The caliber 34 of the swiss ebauche manufacturer Derby originates most probably from the fourties. Technically, it tries to span the bridge between minimum size and low price.
It is equipped with a cylinder escapement, which was already a bit out-of-date then. On this type, the tips of the escapement wheel permanently touch the balance cylinder and brakes it more or less. This leads to comparatively low timing precision and if the movement is not properly serviced, it can easily be brought to a standstill.
The tiny balance is not shock protected; the hairspring is regulated by a long regulator arm and is fixed to the balance cock.
On this movement, all gears are beared in synthetic rubies, except the minute wheel.
The movement brigdes seem to be divided into two parts, but that’s just an illusion, in fact, it is just one piece.
On the dial side, you will find a rocking bar winding mechanism as well as a very simple click spring mechanism - just the way, you would expect it on such a rather cheap movement.
|Number of jewels:||10|
monometallic anular balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Long regulator arm|
|Winding mechanism:||rocking bar winding system|
|Setting lever spring:||1 hole(s)|
|Size:||5 3/4 x 8 1/2'''|
Flume: 1947 146|