AS 340

Description

The 10 1/2 ligne windup movement AS 340, made in the 1920s was part of the 302 caliber series, which came in about two dozen different designs, all of which differed only in the shape of the bridges and in details like the setting lever.

With 15 jewels, which were also neatly set, this movement belonged among the better lever movements that were available at the time.

On the specimen shown here, most of the jewels are only slightly ping, and the lever pallets are even transparent.

The gear train also pleases with its well made execution. Its design is classic, with a directly driven, central minute wheel, third wheel, fourth wheel at 6 o’clock and steel escape wheel.

The AS 340 uses a monometallic, two-leg screw balance used, which of course is not yet shock-protected.

In order to give her an even higher-quality impression, the balance wheel has got two halfway cluouts, so that one can to think at a first glance that you are looking at a bimetallic balance wheel.

It beats with 18000 A/h, which can be adjusted by a long regulator arm, and it regulates a classic swiss pallet lever escapement.

Nice to see is the old AS hallmark at 7 o’clock, a clear indication of the 1920s as production decade.

At 3 o’clock you can see the yoke winding mechanism, which was quite modern at the time.

Another oddity is the filigree setting lever spring and recessed spring for the winding system, at position 4 o’clock.

Technical data

Usage gallery