Seiko 6138A - Chronograph Mechanism; Pre-Assembly Checks; Post-Assembly Checks

6138AChronOgraPhMechanisllfl
Explanations on this
page
are for the nuclcus
of
61 38A.
Sufficiently
check and
adjust the
assernbled
movetnent.
I.Items
to
be checked
before assembling the
iewelled
pallet
fork
and staff, after
setting the chronograph
bridge.
l) Confirm that free running
force is transmitted
unaffectedly. Even
though no roll back motion
exists, as long as it
functions
smoothly there is no
problem.
And at the same time check
the
perform-
ance of starting and stopping actions of
the
hour
recording wheel by turning over
the movement.
2)
Check
for
meshing condition
of
the
first
and
second
coupling /euers
(Refer
to
5139A-8).
3)
Check clearance between
the second coupling lever
and the
intermediate
hour
recording
wheel
stop
lever
pin
and their
actions.
When stopping,
clearance must exist between the
second coupling lever and the intermediate
hour
recording
wheel stop lever
pin;
when
starting, the
second coupling lever
must
push
and move the
intermediate hour recording
wheel stop
lever
pin.
む
{lntermediate
minuterecordin9
wheel}
1.
Mesh the
intermeditte
minute
recording
wheel
and
the minute recording
wheel.
Refer to Fig. l0 for
assembling
this
spring
(6138A-7)
RefertoFな
.7foFaSSemblingthis
spring(6139A‑5)
StopStart
嗅
χ
二
斐
ζ
iI:‖
∬:l11:"r
缶
reco rdi ng
wheel
stop lever
Fis.4
Should they
malfunction,
adjust
them
by tuming
the second coupl-
ing lever axle
eccentric
pin.
In this
case,
perform
this
adjustment
while
observing
the delicate clearance
be-
tween
the second coupling
lever and
the clutch
lever.
2. Items to be checked
after
assembling the balance
l) Check
for strength
and
height
of the
minute
recording
iumper
(Refer
to
6139A-8).
2) Check
for
meshing
position
of the
chronograph
finger
(Refer
to
6139A.-9).
3) Check
for contacting condi-
tion of the
hammer
and
hearts
(Refer
to
61394-10).
Balance cock screws
(2
pcsl
Balance
cock
Balance complete
with stud
Pallet cock
screws
(2
pcs)
Pallet cock
Jewelled
pallet
fork and staff
\
-
First coupling lever screw
\--
First
coupling lever
Holdlnぃ¨wforco¨eVers①
①
①
＼
＼
＼
①
①
①
①
①
①
｀
￨、
Train
wheel
(process
of force
transmission)
Transmission of
force
when chronogtaph mechanism is started.
Transmission offorce when chrenograph mechanism is stopped.
When the minute and second chronographs
are started, the force is
transmitted
to both
chronograph
and
train wheel
by the action ofthe clutch,
and when the
chronographs
are stopped,
the
force is
transmitted
only to the
train wheel.
When the hour chronograph is started,
the
force
is transmitted frcm
the barrel
+
friction
sping
for
intermediate hour recording
wheel
+intermediate
hour
recording
wheel
-
hour recording
wheel. When the hour
chronograph is
Hour
stopped, force transmission
to the hour recording wheel is
stopped by a slip of
the
friction
spring
for
intermediate hour recording
wheel.
It
is not necessiuy to remove the
minute recording
jumper
and,
screws.
g
Minute
recording
jumper
Move them only when adjusting
the
\
minute
recording
iumper.
\
Chronograph bridge screws
(3
pcsl
(Hammer
click)
Chronograph bridge
NOTE:
When
assembling
the
chronogroph
bridge,
pay
attention to the following.
＠
④
9
∠
『
謂
:驚
九賜鰐
耀
Ъ
胤
ノ
昭
″力θα
忠躙
静無
①
Hammer
④
―
―
一
―
Mttterec∝
d…J④
―
∞
¨mgleverttmgO
Completely
set the
center portion
of
the
spring around the tube of the
-
barrel
and train wheel bridge.
\__
A
Second coupting
tever
(5
l,
O
1hc
pinof tlte st'tz-rlld
tottltlittg /t'l
r/
ir ttttttlrlriv
do rrot
rotate
it
e\ccp1 dtrring rditrstrrtcttt.
e
Asserrtblr-
lh(
(t)uplitlX
1t'tr'r'r
iri r \trftitig
ri'ntlilt,,r
to
prcvert
danraging
Lltc
lrttrrllt
vlttli
Center chronograph
wheel
{Fourth
wheel)
Center
wheel
Barrel
Thirdwheel
scape wheel
hour recording
wheel
finger
3.
Interlock
the
hammer
click
andthefly-back
lever
pin.
Screw
for minute
recording
jumper
Wttrマ
hg
ξTamm∝
引ょ
Thisclickis
dr
eninto
1郵
罵
Tiedヾ
L
Neverlubricatethe
v
axle
of this wheel.
(Fig.
5)
‑6138A‑4‑
Intermediate
minute recording wheel
recording
wheel