Minute Repeater is a watch that rings the hour to the minute on demand.
This sound signal is triggered by a lever that directly raises the barrel of the ringing mechanism, whose energy will be used during the twenty seconds following its release.
This lever can be operated in several ways, either by means of a latch also called a pull tab which is located on the side of the case middle. There is another version that is similar to a pusher. A rare version has been directly integrated into the bezel and is therefore completely invisible, which had the advantage of improving water resistance.
At the level of the regulation of the speed of the bell there are two types of mechanisms. One works with an anchor and an eccentric. This system has the advantage that the speed of the bell can be adjusted at the request of the customer. There is another system which is the inertial wheel. This system has a speed that is more fixed but the advantage of being quieter.
Most minute repeaters strike the hours, quarters and then the remaining minutes. Some rarer pieces strike the hours, tens of minutes and then the remaining minutes and are called Decimal Minute Repeaters.
The waterproofness of a minute repeater and of striking watches in general is also an interesting topic. For many years they were only dustproof. Some minute repeaters, even with locks, have become water resistant. However, it is important to know that this water resistance can affect the quality of the ringing.
Minute repeater movements can, also for a non specialist, be easily recognized on the dial side when a timer is engraved on the outside of the mainplate. The watchmaker needs this timer on the dial to set the watch.
There are also watches with simplified repetitions such as half-quarter repeater or five-minute repeater where the precision does not go to the minute.
Generally, the Minute Repeaters do not have a Grande and Petite sonnerie mechanism, so they ring as they pass.