The Otero 846 is a rather late windup movement, which has got a direct read jump hour indication, which was very popular in the 1970s. Every full hour, the “digital” hour indicator advances one step, while the “digital” minute und seconds indicators advance smoothly.
Unfortunatly, the specimen shown here is in a very bad condition, so that the funcionality of the direct read indication cannot be described.
With 17 jewels, it is a fair mid class mass-produced movement.
The minute wheel is still located in the center of the movement, so this is a conventional construction, which was already a little outdated, but very reliable and proven.
So, it’s no surprise, that we have the classical gear train with mainspring barrel, directly driven center minute wheel, third wheel, center seconds wheel and steel escape wheel.
The modern three-leg anular balance already beats with 21600 A/h and is protected against shocks by two RUFA Antishock bearings. The precise frequency can be adjusted on the hairspring key only, but here the key is a little longer, so that the adjustment is easier.
The module for the direct read indication is mounted with three screws on the dial side and has got a slightly larger diameter than the base movement.
The minute- and seconds disc (the latter is missing, unfortunatly) are mounted on the matching axles and advance slowly and not jumping.
The plastic hour ring contains one triangular cutout on its inner side. How it is driven and held im position cannot be determined with the specimen shown here…
… but it seems, as if the hour wheel normally contains a riveted spring, which is responsible for the advancing. It it also possible, that the counter part, which ensures the hour jumps at the full hour only, somehow has to do with the minute indication disc, which contains two holes, that look, like it could carry something.
|Number of jewels:||17|
Nickel anular balance|
|Balance bearing / direction hairspring:||Counterclockwise|
|Adjust mechanism:||Hairspring key|
|Construction type:||solid construction|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||1 hole(s)|
|Functions:||hour, minute, second|
|Size:||11 1/2''' (measured: 25,0 (29,9)mm)|
Flume: K3 N1 18|