In 1950, Helmut Epperlein founded the Uhren-Werk Ersingen (Uwersi) in Pforzheim, Germany, which also operated under the name “Vereinigte Uhrenfabriken Ersingen” and mainly mass-produced simple raw ebauches.Video on YouTube
The caliber Uwersi 57/8 shown here is a 10 1/2 ligne pin lever movement with subseconds indication.
Of this movement, there are implementations known with two jewels (Ellipse and dial side bearing of the balance) as well as with five jewels (with additional movement-side bearing of the balance, and dial side bearing of third and second wheel).
Based on the different diameter and qualities of the drillings and bearings, you can speculate, whether there were different revisions available or whether the manufacturing precision changed during the production period.
Further revisions were also available with date indication and pin lever with ruby pins.
There gear train consists of four wheel, which are all located under one large bridge. It is a classical construction with decentral second indication at “6 o’clock” and a directly driven minute wheel.
The flat and light annular balance is not shock protected and beats slowly with 18000 A/h. The caps of its bearings only consists of metal plated.
The balances controls the movement by a pin lever. The escapement wheel has got an odd construction, it looks, like there were two different metals connected.
It can only be guessed, why on the five-jewels version, the third and second wheel have got ruby bearings on the dial side and not both bearings of the more important escapement wheel.
The Uwersi 57/8 has got a quite crudely shaped out escapement lever cock on the dial side and it’s lacking a ratchet mechanism. Only a simple spring interposes the ratchet wheel, which is driven by a rocking bar winding mechanism.
On all versions, you can easily spot the preparation holes for a cap jewel pair of escapement- and third wheel. The version with 21 jewels makes extensive use of cap jewels.
In the lab
|dial up||+44 s/d||164°||2.5ms|
|dial down||-54 s/d||189°||3.1ms|
|crown right (12 up)||-125 s/d||130°||3.8ms|
|crown up (3 up)||-150 s/d||-°||-ms|
|crown left (6 up)||-147 s/d||134°||3.8ms|
|crown down (9 up)||-138 s/d||127°||3.8ms|
|Size:||10 1/2''' (measured: 23,2mm)|
|Number of jewels:||2/5|
Nickel anular balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Hairspring key|
|Construction type:||pillar construction|
|Winding mechanism:||rocking bar winding system|
|Setting lever spring:||3 hole(s)|
Flume: 1957 43|