FH]

The minute counter wheel has 30 teeth which are switched forward every time the finger of the center seconds passes by. Consider if the counter wheel contained 60 teeth instead of 30, which would lead to teeth half the size shown. The small teeth, however, are basically not the problem. What might turn out problematic is that with smaller teeth the angle between one tooth to the next shrinks as well.

By just adding such tooth wheels (double teeth) to our existing movement we would end up with the problem that the center seconds wheel would switch two teeth forward instead of one. The logical solution therefore would be to reduce the penetration of the finger towards the intermediate wheel. But then everything gets too small, and the tolerances too high, which might lead to an unsecure function.

Therefore the solution of our 60-minutes counter is completely different:

Our 60-mins.-counter is positioned under the dial (since the minute counter wheel needs to run concentric on top of the regular hands). It is driven not by the chrono-seconds wheel from the center (which is on the other side of the movement) but from the second wheel of the train gear (pos. 7). Since the second wheel turns all the time (whether the chrono is activated of not) we have to add a full clutch system with a lever and more wheels as known from the classical chrono function.

And here is the basic answer to your question: The choice of semi-instant driven or continuous is mainly influenced by the technical solution of the very particular minute counter, it’s position, and the space around and (maybe) the very particular preference of the (movement) designer.

Please feel free to short (if needed) and modify this answer for posting it further. Don’t hesitate to re-ask if I remain unclear.

Best 

Richard

P.S. Another one for your list:

Calibre 630 (Meca-Quarz Hybrid) by Jaeger-LeCoultre: continous (sub counter)

The Nivrel, GP and Eterna all featuring the same chrono-module either by Dubois-Depraz or ETA (2984 which basicly a copy of the DD)

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I was so impressed with Richard's generous response. But not surprised. Two summers ago I had a delightful correspondence with Maria, and everyone I've ever heard comment on the pair has spoken of their friendliness and generosity. SO… should questions remain, or arise, I'll be happy to take this discussion further.

And thanks to all of you for your support of my curiosity!

FH