Tourbillon Movement

[SearChart]

Hi folks,

I've been trying to figure out how the Tourbillon escapement works on watches like the Jaeger-LeCoultre Gyrotourbillon and the Zenith Christopher Colomb.

I've figured out that a regular Tourbillon escapement isn't very difficult to understand(correct me if I'm wrong), normally on a regular lever escapement (non-tourbillon) you would find the whole escapement including the escapement wheel in a stationary position where it transfers the energy from the fourth wheel to the pallet fork which will allow the balance wheel to move in an oscillating way.

A 'regular' Tourbillon though has the whole escapement (escapement wheel, pallet fork and the balance wheel with hairspring) placed in a so called Tourbillon cage, bridges will then secure the whole escapement into the cage.
When you then place the fourth wheel underneath the Tourbillon cage so the escapement wheel can get onto it again, you will then see the escapement wheel pulling itself (and the whole escapement) around the whole fourth wheel.

(Sorry for my amateuristic way of expressing the exquisite Tourbillon mechanism, and please correct me if I made a mistake, I'm eager to learn.)

My question is: could someone explain the gyroscopic Tourbillon escapement to me.

[SearChart]

I've read that the 'regular' Tourbillon escapements don't really improve accuracy that much because of the fairly slow rotation speed around the Fourth wheel.

JLC states that their Gyrotourbillon does increase accuracy because it can move free around all axes.

[FeelingTheBlues]

Bas,

Your question made me think about the different types of tourbillon escapements all day long!

Good news is, I believe I may have understood how they all (or almost all) work, pictures are being uploaded as I'm typing this but in the meantime allow me to say that the tourbillon doesn't improve quite improve accuracy, it just compensates the loss of time a hairspring generates by being in a certain position (because of gravity) by making it turn on itself in a minute, making it gain the lost time in the other position. In other words, provided that a hairspring makes a movement lose X seconds in the position A, the position B (which would be the upside down version of A) would make the movement gain back the X seconds.

In all honesty the tourbillon escapement works much better on a pocket watch because it usually always stays in the same position (or for a rather long time at least), making it more useful and convenient to have an escapement that could at least compensate the effect of gravity in order to avoid noticing a lack of accuracy over a certain period of time. Given that wristwatches are in constant movement on our wrists, it is difficult for the tourbillon to be proven useful, therefore it is more for the beauty of horology and the impressive complexity of such a device that we find them in wristwatches nowadays (in my humble opinion).

[FeelingTheBlues]

Below is the picture of a regular tourbillon escapement.



The red arrow points the balance wheel's axis, in the tourbillon's case it would also be the second wheel's pinion as on the other side (underneath the hairspring) you would find small teeth. The intermediate wheel will make the axis turn because of the said small teeth on the pinion, therefore the whole escapement, in the cage you see in the picture and which you have described, will rotate on itself. The whole motion is then regulated by the escapement wheel, which is pointed by the blue arrow, as its pinion will turn on a second wheel that is being represented by the orange circle. Although this circle is too big, imagine it being a wheel that wouldn't move, it would rather be a plate with teeth that is underneath the hairspring and around which the escapement wheel's pinion turns. The escapement wheel is then being regulated by the pallet fork and the hairspring.

Notice how the rotation's center is the balance wheel's axis, this is the difference between the tourbillon and the carousel (in a carousel, the escapement would rotate around a different axis instead of turning on itself).

Below is the picture of a carousel escapement, funny thing is that a lot of time these will be sold as tourbillons. They're quite an amazing piece of art as well (in my opinion) but they are not the same thing.



And now the Gyrotourbillon!



Just like the tourbillon, the red arrow points the second wheel's pinion. However, this pinion is not the balance wheel's axis, it's rather the pinion of the first cage of the Gyrotourbillon, which will make the round cage (shown here in a burgundy-ish color) rotate around the green ring (pointed by the pink arrow). In its rotation, the cage will make a perpendicular wheel (pointed by the orange arrow) turn, this wheel is attached to the second cage of the tourbillon, the one in which you'll find the hairspring. This second rotation will make the difference between a regular tourbillon and a Gyrotourbillon, as the escapement moves in a spheric motion, the pinion I pointed with the brown-ish arrow turns around the grey wheel I pointed with the purple arrow, this pinion is the one that is attached to the escapement wheel, which I pointed with the grey arrow (you can see its green teeth in the drawing). The rest is well known, the pallet fork and the hairspring regulate the escapement wheel which will slow down the whole motion of this complication as well as the other wheels in order to make this watch run at a good speed and give time with a good accuracy.

If I said anything here that was wrong, feel free to correct me, I took a look at this picture the whole day trying to figure out how it worked, I hope it helped a little bit and that my description (and arrows) weren't too confusing!

[FeelingTheBlues]

...And with all this I forgot to talk about the Christophe Colomb...



The main difference between this one and the Gyrotourbillon is that instead of having an escapement that will rotate in a spheric motion, you will have an escapement that is on a place with a weight underneath. Given that the amplitude of the escapement is the best when the hairspring is in an horizontal position, the weight will make sure that however you place the watch, the escapement will remain in the same position. The movements of the whole tourbillon aren't calculated and known, it keeps moving in harmony with your wrists' moves, which can be rather random at times...if not anarchic!

I'm afraid that's all I can say about this one Bas, I didn't find anything that could properly explain how the escapement could work while being in a glass bubble and moving so randomly (without the help of perpendicular wheels that would at least control its movements). If I find anything I'll let you know!

...And the last but not the least, the Spherotourbillon!



