A. Lange & Söhne

Dear Sirs!

I was checking the balance system in the 1815 chronograph. What is the purpose of the swan-neck adjustment system in that watch? I see no hairspring key, which is usually connected to that part.

that will adjust the hairspring key very, very accurately.

As you will know, the pace of the swinging system is adjusted by altering the hairspring length with the hairspring key.

With the swan-neck you can now adjust the hairspring key itself through the little lever "stuck" in the swan-neck.

Additionally the pace of the balance can be adjusted by changing the mass, which would be done by playing with the screws on the balance wheel.



Regards

Moritz

This message has been edited by COUNT DE MONET on 2011-05-16 12:51:51

Thanks. Krtek is great, has a nice taste!
My problem is still the following. When you look closer on the adjusting system of the 1815 Chronograph (or Richard Lange Referenzuhr) I see NO ANY key. Neither pins, nor screws - nothing.
I can see a Philips curve (looks like nr. 100 - where the end of the overcoil is on the same radius as the outer spiral of the hairspring) fixed with one horizontal screw to thar aesthetically beutiful spring-pressed vise. I can see one vertical screw which fixes that vise to the balance cock.
Maybe somebody has a better picture from that part.

... on pictures of the 1815.

That would mean that there has to be also something like an hair spring key somewhere, where this little lever is attached to.



There are also not many other ways left to adjust the hair spring:

- over the mass ( like Patek's Gyromax and Rolex's Microstella )

- swan-neck ( GO's Duplex and Lange )

- Triovis ( Vacheron )




Regards

Moritz

Ok. Now I clearly understand it. Thanks.

The new 1815 Chrono, and the RL, actually use an adjustable-maxx "gyromax" style balance to control rate.

What looks like a swan neck regulator is in fact a beat adjustment mechanism.

If you look at the free-spring Langes (like the RL and new 1815 Chrono) their "swan-neck" is in fact very different to the one found on non free-sprung models.

Still there is that lever that regulates the hairspring key.

The new mass elements on the balance are possibly just decorative, like the former balance screws are.

At the end of the day the balance will be adjusted by laser, I read in an article somewhere.


Regards

Moritz

ThE weights aren't decorative. It's a true free sprung balance a la the Patek gyromax.

The apparent swan neck regulator in these watches only adjusts the beat.

I have this info from Lange direct.

Is used to poise the balance. A different thing.

No message body

from my layman point of view and looking at what I can recognize in the movement:

the lever is there.

The swan neck, the mass-weights on the balance, the srews ... all is at the end regulating the beat.

Same the hairspring key does.

It all effects the beat, at the end of the day.

You can call it changes in amplitude, length of the coil ... all results in an alteration of the beat.

 

What I "feel" why Lange does this is:

- firstly it is a tradition for watchmakers from Glashuette and for Lange in particular to use the swan-neck.

It is nearly a trademark for Lange and it looks simply good, gives the watch an even more traditional look.

- secondly luxury has got a main principle: everything in abundance!

Look at 500 bhp cars: just to que in at 120 km/h on most european motorways?

 

As I said, from what I have gathered as knowledge and looking at the balance system:

I still can see the basic principles of adjustment, but in abundance ...

 

Regards

Moritz

I see the 6 mass on the balance. It has influence on the inertia of the balance itself, since the inertia radius varies by rotating those excentrical masses.

My original question was the adjusting method of the active length of the hairspring which also has influence on the period of oscillation.

Hi,
it's a freesprung hairspring, i.e. the actual length is fixed. Different from the commonly used systems, where the hairsrping end is either glued, laser welded or fixed with a conical pin to the hairspring stud - the Lange system is a sort of clamp, fixing the hairspring with help of two "rounded jaws" (hope this isn't a misleading term). 
This clamp system is movable, which is guided by the index with swan neck/micrometer screw. This regulation only changes symmetry of beat - not the rate.
The actual rate is adjusted firstly by the actual length of the hairspring (rough pre adjustement), fine adjustement is done through the variable inertia weights on the balance rim. Of course any change to the clamping point/length asks for a re-adjustement of beat symetry (i.e. same length of the tic and tac ;-)  ).

Having a fine adjusting micrometer/swan neck for the symetry of beat isn't necessary IMHO, but of course looks nice and of course the swan neck is used as a trademark for any precision movement for long time.

Hope this isn't explained too confusing though.
Best regards
Suitbert

*

Managed to find a review of the RL, released when it came out:

the hairspring clamp is movable, but for adjusting the balance wheel to the hairspring.

The article does not say unfortunatelly that the hairspring length is variable - so I assume it is fixed.

The swan neck ( Ruecker) and this particular hairspring clamp together are a mechanism to adjust the pivot ( Hebestift / Hebelstein) of the balance that hits the ancher and subsequently the anchor wheel. ( Abfall-Regulierung )

The mass screws on the balance wheel in the case of the RL and also the current 1815 chrono are more than just decorative, here you are right.

I was thinking the old 1815 chrono was ment, where they do not serve any purpose.



This is how I understand this matter having read the review today again ...


Regards

Moritz

I'd like answer some of your remarks point by point , as I find them a bit unclear:

"....the hairspring clamp is movable, but for adjusting the balance wheel to the hairspring."
At least technically, that's incorrect. Adjusting the hairspring relative to the balance wheel, can only be done
by moving the inner collet on the balance arbor (die Spiralrolle auf der Unruhwelle).

