Breguet

Dear All,

 

Following on from our recent consideration of the anatomy of the La Tradition, below is a labelled image of the anterior surface of the Breguet 7027.

 

Andrew

I'd make only one change, make the "intermediate wheel" label a bit more specific, indicating that it is part of the keyless works
a

Hi Aaron,

 

It was our ‘discussion’ on this Forum and your overlayed images the other day that helped me add some more pieces to the puzzle. I really appreciated and enjoyed that.

 

The keyless works are quite complicated (and rather more hidden than the going train on the front) and I wasn’t sure about calling this an “intermediate wheel”, but I suppose it has that function.

 

I will post the reverse of the movement shortly.

 

Cheers

 

Andrew

Thank you very much!
Regards,
Vince

No message body

Fantastic pic and work...

You surely made the day of All 7027 owners!

Thanks for all these explanantions.

Nicolas

Hi Nicolas,

 

Thanks for your kind comments. When you start looking closely at the La Tradition, what seems initially simple is actually rather complex.

 

I do not understand that power reserve system on the back of the watch, nor the keyless works as yet.

 

It’s like a jigsaw puzzle and dissecting it in this way makes me appreciate the watch even more.

 

Regards

 

Andrew

Hello Andrew,

Watchmaking nomenclature is notoriously inconsistent, sometimes even within the same company. Do the labels above come from Breguet CH?

_john

Hi John,

 

This labelled diagram is just the work of an amateur enthusiast trying to understand the anatomy and physiology of the La Tradition. I acknowledge that nomenclature may vary, but these parts at least mean something to me! Would you have any additions, corrections or other suggestions? Any help would be much appreciated.

 

I would love to have some diagrams or an exploded image of the La Tradition but I have never seen anything like that from Breguet.

 

Don’t worry, I am not planning to design my own watch or open a watch repair business; the world of horology is safe for a little longer!

 

Cheers

 

Andrew

Andrew,

Thanks for the labels  -  they mean something to me too.

In the Land of the Blind, the one-eyed man is King. Unless we have better examples, this anatomical diagram will do for me! 

Over to ei8htohms.........

Regards,

MTF

Thanks MTF.

 

John does raise an important point about standardized nomenclature. You and I know the importance of this in the medical field when communicating with colleagues.

 

Not really life-threatening, but you wouldn't want to get your third wheel mixed up with your fourth...

 

Andrew

Hello Andrew,

Any labels I can offer will also be subject to debate of course since I don't have any official word from Breguet, but I think these changes would make it more easily understood by most watchmakers at least:

"main  wheel" =  barrel, the toothed portion of the barrel is sometimes referred to independently of the barrel in some manner, but most frequently the barrel is referred to as a single piece.  The components of the barrel might be the barrel drum, the barrel cover, barrel arbor and mainspring

"transfer wheel" - I'm not sure there is a good consistent way to refer to this type of wheel, but transfer wheel may be as good as any.  In the article I wrote about the Union Glashuette Julius Bergter Small Seconds, I called the pinionless wheel in that power train the "second intermediate wheel", which is surely not the best thing to call it by any stretch.  Intermediate wheel is generally a safe thing to call just about any wheel between two others without a clearly identified name however, and transfer wheel sounds good to me too.

"centre wheel" - I can't go there for this wheel for obvious reasons.  Some manufacturers used to refer to this type of wheel as an "offset center wheel", ETA refers to it as an "intermediate wheel" (clever) and most modern manufacturers refer to it as a "great wheel" (the likelihood of it being confused with a great wheel in a fusee power train is minimal in this day and age).  No idea what Breguet calls it.

"third wheel" - Agreed.

"fourth wheel" - This is clear to most English speaking watchmakers, although whether it is British or American nomencalture originally is unclear to me.  Most Europeans refer to it as the "seconds wheel" or even "second wheel", which can be very confusing to us yanks, where "second wheel" very often meant "center wheel" (great wheel), being the second wheel in the train after the barrel.  It's possible our European brethren are counting the escape wheel as the first wheel in the train, but more likely they're referring only to the fact that this wheel generally carries the second(s) hand.  In this instance, it does not carry the second hand and may or may not turn once per minute, but I think I'd still call it a seconds wheel.  Fourth wheel is not completely unclear though, as mentioned above.

"spring stud" - This label is pointing to the movable stud carrier, which of course carries the stud itself.  Breguet appears to be using a Geneva stud-style mecahnism here a la Patek, Vacheron, etc.  The "movable stud carrier" label is actually pointing to the locking screw for the movable stud carrier.