Invented by Jaeger-Lecoultre (before the Gyrotourbillon), this device makes the tourbillon (pointed by the orange arrow) turn in a "cone" motion. The red arrow shows the pinion that will make the escapement turn on itself, as you can see, it is attached to a set of wheels (pointed by the blue arrow) that will not only keep the escapement in an angle but, as they're moving, will make the balance wheel "point" in a different place as the gears are moving. I believe the grey wheel underneath (the one with the teeth pointing up) is not moving whilst the dark yellow one (with the teeth pointing down) is attached to the escapement.

I hope it helped a bit as well! Again, feel free to correct me if I said something that was not true.

[SearChart]

Carl,
Thank you very much for putting so much effort into this, I really appreciate it

A regular watch movement would lose X seconds a day because it's affected by gravity(if it's in in the same position for long periods of time), without tourbillon these seconds would be lost, meaning that it would be less accurate than a tourbillon because a tourbillon is made to regain those lost seconds, or am I completely missing the point here?


I'm still slightly confused about the regular tourbillon now.
If the teeth on the escapement's wheel pinion pull on a stationary wheel underneath the balance, how could it then possibly get it's power from the fourth wheel of the gear train? (I guess it's probably very obvious, but I can't figure it out atm)

I'm going to study the part of the gyrotourbillon for some time, I am starting to understand how it works.


Technically I prefer the look of the Colomb, however the bubble on top of the crystal is a bit hideous.
The bubble would be annoying if you are wearing a formal shirt



Again, thank you very much for your explanation

[FeelingTheBlues]

Bas, it was really a pleasure as I had a whole lot of fun trying to understand how it workedas well, I'm glad to see it helped a little bit!

Originally Posted by SearChart

Carl,
Thank you very much for putting so much effort into this, I really appreciate it

A regular watch movement would lose X seconds a day because it's affected by gravity(if it's in in the same position for long periods of time), without tourbillon these seconds would be lost, meaning that it would be less accurate than a tourbillon because a tourbillon is made to regain those lost seconds, or am I completely missing the point here?

It's more like a play of words as the fact that the tourbillon improves the accuracy is a little misconception. Rather, it hides the lack of accuracy by using it the other way: if your watch loses time in a certain position, the tourbillon hides it by making the watch gain those seconds back in the other position.

Accuracy can be improved much more by researching ways to reduce the friction and really cancel the effect of gravity, this is why watch brands keep coming with new materials and way to reduce it (see, for instance, Audemars Piguet's escapement). The tourbillon doesn't cancel the effect of gravity, it uses it to hide its bad effects (am I being repetitive or what? Never try to write a long paragraph in the morning...), the watch looks more accurate but it's just an illusion, if you put it on a timegrapher you will see that the accuracy will change as the escapement turns.

Originally Posted by SearChart

I'm still slightly confused about the regular tourbillon now.
If the teeth on the escapement's wheel pinion pull on a stationary wheel underneath the balance, how could it then possibly get it's power from the fourth wheel of the gear train? (I guess it's probably very obvious, but I can't figure it out atm)

See it this way, usually the fourth wheel (the wheel and its pinion, that is) would turn on itself and will make the escapement wheel turn when the contact is being made by the fourth wheel and the escapement pinion. In this case, however, only the pinion move. This pinion will make the tourbillon cage (which includes the escapement wheel) turn on itself. Since the escapement wheel is attached to it, it rotates as if it was in orbit around the fourth wheel/balance wheel axis's pinion. The escapement wheel's pinion then gets in contact with another wheel (that doesn't move) underneath.

To help you visualise it, imagine yourself with two watch wheels in your hands. The one in your right hand doesn't move. With your left hand, put the left hand's wheel's pinion's teeth on the right hand's wheel's teeth. Then do a circular motion with your left hand, the left hand's wheel is turning but not the right hand's one. Now imagine that your left hand is not what makes the left hand's wheel turn, rather, imagine that it's the right hand's wheel's pinion (the pinion wouldn't be attached to the wheel).

I hope I'm not more confusing now...

[SearChart]

Originally Posted by FeelingTheBlues

See it this way, usually the fourth wheel (the wheel and its pinion, that is) would turn on itself and will make the escapement wheel turn when the contact is being made by the fourth wheel and the escapement pinion. In this case, however, only the pinion move. This pinion will make the tourbillon cage (which includes the escapement wheel) turn on itself. Since the escapement wheel is attached to it, it rotates as if it was in orbit around the fourth wheel/balance wheel axis's pinion. The escapement wheel's pinion then gets in contact with another wheel (that doesn't move) underneath.

To help you visualise it, imagine yourself with two watch wheels in your hands. The one in your right hand doesn't move. With your left hand, put the left hand's wheel's pinion's teeth on the right hand's wheel's teeth. Then do a circular motion with your left hand, the left hand's wheel is turning but not the right hand's one. Now imagine that your left hand is not what makes the left hand's wheel turn, rather, imagine that it's the right hand's wheel's pinion (the pinion wouldn't be attached to the wheel).

I hope I'm not more confusing now...

Carl,

Sorry for my late response, I didn't have a pc or laptop to use last week since I was on skiing vacation in Austria with school.

Imagining myself with those wheels did explain it quite well it took me a while to figure but I understand it now.

Thank you very much

[FeelingTheBlues]

Originally Posted by SearChart

Carl,

Sorry for my late response, I didn't have a pc or laptop to use last week since I was on skiing vacation in Austria with school.

Imagining myself with those wheels did explain it quite well it took me a while to figure but I understand it now.

Thank you very much

Explaining it in a paragraph wasn't the easiest thing to do for me, I should have made a video instead...