Sooooooooo Slippery

In 1943, Navy engineer __x__ was trying to figure out how to use __y__ to keep the sensitive instruments aboard ships from rocking themselves to death, when he knocked one of his prototypes over. Instead of crashing to the floor, it gracefully sprang downward, and then righted itself. So pointless — so nimble ,thus came the name __z__. The __y__ became a goofy toy of many childhoods—that is before every kid inevitably gets theirs all twisted up and ruins it. 300 million sold worldwide!

Find x , y , z