You think Iron Man was really original, don't you? Well, you're wrong. Iron Man had similar predecessor.
The first "Iron Man" was a real person: Lou Gehrig. He worked for the Ironman Batteries and was called Iron Horse, because he never got hurt in a baseball game. Illness made him too weak to play.
The second "Iron Man" was a Japanese cartoon character, who was known as Gigantor. He was originally called "Tetsujin" ("Iron Man"). He kinda looked like the original Iron Man.
Iron Man's next predecessor was Rocketman. He was a serial hero with an atomic-powered jet pack and a helmet that looks likes the original Iron Man's.
Stan Lee created a robot that was kinda a prototype-Iron Man that appeared in I Became A Human Robot!
Before the appearance of Stan Lee's Iron Man, there was a story called Man of Iron, which had the similar "iron lettering" Iron Man's logo.