Automatic watch

from Wikipedia, the free encyclopedia

An automatic watch or automatic wristwatch (often referred to as automatic , in French also montre perpetuelle ) is understood to mean a mechanical wristwatch in which the spring is automatically wound (tensioned) in small steps by means of a rotor when the wearer's arm moves. One also speaks of a watch with an automatic winding mechanism or a watch with a self- winding mechanism . Early models of automatic wristwatches were partly equipped with a pendulum flywheel (colloquially also “hammer automatic”) instead of a rotor.

Working principle

Back of an automatic watch ETA - caliber 2824-2
Another photo with an Asian replica

The rotor (a weight rotating around an axis), which is usually mounted on ball bearings, wants to stay in its position in space when the watch case moves due to its inertia and gravity. This exerts a torque on the winding mechanism. The spring is wound bidirectionally in both directions of rotation of the rotor, unidirectionally in only one. If the rotary movement of the housing is in the axis of the rotor, the principle is based solely on the moment of inertia of the rotor (shown in the photo in the upper half). So this also works in weightlessness . In the case of rotary movements perpendicular to the axis of the rotor, the eccentricity of the same comes into play: The rotor is mostly only semicircular, so its center of gravity does not coincide with its axis. If the clock is only turned slightly from the horizontal, this may be sufficient. U. for a 180 degree rotation of the rotor. A slip clutch (so-called bridge ) prevents the mainspring from overwinding when the watch is already fully wound. Instead of a classic rotor, as can be seen in the two photos, a microrotor is used in particularly flat automatic watches , which is integrated into the movement to reduce the height of the watch. In most cases, microrotors are made of solid fine gold in order to achieve the necessary weight for efficient winding of the spring.

Automatic watches (watches with self-winding) are not only characterized by their easy handling, the always evenly tensioned spring also leads to a more even run than with a mechanical watch with manual winding. Their introduction thus brought progress in reducing the rate deviation . Important manufacturers of movements for automatic watches are the Swiss manufacturer ETA SA , the Japanese manufacturers Seiko and Citizen Miyota, and the Chinese manufacturers Tianjin Seagull and Hangzhou .

On the right in the picture (automatic movement ETA 2824-2 ) the rotor mounted on five balls can be seen in the foreground. The balance of the ETA 2824-2 runs at 4 Hertz (28,800 vibrations per hour). So-called "hi-beat works" (synonymous with fast oscillators) vibrate at 5 Hz (36,000 vibrations per hour), e.g. B. the Longines Ultrachron , the Girard-Perregaux Gyromatic Chronometer HF , the Zenith El Primero or the Grand Seiko Hi-Beat 36000 . A pointer is advanced with each half-oscillation, i.e. 8 or 10 times per second in the examples mentioned. Alternatively, most automatic watches can also be wound with the crown .

The power reserve or power reserve is the length of time in which the (fully wound) movement is still running after the watch was last moved. It varies depending on the movement and is usually around 35 to 60 hours, in combination with several barrels even up to 30 days. Automatic watches with a pendulum flywheel do not use the maximum available winding path like automatic watches with a rotor, the flywheel is braked on both sides by additional spiral springs , so the power reserve is usually lower.

For the collectors of automatic watches , electric watch winders are offered that keep the movement in motion so that the watches do not stop even when they are not being worn. The advantage of continuous movement should be weighed against the inevitable wear and tear when using the watch winder. A revision of the movement can therefore be expected at the latest as with normal use of the watch, and even earlier if the watch winder is set incorrectly.

Auto quartz movement

Swatch Swiss Autoquarz, 1998

A so-called auto- quartz movement is a quartz watch that draws its drive energy from a mechanical winding rotor. The kinetic energy that the movements of the wrist supply to the watch sets the eccentric winding rotor in motion, just like in a mechanical automatic watch. This rotary movement drives a tiny electrical generator , which in turn charges an accumulator or capacitor , from which the quartz watch is supplied.

In 2007 there were two such movements: the Japanese Seiko Kinetic and the Swiss ETA Autoquartz . The younger and more expensive ETA movement differs from the Kinetic movement in that the rotor does not drive the generator directly, but winds a small barrel . Whenever it is fully wound up, it will automatically drain and drive the generator. The advantage of this solution: The generator either does not run at all or at full speed. This protects it and at the same time works more efficiently. In addition, unlike the Kinetic movement , the barrel of the auto quartz can also be wound by hand over the crown, as in a conventional automatic watch.


