The Osco 72 is a rather modern ladies’ watch form movement, which is relatively large with its size of 6 3⁄4 x 8 lignes.
It contains 17 jewels, with four of them (both bearings of the escapement wheel and the lever) being made of transparent material. Probably, they wanted to test new, cheaper materials, for the most critial bearings?
The mainspring barrel is beared in one jewel on the movement side, which is a bit odd. Technically, there’s no need for it, but with that bearing, the number of jewels sums up to 17.
A pretty large ring balance, which is beared in two KIF Trior shock protections, controls the movement. Its hairspring is of course connected to a moveable stud but can be regulated in its effective length only directly at the hairspring key.
The escapement wheel is large, too, and noteably thin and fragile. Maybe, it was espected to enhance the precision at low or no costs.
On the dial side, you see the rocking bar winding mechanism, which shows a bit the cost-efficient construction of this movement.
|Number of jewels:||17|
Nickel anular balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Hairspring key|
|Winding mechanism:||rocking bar winding system|
|Setting lever spring:||2 hole(s)|
|Size:||6 3/4 x 8''' (measured: 14,9 x 17,95mm)|
Flume: K3 87|