The AS 1287 is a typical, well made swiss hand wound movement, which debuted in the late 1940ies. It’s direct relative is the AS 1187, which only differes by a taller and more angeled gear bride.Video on YouTube
The screw balance is beared in two shock protection systems. On the specimen shown here, they are Unishock bearings. The Balance beats slowly with 18000 A/h.
The gear train with its center minute wheel, located under an own bridge, was state of the art at that time.
The center second is directly driven.
The AS 1287 uses rubies on all important bearings. On the specimen shown here, there are also three additional cap jewels, two for the escapement wheel and one on the dial side of the third wheel. On this position, a cap jewel is almost overkill, since the third wheel turns pretty slow and with big force, and additionally, since the dial side of a watch is normally on top, the axle won’t even touch that cap jewel.
Of course, the AS 1287 uses a yoke winding system.
|Number of jewels:||17|
Nickel screw balance|
|Balance bearing / direction hairspring:||Counterclockwise|
|Adjust mechanism:||Long regulator arm|
|Construction type:||solid construction|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||2 hole(s)|
|Functions:||hour, minute, second|
|Size:||10 1/2''' (measured: 23,2mm)|
Flume: 1952 4|