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Fig. 1

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Fig. 2

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Fig. 3

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Fig. 4

AS 1520

Features
automatic
sweep second
power reserve display 36h

Data
11.5''', Dm= 25.6mm, Do= 26.0mm
H= 5.75mm
F= 1.2mm
T= 2.2mm
17/21/25 jewels
f = 18000 A/h
power-reserve 38h

Balance staff U2423

Stem W2056

Mainspring / battery
Zf1121, 1.45 x 8.5 x 0.10 x 250mm

Hands
1.30 x 0.90 x 0.20mm

Comments about the data

Remarks
detached manual wind
differences not known between 1512, 1520, 1523

Fig. 4: For the power-reserve display the difference between revolutions of barrel arbor (winding) and barrel (running down) must be registrated. As in automatic movements the mainspring is coupled to the barrel with a slip clutch, a further slip clutch is needed to enable stopping the display, when the spring is fully wound.
The combination of differential gear and friction clutch is sophisticated: An elastic steel cock A is pressing three wheels B together (only upper visible). The middle wheel has three holes in which balls are circularely rolling between upper and lower wheel. So the balls drive the middle wheel with the difference of upper and lower wheel. The upper wheel is driven by a gear C on the barrel, the lower by a gear D on the arbor. To form the difference and not the sum, the revolutions of gear D are inverted by an intermediate wheel E. The middle wheel turned by the balls moves over wheel F the power-reserve display. As wheel F is only partially geared, the display is stopped when fully wound.
Thus the planet wheels commonly used in differential gears are replaced by planet balls, which simultaneously act as friction clutch. This assembly fits in just 4mm diameter, and 0.6mm height.

family/generations:
separate bridge for automatic click:
1336, 1427: smaller pillar plate 11.25'''
1361, 1423, 1457, 1490, 1519: -
1382, 1424, 1448, 1479: power reserve display, hand
1395, 1468: day, date pusher
1396, 1447, 1476: date pusher
1402, 1493: calendar, moon phase
1463, 1488: power reserve display, window
1555: date
automatic click beared in automatic brige:
1512, 1520, 1523: power reserve display, hand
1515, 1571: day, date pusher
1572, 1578, 1659: date
1574: power reserve display, window
1583, 1584, 1585: -
suffix N (not all calibres): modifications of automatic parts, not visible from outside

Example, year: signature; shock device
ca. 1950: YOU, V, Hallmark Watch Corp, Swiss, 17 Jewels; Incabloc
(AS 1382N)

Not for Sale!
The movements presented in this caliber finder are not for sale. This is only a data sheet for identification and evaluation of the movement calibre, as well as for approximate dating.

bidfun-db 21.3 © 02-08-15, mtr-Ranfft


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