UMF 39-50

Description

The UMF 39-50 is the base version of the so-called “Darling” caliber, an 8 3/$ ligne windup movement, made from 1961 until 1971.

The earlier version of this movement was known as caliber 33-50.

The base plate of this pillar movement, which by a few tricks should look like a massiv construction, shows, that it is not of too high quality.

Aside of the balance wheel bearing, there are no further bearing jewels, so that together with the ellipse and the two lever pallet, this movement has a total of seven jewels.

We have the classical gear train here, with directly driven center minute wheel, third wheel, seconds wheel and escape wheel.

To reduce the height play of the flat mainspring barrel, a bauble was put onto its axle.

The UMF 39-50 was available with an anular balance as well as with a screw balance. There was no shock protection in any version.

The beating rate of 18000 A/h is classically slow and the regulation of the pallet lever movement (at least not a pin lever movement!) happens directly at the hairspring key.

The hallmark on the movement were not always consistent, so this movement was once marked as “UMF 33” and once as “UMF 39”.

On the dial side, you see the yoke winding system and the sturdy ratchet with its conical locking lever.

In all versions, you can see the large cutout for the filigree escape wheel and the lever pallets, which engage with it.

Technical data

Usage gallery