Breguet has reinvented the mechanical watch. We translate the complex physics of the Expérimentale 1 into plain English. Discover how magnetic "slingshots" eliminate friction and deliver constant force.
Worth a comparison here is the Spring Drive movement, which Seiko manufactures in large quantities at relatively affordable prices. Here, too, the movement is powered by a spring and regulated magnetically, with accuracy of (in my experience) a second per day. The difference is that in the Spring Drive, regulation is by means of a pair of electromagnets astride a smoothly turning escape wheel, with accuracy governed by a quartz device, which itself is powered by the mainspring via a tiny generator.
Yeah exactly; SD relies on the current generated at the glide wheel. The Breguet magnetic escapement requires no electrical power input at all, and while there are a number of electromagnetically impulsed watches (Elgin, Hamilton, Lip and others, including tuning fork watches like the Accutron) there are as far as I know, only two escapements where there's no power source and impulse is delivered magnetically; Clifford's, and Breguet's
At the risk of exposing how much of my high school physics I've forgotten, couldn't the argument be made that since magnetism and electricity both fall under the umbrella of electromagnetism, Breguet's use of "just magnets" actually does put this watch at least somewhat in the same neighborhood as Spring Drive? Granted, the magnets used in the Breguet are static, not the electromagnetic field used in Spring Drive, so they're not identical. But still...some overlap at least? And thus neither is fully in the realm of "mechanical"? Or am I being hopelessly pedantic?
US11640141B2, which presents three variants (one of which, as far as I can tell at a cursory examination, is very similar to Clifford's).
In that filing, the stop wheel's function (it's part no. 70 if you want to find it quickly) is described thus: " In an advantageous variant, represented in FIGS. 2 and 6 to 9 , a safety mechanism is envisaged in the event of shocks or other high accelerations liable to be sustained by the magnetic escapement. It is obtained by teeth 70 secured to the escape wheel set arranged at the arms 54 and 55 of the pallet fork bearing respectively both magnets 32 and 33 , these teeth being suitable for engaging with two fingers situated respectively at the ends of both arms. In each rest position of the pallet fork, if the magnetic barrier described above does not exert a sufficient stopping torque to prevent the escape wheel set from not traversing same, one of the two fingers then comes to a stop against one of the teeth 70"
The video published by Breguet seems to show one of the pallets in physical contact with the stop wheel – I have an ask out to Breguet on this. I had a quick DM exchange with Flavio – it may be that between the patent filing and the actual implementation, Breguet decided to buy itself a little extra insurance against accidental unlocking. The actual locking, however, seems to be entirely due to repulsive magnetic forces, and critically, the Breguet video shows, albeit very briefly, that the escape wheel doesn't move when the pallet is propelled away from escape wheel.
It's also possible that the clearance between the stop wheel and the pallet is so small that it's not clearly visible in the video. Anyhow, hoping to hear from Breguet on this. This is a very challenging escapement to understand even if you have a general understanding of escapements already, and my take is that anyone who tries to tackle it deserves some credit for taking a shot at it. Your conclusion is very apt:
"I don’t think this tech will become an industry standard anytime soon, but perhaps, in due course, this will give rise to a new wave of innovation in escapements. Asking and answering ‘stupid’ questions is how we expand what we understand to be possible, within the physics of a mechanical watch. To me, this watch is about keeping alive a tradition of intellectual curiosity that has nothing to do with telling time and everything to do with human ingenuity smashing up against its own limits." 👏
Also you know what's cool and kind of weird is that the US patent linked to above includes a chain and fusee 😀
That is a very good question. I'll see what I can find – the initial research was done at Suwa Seikosha, which didn't merge with Epson to become Seiko Epson until 1985, and Grand Seiko says that the first registered patent is from 1982, although their timeline also says the first patent (not described as registered) is from 1978. Yoshikazu Akahane is supposed to have been the guy who came up with the idea, but I haven't found any patent filings under his name that are unambiguously related to Spring Drive in any way.
Did Ebauches SA conceive the idea first, and then fail to create a commercially viable or successful product from it at the time? This patent describes a spring-driven generator regulated by a quartz signal... 😀
"PURPOSE:To obtain a watch with high reliability and high accuracy requiring no exchange of a battery and also dispensing with a chemical battery, by providing a mechanism for accumulating mechanical energy, a train wheel supplied with energy from said accumulating mechanism and a power generator for regulating the speed of said train wheel while providing a crystal oscillator driven by the electric energy obtained from the power generator, an electronic circuit and a mechanism for controlling the power generator by the electronic circuit."
