Ebosa 131

Ebosa 131 | 17jewels.info - The Movement Archive

Ebosa 131


The large, 13 ligne diameter, Ebosa caliber 131 is a rather simple and crude pin lever movement.

In the whole movement, only one jewel is used. It is on the place, which can be seen best: The cap jewel of the balance. At least, the balance uses a regulation mechanism with a long regulator arm. On its other end, a “U” shaped wire is used as hairspring regulator. Not exactly, what you see as precision…

From a technical point of view, this movement is a little bit interesing, as it uses a very low beating frequency, from 17280 A/h, which is pretty unusal. The balance uses a finger to drive the escapement. The indirectly driven center second wheel uses a weird mechanism: The outer gear ring of the second wheel drives the ring(!) of the center second wheel…

On the dial side, a simple yoke winding mechanism is used; the hands are driven indirectly by the mainspring and just like on Roskopf movements, minute and hour axle can be easily removed.

The movement seen here does not run any longer, probably due to the fact, that its simple construction teared away too much material inside.

Ebosa 131: Ebosa 131 dial side

Ebosa 131 dial side

Technical data

Number of jewels:1
Escapement:Pin lever
Balance types: Nickel anular balance
Shock protection(s): none
Balance bearing / direction hairspring:Counterclockwise
Moveable stud:no
Adjust mechanism:Long regulator arm
  • lever
  • escape wheel, seconds wheel, third wheel, mainspring barrel
  • center second pinion
Winding mechanism:yoke winding system
Setting lever spring:1 hole(s)
  • SCI (indirect center seconds)
References: Flume: 1952 25

Usage gallery

Ebosa 131: Burgana gents watch

Burgana gents watch