Regulo is one of those words like hoover; a former trademark that got conscripted into the language. Before the invention of the Regulo gas oven controller, the cook had to keep checking the stuff in the oven to get the heat right.

As a kid, I thought a spong was a generic term for a mincer. And the Russians adopted "vokzal" as the name for railway stations, apparently because the first Russians studying railways arrived in London at Vauxhall station.