Watch function (complication)
(Also: Repetition watch, repeater)
Repetition means the repeated playing of an acoustic signal at a clock or watch. In mechanical watches this requires a special, expensive additional mechanism (complication), the repetition carillion (see below).
Repetitions are well known by the sounds played by church tower clocks (Big Ben, for instance).
Essentially there are repetitions of the following type:
- Hour repetition
- Quarter repetition (French: Repetition à quarts)
- Half quarter or 7½-minutes repetition, also: one-eighth repetition
- Five minutes repetition
- Minutes repetition
Due to the high mechanical effort repetitions are regarded as one of the most value-adding complications in a mechanical watch.
To represent the time acoustically, the carillion (or chime movement) needs power. This it activated by the operation of a slider or pusher at the case edge. At the same time, this process also triggers the percussion mechanism. If pusher or slide have not been moved to the stop, simple repeaters beat the time incompletely. In fine constructions this is prevented by a so-called all-or-nothing switch. They then repeat properly or not at all.
Three quarter strikes
- All quarters are stroken, whereas at the fourth quarter the full hour is beaten on a large bell.
- Here the quarter-hours are indicated — possibly with a double strike on two bells. On the full hour the number of hours is beaten on a larger bell, without the quarters.
- On each quarter of an hour, first the full hour is given on a larger bell, and then the quarters (usually with a double hit) - but not on the full hour: this is beaten without the quarters.