 The flame-grilling machine at Burger King, Carl's Jr./Hardee's, and other fast food restaurants is called a 'broiler'.It works by moving meat patties along a chain conveyor belt between top and bottom burners, grilling both sides of the meat patty at the same time.This concept was invented in 1898, when the Bridge and Beach Co. of St. Louis, Missouri, started manufacturing a vertical cast iron stove.