CROWNING GLORY

How is a watch adjusted using the crown? And what does that have to do with Patek Philippe?

Today, we take it for granted that a watch can be wound and adjusted by means of a rotating, pull-out button called the crown. Compared to how long mechanical watches have been around, however, it took quite a while for someone to come up with this ingenious solution.

It was not until 1844 that a young Frenchman named Jean-Adrien Philippe presented a pocket watch at the French Industrial Exhibition with the crown winding mechanism he had invented. Its construction already had all the features of the crown as we know it. In the rest position, it could be used to wind the movement, while in the pulled position, the hands could be adjusted. The control devised by Philippe has remained unchanged to this day: on the winding shaft there sits a tiny steel cylinder that can slide back and forth on the square cross-section of the axle. Its two ends have a face gearing that sometimes engages in the winding position and sometimes in the hand position. A rocker ensures that the cylinder is decoupled from the winding mechanism when the crown is pulled and connects to the
hand position. When the crown is pressed, it returns to its original position.

Jean-Adrien Philippe not only received a gold medal for his invention, but also the job of a lifetime. It was at the exhibition that Antoine Norbert de Patek discovered him while searching for a new business partner for his Geneva watch brand. It has been known under the name Patek Philippe ever since.

The Beyer watch studio is the largest of its kind in Zurich:
Beyer employs ten watchmakers and two apprentice
watchmakers above the shop at Bahnhofstrasse 31.

THE POISING TOOL

Tiny components like the balance rim must be accurate to the ten-thousandth of a gram. This tool shows where to cut.

The construction of a watch starts with the balance rim, which is manufactured by punching, milling and turning as well as by electro-erosion. On a miniature lathe, holes are drilled for weight and adjustment screws, which are later important for the fine adjustment of the construction. The balance rim is then riveted to the balance staff.

The manufacturing of the balance rim leaves it with centre-of-gravity errors which are then corrected in a process known as poising. It is almost impossible to avoid having too much mass in one or several places. A “heavier” spot on the balance wheel would pull the rim downwards if the watch is placed vertically, i.e. on its side; it could no longer oscillate evenly, and the accuracy of the watch would be impaired. This makes it necessary to identify and correct any centre-of-gravity errors.

To do this, the rim is placed on the poising tool and set
spinning with a tiny brush. If the rim rotates eccentrically or swings back, this indicates centre-of-gravity errors. The watchmaker corrects them by removing wafer-thin shavings of material in the range of ten-thousandths of a gram using ultra-fine drills and cutters.

The watchmaking profession is considered the “profession
of 100 tools”. We present the most important ones in no
particular order.