Set of parts comprising the regulating system (sprung balance) and the escapement (escape wheel, lever and roller).
Watch that strikes the hours by means of a mechanism operated by a push-piece or bolt. There are various types of repeaters. Quarter-repeater: sounding a low note for the hours and a "ding-dong" for each quarters; five-minute repeater: striking the hours, quarters and minutes; minute-repeater: striking the hours, quarters and minutes; Grande sonnerie (grand strike): striking the hours and quarters automatically and repeating when a push-piece is pressed down; chiming repeater: in which the quarters are struck three or four gongs each on different pitch.
Half-disc of heavy metal, which is made to rotate inside the case of an automatic watch by the energy produced by the movements of the wearer's arm. Its weight tends always to bring it back to the vertical position. Demultiplied by a specially designed device, its rotation continually wind the mainspring of the watch.