I don't know about first, but IIRC Berney's design was used by Piaget for the XL 700P after the patent lapsed. Although, this 1968 from Suwa Seikosha patent is cited in Berney's patent: https://patents.google.com/patent/US3648453A/en
This is wonderful--your article, and the comments that it already inspired, are why I keep coming back here. I can't begin to add anything of substance, but this part of your article (the part that includes your observation that "spending a decade perfecting a magnetic escapement is fvcking absurd.") got me to thinking. I know, of course, that there's way, way more to your thoughts on this than that one sentiment. And I completely agree that if we take a purely functional viewpoint, mechanical watches are absurd; even without going to the smartwatch extreme, a relatively cheap solar-charged quartz watch that connects to the Ft. Collins radio keeps perfect time and makes the quest for greater accuracy in mechanicals seem, well, kinda silly.
But to insist on the purely functional misses the point. Those of us who love mechanical watches don't love them purely for functional reasons, though we can and do applaud functional improvements, like this one. I look at it a bit like some athletic achievements. Other than winning competitions, is there any real-world functional point whatsoever to being able to run a marathon in 2 hours and 1 minute rather than 2 hours and 5 minutes? No, but people spend years training to achieve just that, and I have never heard anyone, ever, wonder why those people bother. And why is that? It's because people recognize mastery, they recognize the quest to do something better, and they realize that that quest is in itself the answer to the question.
I can't begin to afford this watch, but if I could, I would damn well buy one right this minute. And here's to Breguet for spending the last eight years making it happen.
Thanks for taking the time, Rip... I loved that analogy which asks what the point of running faster marathons is; that's so true! Mastery is the neverending goal, and it doesn't end. On your last point, I do wonder whether they actually spent all this time developing it, or whether the patent sat in a drawer for most of that time while executives sat around watching the brand waste away. Glad they're in the mood now, for sure!
It's reasonable to assume that this system of oscillating objects (governed by proximity to alternating, ramping magnetic forces) has certain design limits. While the magnetic step is strong enough to halt the escape wheel during normal conditions (until the anchor repositions to release magnetic opposition), a mechanical shock could introduce enough impulse to interrupt the anchor's normal swing. If the anchor's hiccup causes it to misalign with the magnetic rings of the escape assembly, then perhaps the anchor could get magnetically pinned if it falls behind its intended relationship. In other words, perhaps it could get caught behind (on top of?) that magnetic barrier - this is beyond the system's designed interactions - and it could become magnetically locked (now it's the escape assembly imposing its magnetic influence on the anchor, defeating the system design). This is where the traditional shape of the central (non-magnetic) escape wheel comes into play. As you stated, in upset conditions, it's there to impart a physical positioning on the anchor. It's a guard rail - something we never intend to hit, but serves a valuable purpose should we lose control of our car in an upset condition.
The sandwich construction of the escape assembly is elegant. I imagine it solved two issues… first, that a single magnetic ring would impart an unbalanced force on the anchor and put more stress on jeweled pivots. Second, that they might have needed more magnetic material (therefore force) than a single ring could provide.
I struggle to grasp exactly how/why the escape wheel remains motionless as the magnetic repulsion imparts its force on the departing anchor. If the mainspring is constantly torquing the escape wheel, then this release of magnetic repulsion would also seem to allow the escape to resume its rotation in a more fluid motion. Maia's writeup makes it sound more binary, that there's a full release of magnetic potential before the escape motion resumes. Perhaps this is just semantics, that the forces involved (and perhaps the very short timescale) are strong enough that it's binary-like.
A mechanical engineer such as myself recoils in disgust during the Breguet video, when the hint of the mechanical explanation gives way to the animation of a magnetic schooner sailing the ferrous seas. Alas, such is marketing.
I'd agree ref the function of the central non-magnetic wheel... "guard rail" is a good term!
I'd say the binary motion during impulse is the holy grail of their design. Fully agree that on a theoretical level, the movement should be fluid, but I think the physics here are designed to make it instantaneous.
The short answer is that the escape wheel remains motionless because the magnetic "holding force" exceeds the torque of the mainspring until the pivot forces a geometrical shift in the magnetic field. This means the energy release will seem "binary" due to the extreme gradient of the magnetic ramp/barrier.