"intermedaite wheel" - This term is generally safe as I mentioned above, but also not very descriptive unless the manufacturer has used it on some technical documents and it's the only intermediate wheel identified on the movement.  This is probably a setting wheel of some sort (used to set the hands), and in such case "intermediate setting wheel" would be more descriptive, but I really don't know if it would be correct.  Barring the use of Breguet's actual terminology for this wheel, I would resist referring to it at all if possible, to the point of pretending it is not really there or, if pressed, being as non-technical as possible, "You know, that little wheel to the right of the dial!" 

Regarding the picture of the back of the movement, I think the vast majority of the labels are more descriptive and helpful than confusing, with the exception of "crown wheel".  When more than one wheel is present between the winding pinion and the ratchet wheel, only the first wheel is generally referred to as a crown wheel, all others being "intermedaite crown wheels" or "winding wheels" or something of that sort.  If Breguet does in fact refer to it as the crown wheel, then so be it.

"detent spring"  -  More commonly referred to as setting lever jumper, but to American and English watchmakers detent spring is clear too.

Thanks for taking the time to create these labelled pictures.  I'm sure many Tradition owners will get a lot of pleasure out of learning what to call some of the bits they can see through the front and back of their watches.

_john

John,

Thanks for the patient explanation to us bozo-s.

So....ze 4th wheel is ze seconds (or second) wheel? 

And ze Great wheel is no longer great...or at least not to be confused with ze once great fusee wheel......

 

Hey! we have the something similar in Medicine:

The toe bone is connected to the foot bone that is connected to the ankle bone that is connected to the shin bone that is connected to the knee bone that is............you know the rest! 

Best regards,

Melvyn

This message has been edited by MTF on 2008-07-26 18:36:18

Dear John,

 

This is brilliant, thanks so much. I have an even clearer understanding of these parts now. I will update the images and labels and post again shortly.

 

As I mentioned in my post above on the reverse of the La Tradition, I am still confused by the workings of the power reserve and the keyless works as well as how the hour & minute hands are getting their information from the gear train – is this via the third wheel, the “main wheel”, or something else that is not visible?! If you have time to provide a dummies explanation I would appreciate it very much.

 

How do watchmakers get information about movements? Do companies like Breguet, ETA etc. make this available or do they expect all their watches to go back to them for service?

 

Kind regards

 

Andrew

Hello Andrew,

In the picture of the back of the movement, what you have labelled the "hour pinion jewel" is in fact the "minutes pinion jewel".  Instead of having the minute hand mounted directly on a center wheel (as is traditional) or mounted on a compound cannon pinion that is driven by the the third wheel pinion (as is common in modern ETAs), the Tradition uses an indirect minutes pinion to carry the cannon pinion and minute hand as is also quite common in modern movements.  As the barrel turns, it drives the minutes pinion which turns once per hour and carries the minute hand.  Underneath the dial there is a reduction train whereby the cannon pinion drives a minute wheel, the pinion of which drives the hour wheel.  These part are controlled during hand setting via the rather complicated arrangement of gears just north of the keyless bits.

Planetary gearing is generally not easy to wrap your head around in my opinion without a good drawing of all the gears in the system.  For power resereve mechanisms, the super simple explanation is that the ratchet wheel drives the series of gears one direction when handwinding the watch and the barrel drives the system the other direction when unwinding (while the watch is running), and the difference between the two is shown by the power reserve display.  The "difference" part being "calculated" by the planetary gearing a little like a differential in an automobile.  To see how an automobile differential works, click here, and imagine that rather than the two axles being driven by the pinion shaft, the two axles were instead driving the pinion shaft in contradictory directions and the pinion shaft was showing the net output of the two.

Most watch companies these days do not sell parts to independent watchmakers, and certainly not without some kind of certification or authorization process.  If they don't sell parts, they are certainly not going to give out technical documentation about their movements, so unless you work directly for the brand or are authorized to repair them, you're not likely to get tech docs at all.  Some watchmaking organizations like the AWCI have technical documentation in their libraries for a wide variety of movements that they will copy for their members, but I rather imagine its only for older movements.  Basically yes, they expect all their watches to go back to them for service.

_john

Thanks John,

 

Your patient and clear explanations have been very useful. I have updated the labelled images which can be found below. Some of the labels are now hybrids of different nomenclature, but this should make it (relatively) clear for different readers.

 

Thanks also for reminding me of your eloquent review of the Union watch. Your point about the movement layout making “engineering allowances at the most fundamental levels for the sake of an aesthetic vision” perfectly applies to the gear trains in the La Tradition.

 

Kindest regards

 

Andrew

Thanks Andrew for posting the labels.  I've always wondered what each of the gears were.

Regards,
ED-209

Dear Purists,

 

Please find below my final labelled images of the anterior and posterior surfaces of the La Tradition 7027BA/11/9V6 (Cal. 507DR). Many thanks to Aaron and John who contributed greatly to my understanding of the anatomy and physiology of this unique timepiece. Please note that the labels used are not based on any official Breguet nomenclature.

 

Andrew