Identifying cylinder movements is often very complicated, since, when these movements were most popular, only a few of them were marked, probably, since there was no professional supply chain with spare parts.
Fortunately, this 11 ligne movement is an exception, since below its mainspring barrel bridge, it has got a hallmark, which lets it identify as a movement from the manufacturer Sigma (Pèry Watch Co.). Due to the marking “065” on the dial side, it itentifies as Sigma 65.
As common on these kind of movements, the cannon pinion cannot be safely removed, since the axle, which goes through it and acts as slipping clutch, sits very strong.
But even with an only partially tore down movement, you can see that with its 10 bearing rubies, it belongs to the better cylinder movements.
The gear train is the common one for a cylinder movement: The mainspring barrel drives the center minute wheel, followed by third wheel, fourth wheel and cylinder wheel. As usual the cylinder wheel is beared below an own cock.
The three leg anular balance with its steel cylinder is not yet shock protected. It beats with 18000 A/h, which can be roughly adjusted with the help of a long regulator arm.
On the dial side, you see the yoke winding system with a pusher at four o’clock. On the lower half, you see the block consisting of dial side balance wheel bearing and cylinder wheel bearing. Both bearings have to be matched optimally to ensure a proper functionality, probably this was easier outside the movement.
|Number of jewels:||10|
Nickel anular balance|
|Balance bearing / direction hairspring:||Counterclockwise|
|Adjust mechanism:||Long regulator arm|
|Winding mechanism:||yoke winding system|
|Size:||11''' (measured: 25,0mm)|