Brass Coca-Cola Safety First?

Saw this piece in an antique shop. On the front it says Saftey First and in between it says drink Coca-Cola with the registered trademark. On the back it says PAT'D 4-11-33 NATIONAL SAFTEY MARKER CO. PONTIAC, MICH. It look like something that would be put on a sidewalk or something. Any help would be appreciated.