Minute repeater

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.

Meanwhile, the striking device is composed of a mechanical memory system, hammers and gongs. At the same time as it winds the strike mechanism barrel, the slide-piece also releases three feeler-spindles, which read (sample) the information on the hours snail, the quarters snail and the minutes snail. The latter are spiral-shaped rotating cams, which serve to adjust the number of blows that must be struck by the hammers. The first (for the hours) comprises 12 steps, the second four (corresponding to quarter-hours), and the third (for the minutes) has four wings with 14 steps each. The minutes snail is shaped like a four-pointed star, each comprising 14 steps. Once they have dropped onto the snails, the feeler-spindles then position the same number of toothed segments at a distance corresponding to the time to be indicated.

Once released, these toothed segments activate the hammers by means of gathering pallets, one fingerpiece per blow. Having thus received the command, the hammers strike their corresponding gong, producing as many notes as the time indication requires. Therefore, to strike 11:38 for example, the hours feeler-spindle will stop at the 11th step of the hours snail; the quarters feeler-spindle will drop onto the second step of the quarters snail; and the minutes feeler-spindle will come to rest on the 8th step of the minutes snail. These actions thus enable the toothed segments, positioned at the other end of each lever to place in front of the hammer fingerpieces the number of teeth corresponding to the blows to be struck. The hours rack will activate the hours hammer 11 times (11 low notes); the quarters rack will in turn activate the quarters hammer twice (two high-low notes) and then the minutes rack will set the minutes hammer into motion eight times (eight high notes). The quality of a minute repeater depends on a multitude of factors: the shape and direction of the hammers; the cross-section (square or round), the material, the length and shape of the gongs; their point of attachment on the watch (caseband, mainplate or crystal), and finally, the material and architecture of the case, which may house a resonance chamber or openings enabling enhanced sound diffusion.

Repeater watches date back to the time when, in the absence of electricity, strike mechanisms made it possible to tell the time in the dark. The invention of the quarter repeater principle – sounding only the hours and quarters – was the work of English watchmakers Edward Booth, alias Barlow, Thomas Tompion and Daniel Quare in 1685. It was the latter who, by decision of the Privy Council of London, was granted the patent for this invention in 1687. The first minute repeater watches were made in the southern German town of Friedberg in about 1710. While their maker is unknown, they predate the one made in 1750 for Ferdinand VI of Spain by Thomas Mudge, a British horologist who was long regarded as the father of such watches. In 1787, Abraham-Louis Breguet made his own contribution by replacing the previously used clapper-free bells by gong-springs, the rings he had invented. Perfected by François Crispe of Switzerland in 1804, they would enable a considerable reduction in the thickness of cases, thus serving to achieve a purer sound.

Greatly appreciated by the nobility and the middle classes, repeater watches were also very difficult to produce and thus extremely expensive – and especially minute repeaters. The invention of the modern matchstick in 1845, making it easy and far less dangerous to light candles and oil lamps, led to a downturn in production of such models. It was not until 1870 and the first repeater movements mechanically machined by Antoine LeCoultre, that a resulting price reduction helped broaden the customer base and revive production.

The minute repeater watch nonetheless represents one of the greatest challenges for master watchmakers. The function thus continued to be developed in Grand Complication models, combined with the split-second chronograph and the perpetual calendar. In response to an order placed by Louis Brand & Frères of Biel/Bienne, which would later become the Omega brand, Audemars Piguet developed the first minute repeater wristwatch, which was completed in 1892. Today, the minute repeater is still considered one of the most prestigious complications and has been developed by an extremely small number of Manufactures. These include those of the Swiss-based Finnish watchmaker Kari Voutilainen, who made to order in 2013 his Decimal Minute Repeater GMT watch. This one-of-a-kind model strikes the time decimally, meaning by indicating the hours, ten-minute increments and minutes, which the watchmaker regards as easier to ‘read’ than a traditional minute repeater.