A minute repeater watch is equipped with a strike mechanism which indicates the exact time whenever one so wishes. The term ‘repetition’ refers to the fact that it is possible to activate the system as many times as desired, as opposed to the passing strike mechanism that is automatically activated on passing the hours.
In a minute repeater mechanism, two hammers strike two different gongs, thereby audibly indicating first the hours by low-pitched notes, then the quarters with a double high-low note, and finally the minutes on high notes. Although very complex and extremely difficult to fine-tune, this complication is the best-known of all repeater mechanisms. According to the precision of the information the watch is capable of reproducing, this complication is divided into various categories: quarter repeater, 10-minute repeater, half-quarter repeater, five-minute repeater – and the most accurate of all, the minute repeater.
The repeater mechanism comprises a pusher or a slide-piece (bolt), a barrel and a regulating system. This device is generally independent of the watch mechanism. By pressing the pusher or sliding the bolt along the caseband, a rack – a lever tipped with a toothed segment – serves to wind the spring of the strike mechanism, which will thus be primed for use. An ‘all or nothing’ system prevents activation until winding is complete, thus preventing the watch from striking a random time. Once released, the energy is transmitted via the wheels and regulated either by a recoil pallet, or by an inertial flywheel, so as to maintain the sound at a constant pace.