EB 8481-74

 
EB 8481-74

EB 8481-74

Description

The EB 8481-74 is a typical pin lever movement from the seventies, made by the Ebauches Bettlach in Switzerland.

The german manufacturer Emes acquired this movement in parts, assembled it inhouse in their factory and used it as caliber Emes 12:

Emes 12 = EB 8481-74

Emes 12 = EB 8481-74

With its characteristic construction, consisting of one single main plate, which contains everything, starting from the anchor and ending with the mainspring barrel. For a watchmaker, this is not easy to service, but it’s cheaper and suitable for a construction robot.

open lever bearing

open lever bearing

The lever bearing looks like a cap jewel holder:

lever bearing

lever bearing

With its construction like a Roskopf movement, there’s more free space for a larger mainspring barrel and a larger screw-less balance wheel.

base plate

base plate

There are no bearing jewels on this pillar construction.

gear train

gear train

It is noteable, that all gears have got a very small diameter. In the version shown here, there’s no center second wheel, but there do exist other versions, on which the center second axle is longer, so that it can carry a hand.

side view of the gear train

side view of the gear train

You see very well, that the ratchet wheel is on the movement side, but below the gear train bridge. This means, that the whole click mechanism including the crown wheel is also located on the inner side of this bridge. It is a very simple construction, consisting of only one tiny spring. On one of the movement in the archive, the crown wheel is a bit loose, so the click spring cannot securily interfere and block.

inside the gear train bridge

inside the gear train bridge

A little speciality of this movement can be seen on the balance: It does not contain a (vertical) ellipse jewel, but a horizontal (like a finger, hence the name!) finger jewel. The fact, that it is a synthetic ruby and not a metal finger is noteable, since generally, balances with a finger are only found on the cheapest pin lever and Roskopf watches, and there the finger is of course made out of metal. So, in this point, the EB 8481-74 distinguishes in a very positive way from other pin lever movements.

balance wheel with jewelled finger

balance wheel with jewelled finger

Besides that, the escapement is not very spectacular: The flat and light ring balance has got a hairspring, which is connected to a moveable stud. Its effective length is adjusted by a simple, U-shaped hairspring key and makes the balance beating is slow 18000 A/h. The balance controls the escapement wheel by a pin lever.

EB 8481-74 dial side

EB 8481-74 dial side

The dial side is surprisingly empty, since the keyless works are below(!) the dial plate. The minute wheel is, like on a Roskopf movement, driven by a sliding clutch on the mainspring barrel. Different to a Roskopf movement, the hour wheel is driven by an exchanger wheel.

This odd construction is often used on EB movements, but rarely elsewhere.

Technical data

Manufacturer:EB
Caliber:8481-74
Number of jewels:1
Escapement:Pin lever
Balance types: Nickel anular balance
Shock protection(s): Novodiac
Balance bearing / direction hairspring:Clockwise
Moveable stud:yes
Adjust mechanism:Hairspring key
Construction:
  • lever, escape wheel, seconds wheel, third wheel, large driving wheel, mainspring barrel
Winding mechanism:yoke winding system
Functions:hour, minute
A/h:18000
Size:10 1/2''' (measured: 23,2mm)
Inventory number:17015

Usage gallery

fake gents watch

fake gents watch

This movement in the Emes version was donated by Christoph Reiner and the movement in the original EB version together with the watch was donated by Harald Hoeber. Thank you very much!