Archive for the ‘Watch terms E-T’ category

Watch Glossary E-T

February 19, 2010

Tags: Know watches. Get conversant with watch terms from Escapement to Tourbillon

Escapement: Set of parts (escape wheel, lever, roller), which converts the rotary motion of the train into to-and-fro motion (the balance).

Jumping Hour: System of timekeeping whereby traditional hands show the seconds and minutes but the hour is shown in a dial cutout (often at 12), on the minute’s hand reaching 59 minutes, the hour disc under the dial will jump to the next hour.

Manufacture d’horlogerie: French term for a watch factory which itself produces the components (particularly the “ébauches”) needed for the manufacture of its products (watches, alarm and desk clocks, etc).

Marine Chronometer: Highly accurate mechanical or electronic timekeeper enclosed in a box, used for determining the longitude on board ship. Marine chronometers with mechanical movements are mounted on gimbals so that they remain in the horizontal position is necessary for their precision.

Movement: Assembly consisting of the principal elements and mechanisms of a watch or clock: the winding and setting mechanism, the mainspring, the train, the escapement, the regulating elements. “Anatomically”, the movement consists of the “ébauche”, the regulating elements and the other components.

Power Reserve: In its purest sense, used to refer to how long a watch will run once fully wound. Thus a watch with a power reserve of 48 hours should run for that period. Often used to describe a watch that has a power reserve indicator on the dial (usually a small pointer hand and a relevant scale).

Repeater: Watch that strikes the hours by means of a mechanism operated by a push-piece or bolt.

Skeleton Watch: Watch in which the case and various parts of the movement are of transparent material, enabling the main parts of the watch to be seen.

Stopwatch:Timekeeping instrument that can be used for measuring intervals of time.

Tachometer: Instrument for measuring speed. In watchmaking, a timer or chronograph with a graduated dial on which speed can be read off in kilometres per hour or some other unit (see timer).

Tourbillon: (pronounced turbion) Device invented to eliminate errors of rate in the vertical positions. It consists of a mobile carriage or cage carrying all the parts of the escapement, with the balance in the centre. The escape pinion turns about the fixed fourth wheel. The case makes one revolution per minute, thus annulling errors of rate in the vertical positions.

Courtesy Illustrated Professional Dictionary of Horology and Federation of Swiss Watch Industry