I love analogies so I'm gonna try once more... perhaps it's like a dam breaking fully and instantaneously? The force holding the water back is huge (the magnetic barrier) but once the anchor’s push triggers the release, the energy snap is also huge (and the timescale so small) that the entire stored magnetic potential is delivered as a single kick... as opposed to a dam breaking slowly. Ok, that was a rubbish analogy but I'm not typing out another one 😂
There is a sleight of hand here but epic coolness has been delivered for sure. The sleight of hand is that the physical phenomenon of magnetic field is entirely due to the alignment and misalignment of electrons. In the case of spring drive, such magnetic field is delivered via electronic current. In the case of permanent magnets, it’s due to atomic alignment of spinning electrons. They are kind of different but really the same… I think a more scientifically honest way of describing this escapement is that “26 years after the commercial release of the spring drive and its use of magnetic field to regulate the linear speed of an escapement, Breguet has implemented a commercially viable application of magnetic regulation of an oscillating escapement.” In a way, the progression from SD to this seems to have some resemblance to the progression from a verge escapement to detached escapements with a balance.
I don't think it is fair to call this sleight of hand.
It is true that in SD, the quartz crystal is a reference provider, and not a force provider... the quartz crystal does not provide the energy to correct the time or apply the brakes, it simply provides the reference signal via a crystal that vibrates when fed with electrical power. So yes, the actual 'regulating force' in SD, is magnetic. But there is no slight of hand because this magnetic force in SD is created by an electrical current, not pure mechanics.
Breguet uses magnetism generated by permanent magnets to lock the wheel, and the Spring Drive uses magnetism generated by an electrical current to brake the wheel. In both cases, the final governing and regulating forces are mechanical in origin (mainsprings), and magnetic in implementation... but to be precise, one is fully mechanical, and the other is electro-mechanical. This is not comparing apples with apples.
That doesn't mean SD isn't a different kind of epic coolness; it sure is. But again, it is not sleight of hand because this is more than "Breguet has implemented a commercially viable application of magnetic regulation of an oscillating escapement" - they have also done so mechanically, which is a significant operating-constraint being discounted entirely.
Now, on the progress from verge... non-detached, to detached, to this Breguet, which is perhaps "fully detached" or zero contact - yes, that progression makes sense.
SD belongs in a parallel, separate category because it abandoned the idea of purely mechanical watchmaking and did not do anything with regards to perfecting oscillation mechanically.
I am glad both exist, but they are different things. This feels like comparing a Lamborghini to John Deere's latest tractor. They might cost the same, and they might both be on 4 wheels... but as vehicles, they're good at different things.
Okay, but still...unless I'm badly misunderstanding the way the Breguet movement works, there is no physical contact between the pallet fork and the escape wheel. There is only the force of the magnetic field. So wouldn't it be fair to say that the use of magnetic fields takes the Breguet mechanism at least somewhat beyond the realm of the purely mechanical and into the realm of "fields," and thus at least somewhat into the neighborhood of the SD? I'll grant, certainly, that the Breguet lies much closer to the fully mechanical end of things than SD does, and yes, they definitely are different approaches. But still...it's hard for me to deny that they share the use of magnetic fields for their operation, and in that regard both are distinct, in somewhat similar ways, from almost any other mainspring-driven watch.
I do not disagree with anything you're saying, and I do not believe you've misunderstood anything either.
I just think that 'fields' here is being (mis)used as a point of strong alignment much like 'shoots projectiles' can be used to align archery and firearms. One uses igniting gunpowder and the other uses kinetic energy input from humans.
All I am saying here, is that SD uses electronics, and Breguet is purely mechanical... the fields are absolutely a shared principle, and yes, that perhaps puts them in a class of two... but like archery and firearms, I am left asking... so what?
With regard to the "so what?" question, well, my friend, you got me there. In the end I'm pretty much just counting angels on the heads of pins.
But that said, sometimes doing that is kinda fun, and I think a better analogy (meaning, one that better suits my argument 😂) would be a comparison of a traditional bow and arrow to a crossbow (the Breguet and the SD), and then both to guns (the quartz watch). The crossbow and traditional bow and arrow both use bows and strings to fire arrows, and they also share the fact that human muscles pull back the bowstring. But the aiming mechanisms, and the device that holds back the string until release, are different. And both are way, way different--and less effective in most cases--from guns.
