A Minute Repeater Tutorial
by Ron DeCorte
While visiting Vacheron
Constantin in March, I was offered the opportunity to photograph some
interesting watch movements in various states of completion, one of them
being a minute repeater. Unlike a lot of other watch complications, the
repeater is a bit mysterious, having most of its mechanism hidden under
the dial. And so I thought it would be interesting to present an article
on the subject of repeaters, particularly the minute repeater. This is not
a definitive article on the subject, but rather a brief tutorial.
repeaters, were developed prior to electricity when checking the time
during the night wasnâ€™t as easy as turning on a light bulb or looking at
the illuminated electric clock. And during some of those long Sunday
church services many a man was known to reach into his pocket, cradle his
repeater in his hand, and count the hours and minutes until he was free to
go fishing, drinking with his buddies at the pub, or visit his mistress!
A Vacheron Constantin minute repeater
wristwatch movement, topless. The minute repeater strikes the hours,
quarter hours, and minutes, on two gongs, each with a different pitch.
Yes, there are exceptions to this two-gong rule, but they are very rare.
Basic operational and striking components of a
minute repeater (see detail below).
Setting the hour strike: The main operating
lever â€śAâ€ť (inside the ellipse) slides along the perimeter of the watchcase
and pushes the hour-foot â€śBâ€ť against the hour-snail â€śCâ€ť containing 12
steps (hence 12 hours). The hour-foot is shaped like a boot, itâ€™s the toe
of the boot (hidden) that contacts the hour-snail and sets the number of
hours to be struck. The hour-snail is attached to a star wheel and is
indexed once each hour.
Setting the quarter strike: When the main
operating lever (slide) has been completely cocked and the hour-foot toe
has contacted the hour-snail, the all-or-nothing spring â€śDâ€ť will release
the quarter-rack â€śEâ€ť allowing it to rotate (fall) and make contact with
the four step quarter-snail (hidden) that is located directly under the
minute-snail. Note: The all-or-nothing spring gets its name for the fact
that it only allows the watch to strike when the repeater mechanism has
been fully cocked, eliminating false (incorrect) striking.
Setting the minute strike: When the
all-or-nothing spring releases the quarter-rack it also releases the
minute-rack â€śFâ€ť that will rotate (fall) against the minute-snail â€śHâ€ť. The
minute-snail has four leaves, each with 14 steps (look closely, one leaf
is hidden), and makes one revolution each hour. Notice the saw-toothed
teeth on the edge of the minute and quarter racks (and similarly for the
hours, hidden). These teeth will pass by the hammer-trips â€śJâ€ť and â€śKâ€ť when
the racks fall and then engage the trips as the racks are retracted during
the strike sequence, causing the hammers to strike the gongs.
Lets examine the process so far: The main
operating lever (slide) is cocked, pushing the hour-foot toe against the
hour-snail, the all-or-nothing spring releases the quarter-rack and
minute-rack allowing them to fall onto their respective snails. At this
point the mechanism is â€ścockedâ€ť and ready to strike the hour(s), quarter
hour(s), and minute(s). Note: cocking the main operating lever also winds
the strike-spring, a small main spring located at â€śGâ€ť (hidden) that will
provide the power to raise the racks and make the striking.
A view of the Vacheron Constantin minute
repeater movement from the back.
As mentioned earlier the hammers â€śAâ€ť and â€śBâ€ť
will strike the gongs â€śCâ€ť to mark the hours, quarter-hours, and minutes
accordingly. Hammer â€śAâ€ť is the â€śhour-hammerâ€ť and â€śBâ€ť is the
â€śminute-hammerâ€ť. The hour and minute hammers are used in alternating
sequence to mark the quarter hours. Note that the hour-gong has a slightly
lower tone (dong) than the minute-gong (ding), hence it is slightly longer
and tuned differently.
Note: â€śJeweled-To-The-Hammersâ€ť is a common
statement when referring to high-grade repeater watches. Notice that the
above Vacheron Constantin watch has two hammer-jewels â€śDâ€ť and the
entire strike train is also jeweled, on both sides, making for a more
friction and wear resistant watch. In some cases there is little, or no,
jewelling of the strike train and in certain cases only jewels on the
(visible) back side of the watch creating an illusion of quality that
might not exist.
OK, lets make some noise, or music as the case
may be. Lets say itâ€™s 03:35, and the slide has been cocked and released.
The third hour will be marked by three strikes on the hour-gong
(dong-dong-dong), the second quarter of the hour is marked on the minute
and hour gongs (ding-dong/ding dong), and the minutes are marked on the
Sounds simple doesnâ€™t it? But believe me a
striking watch requires a lot of precision to fu8nction properly and this
article is only the tip of the ice-berg!
Some important notes and comments about
Early repeating watches,
â€śquarter repeatersâ€ť, marked the hours and quarter-hour. Later the â€śhalf
quarter repeaterâ€ť was developed to mark the hour, quarter hour, and
half-quarter hour. The â€śfive-minuteâ€ť repeater marks the hour and indicates
the minutes within five. And then of course the minute repeater.
A minute repeater is extremely
complicated, far more complex than a tourbillon or perpetual calendar
complication, surpassed in complexity only by the
All repeating/striking watches
demand the most careful attention in operation and servicing.
Itâ€™s imperative that striking
watches be serviced by highly qualified technicians. Each and every, and I
mean EVERY, component should be removed and cleaned by hand. Anything less
will result in corrosion and/or a sticky mess that will not operate
correctly. You wouldnâ€™t take your expensive automobile to a back-yard
mechanic would you?
Never force the strike operation
or setting of the hands. Stop and get professional help.
Moisture is the death of
complicated watches. If you have complicated watches in storage, make sure
they are stored in a dry wooden box (cigar boxes work very well), wrapped
in a piece of wool (or a wool sock).
If you would you like to see a more technical
article regarding minute repeaters let us know, it might be arranged!
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Copyright Ron DeCorte 2004