Toshiba 4580, Service Manual

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6570/5570 PAPER FEED SYSTEM 9 - 18 Mar. 1999 © TOSHIBA TEC
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Paper separation function
Since the paper cassettes do not have separation
claws, a pair of rollers (feed roller and separation
roller) are used inside the machine, as shown in
Fig. 9.3-1.
The separation roller is connected to its shaft
through a spring joint torque limiter. The feed roller
is rotated in the direction of the arrow ( ) at the
same timing as the pick-up roller by the feed mo-
tor. The sepatation roller is driven in the direction
of the arrow ( ) through the torque limiter. But
when there is no paper or only one sheet between
the rollers, the friction between the rollers or that
between the sheet and the separation roller is large
enough to force the separation roller in the direc-
tion of the arrow ( ), causing a slip in the torque
limiter.
However, if multiple-sheet feeding occurs (Fig. 9.3-
2), since the friction between the sheets is small,
the lower sheet is forcibly separated from the up-
per sheet and is sent back in the direction of the
arrow ( ) by the separation roller. The Upper
sheet is fed in the directino of the arrow ( ) by
the feed roller.
Examples:
If only sheet of paper
1
arrives at the separa-
tion roller, the force of the feed roller, which is
greater than that of the separation roller, causes
the separation roller to rotate in the ( ) direc-
tion, sending the paper on to the aligning roll-
ers.
If two sheets of paper (
1
and
2
) arrive at the
separation roller, the force of the respective
rollers is greater than the friction between the
sheets of paper, and the top sheet
1
is sent in
the ( ) direction by the feed roller while the
bottom sheet
2
is sent in the ( ) direction
by the separation roller.
Fig. 9.3-1
Fig. 9.3-2
Paper-feed roller
Sparation roller
Spring joint
(torque limiter)
The direction of
paper feeding
Paper-feed roller
Separation roller
1
2