I like the pivot to crossbows, and clearly this suits your argument better... but I refute this pivot entirely 😂 They are both using bows and strings, but SD and Breguet are not the same in their construction as one is using electronics... again, I appreciate you are saying the use of magnetic fields is where they are super similar, and frankly, we do not disagree on this at all! I think we both like talking about this for the heck of it 😁
This POV is absurd - is all science and technology a "sleight of hand"? Rhetorical question.
GS SD is effectively a magnetic, non-contact drag brake. Exp1 is a magnetic, non-contact escapement in the traditional stop/start, reversing sense of the design. To conflate these as similars would be akin to conflating a rotary jet turbine with a reciprocating combustion engine. An imperfect analogy, lol, but really let's not mistake apples for oranges.
I’m being intentionally provocative with that phrasing but as a fan of magic, “sleight of hand” is used with heartfelt respect and admiration. I agree with the factual statements by both you and kingflum. I’m only trying to point out that there is no standard physics definition of “mechanical magnetic” so really in both cases, magnetic fields were introduced as a new and unconventional element. Distinction is SD uses electromagnets and this Breguet uses permanent magnets. I feel like the exclusion of an external electrical power source makes the two solutions more similar than they are different. I admit that this assessment is perhaps more subjective than objective given the lack of any framework for that assertion.
Does anyone know what sound the escapement makes (if any)?
Since there isn't the same contact, what happens to the traditional "tick, tick, tick" that we all know and love ? One of my favourite things to do with watches is listen to them - curious to know how this experience might differ for the Breguet
Worth a comparison here is the Spring Drive movement, which Seiko manufactures in large quantities at relatively affordable prices. Here, too, the movement is powered by a spring and regulated magnetically, with accuracy of (in my experience) a second per day. The difference is that in the Spring Drive, regulation is by means of a pair of electromagnets astride a smoothly turning escape wheel, with accuracy governed by a quartz device, which itself is powered by the mainspring via a tiny generator.
Yeah exactly; SD relies on the current generated at the glide wheel. The Breguet magnetic escapement requires no electrical power input at all, and while there are a number of electromagnetically impulsed watches (Elgin, Hamilton, Lip and others, including tuning fork watches like the Accutron) there are as far as I know, only two escapements where there's no power source and impulse is delivered magnetically; Clifford's, and Breguet's
At the risk of exposing how much of my high school physics I've forgotten, couldn't the argument be made that since magnetism and electricity both fall under the umbrella of electromagnetism, Breguet's use of "just magnets" actually does put this watch at least somewhat in the same neighborhood as Spring Drive? Granted, the magnets used in the Breguet are static, not the electromagnetic field used in Spring Drive, so they're not identical. But still...some overlap at least? And thus neither is fully in the realm of "mechanical"? Or am I being hopelessly pedantic?
See my reply to PZ below, which I think covers this pedantry 😂
And see my reply to your reply below, 'cause I'm not entirely convinced yet! 🤔🤓😂
For those interested there is a US patent, published in 2023: https://worldwide.espacenet.com/patent/search/family/062563079/publication/US11640141B2?q=pn%3DUS11640141B2
US11640141B2, which presents three variants (one of which, as far as I can tell at a cursory examination, is very similar to Clifford's).
In that filing, the stop wheel's function (it's part no. 70 if you want to find it quickly) is described thus: " In an advantageous variant, represented in FIGS. 2 and 6 to 9 , a safety mechanism is envisaged in the event of shocks or other high accelerations liable to be sustained by the magnetic escapement. It is obtained by teeth 70 secured to the escape wheel set arranged at the arms 54 and 55 of the pallet fork bearing respectively both magnets 32 and 33 , these teeth being suitable for engaging with two fingers situated respectively at the ends of both arms. In each rest position of the pallet fork, if the magnetic barrier described above does not exert a sufficient stopping torque to prevent the escape wheel set from not traversing same, one of the two fingers then comes to a stop against one of the teeth 70"
The video published by Breguet seems to show one of the pallets in physical contact with the stop wheel – I have an ask out to Breguet on this. I had a quick DM exchange with Flavio – it may be that between the patent filing and the actual implementation, Breguet decided to buy itself a little extra insurance against accidental unlocking. The actual locking, however, seems to be entirely due to repulsive magnetic forces, and critically, the Breguet video shows, albeit very briefly, that the escape wheel doesn't move when the pallet is propelled away from escape wheel.
