Stripped to its bare essentials, reduced functionally to a skeleton of devices, a mechanical watch is actually a simple device. A simple device that is designed to transform energy from one form to another, while using this translation to tell the time.
In a quartz watch, the energy from a battery is used to vibrate a quartz crystal. This vibration is measured and used to tell the time. In a more traditional mechanical watch, a series of springs, gears and an escapement mechanism is used to transfer the energy of wound springs into a vibration of the balance wheel, which is then measured to produce time intervals.
Simply put, the hairspring, at the heart of a mechanical watch, functions like a quartz crystal. And it has remained at the heart of a timepiece since 1675, when Christian Huygens invented the hairspring. While several inventors have worked on refining this hairspring— even a Nobel Prize has been awarded for work in the field—the basic principle of the mechanical watch has remained the same for centuries.
But this year at BaselWorld 2010, Tag Heuer introduced the new Pendulum concept that for the first time poses a serious challenge to the presence of a hairspring in a mechanical watch. Jack Heuer, scion of the Heuer family and honorary president of Tag Heuer, said in an interview with Mint that the Pendulum was the first time since Huygens that anyone had thought of an alternative for the hairspring. “It is still early days, and we are still testing the concept, but it is truly a revolution. And a great way to celebrate 150 years of Tag Heuer.”
The Pendulum replaces the oscillating hairspring with an oscillating magnetic field. Using four magnets, and specially-shaped parts, the Pendulum uses a combination of attracting and repelling magnetic fields to simulate the functioning of a hairspring.
This concept also helps avoid some of the weaknesses of hairspring-enabled systems, especially sensitivity to gravity, thermal variations and irregularities in spring structures.
However, the Pendulum is still a concept in an early stage of development. Heuer explained: “While we have proven that this concept will work, we still have some challenges. The most important is a magnetic assembly that will be stable across a variety of temperatures.”
At BaselWorld, Tag Heuer showcased the TAG Heuer Grand Carrera Pendulum Concept, a watch assembled with the new system.
However, when collectors and connoisseurs are finally able to buy watches with Pendulums, the pieces will not be available in large numbers. “The idea is not to replace the hairspring in all watches. But to produce an engineering marvel, in limited numbers, for enthusiasts,” Heuer explained.