The 12 ligne pin lever movement EB 8800, which was launched in the mid 1960s, was for about ten years one of the most used swiss movements. Its very simple construction, the many different enhancements, up to a simple chronograph were responsible for its popularity.
The base place already shows the very economical construction: The movement is a pillar construction, where even the mainspring barrel is beared on a pillar. The number of jewel bearings on this movement depends, from one (as cap jewel for the balance wheel) to 21 (with cap jewels virtually everywhere). The specimen shown here has got only one jewel.
The EB 8800 has got a modern gear train, on which the large mainspring barrel drives the second wheel, which drives the time indication works on the dial side by a slip clutch (later shown in detail), followed by third wheel, seconds wheel at 6 o’clock (which can drive a decentral second hand at 6 o’clock - this movement also has got the name EB 8800) and the filigree escapement wheel with its relatively small teeth.
On the side view, you see, how flat this movement is in relation to its diameter.
As already written above, the second wheel drives the hands on the dial side. This is done by a slip clutch, you can see here. The slip clutch is required to disengage the movement when setting the time. It can easily be imagined that this clutch can lose its friction over time.
Since theb ase place of the EB 8800 has got no anchoring pins for the lever, EB used a trick: On the lower side of the lever (on the photo, the lever lies lowerside up), the mounting pin of the fork is extended, so that it engages in a hole on the base plate. The diameter of this hole is chosen so that the pin touches its edge on both end positions of the lever. This prevents the fine lever pins from being damaged, when the balance bounces.
The very flat, screw-less anular balance beats with 18000 A/h and on some versions, it is shock protected.
On the dial side, this movement is also pretty modern. It has got a yoke winding system with a punched setting lever spring, which also locks the changer wheel. At 3 o’clock, you see the dial-side clutch wheel of the second wheel. It drives the minute hand and is also the connection to the Breguet winding pinion.
At 9 o’clock, there’s the KIF Protechoc bearing of the balance wheel. Here, it does not use synthetic rubies as bearing, but a metal bushing and a metal cap plate. And if you look a little bit to the right and down, you see the pin of the lever, described above.
|Size:||12''' (measured: 26,4mm)|
|Number of jewels:||1|
Nickel anular balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Hairspring key|
|Construction type:||pillar construction|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||2 hole(s)|
Flume: K3 69|