The Model CROSSNROLL

From Nord Zeitmaschine -

Courtesy of Nord Zeitmaschine

This is the latest from Daniel Nebel and his Nord Zeitmaschine brand.

Courtesy of Nord Zeitmaschine

This one is a wee bit technical, and time is a wee bit tight here at Tempus Fugit HQ this morning (the Executive Publisher still needs her breakfast, and I have train to catch ; )  

So I'm going to cheat a bit and let Nord Zeitmaschine tell you about it in their own words.

Courtesy of Nord Zeitmaschine

The name CROSSNROLL borne by the new NORD Zeitmaschine watch is composed in part from the word CROSS, which describes that the hand  runs on a cross-shaped minute-track.

The tip of the minute hand is mounted on a slide, which rolls back and forth on the hand platform, hence the word ROLL in the name of the watch.

28 rubies and 18 precision ball bearings are integrated in the NORD Zeitmaschine  CROSSNROLL movement, of which 14 ball bearings are mounted in the hand assembly alone. Others are found on the winding rotor and the hour indicator.

Patented Hour indicator:

The hour indicator disc is mounted on a swivel arm, which in turn is connected with the central mounting cross by ball bearings. The entire hour indicator mechanism is mounted over the hand assembly. The swivel arm on which the hour indicator disc is mounted has no mechanical drive and only starts moving due to gravitation, effected through a change in the position of the wrist on which the watch is fastened. The hour disc itself is driven via mechanically driven cogs, independent of the swivel arm. This hour indicator, for which a patent is pending (N°  EP18405009.4    and  CH252/18)  , facilitates the hour indicator disc being in any geographically undefined position over the dial, as a result of the movement of the wrist on which the watch is fastened, and the resultant gravitation. Irrespective of the position of the swivel arm with hour indicator, the red arrow on the hour indicator always points to the correct hour of the day, aligned with the longitudinal axis of the watch case. 

- Display of the hours in conjunction with hour indices:

Hour indices are applied to the underside of the glass, to facilitate reading off the hour of the day in conjunction with hour indices if necessary. By holding the wrist vertically, the swivel arm moves with the hour disc, driven by gravitation,  into the desired position of the hour indices. As soon as the swivel arm comes to a standstill after moving back and forth a few times, it is possible to read off the hours in conjunction with the hour indices. Furthermore, this special hour indicator mechanism, effected through strong movement of the wrist, allows the swivel arm and the hour indicator mounted on it to begin strongly rotating. The swivel arm with the mounted hour indicator can rotate through multiple rotations of its central pivot point here, whereby the hours are displayed correctly at all times.

Minutes:

The complicated hand assembly is constructed such that the centre of gravity is always located precisely over the central pivot point, regardless of the position of the group. To achieve this, alongside numerous other parts, 2 counterweights are mounted on the lower end of the hand assembly, which always move in the opposite direction to the extending and retracting (ROLL-ing) pointer tip. These 2 opposing counterweights are connected with the pointer tip by a connecting rod system. In addition to the centre of gravity of the complete hand assembly always lying over the central pivot point, the mechanism is designed and constructed such that the gravitational forces that act on the pointer slide with pointer tip and counterweights always counteract each other. In a level position, no gravitational forces act on the pointer slide with pointer tip and the two counterweights. However, gravitational forces act on the pointer slide with pointer tip and counterweights in all other possible watch positions. At all times and in every possible position of the hand assembly, the acting forces mutually counteract each other. In order to achieve all these characteristics, it was necessary to find a solution that took multiple factors into consideration.

 1. Was it necessary to work with a number of different materials such as steel, brass, aluminium, titanium, platinum etc.  and their varying densities. 

2. Must all pivot points and lever lengths be calculated precisely. 

3. Additionally, must the volumes of the individual components be precisely tailored to each other. The use of 18 ball bearings in total facilitates a mechanism with maximum precision and minimal friction. Many individual parts of the hand assembly consist of very light materials such as aluminium and titanium. However, in order to achieve the centre of gravity always lying directly above the central pivot point, it was also necessary to use one of the heaviest metals. As such, a balancing weight produced from solid platinum (density 20.7) is mounted on the platform in the front area beneath the pointer tip. This solid platinum weight balances out the somewhat larger and heavier structure at the lower end of the hand assembly.

MOVEMENT , NORD N5

28 ruby jewels and 18 integrated  precision micro ball bearings.

Minutes: by a complicated hand assembly where 14 ball bearings are mounted in and which runs on a cross-shaped minute-track.

Hours: via a swivel arm on which the hour indicator disc is mounted. The swivel arm has no mechanical drive and only starts moving due to gravitation, effected through a change in the position of the wrist on which the watch is fastened. The hour disc itself is driven via mechanically driven cogs, independent of the swivel arm.

Automatic winding , driven by a symmetrical 360° rotor

28800 vibrations per hour / power reserve to 42 h

CASE

Stainless steel / bezel and sapphire crystal back, secured with 8 screws.

Crown with double o-ring seals.

Diameter  44,7 mm  /  height  15,8  mm (17,2  over the domed glass)  / weight  110  grams

GLASSES      

top :  sapphire crystal double- curved /  both sides anti reflected
bottom :   sapphire crystal  flat