The Osco 70 is an unusually constructed ladies’ watch form movement.
Unlike compareable movements, the balance is located at “6”, while at “12”, a rather large plate holds the mainspring barrel and the minute hand.
Technically, the reason might be, that this movement does not use a yoke winding system with safety catch on the movement side, but instead, it chose the (cheaper) rocking bar winding system with click sprint on the dial side.
The remaining construction is pretty basic with shock protected screw balance, plallet lever escapement and an anchor wheel, which has got one cap jewel at the movement side.
|Number of jewels:||17|
Nickel screw balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Hairspring key|
|Winding mechanism:||rocking bar winding system|
|Setting lever spring:||2 hole(s)|
|Size:||5 1/4''' (measured: 12,9 x 18,9mm)|
Flume: 1957 48|