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Wednesday, 10 October 2018 21:32

ETA's Crown Function Display

This is one of those patent's that is so simple and obvious that I was a little surprised not to have seen it before. I think this could be useful on watches with a million little complications, but then the question becomes where do you put the function indicator?

In this patent, the crown is connected to an indicator dial on the face of the watch. When the crown is pulled out to its first position, a finger engaged with the sleeve of the crown pulls a rack attached to the function dial. This rack and pinion connects the function dial on the face to the crown. 

One thing this doesn't account for is indicating how to turn the crown to adjust it when a given position on the crown controls two functions on the watch. I admit that every time I grab a day-date or a GMT watch with a date function I almost always rotate the crown the wrong way to adjust it first. As a result, my GMT watches are perpetually on some random timezone that I don't care a wick about.

In the 1970s, Certina had a problem. There were already watches that were sealed and at low pressure to minimize oxidation of the gears and lubricating oils, but they were less accurate than other watches. Moreover, they were impossible to adjust while they were still sealed. 

So, Certina sought a way to adjust a fully sealed watch. And this is what they came up with. 

Certina put two bimetallic strips on either side of a regulation point, when heated, the bi-metaltic strips would push on the regulation point, adjusting the speed of oscillation. 

You may be familiar with bimetallic strips from older-style thermostats. They are exactly what they sound like. A strip of two metals, joined together. Because they are not the same, the metals expand differently when heat is applied, and the metal curves. For a thermostat, it typically has a mercury switch on one side, so when it bends too much in one direction (or unbends) it will turn the heater on or off.

Similarly here, these two bimetallic strips are able to be heated from the outside of the case, and then bend to adjust the oscillation of the movement and make a more accurate timekeeping device.

Tuesday, 02 October 2018 00:52

Breguet's North-South Moon Phase

You probably don't think too often that you need slightly different moon phase mechanisms for a watch in the northern hemisphere compared to the southern. In fact, all you need is for the moon phase wheel, the wheel that has the moon on it, to rotate in the opposite direction: right to left on most watches.

In most watches, this would just be a matter of adding a gear, or assembling the mechanism differently. But what, Breguet asks, what do you do for someone who travels from the northern hemisphere to the southern, or vice versa?

Well, for that world traveler, who only wants to bring one watch with them, Breguet has an answer: a moon phase mechanism with counterrotating wheels, two heart cams, and a selection mechanism to engage one or the other. 

This is an interesting patent in that it may do fewer new things than any other modern patent we've featured here. It's basically two moon phases, with a selector between them. The heart cams allow the selection lever to engage one wheel or the other.

Like many of the patents here, this one is unlikely to see manufacture. It's not a really meaningful improvement on the existing mechanisms, and has incredibly limited real world use. 

Tuesday, 25 September 2018 22:09

Blancpain's Adjustable Snooze

This is a delightfully over the top patent. Granted in December, 2017, this patent describes an adjustable mechanical snooze function on a watch with an alarm.

I say this is over the top because watches with alarms are rare enough. It seems unlikely that anyone would actually manufacture one with a snooze feature (prove me wrong if they exist already), let alone an adjustable snooze.

The mechanism by which the snooze is achieved is pretty straight froward. There's a rack and cam (pictured above). The angle of the rack determines the duration of the snooze, and the cam has multiple points where it can set the angle of the cam. 

This is really one of those patents that would make an absurdly high-end watch. Would I use this if I had it on a watch? Of course I would. Would I ever buy one? I cannot imagine a world where I would.

Wednesday, 12 September 2018 19:47

Audemars Piguet More Accurate Moon Phase

Here's the thing with moon phase complications: they're popular, they're mechanically simple, and they're very bad at accurately displaying anything other than full and crescent moons.

The way most work is to have a semicircular opening with a smaller semicircle, or occulation disk on either end of the semicircle. As the moon emerges over left side, it starts as a tight crescent, and slowly grows to a full moon, before waxing. But the middle areas between the full moon and crescents are poor representations of the moon. If you check your moon phase at a half moon, it will look like a moon cookie with a bite taken out of it more than a half moon.

Enter Audemars. Their stated goal with this patent was to create a complication that did not add substantially to the complexity of the movement, while providing a more accurate representation of the moon at any given phase. What they've come up with is a really clever mechanism that was patented in the United States on July 30, 2013.

They maintain a few staples of more common moon phase complications. As shown in the patent, it keeps the semicircular opening for the complication, a moon disk with two moons opposed at 180 degrees from one another, and the traditional rotation rate of 29.5 days per half-turn. That is where the similarities end.

Instead of having semicircular occulation disks, the patented complication has two rotatable occulation disks that look vaguely like those three winged boomerangs. The disks can be calibrated to provide more accurate occulation of the moon at particular parts of its orbit. As the moon disk rotates it engages gears that move the occulation disks, typically in one quick movement, like with a date change.

In the end, this is a very interesting, but very high end complication. It adds a lot of pieces to what is typically a simple and inexpensive addition to a watch. I would really love to see this make its way into a watch, either by AP or licensed by someone else.

Monday, 10 September 2018 21:50

Rolex's Cheap Alternative to a Chronograph

In late November, 2016, Rolex was granted a patent for a complication that would serve a similar purpose to a chronograph, but with fewer parts, thereby making it more reliable, smaller, and lighter than traditional mechanical chronograph movements.

