Fig. 4-105 Ratchet Wheel Position - Canon NP-70 Service Manual

NP -70
4-93
1) STOP BUTTON
When pressed, this button causes the release lever to trip the release arm, thus, stopping
further copying.
2) COPY BUTTON
When pressed, this button activates the components for the start of subassembly mechanical
operation. Also, MS7 is actuated to start copy operations.
3) COPY SELECTOR DIAL
This dial is used to set up the click wheel for the desired number of copies.
4) DRIVE PLATE UNIT
This unit is cycled by the back &forth motion of the copyboard to advance the ratchet
wheel each time a copy is made.
5) REMAINING COMPONENTS
As the mechanical operation of the selector is complex, the following operation explanation
(25 copies or less) of the remaining components is provided.
a) Rotation of the copy selector dial sets the click wheel to its reference position, held fast
by the click lever.
b) Due to torsion spring force, the ratchet wheel "A"
stud will remain positioned against the "B" stopper
of the click wheel, as shown in Fig. 4-105.
Ratchet Wheel
Fig. 4-105 Ratchet Wheel Position
c) Depressing the copy button causes the start shaft 'to actuate MS7. Additionally, shaft
stud "C" drops and allows the release arm to move (due to spring pressure) against the
ratchet wheel. The movement of the release arm results in arm projection "B" locking
the start shaft in its downward position to hold MS7 "ON" (see Fig. 4106).
© CANON INC.
Second Printing-June, 1974