Whose patent is Bao Er knob?

Bao Er has a patent in the United States, but it doesn't seem to be in China.

Boa knob was first invented by skier Gary Hammerslag. He found that traditional shoelaces were of little use to those heavy ski boots, so Gary Hammerslag began to try what he thought was a better solution: replacing knots with a brand-new knot tying system.