I find old egg beater designs fascinating. I found this one at a yard sale this weekend. On this one, the gears are simply metal stampings. Cheap to manufacture, it still works perfectly today. It has a U.S. patent date of October 9, 1923. There were actually 2 patents assigned on that day: 1,470,169 and 1,470,170, both to Charles E. Kail of Binghamton, New York, and both assigned to the A&J Manufacturing Company of the same city.
As for A&J, see my previous post. Interestingly, on google patents you can find various 1930's patents for egg beaters are assigned either to the A&J Manufacturing Co. of Binghampton, NY or to the A&J Kitchen Tool Co. of Chicago, Illinois. Was this the same company? In any event, A&J Manufacturing was bought by Ekco in 1929. Ekco was founded by Edward Kaztinger, an Austrian ex-patriate in Chicago in 1888. It is now arguably the largest kitchen tool supplier in the U.S.