Regulator
An observatory clock’s dial, borrowed for the wrist
What it is
A dial on which hours, minutes and seconds are read from three separate axes rather than a shared centre, with the minute hand given the large central sweep and the hours relegated to a subdial. Nothing about timekeeping changes; the reading order changes. It is a display arrangement with a precision-instrument pedigree, not a complication in the sense that a perpetual calendar is.
History
The layout is borrowed from the precision regulator, the weight-driven pendulum clock used in observatories and in watch manufactures as the local reference standard against which everything else was set. On those clocks the minutes matter most for a setting operation, so the minute hand was made the large central one and the hours and seconds were moved to separate registers where the hands can never obscure each other. Clemens Riefler's regulators had become the primary standard in observatories worldwide by the early twentieth century. On the wrist the layout stayed rare until Chronoswiss, founded in Munich in 1983 by Gerd-Rudiger Lang, launched the Regulateur in 1987. Regulator wristwatches existed before that, but as one-offs and prototypes; Chronoswiss was the first to produce them in series, which is the claim worth making rather than "the first regulator wristwatch".
How it works
In a standard movement the minute hand rides on the cannon pinion at the centre and the hour hand on an hour wheel concentric with it, geared 12:1 through the motion work. A regulator keeps the central cannon pinion for the minutes but reroutes that 12:1 output through additional motion-work wheels to a pinion under the hour subdial. Seconds are then taken wherever that calibre's fourth wheel sits, which is why regulator dials so often place seconds at six. Because the going train and escapement are untouched, a regulator wristwatch is neither more nor less accurate than the same movement with conventional hands; the benefit is legibility of the minutes, which is what a regulator clock was for.
Parts required
Extra motion-work wheels and an offset hour pinion to relocate the hour display away from the centre, plus a dial and hands laid out for three axes. The going train itself is unchanged.
In the catalog
Related
- Small seconds: A layout that follows from how the movement is built, not an added complication
- Hands: The moving pointers that display time
- Dial: The face of the watch; its most expressive surface