UMF 24-31

Description

With a decentral seconds indication, the UMF 24-31 is a little outdated variant of the legendary caliber UMF 24, which in total over all variants was made more than 100 million times between 1963 and 1991.

The base caliber is the already highly automated made, ruby-less caliber 24, a 10 1/2 ligne pin lever movement in pillar construction, which construction-wise dates back to the 1930s.

Accordingly classical is the gear train with directly driven center minute wheel, third wheel, decentral seconds wheel at 6 o’clock and escape wheel.

The ratched, which consists only of a single spring, is located on the inner side of the base plate.

As escapement, a pin pallet escapement is used, which is controlled by a three-leg anular balance. Since it has got a v-conic axle, there’s no need for a shock protection.

It beats with 18000 A/h, which can be roughly regulated at the hairspring key directly.

The specimen shown here already uses the plastic rocking bar keyless works.

In the lab

Timegrapher result

No matter how hard you try, a UMF 24 will probably only give a barely usable result on the timegrapher. On average, however, the large deviations should balance out to such an extent that the daily rate deviation when worn is within reasonable limits.

Technical data

Usage gallery