Derby 34

 
Derby 34 | 17jewels.info - The Movement Archive

Derby 34

Description

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It is equipped with a cylinder escapement, which was already a bit out-of-date then.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.

Derby 34: Zylinderrad

Zylinderrad

The tiny balance is not shock protected; the hairspring is regulated by a long regulator arm and is fixed to the balance cock.

Derby 34: base plate

base plate

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.

Derby 34: Derby 34 dial side

Derby 34 dial side

Technical data

Manufacturer:Derby
Caliber:34
Size:5 3/4 x 8 1/2'''
A/h:18000
Number of jewels:10
Escapement:Cylinder
Balance types: monometallic anular balance
Shock protection(s): none
Balance bearing / direction hairspring:Clockwise
Moveable stud:no
Adjust mechanism:Long regulator arm
Construction:
  • escape wheel
  • seconds wheel, third wheel, center minute wheel, mainspring barrel
Winding mechanism:rocking bar winding system
Setting lever spring:1 hole(s)
References: Flume: 1947 146

Usage gallery

Derby 34: Mady ladies' watch

Mady ladies' watch

Other movements from Derby