Tech Specs from F.P. Journe:
VAGABONDAGE II
Movement
Calibre 1509
Manual winding
Movement in 18K rose gold
30 jewels
Dimensions of the Movement
Overall diameter: 29.3 x 28.2 mm
Casing-up diameter: 29.3 x 28.4 mm
Overall height: 5.28 mm
Height of winding system: 3.13 mm
Diameter of stem thread: S0.90 mm
Balance
Four inertia weights
Flat Anachron microflamed spring
Mobile stud holders
Free sprung
Nivatronic laser-welded to collet
Pinned GE stud
Frequency: 21,600 v / h, (3Hz)
Inertia: 10.10 mg /cm2
Angle of lift: 52°
Amplitude: 0h dial up: > 260°
24h dial up: > 260°
Principal characteristics
1 minute constant force device, patented No EP 1528443Digital indication of hours and minutes
Time adjustment via crown in position 2
Pallets escapement with 15 tooth escape wheel
Two position crown
Sub-second at 6h00
Power reserve at 12h00
Allora, io ho trovato il link, adesso se avete tempo cercate di estrapolare qualcosa
http://www.google.com/patents/EP1528443A1?cl=enQui più in generale i brevetti di "forza costante"
http://www.google.com/patents/US7473027