ETA 2370

ETA 2370 | - The Movement Archive

ETA 2370


In the early 1950s, ETA launched their modern movement construction with indirectly driven hands on the dial side by the pinion of the third wheel, to provide more space for the balance and mainspring barrel.

The ETA 2370 shown here is one of the earliest (perhaps even the very first) version, and thus the direct forerunner the extremely successful caliber series 2390.

ETA 2370: base place

base place

With the exception of the center second axle, which is beared in a long tube, and of course the slowly rotating mainspring barrel all bearings of this solid 11 1/2 ligne movement equipped with jewels.

ETA 2370: gear train

gear train

As said above, the modern ETA gear train is used, with mainspring barrel, second wheel, third wheel, center seconds wheel and escape wheel.

ETA 2370: side view of the gear train

side view of the gear train

It’s clearly visible, how the third wheel not only engages with its drive into the second wheel, but also on the, here not yet mounted, minute wheel on the dial side.

ETA 2370: side view of the gear train

side view of the gear train

As regulating device for this swiss pallet lever movement, the version shown here uses a very beautiful golden toned Glucydur screw balance.
Visually, this is the best of the best, and also technically, it was top of the line.

Of course, the balance wheel axle is beared in two Incabloc shock protections, and the effective length of the hairspring can be adjusted by a long regulator arm with embossed dial on the balance wheel cock, so that the frequency of 18000 A/h can be adjusted as good as possible.

ETA 2370: empty dial side

empty dial side

At position 8 o’clock near the center, you can see the drive, which will later engage into the minute wheel.

ETA 2370: minute wheel with slipping clutch

minute wheel with slipping clutch

The cannon pinion is mounted with a slipping clutch onto the minute wheel.

ETA 2370: minute wheel mounted

minute wheel mounted

Here, you can see, how the minute wheel engages with the third wheel, and how the cannon pinion engages with the change wheel.

ETA 2370: ETA 2370: Dial side

ETA 2370: Dial side

Of course, the ETA 2370 uses a yoke winding system (with a broken setting lever spring on this specimen, unfortunately).
At position 12 o’clock, you can see the Incabloc shock protection, and at 9 o’clock the useful cap jewel for the escape wheel.

The base plate is slanted on its outer edges to save some height, because at the time being, extra flat watches were highly demanded.

Last but not least, a partial minute scale can be seen. With that, a non-cased movement without dial could be adjusted easier.

Technical data

Size:11 1/2''' (measured: 25,5mm)
lift angle:52.23°
Number of jewels:17
Escapement:Pallet lever
Balance types: Glucydur screw balance (two legs)
Shock protection(s): Incabloc
Balance bearing / direction hairspring:Clockwise
Moveable stud:no
Adjust mechanism:Long regulator arm
  • lever
  • escape wheel, seconds wheel, third wheel, large driving wheel
  • mainspring barrel
Construction type:solid construction
Winding mechanism:yoke winding system
Setting lever spring:2 hole(s)
  • SCD (direct center seconds)
References: Ebauches: 1953 55.2
Feilner: 34 2685
Flume: K1 1957 32
Mentioning in literature (years): 1964
Inventory number:22009

Usage gallery

ETA 2370: Stowa gents watch  (case missing)

Stowa gents watch (case missing)