1960, Pforzheimer Uhrenrohwerke lauched with the series 1260 their standard series of modern selfwinding movements. Their construction was so advanced, that it was used until the very last series 1660 in the mid 1970ies and over the time only a few details changed from series to series.
The caliber 1261 still uses the old balance with two legs (in contrast to the balance with three legs, which first appeared in the 1360 series) and the low beating rate of 18000 A/h. The balance was secured in two Incabloc shock protectors, which let the movement shown here survive a hard shock. Afterwards, the balance just had to be put back in position, which is just “peanuts”.
The axle-beared rotor winds the mainspring in both directions. This construction was used without changes in all further movement seriess including the series 1560. And even the last series, 1660, used that mechanism, but applied just a minor number of changes for cheaper production.
The movement contains 25 rubies; the anchor- and seconds-wheel are located in deck jewels, as you can see on the dial side photo. The date indication switches slowly between 9 and 12pm; if you turn back to 8pm, you can afterwards advance the date semi-fast one position. This was achieved by a moving wheel, you can see at position “7” on the dial side.
1963, the series 1360 superseded the series 1260. The 1360 was basically the same, but contained a more modern balance wheel with three legs and also offered a moveable hairspring stud.
|Number of jewels:||25|
Nickel anular balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Hairspring key|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||1 hole(s)|
|Functions:||hour, minute, second, day, selfwinding|
Flume: 1962 88|