Sheet feeding or delivering – Delivering – To receiver for pack of sheets
Reexamination Certificate
1999-11-08
2001-07-24
Ellis, Christopher P. (Department: 3651)
Sheet feeding or delivering
Delivering
To receiver for pack of sheets
C271S221000, C271S213000, C271S314000, C270S058120
Reexamination Certificate
active
06264194
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sheet handling device, and more particularly, to a sheet handling device adapted to align and fasten ejected sheets having images formed on the surfaces thereof by an image forming apparatus, such as a copying machine or a laser beam printer, and in particular, to collect sheets into a stack and effectively align the stack of sheets by an aligning means in a sheet aligning operation. The present invention also relates to an image forming apparatus having the sheet handling device.
2. Description of the Related Art
Hitherto, numerous image forming apparatuses have been proposed, for example, in Japanese Laid-Open Patent Application No. 2-144370, which are equipped with a first handling means (hereinafter referred to as a “handling tray”) for aligning and collecting sheets having images thereon into a stack and for stapling a part of the sheet stack as necessary, and a second handling means (hereinafter referred to as a “stack tray”) for receiving and holding sheet stacks which have been aligned or stapled.
FIG. 34
schematically shows the configuration of an aligning section in this kind of conventional sheet handling device.
Referring to
FIG. 34
, the conventional sheet handling device comprises a pair of feeding rollers
701
consisting of a lower feeding roller
701
a
and a feeding roller
701
b
for feeding sheets from a sort path, a handling tray unit
800
for receiving the conveyed sheets, and a stack tray
900
for holding stacks of sheets ejected in stacks after processing.
Knurl belts
702
are wound on the lower feeding roller
701
a
of the pair of feeding rollers
701
at several positions in the axial direction between the lower feeding roller
701
a
and the feeding roller
701
b
. Sheet guides
703
are placed at appropriate positions between the knurl belts
702
.
The handling tray unit
800
comprises a handling tray
801
inclined so that the downstream side in the sheet ejecting direction (the upper left side in
FIG. 34
) is placed on the upper side and the upstream side (the lower right side in
FIG. 34
) is placed on the lower side, a rear end stopper
802
disposed at the upstream end of the handling tray
801
, a pair of aligning members
803
disposed on the right and left sides in the sheet width direction, a pair of stack ejection rollers
804
composed of lower and upper stack ejection rollers
804
a
and
804
b
disposed on the downstream side of the handling tray
801
, a pivoting guide
805
for supporting the upper stack ejection roller
804
b
at the leading end on the lower surface so that the upper stack ejection roller
804
b
can make contact with and separate from the lower stack ejection roller
804
a
, and a pull-in paddle
806
disposed in the upper middle section.
In this case, the lower and upper stack ejection rollers
804
a
and
804
b
are allowed by the control of pivoting of the pivoting guide
805
to receive sheets P from the feeding rollers
701
into the handling tray
801
in the state in which the upper stack ejection roller
804
b
is separated from the lower stack ejection roller
804
a.
The sheets P are continuously pulled back by the rotational driving of the pull-in paddle
806
, are aligned by the action of the aligning members
803
, and are put into contact with the rear end stopper
802
via the sheet guides
703
by the action of the counterclockwise rotation of the knurl belts
702
for feeding the ends of the sheets, whereby the aligning operation is completed.
Subsequently, the sheets aligned in the handling tray
801
are subjected to stapling or other processes at the aligning position, and are ejected in a stack into the stack tray
900
by putting the upper stack ejection roller
804
b
into contact with the lower stack ejection roller
804
a
and rotating the lower stack ejection roller
804
a
counterclockwise.
In the above-described conventional structure, however, as the number of sheets P stacked in the handling tray
801
increases, the contact pressure of the knurl belts
702
with the sheets P also increases. Therefore, the pulling force toward the rear end stopper
802
increases, whereas an increased resistance is applied to the movement of the aligning members
803
in the aligning direction orthogonal thereto. As shown in
FIG. 35
, the knurl belts
702
first follow a sheet P
1
moved by the aligning members
803
and are bent and tilted on the nip between the knurl belts
702
and the rollers
701
b
, but the knurl belts
702
cannot follow further movement of the sheet P
1
, whereby slip occurs therebetween. Therefore, when the stiffness of the sheet P
1
is less than the slide resistance, the sheet P
1
is raised, as shown by a broken line Pa (at worst, it is buckled), and does not reach a reference position
803
a
, which may cause misalignment.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a sheet handling device and an image forming device having the device, and more particularly, to provide a sheet handling device which prevents interference between the pulling operation of a sheet on a stack means to a stopper means by an endless feeding member and the aligning operation by an aligning means, and which prevents failure in stacking sheets due to the interference.
In order to achieve the above object, according to one aspect of the present invention, there is provided a sheet handling device including: an ejection device for ejecting sheets; a stack device for stacking thereon the sheets ejected by the ejection device, and having a stopper portion for supporting the ends of the sheets; a rotatable feeding member shaped like an endless belt for making contact with the sheets stacked on the stack device and to pull the sheets toward the stopper portion; an aligning device for aligning the sheets on the stack device by moving the sheets in the direction orthogonal to the sheet feeding direction; a shift device for moving the endless feeding member between the acting position to act on the surface of the sheets on the stack device and the retracted position to separate from the sheet surface or to reduce the force acting thereat; and a control device for exerting control so that the endless feeding member is retracted to the retracted position during the aligning operation by the aligning device.
Preferably, the shift device is a pulling device, and the endless feeding member at the retracted position is pulled by the pulling device so as not to be in contact with the sheets on the stack device.
Preferably, the shift device is a pulling device, and the endless feeding member at the retracted position is pulled by the pulling device so as to be in slight contact with the sheets on the stack device.
Preferably, the aligning device makes a forward motion for pushing the sheets to the aligning position, and a reverse motion for separating from the aligning position. The endless feeding member is shifted to the retracted position during the pushing of the aligning device, and to the acting position during the reverse motion.
The sheet handling device may further include a counting device for counting the number of sheets ejected in the stack device, wherein, when the number of sheets on the stack device counted by the counting device exceeds a predetermined number, the control device is activated during the aligning operation so as to shift the endless feeding member to the retracted position.
According to the above structure, sheets ejected into the stack device by the ejection device are pulled to the stopper portion at the end of the sheets by the endless feeding member, and are aligned by being shifted in the direction orthogonal to the sheet feeding direction by the aligning device. During the aligning operation by the aligning device, the endless feeding member is shifted from the acting position in contact with the sheets to the retracted position so as to separate from the sheets or to reduce the force acting on the sheets. Therefore, it is possible to re
Hayashi Ken-ichi
Hirai Katsuaki
Canon Kabushiki Kaisha
Ellis Christopher P.
Fitzpatrick ,Cella, Harper & Scinto
Mackey Patrick
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