The movement shown here, an AM 395, is with a a diameter of
12 lignes a rather large, classically constructed mens' watch
movement with indirect center second.
It bases on the calibar AM 390, which is enhanced by
a center second indication, but it is still marked as
"AM 390" on the dial side.
The construction of this movement is really classy: The large
screw balance, which is of course not yet shock protected, regulates
a pallet lever movement and beats with 18000 alternations per hour.
The effective length of the hairspring, which is fix connected to the balance cock,
is adjusted by a long regulator arm.
Since the base movement, the AM 390, only uses a decentral center second hand at "6",
all gears are on the same level of height.
without center second indication
For the center second mechanism, the third wheel has got an upper wheel connected
to it on the outer side of the bridge. This wheel drives the small sweep second
pinion, which is located under a tiny bridge with a jewel bearing. This jewel bearing
is the 16th jewel of this movement, since here, as usual on old movement, the minute
wheel is not yet ruby-beared.
A friction spring, which is positioned in a cutout of the main bridge, is responsible, that
the center second runs smooth, since it gives a little tension to it.
main plate
On the dial side you see the yoke winding system with a very unique
shaped setting lever spring and a partial helping minute dial,
which was required in former times when the timegrapher was not yet invented, to regulare
the movement without dial and hands.
dial side view
Later on, the AM 395 was produced by Felsa as Felsa 395.
Technical data
Manufacturer
AM
Caliber
395
Number of jewels
16
Escapement
Anchor with pallets
Balance
Nickel screw balance
Shock protection(s)
none
Balance cock direction
clockwise
Hairspring stud
fixed
Regulator type
Long regulator arm
Movement construction
Fork Escapement wheel, Fourth wheel, Third wheel, Center wheel Center second pinion Mainspring barrel
Construction type
solid construction
Bridge shape
Axe, notch at mainspring barrel, 4 gears
Winding mechanism
yoke
Setting lever spring
3 holes
Features
SCI
Functions
Hour, minute, second
Beats per hour
18000
Size
12'''
Image in Flume Werksucher
(1947 40)
Factsheet
Test Results
The specimen shown here was completely gummed and therefor had
to be dissected, cleaned and oiled completely.
Timegrapher Protocol
The AM 395 runs very well in the horizontal positions. Why it has got very
large deviations in the vertical positions is unknown.
