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AS 52
Manual · 12.5‴ · Switzerland · 1939
Timegrapher
Beat rate
18,000bph
Frequency
2.5Hz
Reference: healthy amplitude ≈ 270–315° fully wound (>200° at 24 h); beat error ideally < 0.5 ms.
Movement
| Movement type |
Manual
Purely mechanical movements wound by hand via the crown, which tensions the mainspring to store energy. As the spring unwinds, it drives the gear train at a controlled rate set by the escapement and balance. Typical power reserves range from 38 to 80 hours, requiring daily or near-daily winding to keep the watch running.
|
|---|---|
| Winding type |
Stem Winding (Crown)
Winding the mainspring by turning the crown attached to the stem, transmitting torque through the winding pinion. Patented by Adrien Philippe in 1842, it replaced key winding and remains the standard manual winding method for both pocket watches and wristwatches.
|
| Setting type |
Pin Set (Pin-Push)
A small pin or button next to the crown is depressed to engage the setting mechanism while the crown is turned. A transitional system between key set and modern stem set, common in pocket watches from the 1860s to early 20th century and in some lower-cost wristwatches.
|
| Escapement type |
Cylinder
Invented by Thomas Tompion and perfected by George Graham around 1726, the cylinder escapement uses a slotted hollow cylinder on the balance staff that engages directly with the escape wheel teeth. Common throughout the 18th and 19th centuries, it offered flatter calibres but suffered from friction and wear.
|
| Control type |
Balance Wheel
The heart of mechanical timepieces, the balance wheel is an oscillating component that, together with the hairspring, forms a harmonic oscillator regulating the gear train's pace. Its steady back-and-forth motion ensures the even release of energy from the mainspring, governing the watch's accuracy.
|
| Regulator type |
Pinned Regulator (or Index Regulator)
The most traditional regulator, consisting of a movable index pointer fitted with two curb pins (or a pin and a boot) that embrace the hairspring. Sliding the index along its scale changes the spring's active length, adjusting the rate. Simple, reliable, and easy to service, it remains the workhorse standard across countless mechanical movements.
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Specifications
| Lignes | 12.5‴ |
|---|---|
| Shape |
Round
It is the most common form that we can find.
|
| Complications |
Sweep Second
Contrary to the ticking motion of quartz watches, the sweep second hand in mechanical watches moves smoothly around the dial, offering a visual representation of time flowing continuously. This has become synonymous with the precision and craft of mechanical horology.
,
Perpetual Calendar
An engineering masterpiece, it accounts for month variations and leap years. It's a testament to horological excellence, programmatically tracking the intricacies of the Gregorian calendar.
|
| Hand count | 3 |
| Hand sizes | 1.50 x 0.80mm |
| Further measures | Mounting Diameter (Dm): 27.9mm |
Origin & References
| Manufacturer | AS |
|---|---|
| Country | Switzerland |
| Launch year | 1939 |
| COSC certified | No |
| Signature | 1939: old data sheet |
Notes
Remarks: open face calibre
cylinder escapement
unusual: crown mechanism with rocker bar, but ratchet on back side
unknown whether the completely functionless crown wheel is standard
Other data: balance staff: Cyl 0.80 x 4.30 x ?mm mainspring / battery: Zf1246, 1.50 x 10.5 x 0.13 x 300mm
cylinder escapement
unusual: crown mechanism with rocker bar, but ratchet on back side
unknown whether the completely functionless crown wheel is standard
Other data: balance staff: Cyl 0.80 x 4.30 x ?mm mainspring / battery: Zf1246, 1.50 x 10.5 x 0.13 x 300mm
Family