Solution to the previous challenge

US3171683A, "Windscreen assembly for motor vehicles and the like" patented in 1965. This patent is almost 60 years old and has never been used in the mass production of cars. To date, there are only a small number of examples of its use in supercars.

How do you make Japanese inside-out boiled eggs?

Inventions are basically technical solutions to problems. If inventors want to protect their invention, they might opt to file a patent application. But since all patent applications have to be published, this also works the other way round - if you're looking for a technical solution to a problem, why not search in a patent database? The solution might already exist.

Some problems might be less obvious or pressing but still intriguing. Japanese cuisine has been popular in Europe for quite some time, so many people tend to know that it's more than just sushi. But what some might not know is that the Japanese have long loved finding solutions to make unusual foods.

Just look at these inside-out boiled eggs, where the yolk is on the outside and the white on the inside.

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Fig. 1: "Yellow eggs" (Kimigaeshi tamago). Taken from: ROIS-DS Humanities Open Data Joint Support Center: Edo cuisine recipe data set

One way of producing these eggs was published as early as 230 years ago during the Edo period (1603-1868) in the popular cookbook "Secret treasure trove of ten thousand recipes".

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Fig. 2: Secret treasure trove of ten thousand recipes (Manbo ryori himitsubako, 1785). Taken from: ROIS-DS Humanities Open Data Joint Support Center: Japanese Classics Data Set.

However, the recipe is perhaps not the most straightforward:

"Take an egg which has been incubated for three days; make a small hole in the side; when there is a little air in the egg, pickle it for three days in miso ..."

When this cookbook was unearthed, the Japanese were determined to find out how to produce these inside-out boiled eggs, with pictures of them springing up everywhere online. But do you think there are any patent applications with a technical solution for making them?

The answer is, of course, yes. In fact there are several different applications with different methods for producing the inside-out eggs.

Have a look at this one:

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Fig. 3: Abstract and representative drawing, JP-B 2988880, taken from the Japan Patent Office's J-Plat Pat search tool.

The solution proposed in this patent (application filed in 1996 and granted in 1999 with the number 2988880) is rather different from the one in the old Edo-period cookbook. It introduces an apparatus that rotates the egg to make the heavier yolk move outwards towards the shell while the lighter egg white heads to the middle.

However, this patent only had a short lifetime: as early as 2002, three years after grant, it was deemed withdrawn as the annual fees stopped being paid (see Fig. 4). It seems that the invention was no longer of value to the patentee - or perhaps he simply didn't want to put all his eggs in one basket...

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Fig. 4: Legal status information from the Japan Patent Office's J-Plat Pat search tool
(click on "Details" and afterwards on "Registration Information").

For more information:

EPO's web pages on Asian patent information: collection of step-by-step search guides for the J-Plat Pat search tool

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