>applied for by a Korean and manufactored in Korea
Foreign patent protection became very common after the turn of the century. It prevented some American company from copying the design and exporting them back into or near the inventors country.
It also happened a lot the other way, American inventors often cross patented in England to protect their markets there....(This caused interesting problems in it's own right, with the Brit's passing some rather interesting patent laws..)
It still is common today, tho it is often not as critical. Getting a patent in another country will generally bar someone here from getting a patent on the same thing here because it runs afoul of the prior art rules (it's not new and novel anymore). However, to licence the patent here you generally want to have a patent here (multi country litigation is not pretty), so many things still get patented across multiple countries.
Interesting and unusual ratchet :)