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.
|Number of jewels:||1|
Nickel anular balance|
|Balance bearing / direction hairspring:||Counterclockwise|
|Adjust mechanism:||Long regulator arm|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||1 hole(s)|
|Functions:||hour, minute, second|
Flume: 1952 25|