The Harwood Automatic Wristwatch

I have over the years collected a few examples of earliest self-winding wristwatches covering the developments of the first experimental phase from 1929 to 1935. I will be posting these watches over the next few weeks and I hope you will enjoy seeing them.

THE HARWOOD AUTOMATIC - Hammer Winding

The first "self-winding", or "automatic", wristwatch was the invention of a British watch repairer named John Harwood in 1923. The winding mass was a 'hammer' that was mounted on both sides of the movement but wound the watch only in one direction as it would 'swing'. Its impact was dampened by spring buffers. The back-and-forth motion of the hammer couples to a ratchet to automatically wind the mainspring. The first Harwood Automatic was first displayed at the Basel Fair in 1929.