THE FLYBACK FUNCTION AND THE PRECISELY JUMPING MINUTE COUNTER

In 1999, A. Lange & Söhne introduced the DATOGRAPH, its first manufacture chronograph of the modern era. It was endowed with two additional useful complications that today are still integrated in many Lange chronograph models: the flyback function and the precisely jumping minute counter.

The so-called flyback function allows an ongoing time measurement to be interrupted and a new one to be started instantaneously by merely pressing a button. It combines three steps – stop, reset to zero, and restart – into one. In chronographs without the flyback function, these three steps must be executed consecutively.

The concept behind this complex function dates back to the era when flight-deck crews still navigated with maps and watches and often had to react very quickly to suddenly occurring events. With the triumph of electronic measuring instruments, this classic function, mainly used by pilots, sank into oblivion. In Lange chronographs, the flyback mechanism is experiencing a renaissance – with a newly developed design.

Many chronographs have a minute counter that advances minute by minute rather than continuously. The switching process sometimes takes one or two seconds. If such a watch with a delayed-action minute counter is stopped in the vicinity of a full minute, it is often unclear whether the counter hand has already incremented forward or not.

The precisely jumping minute counter, however, advances by one graduation exactly after 60 seconds have elapsed, even if the time measurement is stopped at that very moment. This useful mechanism was already incorporated in historic pocket watches and high-end wristwatches crafted during the last century. But Lange’s calibre engineers refined it in an ingenious way: a patented switching lever now allows the watchmaker to precisely determine the timing of the minute counter jump without having to disassemble the movement.