Who invented auto directional signals?

Who invented the Automatic Direction Signal? Frederick E. Voigt of Los Angeles California. The patent application was filed March 16, 1922 serial No. 544,269. The patent was granted April 7, 1925 Pat. No. 1,532,563. Fred Voigt is my great grandfather. He has passed away but I have pictures of the Voigt Automatic directional signal, and copies of his patent.