"....The article does not say unfortunatelly that the hairspring length is variable - so I assume it is fixed."
The hairspring length isn't fixed, depending on where it's exactly placed in the "clamp" some variation is possible. This is different form
a usual "stud" where the end of the hairspring is fixed.

"...The swan neck ( Ruecker) and this particular hairspring clamp together are a mechanism to adjust the pivot ( Hebestift / Hebelstein) of the balance that hits the ancher and subsequently the anchor wheel. ( Abfall-Regulierung )"
That is basically correct, although a "pivot" would be "Unruhzapfen" and "Hebelstein" would be the impulse jewel.
What I tried to point out in my first post, that the swan neck micrometer screw is for adjusting the symetry of beat (or called more shortly, the beat) is exactly that, "Abfall Regulierung" ;-)

"...I was thinking the old 1815 chrono was ment, where they do not serve any purpose."
Even with a classical (non freesprung) hairspring system, adjustable inertia screws can be quite helpfull for pre adjustement and adjusting to positions....
First Gyromax movements form PP for example were also featuring this double adjustement and werent true freesprung systems.

Best regards
Suitbert

At least in one point we agree: the swan neck is not really "necessary" and that Lange uses it as a trademark, to make the watches look better.

And they do look good!

That is also a big reason why we love watches ...

 

 

Regards

Moritz

Hi there SuitBert,

Thank you very much for the explanation.

Oftentimes this issue about free-sprungness, and the presence of the swan neck regulator despite the latest models from Lange mainly being free-sprung, comes onto my mind.

I still don't really get free-sprungness at times.

But i'm glad for folks like you.

Danke!

Stephen

re. the freesprung principle, let me try to explain it with a comparison.

Imagine a guitar with it's strings. If you pluck an empty string - you could call this string freesprung.
It has a fixed length and only it's physical properties limit the base frequency. Now, press down the string with
your finger towards the fret board and pluck again - now it's not freesprung anymore. Your finger pressing it
towards the fret board is like the index regulator to the hairspring - frequency will be higher of course. Moving up and
down your finger on the fret board is exactly the same as moving back and forth the index regulator on a "non freesprung"
hairsrping.

Acoustically, the "empty" string will allways create the more "perfect" (i.e. less disturbed") vibration. That's exactly the same for hairsprings,
the "dead" end of the string(spring) between finger(index pins) and peg (hairspring stud) will allways create some disturbations.
Of course in very complicated circumstances a very good watch regulytor can sometimes make use of those
disturbations to average other disturbing influences from the escapement, for example. That's one reason precision watches form the past
often still had non freesprung balance systems - despite the fact that theoretically a freepsrung balance would be superior.

Personally I find it quite interesting, it's one of the fewer occasions were a theoretically superior system finally is found to be superior for
large series production - while a the theoretically lesser sytem is perhaps offering more for the absolute specialists in introducing wanted errors.
It should be said though, suitability for mass production of freesprung hairspring has seen a tremendous evolution thanks to new
production methods/machines and the pioneering companies, mainly Rolex.

Best regards
Suitbert

Hi there SuitBert

Your analogy makes it easy for me to understand the idea of freesprung-ness. So by moving back and forth the index regulator, this adjusts the oscillating speed of the hairspring? Or the rate stability of it? And in that case, if say that the case such as in Lange's novelties which are free sprung YET still has an index regulator, what is the purpose of the index regulator for these models then? ( Besides it's aesthetic appeal)

As for the disturbations you are mentioning that can be used in a beneficial manner, is this the phenomenon of the resonating balances such as that utilised for the Journe Chronometre Resonance?

Also in a topic similar to my 1st paragraph, would you mind explaining what are the parts that determines the oscillation speed of a watch? Say what sets a watch to beat at 18,000 alternations per hour and another 28,800? Is this the job of the index regulator, or if there is a lack of it, then the pins on the balance wheel, the "Gyromax" masslots?( Is this even the correct spelling for those pac-man looking weights?) Or maybe the hairspring itself?

I would appreciate any explanation. Thank you in much advance! And apologies if this is a topic that has been discussed till boredom on the forums. Just wanting to learn more.

Stephen 

Hi Stephen,

Imagine a simple system, where the balance is only one point, rotated around an axis by the spring.

1. Momentum (of balance) contains mass and velocity values. Position of mass can be variable by the construction, velocity will change continuously during oscillation.
2. Work (of spring) contains some "specialities" like "elastic couple", "elastic modulus". Those physical values are depends on the physical properties of your spring, eg. width, thickness, lemgth, material. You can change those by construction, especially the length. Unfortunatelly, temperature change them also
3. in the neutral position of the balance wheel, the work of the spring equals the momentum the balance. In the neutral position the momentum value is the maximum (maximum velocity). From that, the oscillation could be calculated, so you can determine the sizes of your system.

For adjusting you have to define first, what to adjust: of course, the most important will be the time (oscillation, beat, etc. - depends on the applied math). These gadgets are TIMEkeepers. There is a lot of effect on the time, and a lot of solution born already. All of them tries to decrease the error (gain or loss).

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