It's also possible that the clearance between the stop wheel and the pallet is so small that it's not clearly visible in the video. Anyhow, hoping to hear from Breguet on this. This is a very challenging escapement to understand even if you have a general understanding of escapements already, and my take is that anyone who tries to tackle it deserves some credit for taking a shot at it. Your conclusion is very apt:
"I don’t think this tech will become an industry standard anytime soon, but perhaps, in due course, this will give rise to a new wave of innovation in escapements. Asking and answering ‘stupid’ questions is how we expand what we understand to be possible, within the physics of a mechanical watch. To me, this watch is about keeping alive a tradition of intellectual curiosity that has nothing to do with telling time and everything to do with human ingenuity smashing up against its own limits." 👏
Also you know what's cool and kind of weird is that the US patent linked to above includes a chain and fusee 😀
Thanks for this, Jack.
Do you happen to know which is the 'main' or 'original' GS Spring Drive Patent? https://patents.google.com/patent/JP3601268B2/en&authuser=2
I believe this is for the eventual watch they launched in 2004, but I can't seem to find the original from the late 1980's...
That is a very good question. I'll see what I can find – the initial research was done at Suwa Seikosha, which didn't merge with Epson to become Seiko Epson until 1985, and Grand Seiko says that the first registered patent is from 1982, although their timeline also says the first patent (not described as registered) is from 1978. Yoshikazu Akahane is supposed to have been the guy who came up with the idea, but I haven't found any patent filings under his name that are unambiguously related to Spring Drive in any way.
Can I offer you a patent for a "Electronic clock with fortunetelling function" in the meantime 😀 https://worldwide.espacenet.com/patent/search/family/012690837/publication/JPS57158579A?q=pn%3DJPS57158579A
😂 yes, that'll do!
There's also this: https://patents.google.com/patent/US3937001A/en
Did Ebauches SA conceive the idea first, and then fail to create a commercially viable or successful product from it at the time? This patent describes a spring-driven generator regulated by a quartz signal... 😀
Hey, check this out, from 1983: https://patents.google.com/patent/JPS59135388A/en
"PURPOSE:To obtain a watch with high reliability and high accuracy requiring no exchange of a battery and also dispensing with a chemical battery, by providing a mechanism for accumulating mechanical energy, a train wheel supplied with energy from said accumulating mechanism and a power generator for regulating the speed of said train wheel while providing a crystal oscillator driven by the electric energy obtained from the power generator, an electronic circuit and a mechanism for controlling the power generator by the electronic circuit."
I don't know about first, but IIRC Berney's design was used by Piaget for the XL 700P after the patent lapsed. Although, this 1968 from Suwa Seikosha patent is cited in Berney's patent: https://patents.google.com/patent/US3648453A/en
This is wonderful--your article, and the comments that it already inspired, are why I keep coming back here. I can't begin to add anything of substance, but this part of your article (the part that includes your observation that "spending a decade perfecting a magnetic escapement is fvcking absurd.") got me to thinking. I know, of course, that there's way, way more to your thoughts on this than that one sentiment. And I completely agree that if we take a purely functional viewpoint, mechanical watches are absurd; even without going to the smartwatch extreme, a relatively cheap solar-charged quartz watch that connects to the Ft. Collins radio keeps perfect time and makes the quest for greater accuracy in mechanicals seem, well, kinda silly.
But to insist on the purely functional misses the point. Those of us who love mechanical watches don't love them purely for functional reasons, though we can and do applaud functional improvements, like this one. I look at it a bit like some athletic achievements. Other than winning competitions, is there any real-world functional point whatsoever to being able to run a marathon in 2 hours and 1 minute rather than 2 hours and 5 minutes? No, but people spend years training to achieve just that, and I have never heard anyone, ever, wonder why those people bother. And why is that? It's because people recognize mastery, they recognize the quest to do something better, and they realize that that quest is in itself the answer to the question.
I can't begin to afford this watch, but if I could, I would damn well buy one right this minute. And here's to Breguet for spending the last eight years making it happen.
Thanks for taking the time, Rip... I loved that analogy which asks what the point of running faster marathons is; that's so true! Mastery is the neverending goal, and it doesn't end. On your last point, I do wonder whether they actually spent all this time developing it, or whether the patent sat in a drawer for most of that time while executives sat around watching the brand waste away. Glad they're in the mood now, for sure!
