UMF 80-52

Description

Between 1953 and 1963 this 18 1/2 ligne stopwatch caliber UMF M65 (here in version M 65 A with a 1/10 seconds resolution) was made, later called UMF 80-52.

It was originally made in Glashütte as GUB 65, and then, 1953, the production shifted, with a few modifications, to Ruhla.

The movement shown here is the pretty late version “e”, which e.g. has got the caliber number on the dial side, but still uses a long regulator arm.

Quality-wise it is quite well made for a stopwatch, two bearing- and cap jewel pairs for the balance wheel, one for the ellipse and two for the lever pallets, in total the UMF 65A (UMG 80-52) uses seven jewels.

The gear train is standard for this kind of stopwatch calibers: Mainspring barrel, decentral minute wheel at 12 o’clock, third wheel, center seconds wheel and steel escape wheel.

The UMF M65 uses a two-leg anular balance, which beats, according to which kind of hairspring is used, either with 18000 or 36000 A/h. This means, that without any changes in the gear train, the minimum resolution is 1/5 or 1/10 seconds.

Of course, the balance wheel is not yet shock protected, but its beating rate can be adjusted with a long regulator arm.

The control (start - stop - reset) happens by the column wheel on the dial side.

It is driven by an L-shaped lever, which translates the crown pushes into advancing of the wheel. In its upper part, two levers engage. The top lever falls in “reset” position and resets the hearts of the minute- and center second hands. The lower lever starts and stops the balance wheel it a tiny spring lever at position 5:30. It also ensures, that when the stopwatch is started, the balance wheel instantly starts beating.

Technical data

Usage gallery