A timekeeper for globetrotters

Calibre 100.7

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Details

The movement

The Grossmann balance

ratchet wheel is finished with a delicate snailing decoration

The engravings by hand

Setting the time windows and the main time via the crown at 3 o’clock

Setting the main time separately via the crown at 10 o’clock

The movement

The new calibre 100.7 of the UNIVERSALZEIT was specially developed by Grossmann’s designers in the manufactory.

The calibre 100.7 is testimony to the consummate craftsmanship and ultimate in finishing from the house of Moritz Grossmann.

The sophisticated design of the pillar movement is complemented by the intricate workmanship seen in every component, which are all finished by hand. The floral pattern on the balance and escape-wheel cock is engraved by hand, as is the lettering on the wheel bridge. Traditional cuts and polishes have been applied to the surfaces of other parts.

The Grossmann balance

The UNIVERSALZEIT breathes at a calming traditional rate of 18,000 semi-oscillations per hour. The calibre 100.11 incorporates the newly designed Grossmann balance and demonstrates that rate accuracy is not achieved solely with a higher frequency. Optimised for artisanal manufacturing techniques, the design of the balance improves the adjustability of inertia and achieves high kinetic energy combined with minimised air resistance and the smallest possible mass. The number of screws in the balance-wheel rim was minimised as well. Mass screws with different head lengths are used to incrementally vary the moment of inertia. Additionally, the rim is provided with uniformly spaced bores that allow reductions in mass or contribute to the poising of the balance. The smooth cylindrical balance staff is integrated in the hub and can easily be replaced if necessary. The Grossmann balance interacts with a Nivarox balance spring which is overcoiled with a quarter arc on the inside and secured to the slotted roller with a brass pin.

ratchet wheel is finished with a delicate snailing decoration

Further evidence of the highest standards of German craftsmanship can be seen on the ratchet wheel with its three-band snailing, framed by broad chamfers polished to a high gloss sheen.

The engravings by hand

All engravings and inscriptons on the 2/3 plate and the balance cock are always engraved by hand.

Setting the time windows and the main time via the crown at 3 o’clock

The hours in the time windows and the main time are set via the crown at 3 o’clock. When the minute hand passes 12, the time in the time windows jumps forward by one hour.

A disc connected to a 24-tooth ratchet wheel moves beneath the dial. This is printed with a multitude of numerals from 1 to 24, each arranged at an angle of 15 degrees across a total of six rings.

When the minute hand moves over the 12, the ratchet wheel and with it the disc move forward by one position. The disc is precisely positioned by a ratchet spring. Thanks to the optimal alignment of the numerals on the disc, the hours are aligned horizontally in the windows, making it easy for the wearer to read them.

When setting the watch, the time in the time windows must be adjusted in advance. Knowing the current time zone for one location is sufficient for this. The time in the other windows is automatically synchronised when it is set.

Setting the main time separately via the crown at 10 o’clock

The hour hand of the main time can be moved backwards and forwards separately in hourly increments using the quick adjustment mechanism. This does not change the time display in the windows. The mechanism allows the operator to engage the crown in two positions at 10 o’clock and then use a pusher function to correct the hour hand independently of the disc. In the middle position, a stop prevents the pusher from being operated. This prevents accidental adjustment of the time.

Tech Specs

Movement

Manufactory calibre 100.7, manual winding, regulated in five positions

Special features

Grossmann balance; hand setting override and start of movement with lateral pusher; space-saving, modified Glashütte stopwork with backlash; adjustment with Grossmann micrometer screw on cantilevered balance cock; pillar movement with 2/3 plate and pillars made of untreated German silver; balance cock and escape-wheel cock hand-engraved; broad horizontal Glashütte ribbing; 3-band snailing on the ratchet wheel; separately removable clutch winding mechanism; stop seconds for hand setting; central second wheel; newly developed module for displaying the full hours in selected metropolitan areas; correction mechanism at 10 o’clock to adjust the hour hand when changing one’s own location

Functions

Hours, minutes and seconds, centre second with stop second, Grossmann manual winder with pusher

No. of parts

292

Jewels

31 jewels, of which one in a pressed gold chaton

Escapement

Lever escapement

Oscillator

Shock-resistant Grossmann balance with 4 inertia screws and 2 poising screws, Nivarox 1 balance spring with No. 80 Breguet terminal curve, Gustav Gerstenberger geometry

Balance

Diameter: 14.2 mm, frequency: 18,000 semi-oscillations/hour

Power reserve

42 hours when fully wound

Operating elements

Crowns in stainless steel to wind the watch and set the time and the windows, pusher in stainless steel to start the watch; crowns in stainless steel to correct the hour hand

Movement dimensions

Diameter: 36.4 mm, height: 7.45 mm

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Calibre 100.7

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