In the late 1950ies, the german manufactury Förster released a quite modern manual wind movement for gents’ watches, which already had a screw-less anular balance.
As it should be for a good lever movement, all important bearings are here equipped with rubies. Center minute wheel and mainspring barrel don’t run in rubies, since they rotate too slow.
In the fifties, it was state of the art to use a directly driven center minute wheel, which is beared under an own cock.
Not only the minute wheel is directly driven, but also the center second wheel.
The Förster 51 uses a screw-less anular balance, which is beared in two inhouse Elastor-Förster shock protections and beats with 18000 A/h. It regulates a conventional pallet lever movement of swiss type.
The Förster 51 not only uses three cap jewels on the gear train bridge, but also two cap jewels on the dial side, so that in total, 21 jewels are counted. Why the lever axle, which is olied, has got a cap jewel instead of the third gear, is unknown.
|Number of jewels:||21|
Nickel anular balance|
|Balance bearing / direction hairspring:||Counterclockwise|
|Adjust mechanism:||Hairspring key|
|Construction type:||solid construction|
|Winding mechanism:||yoke winding system|
|Functions:||hour, minute, second|
|Size:||10 1/2''' (measured: 23,3mm)|
Flume: 1958 b.32|