Mühle developed the woodpecker neck regulation in 2003 to ensure the accuracy of their movements even under the harshest conditions. With traditional fine regulation systems, more violent shocks may cause the index hand between the regulation screw and the counter-pressure spring to jump upwards. This may in turn change the position of the balance shaft or the watch's regulation.
By engaging in a semicircular shaped hollow in the index, our specially shaped woodpecker neck spring prevents the index hand from moving upwards. The index hand thus not only presses sideways against the fine regulation screw, but at the same time downwards on the balance cock.
The name "woodpecker neck" regulation is based on the very special shape of the spring, which resembles the neck and head of a woodpecker. By analogy, Mühle named the improved index hand as the "woodpecker neck hand".
The Mühle watch is regulated as usual by turning the fine regulation screw. This moves the woodpecker neck hand and increases or decreases the effective length of the balance spring. After regulation, the fine regulation screw is additionally held in position by a clamping screw.