The Cupillard 55-A 21 is a pretty interesting movement, since according to the Flume K3 list, it should not exist.
Cupillard made a caliber 55-A, beating with 18000 A/h, but did not produce a 55-A 21, beating with faster 21600 A/h. However, France Ebauches, which was a union of large movement manufactories, including Cupillard, released a caliber 55-A 21, so the “Cupillard 55-A 21” was probably made during the transition and creation process of the France Ebauches.
The three-leg ring balance is beared in two french shock protections of type Antichoc S 65 and golden-toned. Its hairspring is connected with a moveable stud onto the balance cock and has got no long regulator arm for adjustment.
The movement works is pretty much standard with its directly driven minute hand.
On the dial side, you see the yoke winding system and preparations for alternative shock protection systems and cap jewels.
|Number of jewels:||17|
Nickel anular balance|
|Balance bearing / direction hairspring:||Counterclockwise|
|Adjust mechanism:||Hairspring key|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||3 hole(s)|
|Size:||5 1/4 x 8 1/2''' (measured: 12,7 x 19,1mm)|
Flume: K3 N1 -|