The AHS is a simple made pallet lever movement, on which a selfwinding module was added, which was used under the term “Robot-Automatic” on other movements.Video on YouTube
Unlike most other AHS movement, the AHS 154 is a true lever movement and hence pretty rare.
The selfwinding mechanism consists of an excenter changer with ruby wheels.
As you can see, the selfwindig mechanism is pretty crude and the oscillating weight is just axle beared and will scratch on the movement or on the back sooner or later.
It’s not haute horlogerie, but crude and rivetted metal. If the mechanism doesn’t work any more, it had to be replaced as a whole. This was pretty easy, since it was only held by two screws on the movement.
The click moves the winding wheel and decouples it on hand winding. This leads to abrasion, which can be seen on the dark spots at the tip of the click and on the gear.
When you see the movement without selfwinding mechanism, you would hardly think, that there’s something missing. The only indication is the ratchet wheel at “11”, which has got no connection to a crown wheel, but is driven by the selfwinding mechanism and by the barrel wheel on the dial side.
Such a construction with (rocking bar) winding mechanism on the dial side and click mechanism on the movement side is an odd rarity.
The complete wheel works are located under one 3/4 bridge. This makes a service pretty hard, but is a very cheap construction.
The AHS 154 uses a screw balance, which is beared in two Rufarex shock protections. The hairspring is fix connected to the balance cock and is adjusted in its effective length by a short regulator arm with scale.
The gear construction is classic, but not outdated, since here, they used already a construction with concentric minute wheel and center second pinion. The minute wheel is located under an own cock.
The indirectly driven center second consits of a pinion, whose number of theeth (8) is the same as the number of teeth of the fourth wheel gear (at “6”). Since both work with the third wheel, they have got the same number of rotations per minute (1).
The center second pinion is “braked” by tiny spring to avoid a jumpy center second hand.
Of course, all bearings (except the minute wheel bearing) contain synthetic rubis, and additionally, there are many cap jewels (on the dial side even for the lever) used. In sum, when you also count the ruby wheels of the selfwindig mechanism, you get the number of 23 jewels.
This movement uses a cheap pillar construction with non-massive plates.
There’s no technical neccessity for using ruby bearings on the mainspring barrel and for using cap jewels for the lever bearing, but it helps increasing the number of jewels on the dial.
The AHS 154 uses a rocking bar winding system with the click mechanism located on the movement side.
The date mechanism is pretty simple and is an own unit, which is held by three screws on the main plate. It has got no quickset feature and only drives a date disc. Because of that, the date indication is located quite near the center of the dial.
In the 50ies, tiny red date indicators were used quite often, but at the early sixties, this was already out-of-fashion.
Timegrapher resultThe movement, when entered the lab, showed large abrasion, especially on the selfwindig mechanism. It was dissolved, cleaned and oiled. On the timegrapher output, you can see the bad condition of the movement. It was extensively worn out and is beyond justation.
|crown right (12 up)
|crown up (3 up)
|crown left (6 up)
|crown down (9 up)
|10 1/2''' (measured: 23.3mm)
|Number of jewels:
Nickel screw balance
|Balance bearing / direction hairspring:
|Short regulator arm
|rocking bar winding system
|Setting lever spring:
Flume: 1962 109