UMF 53-52 (M 9)

Description

The five-jewels caliber M 9, which after its discontinuation got is new name UMF 53-52 in the new caliber number system, is a simple pin lever movement with center second and ruby beared anular balance.

The brass colored base plate shows, that it a simple pillar construction. Aside from the balance wheel, none of the other bearings is equipped with synthetic rubies.

The gear train is a classical one with directly driven minute wheel, third wheel, fourth wheel and escapement wheel.

The indirectly driven center second is driven on the movement side by the third wheel.

The non shock protected anular balance has got ruby bearings for its cones and so a higher fracture risk. Its beats contemporarily slow with 18000 A/h and controls by a ruby ellipse a conventional pin lever movement, which builds pretty high.

By moving the locking lever on the movement side, the mainspring barrel can be released without dismantling the whole movement.

On the dial side, you can easily spot the rocking bar winding system, the currings for oiling the lever pins and the simple ratchet, which consists of only one simple spring.

Technical data