Underneath the dial a newly developed Remontoir movement, the caliber LANG & HEYNE Cal. VI-I, is responsible for the accurate display of the time.
Through the sapphire glass case back it is obvious, that the main parts of the movement were manufactured of an entire new material – titanium. Commonly used for manufacturing cases, it has found its way into an unusual use.
The use of titanium has presented entirely new challenges to the master watchmakers of LANG & HEYNE. In order to meet the very high demands on the quality of the technology but also on the aesthetics, it was necessary to adapt and modify traditional skills and processes.
Medium-hard titanium of purity grade 2 is used to manufacture the movement plate, gear bridge, lever bridge and balance cock. To create a matte sheen, the graining is achieved by blasting with ceramic beads which, unlike glass beads, do not shatter when they hit the material. For brass frame parts, the polished chamfers are then pressed on with the smoothing steel. This is not possible with titanium. It has unfavorable friction behavior, which would cause the spinning tool to leave cracks. So here the chamfers have to be polished very laboriously with wood and polishing paste.
Read more about the whole project and where to find this stunning piece: Phillips Auction May 2022.
The poor behavior under friction also forces a different design for the bearings of all parts that were previously supported in the brass of the plate. Thus, separate bronze bearings are used for the barrel and winding stem. All other assembly steps can be performed in the same way as with conventional plates, line grindings are easily feasible and hand engravings are also possible. Thus, the balance cock also retains its beautiful classic design. Technically, titanium offers greater strength and corrosion resistance, making it an interesting asset to the movement.
For aesthetic reasons, the otherwise blue annealed screws were replaced with purple ones to match the warm gray of the titanium.
This model FRIEDRICH II Remontoir is equipped with a complicated mechanism to improve accuracy, the Remontoir. This so-called “constant force mechanism” compensates for the decreasing force of the tension spring. Its energy tensions a storage spring every five semi-oscillations, which constantly transmits its power to the escapement. This keeps the amplitude of the balance wheel constant throughout the day, minimizing rate fluctuations.
The Remontoir of Cal. VI-I is located on the escape wheel and is responsible for the jump of the small second hand every second and fulfills its function at least for 24 hours.