One of the smallest round movements of AS was the AS 969, a movement with a diameter of only 6 3⁄4 lignes.
It was launched in the early fifties and was, in terms of jewels, completely equipped with 17 jewels. Unlike earlier (15 jewel) movements, the minute wheel is ruby-beared, and the escapement wheel bearing has got a cap jewel on the movement side. Together with the golden toned Glucydur screw-balance, a good precision could be achieved, depite of the tiny size. The hairspring of the balance, which was of course not yet shock protected, was regulated in its effective length by a long regulator arm.Video on YouTube
The construction is a bit unusual: Since there was not enough space, the bearing of the fourth wheel is within the diameter of the escapement wheel, so that a stacked construction had to be used.
An interesting detail is the protection of the escapement wheel, as a kind of sickle shaped piece of metal, which protectes the outher teeth agains dirt and careless watch tinkerers.
On the dial side, there’s of course a yoke winding system.
The escapement pallets can be reached by two holes in the plate - especially on such a tiny movement, this is very helpful, when, in a service, the exit pallet has to get a tiny little drop of oil.
In the lab
|dial up||-10 s/d|
|dial down||+20 s/d|
|crown right (12 up)||-90 s/d|
|crown up (3 up)||-90 s/d|
|crown left (6 up)||-60 s/d|
|crown down (9 up)||-90 s/d|
|Number of jewels:||17|
Glucydur screw balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Long regulator arm|
|Construction type:||solid construction|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||3 hole(s)|
|Size:||6 3/4''' (measured: 14,95mm)|
Flume: 1952 1|