The newest innovation was the automatic zigzag, which could do all that straight-stitch and manual zigzag machines could, plus do embroidery pattern stitches automatically.
They had discs or cams to be inserted or some were built into the machine.
Above are the machines they highlighted. Unfortunately they don't mention the model # and that is not always visible on the machine.
If you have an older machine but don't know when it came out, perhaps it is shown here. These machines would be from 1955 or possibly 1954. The year could certainly be a place to start to find out more about your machine.
