One of the most commonly used swiss pin-lever movements with date indication was the caliber 8805 of Ebauches Bettlach.
It only uses one single jewel, which is used together with a KIF Protechoc shock protection for the very light balance wheel. This balance wheel is so light, that it tends to stop on many external influences. A more thick and heavier Glucydur balance, maybe even with screws, would not be influenced at all, but continue ticking.
The simple construction of this movement leads to some rather curiousities: On the main plate, you see four bearings, but only three of them are used for gears, the fourth one (located at “6:30”) is just empty. Why? No idea… Furthermore, the mainspring is secured on top only by a small metal bracket and the click spring works on the crown wheel instead of the mainspring wheel.
The pin lever movement has got a directly driven center second hand and beats with slow 18000 A/h. On the other hand, a moveable stud and an armless hairspring regulator is used, so you see an interesting mixture of outdated, contemporary and cheap techology on this movement.
On the dial side, this movement is rather familiar constructed with a yoke winding mechanism and a date construction, which switches instantly at 12:00 and can be advanced by turning the hands forth- and backwards.
|Number of jewels:||1|
Nickel anular balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Hairspring key|
Flume: K3 69|