Junghans J90

Description

In all the years, Junghans only produced two cylinder escapement calibers, J90 and J91, where the caliber J91 is smaller, but construction-wise identical to the J90.

The Junghans J90 war released in 1932 and produced for only five years. It had a diameter of 10 1/2 lignes and used, depending on the execution, either one or fix jewels.

Since cylinder movement were already technically obsolete in the 1930s, its short production timespan is no wonder.

The six-jewels version shown here uses a pair of bearing and cap jewels each for the balance wheel axle and two bearing jewels for the cylinder wheel axle.

The gear train construction is typical for a cylinder movement: The mainspring barrel drives the center minute wheel, follwed by third wheel, seconds wheel at position 6 o’clock and the steel cylinder wheel.

As balance, a very typical for cylinder movements, flat, screw-less, three-leg anular balance is used, which beats with 18000 A/h and whose beating rate can be adjusted roughly with a long regulator arm. “Roughly”, because these simple cylinder movements are generally pretty imprecise.

On the dial side, you can see the well made ratchet and the yoke winding system.

The U-shaped balance wheel bearing was made this way, because you can shirt-sleeved correct the depthing of the cylinder wheel into the balance cylinder by bending the bearing, if required.

Technical data

Usage gallery