In 1917 Frank J. Husbands of Los Angeles received a patent (No. 1,236,441) for what would later be known as the Acme Traffic Signal. The city of Los Angles experimented with these signals first by installing the at five locations along Broadway between 3rd and 7th Streets. These signals turned out to be a success and by 1923 31 Acmes, all interconnected, were installed in the central business district. These were the most advanced signals in the world at the time. Acmes greatness did not last forever though, in 1920 William Potts Invented and installed the first three color four way traffic signal in Detroit, Michigan. Cities soon started adopting these automatic signals because they did not use any mechanical parts so they would not jam and they operated noiselessly which worked better for places beyond the central business district. Soon Ornamental Eagleluxes replaced the Acmes along Wilshire Boulevard in September 1931. The last one was removed in December 1956. The Acme still lived on as props in movies and some are still owned by collectors today.