Quite a few. Not sure how long you would make four generations, but let's say 100 years.

There are the obvious famous families; Ford, Rockafellers, Du Pont, Mellon, Mars, Hearst, SC Johnson ("a family company"), etc. But there are a number of billionaire families that aren't recognized much outside of their "home towns" because they started mundane things like retail stores or own mineral rights.

That's not even getting into families whose wealth has diluted, but whose descendents are politicians, actors, or otherwise notable / influential people.

Granted, most billion dollar businesses are <4 generations old, but more sophisticated investment vehicles exists for preserving wealth than existed even 50 years ago.