The basic premise is to have a your normal hour, minute, and second hands (shown as a small seconds in the patent drawings), and then "stored" hours, minutes, and seconds hands. Both sets move in sync until you freeze the "stored" time hands. Then, instead of having a readout of how much time has elapsed as with a typical chronograph, you simply have a display of when you stopped the clock.

Two heart cams then serve to resynchronize the seconds with seconds, and hours and minutes with the actual time. Heart cams are routinely used to zero out chronographs, so they have a long history in watchmaking. 

I feel that it's unlikely this makes it into a Rolex watch. (The discussion of why you patent something if you're never going to sell it is for another day.) It's not clear where it would fit in their line, and it seems like most people would correctly view it as a cheaper, less convenient version of a chronograph. It's easy to read elapsed time. It's harder to do watch-math -- It's 8:37 now and I stopped the watch at 7:18. . . It's an hour and nineteen minutes, but it took you longer to get there than looking at a chronograph.

One thing that's notable about this patent is that it relates to a new complication, rather than improvements in materials or reliability to existing components. It's a little out of the ordinary for Rolex.

Monday, 20 August 2018 19:31

Rolex's Ceramic Lume

We don't plan to cover much of Rolex's materials patent portfolio here. It's not because it's not interesting; it really is. It's just that ceramic chemistry and metallurgy aren't as easily understood by the typical watch nerd as a bunch of gears and some simple drawings. And, if I'm being honest, aren't as easily understood by me either. When we do cover them, it's more likely going to be a "what does this mean," rather than getting too far into the "how."

This recently issued Rolex patent is a decent example. 

The abstract reads: 

Watch component made of a persistent phosphorescent ceramic composite material which is a sintered dense body comprising two or more phases, a first phase consisting of at least one metal oxide and a second phase consisting of a metal oxide containing at least one activating element in a reduced oxidation state, the watch component having a surface which comprises an area which shows phosphorescent emission and an area which does not show phosphorescent emission or which shows phosphorescent emission with an intensity which is lower than that of the emission of the other area.

The patent covers a ceramic element of a watch that is either partially phosphorescent, or has elements that have different phosphorescent properties. Like hour indices that look like one piece in day light, but only the tips glow. Or a solid ceramic bezel where indices on the bezel are luminescent. It's potentially pretty cool.

These patents are dense. Like fruitcake dense. Flourless chocolate cake dense. While most mechanical watch patents are pretty brief, and explain the relevant gearing and positions in relation to other gears in the train, these patents go into great detail (see the image) above regarding how the ceramic was manufactured, and which temperatures and concentrations of metals provided what results. It's good technique for getting a broad patent, but it's not easy for me to post a picture of ceramic crystals and have the implications of that be apparent for watch fans. 

All of which isn't to say we will never cover them, but my feeling is that these will be of less general interest to readers than a day-night complication where the moon also displays the moon phase. 

Wednesday, 08 August 2018 21:24

Benrus' Expanding and Contracting Bracelet

From time to time we will revisit some much older patents. They show us some ideas that either never caught on, or did but have since been improved upon or gone out of style.

This Benrus patent was issued in 1952 and expired in 1969.

This patent disclosed a simpler way to adjust watch bracelets. The bracelet features a traditional tri-fold clasp, but also allows quick adjustment to make the bracelet tighter or looser. An internal spring bar and several notches allow the user to easily adjust the fit of the bracelet while it is still on their arm, all invisible to the user.

The patent suggests that on hot days you may want a little more room in the bracelet, or to quickly push it up your arm while washing your hands.

It's a clever idea, though I don't know that it was ever mass produced. And certainly the spring bar would loose resilience over time and the bracelet would begin to slip, which is a major downside.

Meanwhile, we have seen some quick fine adjust mechanisms on bracelet clasps lately, but none that I'm aware of that let you adjust the fit while it's on your arm.

Wednesday, 01 August 2018 01:24

Lange's Zeroing Second Hand

Even Lange's patent drawings are things of beauty. This patent, which expired in September, 2016, discloses and claims a beautifully simple mechanism to zero a second hand while setting the time. 

The basics of this mechanism is a cam-plate drive. The cam plate can be seen attached to the seconds stem. When the crown is pulled into the setting position the cam is driven by a spring-driven lever into the zero position. By using a heart-shaped cam, the mechanism will also hack - keep the second-hand at the zero position while the minute hand is being set.

For such a desirable feature, there are surprisingly few parts involved, and given that the patent on this mechanism has expired, I'd love to see to lower-end watch companies start to incorporate this into their watches.

Wednesday, 25 July 2018 19:12

What Are Design Patents

Design patents are an integral part of the intellectual property strategy of many watch companies. And design patents are exactly what they sound like: patents on the design of an object.

Typical patents, called "Utility Patents" in the business, protect only the useful, or functional, elements of a product. So, for many brands like Rolex, Omega, and Lange, they file patents on their innovations in the materials that make their cases, their co-axial escapements, or new and wondrous complications. 

But a large number of watch companies don't innovate in technology. They innovate in design and use off-the-shelf movements. 

Companies like Baume & Mercier have their entire patent portfolios (near as I can tell) dedicated to design patents: over a dozen design patents in the US dedicated to the design of watches, watch faces, and watch parts.

Design patents only last 14 years from the date the design patent is granted, and only protect the look of the item, not the way it works.

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