The identification of this golden toned, 8 3/4 ligne windup movement was not easy, most likely it is a Judex 46 SC, which was probably later renamed to Sefea 53.
At first glance, this 21 jewel movement does not seem special, nevertheless, the arrangement of the four, equipped with red rubies, bearings on the base plate is a little unusual. No less interesting is the transparend bearing jewel with its screwed-in mounting at 8 o’clock.
If you take a closed look, you see the interesting construction of the gear train:
The mainspring barrel directly drives the center minute wheel, followed by third wheel, center seconds wheel, double pinion (at 5:30 o’clock), seconds wheel (at 6 o’clock) and steel escape wheel.
Especially the seconds wheel without pinion and the double pinion are noteworthy!
Once again the decentral seconds wheel at the 6 o’clock position (bottom left on the photo). Its only function is, via the double pinion (slanted on the photo), to directly drive the top center seconds wheel.
The lower gear train bridge (the very fact alone that there are two bridges is remarkable!) is only used for bearing the minute wheel and escape wheel.
The axle of the seconds wheel (without pinion) and the double pinion are passed through to the upper gear train bridge, where their bearings have got a cap jewel each.
The second layer of the gear train consists of the third wheel (whose axle is passed through to the base plate) and the center seconds wheel. The latter one is engaged with the double pinion, which is passed through from the first layer.
The third wheel in turn drives with its pinion, which is passed through to the first layer, the center minute wheel.
Who has not yet discovered the fascination of the overall construction has to take a look at the side view. At the latest now everyone - and rightly - ask why a movement with a direct sweep second had to be constructed so incredibly complex.
The description of the regulator is much more sober: The golden-toned screw balance is secured and beared in a three-leg shock protection and beats slowly with 18000 alternations per hour. The exact frequency can only be found on adjusted on the hairspring key directly.
As escapement, a conventional swiss pallet lever escapement is used.
On the dial side, this movement is pretty normal. Of course, it uses a yoke winding system, and at 9 o’clock, you can see the three-leg shock protection with its brass bearing.
|Number of jewels:||21|
Nickel screw balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Hairspring key|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||2 hole(s)|
|Functions:||hour, minute, second|
|Size:||8 3/4''' (measured: 19,3mm)|