UMF 54-31

 
UMF 54-31

UMF 54-31

Description

The large 12 12 ligne pin lever windup movement UMF 54-31 was launched in 1938 as “Thiel Start” and produced until 1961. During that time, it was also available under the names “UMF Start” and “UMF M 54”.

The specimen presented here shows its last but one version from the year 1959, which can be identified by its yellow color, its balance bridge and its missing caliber number engraving.

base plate

base plate

The base plate shows all characteristics of a simple pin lever movement in pillar construction. There are not bearing rubies and the different heigths of the plate are the result of its punching production.

At one o’clock, you can see the ratchet, which consists of only one geniously constructed part - a pawl with an integrated spring.

gear train

gear train

We see the classical gear train here, which consists of a directly driven center minute wheel, followed by third wheel, seconds wheel (whose prolonged axle carries the decentral second hand at 6 o’clock on the dial side) and escape wheel.

side view of the gear train

side view of the gear train

As most pillar movements, the UMF 54-31 builds pretty high, too. When the gears are not beared on both sides, they tilt.

The screw-less anular balance is beared under a bridge and has got no shock protection. Its frequency is 18000 A/h and it regulates a pin lever escapement.

UMF 54-31: Dial side

UMF 54-31: Dial side

Like most other pin lever movement, a rocking bar winding system is used here, too.

At 9 o’clock, you can see the height-adjustable bearing for the balance.

Technical data

Manufacturer:UMF
Caliber:54-31
Escapement:Pin lever
Balance types: Nickel anular balance
Shock protection(s): none
Balance bearing / direction hairspring:Bridge
Moveable stud:no
Adjust mechanism:Long regulator arm
Construction:
  • lever
  • escape wheel, seconds wheel, third wheel, center minute wheel, mainspring barrel
Winding mechanism:rocking bar winding system
Setting lever spring:1 hole(s)
Functions:hour, minute, decentral second
A/h:18000
Size:12 1/2''' (measured: 26,9mm)
Production period:1938 - 1961
Literature: Flume: 1958 90
Inventory number:18010

Usage gallery

UMF gents watch, model 414/4/701

UMF gents watch, model 414/4/701

This movement is a kind donation from Mario. Thank you very much for your great support of the movement archive.