Seiko 6138A - Chronograph Resetting and Safety; Minute and Second Hand Resetting; Hour Hand Resetting; Fly-back Safety Mechanism

6f 3BA Operation
of Chronograph Meehanism
ヽ
一
Resetting
1. Resetting of
the
chronograph
minute
hand and second hand
When
pressing
the second but-
ton, the force is
transmitted'to
fly-back
lever
-
intermediate
fly-back
lever
-
hammer,
and
the
hammer
strikes the minute
heart
and the
second
heart
to
reset the hands
to
"0"
position.
2.
Resetting of
the
chronograph
hour
hand
Simultaneously with
the above,
the
fly-back
lever
presses
the
hour
fly-back
lever
and the force
is
transmitted to the
hour
ham-
mer
to reset the chronograph
hour hand
to
"0" position.
At
this moment,
the intermediate
hour recording wheel
stop lever
revolves
in the
-
direction
by
action
of the
hour
hammer
pin,
and the hour
recording
wheel
is
released. When
the second but-
ton is released,
the chronograph
hour
hand returns
to a stopped
condition.
Resetting
of chronograph
minute
hand
and second
hand
ntermediate
fly-back lever
llar
wheel
Second
heart
Fig.17
Intermediate
hour
wheel stop lever
′
S∝ °
ndbutton
Minute heart
Resetting of
chronograph hour hand
Hour
hammer
Hour hamrneipin
Hour
heart
F!y‐
backlever
Hour
f
ly-lcack
lever
Fly-back
lever
Fly‐backsafetymechanisln
Thismechanismprotectsthe
movementfrorntheshockgenerated
bythesθθ
ο′ご わ

′′
ο

.Endportions
ofthe力 α
″
7′ηθ″
andthe′
η′
θ
/″
θσ
Jα′
θ
/7y―
bαθた ′
θ
ッ
θ
″
arelocatedoutside
thecolumndu
ngstartingcondi―
tion.Whenthesθ θ
οηごb ′′Ottis
depressed,theendportionofthe
J′
′
θ
″

θグ
Ji2′
θ
 ノノ
‐
わαθたJθ ッθ″
slips
amongthecolumnsofthe
ρ
″ια
″
w力
θθ′
(asshOWninFig.18),andthe
forceisnottranslnittedbeyondthe
力
α
″
ッηθた
Ontheotherhand,the
力
ο

″ 力α
″
2′ηθ″
dOesnotmovebe―
causethepinlocatedonitstip
strikestheJκ
′
′

θdiα′θttο

″″
θ
θOrJ―
J″
g″
力
θ
′
s′
ο
ρ
た
ソ
θ″.Atthismo―
ment,momentumofthesθ
εο″ご
b′′0″isabsorbedbyasprihging
chaTacteristicofthettο
夕″
′ン
‐
bαεた
′θ
ν
た
Safetyactionisexhibitedby
integrationofthcabove‐
Inentioned
OperatiOns.
Hour hammer
pin
Intermediate
hour
recording
wheel
stop
(Columnl
Pillar
wheel
Fig.18
Hour
hammer
＼
Second button
.
Hour f ly-back lever
D
艤
＼
‑6138A‑8‑