A particularly high-quality “early work” of the ETA is the ETA 372, a variant of the ETA 371 series. This form movement is only 5 1/4 lines wide and uses 17 jewels.
Of yourse, all impoprtant bearings contain rubies, some red, some transparent.
The movement-side escape wheel bearing has got a large edged cap jewel.
We have the classical gear train here with filigree gears: The mainspring barrel directly drives the center minute wheel, followed by third wheel, seconds wheel and steel escape wheel. For the small size of the movement, the gears are pretty large.
As escapement, a swiss pallet lever escapement is used, which is controlled by a monometallic screw balance. This balance is not yet shock protected and beats with 18000 A/h. Its frequency can be adjusted with a long regulator arm.
The caliber 372 with its covered winding mechanism, called “System Patek”, is a variant of the ETA 371. Besides the very elegant looks, it is questionably, if there are technical advances of this execution.
On the dial side, you can see the old round ETA hallmark at 6 o’clock. This hallmark was used in the 1930s. Besides this, you see the usual suspects, such as the yoke winding system and the cap jewel for the balance wheel bearing.
|Caliber base:||ETA 371|
|Size:||5 1/4 x 8 1/2''' (measured: 12,8 x 19,15mm)|
|Number of jewels:||17|
monometallic anular balance (two legs)|
|Balance bearing / direction hairspring:||Counterclockwise|
|Adjust mechanism:||Long regulator arm|
|Construction type:||solid construction|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||3 hole(s)|
Feilner: 41 3662|
Flume: (1947 119)