JUMPING NUMERALS ACCORDING TO THE LANGE PRINCIPLE.

The manufacture calibre L043.1 features a jumping numerals me-chanism for hours and minutes. Designed according to the Lange principle, it consists of two minute discs and a large hour ring. Pre-cisely once a minute, a constant-force escapement generates the necessary switching impulse. Viewed through the caseback, the movement presents a host of further forwarding-looking inventions.

THE PATENTED BARREL.

The patented mainspring barrel delivers the enormous amount of energy required by the movement, especially when all three discs need to be simultaneously advanced at each full hour. The venerable wind/unwind principle was literally turned upside down for this pur-pose. As the mainspring relaxes, the barrel rotates in the minimised-friction bearing. Conversely, the mainspring barrel bearing with the higher friction rating is involved while the watch is being wound. Thus, a slightly greater effort is required when winding the watch
but in return, more of the energy stored in the mainspring remains available for powering the movement. Additionally, the size of the mainspring itself can be reduced without any concessions in terms
of energy yield.

A MULTI-TALENTED CONSTANT-FORCE ESCAPEMENT.

A constant-force escapement is positioned between the barrel wheel and the balance. This patent-pending mechanism has two crucial functions. On the one hand, it generates the switching steps for the instantaneous jumps of the hour and minute displays, using the strike-train principle with warning followed by drop-and-release as often found in striking clocks. Never before has such a mechanism been integrated in a wristwatch. On the other hand, the constant-force escapement drives the balance with nearly uniform power during
the entire autonomy period and thus enhances the rate stability of
the movement.