About Automatic Watches
Practical, classic, and green!
Automatic watches are similar to mechanical watches except that they don't (usually) need to be wound. They are also sometimes refered to as "self-winding" watches.
The automatic watch was invented by James Harwood in 1923 who devised a swinging weight mechanism called a "rotor" which rotates due to the normal movement of your body. The rotor is combined with a ratcheting mechanism to limit the winding motion to a uniform direction. Together, the rotor and ratchet keep the watch wound automatically. If you stop wearing the watch, however, the watch will normally wind down and stop within 1 to 2 days depending upon the capacity of the mainspring. People that own several automatic watches sometimes use a device called a "watch winder" to keep their watches in motion so that they can be worn anytime without the need to reset and wind them before use.
An automtaic watch with
exhibition back showing the
rotor (the semicircular
object on the right)
Since automatic watches are mechanical watches with an additional mechanism to keep the watch wound, they have the exact same accuracy of mechanical watches, about +/- 5 to 30 seconds per day.
Next to quartz and digital watches, automatic watches have become the next most common type and there are many different models available. Most fine mechanical watches made today are automatic. Vintage automatic watches have become fashionable as the ultimate in "green" wristwear because they don't require batteries and they can be considered to have been "recycled".