Canon NP-70 Service Manual page 148

4-46
NP -70
1)
SKIRT BLADE PORTION
The skirt blade is made of polyurethane rubber, 2 mm thick, and is mounted to contact the
drum in advance of the cleaner blade (relative to drum rotation). In the event of a paper jam,
this blade prevents paper from reaching the cleaner blade.
2)
CLEANER BLADE PORTION
The cleaner blade performs the final wiping to ensure that the drum is completely free of con-
tamination and, thus, ready to begin a new copying cycle.
3) FRAME PORTION
Consisting of the blade mounting brace, the pivot shaft, and the locking arm. This portion is
used to support the blades and ensure proper seating against the drum; when the locking arm is
in its fully lowered position, the blades are seated securely against the drum surface.
4)
PRESSURE ADJUSTMENT PLATE
This plate is adjustable so that the seating of the assembly frame components against the blades
(and, thus, the blade against the drum) can be set to the proper pressure.
5) LIQUID STOPPER PLATES
These two plates are mounted between the two blade portions. They each have an overhanging
finger which contacts the ends of the cleaner blade (one at each end). These fingers prevent
leakage of developer from the ends of the cleaner blade and, thus, should contact their re=
spective ends of the blade.
4.7-3 REMOVAL/INSTALLATION ACTIONS
The following points should be considered when performing replacement actions:
a) Insertion of a new skirt blade is greatly facilitated by wetting the blade with developer
before installing it.
b) The two blades must be seated properly in their mounting components for proper opera-
tion. Check this by pressing at various points along the edge of the blade during installa-
tion.
c) The knobs used for attaching the blade are not the same size -the skirt blade knobs are
shorter than the blade attachment knobs. Be careful not to confuse them during replace-
ment.
4.7-4 REPAIR/SERVICING ACTIONS
1) ADJUSTMENTS
The skirt blade and the cleaner blade should be pressed against the drum with a specified
pressure; otherwise incomplete cleaning or noise results. Begin by performing the cleaner blade
check as follows:
Second Printing~une, 1974
© CANON INC.