The rarely seen Felsa 4072 is a pretty odd and unique ladies’ watch movement.
The construction layout, visible from the movement side, reminds strongly of an ETA 2410.
Although using a screw balance, this movement already has got a moveable hairspring stud. This combination is pretty rare and maybe used here due to the fact, that this movement shown here was used in a (expensive) L.U.Chopard ladies’ watch and therefor had to be more than a “tick” better than average.
On the dial side, the Felsa 4072 differs very much to the ETA 2410.
The advantage of this unusual construction is that the critical transmission from the second wheel on the movement side to the minute wheel on the dial side is not required and of course, a slipping clutch on the large mainspring barrel is much easier and less error-prone than one of the comparatively small minute wheel.
Finally, this movement uses a yoke winding system, seen on the dial side. But for such a well-made movement, this is standard.
|Number of jewels:||17|
Glucydur screw balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Hairspring key|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||2 hole(s)|
|Size:||6 3/4''' (measured: 15,5mm)|
Flume: K3 5|