It's reasonable to assume that this system of oscillating objects (governed by proximity to alternating, ramping magnetic forces) has certain design limits. While the magnetic step is strong enough to halt the escape wheel during normal conditions (until the anchor repositions to release magnetic opposition), a mechanical shock could introduce enough impulse to interrupt the anchor's normal swing. If the anchor's hiccup causes it to misalign with the magnetic rings of the escape assembly, then perhaps the anchor could get magnetically pinned if it falls behind its intended relationship. In other words, perhaps it could get caught behind (on top of?) that magnetic barrier - this is beyond the system's designed interactions - and it could become magnetically locked (now it's the escape assembly imposing its magnetic influence on the anchor, defeating the system design). This is where the traditional shape of the central (non-magnetic) escape wheel comes into play. As you stated, in upset conditions, it's there to impart a physical positioning on the anchor. It's a guard rail - something we never intend to hit, but serves a valuable purpose should we lose control of our car in an upset condition.
The sandwich construction of the escape assembly is elegant. I imagine it solved two issues… first, that a single magnetic ring would impart an unbalanced force on the anchor and put more stress on jeweled pivots. Second, that they might have needed more magnetic material (therefore force) than a single ring could provide.
I struggle to grasp exactly how/why the escape wheel remains motionless as the magnetic repulsion imparts its force on the departing anchor. If the mainspring is constantly torquing the escape wheel, then this release of magnetic repulsion would also seem to allow the escape to resume its rotation in a more fluid motion. Maia's writeup makes it sound more binary, that there's a full release of magnetic potential before the escape motion resumes. Perhaps this is just semantics, that the forces involved (and perhaps the very short timescale) are strong enough that it's binary-like.
A mechanical engineer such as myself recoils in disgust during the Breguet video, when the hint of the mechanical explanation gives way to the animation of a magnetic schooner sailing the ferrous seas. Alas, such is marketing.
I'd agree ref the function of the central non-magnetic wheel... "guard rail" is a good term!
I'd say the binary motion during impulse is the holy grail of their design. Fully agree that on a theoretical level, the movement should be fluid, but I think the physics here are designed to make it instantaneous.
The short answer is that the escape wheel remains motionless because the magnetic "holding force" exceeds the torque of the mainspring until the pivot forces a geometrical shift in the magnetic field. This means the energy release will seem "binary" due to the extreme gradient of the magnetic ramp/barrier.
I love analogies so I'm gonna try once more... perhaps it's like a dam breaking fully and instantaneously? The force holding the water back is huge (the magnetic barrier) but once the anchor’s push triggers the release, the energy snap is also huge (and the timescale so small) that the entire stored magnetic potential is delivered as a single kick... as opposed to a dam breaking slowly. Ok, that was a rubbish analogy but I'm not typing out another one 😂
If only there were this much enthusiasm for engineering, we might be commuting in flying cars today. Well done friend. 👌🏾
Thank you brother, it'll come ;)
If nothing else, a new escapement gives us a week without discussion of interior angles. We can now talk about how a tourbillon is not a complication.
😂
There is a sleight of hand here but epic coolness has been delivered for sure. The sleight of hand is that the physical phenomenon of magnetic field is entirely due to the alignment and misalignment of electrons. In the case of spring drive, such magnetic field is delivered via electronic current. In the case of permanent magnets, it’s due to atomic alignment of spinning electrons. They are kind of different but really the same… I think a more scientifically honest way of describing this escapement is that “26 years after the commercial release of the spring drive and its use of magnetic field to regulate the linear speed of an escapement, Breguet has implemented a commercially viable application of magnetic regulation of an oscillating escapement.” In a way, the progression from SD to this seems to have some resemblance to the progression from a verge escapement to detached escapements with a balance.
I don't think it is fair to call this sleight of hand.
It is true that in SD, the quartz crystal is a reference provider, and not a force provider... the quartz crystal does not provide the energy to correct the time or apply the brakes, it simply provides the reference signal via a crystal that vibrates when fed with electrical power. So yes, the actual 'regulating force' in SD, is magnetic. But there is no slight of hand because this magnetic force in SD is created by an electrical current, not pure mechanics.
Breguet uses magnetism generated by permanent magnets to lock the wheel, and the Spring Drive uses magnetism generated by an electrical current to brake the wheel. In both cases, the final governing and regulating forces are mechanical in origin (mainsprings), and magnetic in implementation... but to be precise, one is fully mechanical, and the other is electro-mechanical. This is not comparing apples with apples.
