The german jeweler Laco of Pforzheim had got an own movement manufacturer with the DuRoWe, the Deutsche Uhren-Rohwerke, which especiall in the 1950ies was famous for their well made and innovative movements. The DuRoWe 435 dates from the mid 1950ies and was available a short time only. It impresses by its unique geometrically shaped bridges.Video on YouTube
The diameter of that movement is the usual 10 1⁄2 and, like on any well made movement, all important bearings contain rubies for reducing the friction.
The minute wheel is directly driven, like it was usual that time, and it is beared under an own cock. Above, there’s the also driven center second.
A nice detail on that movement is, that all gears, except the escapement gear, are copper-colored instead of the usual brass tone color:
The DuRoWe 435 has got a screw balance, which is beared in two inhouse Duroswing shock protection systems, which were very new that time. It controls a typical pallet lever movement with directly driven center second, third wheel and central minute wheel.
On the dial side you see besides the two cap jewels (escapement- and third wheel - on both positions cap jewels are indeed useful) the large copper-colored changing wheel which a pin, which drives the date indication disc forth and back. The wheel is driven by the outer teeth of the hour wheel - a really simple and efficient construction.
The DuRoWe 435 is one of the compareable few movements, which has got a date disc instead of a date ring. Obviously, it was en vouge in the fifties to have the date window quite in the middle of the dial and not on the outside. But from the end fifties on, that changed, and the date window had to be as far from the dial center as possible, and so, only date rings, preferrable with a large diameter were used.
In the lab
The specimen shown here came in good condition in the lab, but for a best possible presentation, it was serviced, cleaned and regulated on the timegrapher.
On the timegrapher, it shows quite well figures, but they are very much position depending. Probably the balance wheel is aged.
Take the amplitude numbers with a grain of salt, since the correct lift angle is unknown and the usual default of 52° was used.
|dial up||+20 s/d||210°||2.4ms|
|dial down||+8 s/d||208°||2.2ms|
|crown right (12 up)||-4 s/d||175°||3.0ms|
|crown up (3 up)||-30 s/d||179°||3.0ms|
|crown left (6 up)||-185 s/d||171°||2.7ms|
|crown down (9 up)||-170 s/d||162°||2.8ms|
|Number of jewels:||17|
Nickel screw balance|
|Balance bearing / direction hairspring:||Counterclockwise|
|Adjust mechanism:||Long regulator arm|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||3 hole(s)|
|Functions:||hour, minute, second, day|
|Size:||10 1/2''' (measured: 23,0mm)|
Flume: 1957 33|