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Valjoux 55
Manual · 17.67‴ · Switzerland · 1945
Also known as: Valjoux 54
Dimensions
39.86 mm
Height
7.90mm
Jewels
187
Power reserve
—
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 |
Stem Set (Crown Pull)
The dominant modern system: pulling the crown out to a setting position engages the hand-setting mechanism. Introduced in the late 19th century and refined into multi-position crowns (date, time, GMT). Used in virtually all modern wristwatches and most 20th-century pocket watches.
|
| Escapement type |
Swiss Lever
The undisputed standard of modern mechanical watchmaking. Through an elegant interplay between escape wheel, pallet fork, and balance, it delivers reliable impulses with the safety of 'draw' to keep the lever locked. Refined since the 18th century, it powers almost every quality mechanical wristwatch made today.
|
| 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.
|
Specifications
| Lignes | 17.67‴ |
|---|---|
| Shape |
Round
It is the most common form that we can find.
|
| Complications |
Chronograph Stopwatch
Functionality meets style as this feature allows wearers to measure specific time intervals, embodying the blend of everyday utility with sophisticated design.
,
Chronograph Second
The heart of the chronograph function, the chronograph second hand provides real-time tracking of elapsed seconds when the chronograph is activated. Usually centrally mounted, its smooth or ticking movement around the dial offers a visual spectacle and allows wearers to measure events with precision up to a second.
,
Chronograph Minute
A fundamental component of the chronograph mechanism, the chronograph minute sub-dial records elapsed minutes once the chronograph is engaged. Typically counting up to 30 or 60 minutes, this feature extends the utility of the chronograph function beyond just seconds, making it invaluable for capturing extended events.
,
Chronograph Hour
Deepening the chronograph's utility, the chronograph hour sub-dial keeps track of elapsed hours when the chronograph function is running. Often located in a dedicated sub-dial, this complication allows for the measurement of longer durations, expanding the watch's timekeeping versatility.
|
| Hand count | 3 |
| Further measures | Nominal Diameter (Dn): 39.86mm |
Origin & References
| Manufacturer | Valjoux |
|---|---|
| Country | Switzerland |
| Launch year | 1945 |
| COSC certified | Yes |
| Signature | ca. 1950: Eska Watch, Swiss |
Notes
Other data: balance staff:
U1543
stem:
W1728
mainspring / battery:
1.50 x 15.5 x 0.20mm
balance staff ronda: 2580 (17,67) stem ronda: 370 (17,67)
Compatible Parts
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