The swiss Ebauches Bettlach, specialist for pin lever movements, is generally only known as producer of really simple movements. That in former times, they also made quite beautiful movements, is hardly known any more.
The EB 1333 shown here is for sure no Haute Horlogerie, but it is constructed and made in a way, that it’s a pleasure to service and show it.
With its diameter of only 8 3/4 lignes, this movement of the late 1950ies was primary made for ladies’ watches, but was also used for elegant gents watches, such as the one shown at the bottom.
The well executed base plate shows, that this movement uses bearing jewels almost wasteful: All bearings, even those of the slowly turning minute wheel, contain synthetic rubies.
Since the type of construction of pin lever movements requires two less jewels (since there are no ruby pallets), two cap jewels for the escape wheel had to be used to achieve the “magical” number of 17 jewels.
The gear train is standard for that time: The mainspring barrel directly drives the center minute wheel, followed by third wheel, seconds wheel and escape wheel. All gears have got a rather large diameter and in comparison a pretty filigree outer sprocket. Something like that can really happen let see!
Since the EB 1333 is a (at least partial) pillar construction (see the two pillars of the balance cock), it builds pretty high. On the other side, a high building movement can use a mainspring of a larger dimension.
Typical for EB is the use of a very flat, non shock protected three-leg anular balance. This construction, together with the traditionally very fragile balance wheel leads to the situation, that there are not many EB movements, on which the balance axle is not yet broken. The specimen shown here belongs to the few lucky ones of that era, which are still working.
The balance beats with 18000 A/h and its exact frequency can only be adjusted at the hairspring key directly.
On the dial side, there’s the ratchet and the rocking bar keyless works. Both are well executed and match the fact, that the EB 1333 is “only” a pin lever movement.
The two cap jewels, the one at 9 o’clock is for the balance, the one at 7 o’clock for the escape wheel, are made of a transparent material, probably glass. They only appear to be read, because the red color of the bearing jewels below shines through.
|Number of jewels:||17|
Nickel anular balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Hairspring key|
|Construction type:||pillar construction|
|Winding mechanism:||rocking bar winding system|
|Setting lever spring:||3 hole(s)|
|Size:||8 3/4''' (measured: 19,2mm)|
Flume: 1958 41|