The large, 12 ligne, brass colored Kienzle 058b12 is likely to be launched in the mid 1960ies. It is part of the caliber series W058, a series of pin lever movements, which were available with and without center seconds in different revisions.
On the base plate of the pillar construction, you can already imagine, that it’s a jewel-less pin lever movement. Like on (almost) all Kienzle movements, the click mechanism is mounted on the base plate.
The biggest difference to movements like the caliber 051 is, that the caliber 058 uses an indirectly driven center second, and that there’s no directly driven minute wheel any more. The hands are indirectly driven by the second wheel and its cannon pinion on the dial side. Nevertheless, it is still possible to lengthen the staff of the fourth wheel at 6 o’clock and use it as decentral seconds indication.
The Kienzle 058b12 has got a large, two leg anular balance, which still beats slowly (and loud!) with 18000 A/h. It is not shock protected and is beared in two punch bearings. It regulates a conventional pin lever movement. The only jewel of that movement is the ellipse of the balance.
At 3 o’clock on the dial side, there’s the cannon pinion. Since it turns clockwise, the minute wheel is driven by a transmission wheel at 4 o’clock. The transmission wheel also drives the hour wheel, which also drives the date mechanism.
As (almost) all Kienzle movement, the Kienzle 058b12 has got a rocking bar winding mechanism.
The rather complicated date indication mechanism has got as main element a large switching wheel (at 1 o’clock) with a moveable switching finger. This ensures, that the date can be corrected semi-fast by turning the hands back and forth for a few hours.
It’s a bit odd, that here a date disc is used and not a date ring.
The gearing of the date disc is also secured by a spring, which ensures the correct position of the figures.
In the lab
Timegrapher resultFor a 50 year old pin lever movement, which was treated quite badly according to the traces of the case, the results are great! Despite a non-moveable hairspring stud, the beat error is below 1 ms in all positions, and the amplitude is optimal with almost 300 degrees in all positions. Even the maximal rate difference with 41 seconds is great for a jewel-less pin lever movement!
|dial up||+13 s/d||286°||0.2ms|
|dial down||+6 s/d||292°||0.8ms|
|crown right (12 up)||+45 s/d||293°||0.7ms|
|crown up (3 up)||+15 s/d||301°||0.3ms|
|crown left (6 up)||+4 s/d||297°||0.6ms|
|crown down (9 up)||+32 s/d||301°||0.9ms|
|Number of jewels:||1|
Nickel anular balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Hairspring key|
|Winding mechanism:||rocking bar winding system|
|Setting lever spring:||2 hole(s)|
|Functions:||hour, minute, second, day|
Flume: K3 -|