That doesn't mean SD isn't a different kind of epic coolness; it sure is. But again, it is not sleight of hand because this is more than "Breguet has implemented a commercially viable application of magnetic regulation of an oscillating escapement" - they have also done so mechanically, which is a significant operating-constraint being discounted entirely.
Now, on the progress from verge... non-detached, to detached, to this Breguet, which is perhaps "fully detached" or zero contact - yes, that progression makes sense.
SD belongs in a parallel, separate category because it abandoned the idea of purely mechanical watchmaking and did not do anything with regards to perfecting oscillation mechanically.
I am glad both exist, but they are different things. This feels like comparing a Lamborghini to John Deere's latest tractor. They might cost the same, and they might both be on 4 wheels... but as vehicles, they're good at different things.
Okay, but still...unless I'm badly misunderstanding the way the Breguet movement works, there is no physical contact between the pallet fork and the escape wheel. There is only the force of the magnetic field. So wouldn't it be fair to say that the use of magnetic fields takes the Breguet mechanism at least somewhat beyond the realm of the purely mechanical and into the realm of "fields," and thus at least somewhat into the neighborhood of the SD? I'll grant, certainly, that the Breguet lies much closer to the fully mechanical end of things than SD does, and yes, they definitely are different approaches. But still...it's hard for me to deny that they share the use of magnetic fields for their operation, and in that regard both are distinct, in somewhat similar ways, from almost any other mainspring-driven watch.
I do not disagree with anything you're saying, and I do not believe you've misunderstood anything either.
I just think that 'fields' here is being (mis)used as a point of strong alignment much like 'shoots projectiles' can be used to align archery and firearms. One uses igniting gunpowder and the other uses kinetic energy input from humans.
All I am saying here, is that SD uses electronics, and Breguet is purely mechanical... the fields are absolutely a shared principle, and yes, that perhaps puts them in a class of two... but like archery and firearms, I am left asking... so what?
With regard to the "so what?" question, well, my friend, you got me there. In the end I'm pretty much just counting angels on the heads of pins.
But that said, sometimes doing that is kinda fun, and I think a better analogy (meaning, one that better suits my argument 😂) would be a comparison of a traditional bow and arrow to a crossbow (the Breguet and the SD), and then both to guns (the quartz watch). The crossbow and traditional bow and arrow both use bows and strings to fire arrows, and they also share the fact that human muscles pull back the bowstring. But the aiming mechanisms, and the device that holds back the string until release, are different. And both are way, way different--and less effective in most cases--from guns.
I like the pivot to crossbows, and clearly this suits your argument better... but I refute this pivot entirely 😂 They are both using bows and strings, but SD and Breguet are not the same in their construction as one is using electronics... again, I appreciate you are saying the use of magnetic fields is where they are super similar, and frankly, we do not disagree on this at all! I think we both like talking about this for the heck of it 😁
W/R/T your last sentence: absolutely right! 😂🤓
This POV is absurd - is all science and technology a "sleight of hand"? Rhetorical question.
GS SD is effectively a magnetic, non-contact drag brake. Exp1 is a magnetic, non-contact escapement in the traditional stop/start, reversing sense of the design. To conflate these as similars would be akin to conflating a rotary jet turbine with a reciprocating combustion engine. An imperfect analogy, lol, but really let's not mistake apples for oranges.
I’m being intentionally provocative with that phrasing but as a fan of magic, “sleight of hand” is used with heartfelt respect and admiration. I agree with the factual statements by both you and kingflum. I’m only trying to point out that there is no standard physics definition of “mechanical magnetic” so really in both cases, magnetic fields were introduced as a new and unconventional element. Distinction is SD uses electromagnets and this Breguet uses permanent magnets. I feel like the exclusion of an external electrical power source makes the two solutions more similar than they are different. I admit that this assessment is perhaps more subjective than objective given the lack of any framework for that assertion.
Excellent article KF! Really appreciate the explanation.
Thank you for reading!
“Epicness” is a word. Can we sue you for saying it isn’t?
As established offline, we can agree to disagree 😂
Pretty sure we established that online.
Does anyone know what sound the escapement makes (if any)?
Since there isn't the same contact, what happens to the traditional "tick, tick, tick" that we all know and love ? One of my favourite things to do with watches is listen to them - curious to know how this experience might differ for the Breguet
Oh my. I’m out of my league to join this discussion. Absolutely love what Breguet is doing here. Thanks all for the brilliant writing.