The invention of the automatic, bidirectional winding mechanism with rotor and changer for pocket watches , which took place in 1775, is attributed to Abraham-Louis Perrelet . By 1778 at the latest, Hubert Sarton had also developed a pocket watch with an automatic winding mechanism. Even Abraham Louis Breguet presented in 1787 a precursor of the modern automatic movement ago. He called his pocket watch with an automatic winding mechanism Perpetuelle .

The simple manual winding via the crown (without the previously required key) initially made it difficult for the more expensive automatic pocket watches to establish themselves, although they had been around since around 1770.

In 1922, the French company Leroy created the first wristwatch with an automatic movement, driven by a pendulum flywheel, which was not sold. John Harwood , a British watchmaker from the Isle of Man, is known as the inventor of this automatic watch . His idea, developed from 1914, resulted in an application for a patent in Switzerland on October 16, 1923 , which he received on September 1, 1924. Together with Fortis or Blancpain , he brought out a watch model each in 1926. The Rolex Oyster Perpetual from 1931 is considered the first functional automatic wristwatch with a rotor that can be wound on one side; the principle of this self-winding rotor, developed by Hans Wilsdorf from Kulmbach , was patented worldwide for the company in 1932. In 1948, Eterna invented the pioneering rotor with ball bearings. The first automatic watches in Germany were built by Bifora , Durowe and Junghans .


  • The automatic clock. Ebauches SA, Neuchâtel o.J.
  • E. Wartmann: The automatic clock. In: The clock. Issue 1, 1950, pp. 5-9 (in continuations).
  • Alfred Chapuis, Eugène Jaquet: La Montre Automatique Ancienne 1770–1931. Neuchâtel 1952.
  • B. Humbert: The Swiss watch with automatic winding. Lausanne 1956.
  • Georg Schindler: Development, current status and repair of the automatic clock. In: The clock. Issue 18, 1964, pp. 18-24.
  • Peter Aebi: Dedicated to John Harwood, the inventor of the automatic wristwatch. In: Neue Uhrmacher-Zeitung. No. 5, 1966, pp. 18-20.
  • Hans Kocher: Automatic clocks. Ulm 1969.
  • Château des Monts, Musée d'Horlogerie (ed.): Horamatic - Montres à remontage automatique de 1770 à 1978. Le Locle o. J.
  • François Mercier: Mechanical watches with automatic winding. In: Old clocks. No. 1, 1985, pp. 21-32, and No. 2, 1985, pp. 27-47.
  • John Harwood: The story of the automatic wristwatch, told by its inventor. In: Swiss watchmaker newspaper. No. 11, 1951, pp. 31-34; Reprinted in: Old Clocks. Issue 5, 1986, p. 65 ff.
  • Henry B. Fried: Some Early Self-Winding Wristwatches. In: Horological Times. June 1989, p. 36 ff.
  • Helmut Kahlert: The momentum that changes the clock. In: Uhren Magazin. No. 4, 1991, pp. 101-112.
  • Heinz Hampel: Automatic wristwatches from Switzerland. Munich 1992.
  • Bernhard Schmeltzer: The automatic wristwatch. Duisburg 1992.
  • Ives Droz, Joseph Flores, André Thiry: Une page importante ajoutée à l'histoire de la montre automatique. In: Horlogerie Ancienne. No. 33, 1st half of 1993, pp. 109-127.
  • Helmut Kahlert: Automatic wristwatches. In: Trödler & Magazin collecting. Volume 5, 1995, pp. 32-37.
  • Heinz Hampel: Automatic wristwatches from Germany, England, France […]. Munich 1996.
  • Helmut Kahlert , Richard Mühe , Gisbert L. Brunner : Wristwatches: 100 years of development history. Callwey, Munich 1983; 5th edition ibid 1996, ISBN 3-7667-1241-1 , pp. 60-70 ( automatic watches up to the present ).

Web links

Commons : Automatic watch  - collection of pictures, videos and audio files

Individual evidence

  1. Microrotor. Retrieved on July 13, 2020 (German).
  2. H. Kühnhanns: Shock protection in self- winding . In: The clock. Issue 23, 1954, pp. 12-14.
  3. See Adolf Benz: The importance of a lockable mass in the automatic winding of a wristwatch movement with a power reserve indicator. In: Chronometrophilia. No. 25, 1988, pp. 87-90.
  4. ^ Hubert Sarton: pocket watch with automatic winding. 1778, Académie des Sciences.
  5. ^ Helmut Kahlert , Richard Mühe , Gisbert L. Brunner : Wristwatches: 100 years of development history. Callwey, Munich 1983; 5th edition ibid 1996, ISBN 3-7667-1241-1 , pp. 12 and 60.