ATUM Hamatic – prototyping a new approach to self-winding

Press Release – Baselworld 2018

ATUM Hamatic – prototyping a new approach to self-winding

Moritz Grossmann’s first automatic watch is on show for the first time

We are showing a prototype at Basel of our first self-winding watch.  It features a modern interpretation of an older-generation device:  a pendulum mass, referred to as an automatic hammer mechanism,

Christened ‘Hamatic’, this piece transforms automatic winding into a fascinating visual experience within a brand new 106.0 calibre.  Compared with standard rotor-based systems, this automatic hammer system is a filigreed work of art.  A bi-directional hammer with a heavy gold head sits on a fine stem.  Not only can it be seen clearly as it oscillates behind the display glass back, it is also visible through cut-outs in the dial.  As well as being a visual treat, the system is highly energy efficient.  And, fully-wound, it has a power reserve of 72 hours.

The aesthetics are inspired by pocket watches crafted in Moritz Grossmann’s nineteenth century workshop.  Long Roman numerals adorn the clean face of this watch. The super-fine, poire shaped hands – as always hand-sculpted in the manufacture – also imitate an original antique piece.  This striking look sits effortlessly in a rose gold case.

Calibre 106.0

This brand new, 324-part, 39 jewel mechanism will be optimised over the summer prior to release around year-end.  It is a classic pillar movement with a 2/3 plate but was extensively redesigned for the Hamatic.  

The bi-directional automatic hammer mechanism relies on the interaction of the hammer body with the hammer head and the hammer spring. The oscillation of the hammer spring is transferred to the hammer body via a sapphire roller. The system is designed for efficiency and dependability.

Under gentle motion of the hammer, energy transmission is nearly loss-free. At higher accelerations, excessive deflections are controlled by a catch slider and fixed end stops.

Reduction gear and yoke winder

The Hamatic system features a click mechanism integrated in the rotary axis of the hammer body; it serves as a bidirectional winder. The oscillations of the hammer body are picked up by two click levers and converted into a continuous rotary motion powered by the alternating direction of rotation of the click wheels. The rotary motion is transferred to the free wheel via the reduction wheel and then to the ratchet wheel of the mainspring barrel.

The manual winder is designed as a yoke winder that is mounted on a separate bridge. Its simple and functionally reliable design has proved to be an ideal complement to the automatic winder. When the Hamatic system is activated by motion, the manual winder is disconnected from the ratchet wheel by the yoke. In the manual winding mode, the reduction gear is isolated from the ratchet wheel by a click-pawl idler. When the crown is pulled, the balance is stopped to enable hand-setting. At the same time, the crown wheel and the ratchet wheel are disengaged by the yoke. When the crown is pushed home again to the winding mode, the balance stop is deactivated and the yoke pivots into the ratchet wheel.