Operation Of Chronograph Mechanism; Stopping; Starting - Seiko 6138A Manual

6f 3BA Operation of Chronograph Meehanism
Stopping of chronograph minute and second hands
Cl ut ch ri ng
C oupl i ng le v e r
Four th wheel (i dl e)
Center chronograph wheel axle
(does not rotatel
Stopping
The minute and second record-
ing wheels are stopped when the
Fis' 15
clutch ring is raised through action
of the coupling levers. The hour
recording wheel comes to a halt by a
slip of the hour recording friction
spring of the barrel. The slip comes
from the fact that the hour record-
ing wheel stop lever brakes the hour
recording wheel by the spring for
hour recording wheel stop lever.
→
Stopping of chronograph hour hand
Hour recording wheel
Hour recording
Starting of chronograph minute and second hands
tf\-
(R ot at es as one un i t l
Fi s . 16
Starting
The minute and second record-
ing wheels are started when the
coupling levers are separated from
the clutch ring. Simultaneously, the
second coupling lever pushes the
intermediate hour recording wheel
stop lever pin, revolving the inter-
mediate hour recording wheel stop
lever in the
-
direction. And then.
the force of the spring for hour
recording wheel stop lever is not
transmitted to the hour recording
wheel stop lever to release the brake
of the hour recording wheel and let
it start.
Intermediate hour recording
wheel stop lever
Spring for hour recording -
wheel stop lever.
Starting of chronograph hour hand
‑ 6 1 3 8 A ‑ 7 ‑
recording wheel stop lever pin
Second coupling lwer