Paper Feed And Registration - Ricoh FT5034 Service Manual

4.4 PAPER FEED AND REGISTRATION

4.4.1 Mechanical Parts
1. Overview
In total this machine has four feed stations. They are three cassette feed stations
and a by-pass feed station.
The 1st and 2nd feed stations each use a size adjustable cassette, but the 3rd feed
station located inside the copier uses only an A3 cassette.
The capacity of each cassette is 250 sheets. The maximum paper capacity of the
by-pass feed station is 50 sheets.
All four feed stations use the feed roller and friction pad system. Only the by-pass
feed station uses a pick-up roller.
2. Feed System
1) Feed Roller
The CPU starts paper feed by energizing
the appropriate paper feed clutch (the
paper feed clutches are all magnetic
clutches).
The CPU turns on the paper feed clutch for
the required station, at a programmed time
after the Start key is pressed.
Upon receiving the signal from the
registration sensor, the CPU turns off the
paper feed clutch.
2) Friction Pad Feed System
When a cassette is inserted into the copier, the friction pad contacts the feed
roller (in the by-pass feed station, it always contacts the feed roller). The friction
pad holder is mounted on one end of the swivel plate with a swivel screw, so it
automatically applies even pressure against the feed roller and the copy paper.
The coefficients of friction are µ1 > µ2 > µ3.
Friction Pad
<Single sheet
feeding>
Feed Roller
µ1
µ2
The coefficient of friction between
the friction pad and paper.
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Feed Roller
1st Feed Clutch
2nd Feed
Clutch
<Multiple sheet
feeding>
µ1
µ3
µ2