This really tiny (only 4 x 6 lignes = 10.4 x 14.3mm) form movement FEF 6640 from Fleurier, here used by Chopard, not only belongs to the smallest, but also to the best quality ladies’ watch movements in the archive.
This beautifully golden and extensivly decorated base plate shows, that it is a high quality movement.
Even the minute wheel is ruby-beared, and the normally invisible plate below the mainspring barrel is decorated with a perlage.
Since the movement is that tiny, the very filigree escape wheel has to be located below the seconds wheel bearing, so we have a multi-storey construction here, which is pretty usual on movements of this tiny size.
The gear train is standard: The mainspring barrel drives the center minute wheel, followed by thied wheel, seconds wheel and escape wheel.
Seconds wheel and escape wheel are beared under their own bridge, a very service-friendly construction.
The FEF 6640 uses a three-leg golden toned Glucydur balance without screws. Of course, it is beared in two Incabloc shock protections.
It already beats with 21600 A/h; the only small drawback is, that it can be regulated at the hairspring key only.
The golden toned dial side makes a perfect impression, too.
Of course, the FEF 6640 uses a yoke winding system. It’s setting lever spring also secures the exchanger wheel.
The position of the dial-side Incabloc shock protection tells us, how few space this tiny movement can offer, because it is pushed to the upper right edge.
|Size:||4 x 6''' (measured: 10,4 x 14,3mm)|
|Number of jewels:||17|
Glucydur anular balance (three legs)|
|Balance bearing / direction hairspring:||Counterclockwise|
|Adjust mechanism:||Hairspring key|
|Construction type:||solid construction|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||3 hole(s)|
Flume: K3 76|
|Mentioning in literature (years):||1968|