U.S. patent application number 09/792736 was filed with the patent office on 2002-02-21 for device for separating an uppermost sheet from a supply stack by means of air blowers.
This patent application is currently assigned to NexPress Solutions LLC. Invention is credited to Dettinger, Karl-Heinz, Konday, Andreas, Straub, Timo, Weber, Markus.
Application Number | 20020020958 09/792736 |
Document ID | / |
Family ID | 7632408 |
Filed Date | 2002-02-21 |
United States Patent
Application |
20020020958 |
Kind Code |
A1 |
Dettinger, Karl-Heinz ; et
al. |
February 21, 2002 |
Device for separating an uppermost sheet from a supply stack by
means of air blowers
Abstract
Mechanism for swiveling, locking/unlocking and
separating/pressing a first and second housing part, which are
connected by means of a swivel axis, of which one housing part can
be swiveled. Such mechanism has a common operating unit in the area
of the free end of the housing opposite the swivel axis, in such a
way that locking/unlocking, swiveling, and separating/pressing the
first housing part is carried out together and with one hand by
means of the operating unit in a single motion.
Inventors: |
Dettinger, Karl-Heinz;
(Ebersbach, DE) ; Konday, Andreas; (Deggingen,
DE) ; Straub, Timo; (Geislingen, DE) ; Weber,
Markus; (Aichwald, DE) |
Correspondence
Address: |
Lawrence P. Kessler
Patent Department
NexPress Solutions LLC
1447 St. Paul Street
Rochester
NY
14653-7103
US
|
Assignee: |
NexPress Solutions LLC
|
Family ID: |
7632408 |
Appl. No.: |
09/792736 |
Filed: |
February 23, 2001 |
Current U.S.
Class: |
271/98 |
Current CPC
Class: |
G03G 15/2064 20130101;
G03G 2221/1687 20130101; G03G 2221/18 20130101; G03G 2221/1639
20130101; G03G 21/1647 20130101 |
Class at
Publication: |
271/98 |
International
Class: |
B65H 003/08 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 25, 2000 |
DE |
100 08 910.0 |
Claims
1. Device (1) for separating an uppermost sheet (S1) from a supply
stack (S) with air blowers (3.1, 3.2) in the area of a sheet
transport unit (4) operating with a partial vacuum and having a
sheet bending means (41), for the purpose of grasping the separated
uppermost sheet and feeding it to a processing station in a sheet
processing device, wherein air blower (3.1) for spreading out
several sheets of an upper sheet stack area (SR) and air blower
(3.2) for separating the uppermost sheet (S1) and holding back an
adhering sheet (S), following the uppermost sheet (S1), are located
downstream in front of the supply stack and transverse to a sheet
transport path (42) and act against a sheet transport device (T)
and the upper area of the sheet stack, which may be positioned at
the same predetermined height by means of a lifting device (5), and
wherein air jets with different pressures, directions, and
diameters may be generated by means of the air blower (3.1; 3.2)
supplied from an air pressure source (6) with at least one air
nozzle (31) located in the area of a center line (Y, Z) of the
stack (2) and the transport path (42), and with several air nozzles
(32) located on both sides of the center line, characterized in
that an additional air blower (3.3), having several air nozzles
(D1, D1', D2, D2'), supplied from a high pressure air source (7) is
located in the area of the center line (Y, Z) of the stack (S) and
the transport path (42), by means of which air jets (ST) may be
generated with a high excess air pressure and small diameter, which
on the one hand support the separation of the uppermost sheet (S1)
from the stack as well as hold back the adhering sheet (S2)
following the uppermost sheet, and on the other hand are used to
spread apart the sheets in the upper area of the sheet stack.
2. Device according to claim 1, characterized in that air jets (ST)
with an excess air pressure equal to or greater than 1.0 bar may be
generated by means of the high pressure air source (7) and the air
nozzles (D1, D1', D2, D2') of the additional air blower (3.3), and
that the pressure ratio of the air jets of the additional air
blower (3.3) to those of the spreading and separating air blower
(3,1, 3,2) is equal to or greater than 20:1.
3. Device according to claim 1 or 2, characterized in that the
additional air blower (3.3) has two nozzle elements (33,1, 33.2)
with several additional air nozzles (d1, D1', D2, D2') and the
nozzle elements are positioned on both sides of the air blower
(3.1), the first air blower (3.1) for spreading and is outside of
the inner air nozzles (32) of the air blower (3.2), the second air
blower (3.2) for separating and holding back.
4. Device according to claim 1 or 3, characterized in that the
additional, third air blower (3.3) has two nozzle elements (33.1,
33.2), in each case with a vertically overlapping arrangement,
wherein the upper air nozzles (D1, D1') are directed toward a
middle front edge area of the second and third sheets of the stack
(6) for the purpose of separating and holding back the adhering
second sheet (S2) following the uppermost stack sheet (S1), and the
lower air nozzles (D2, D2') are directed toward the middle front
edge area of the sheets located thereunder in order to spread them
apart and lift them.
5. Device according to claim 4, characterized in that the upper air
nozzles (D1, D1') of the two nozzle elements (33.1, 33.2) are
located at approximately the height of the upper edge of the air
nozzle openings (32) of the air blowers (3.2) for separating and
above the upper edge of the air nozzle opening (31) of the air
blowers (3.1) for spreading, and that the two lower air nozzles
(D2, D2') of the two nozzle elements (33.1, 33.2) are located at
approximately the height of the middle of the nozzle opening (31)
of the air blower (3.1) for spreading.
6. Device according to claim 4, characterized in that the two
nozzle elements (33.1, 33.2) are located with their air nozzle
openings (D1, D1', D2, D2') along the direction of transport (1) of
the sheet transport path (42) between the air nozzle openings of
the spreading air blower (3.1) and the separating air blower
(3.2).
7. Device according to claim 1 or 5, characterized in that the air
nozzles of the additional air blower (3.3) and thus the air jets
(87) thereof are directed parallel to the horizontal plane of the
sheets of the stack (S) and parallel to the center line (Y, Z) of
the stack and the sheet transport path, and that the air jests (31,
32) of the spreading (3.1) and separating air blowers (3.2) and
this the air jets are directed at an angle rising from the
horizontal plane of the stack sheets to the upper area (SR) of the
stack.
8. Device according to claim 1 or 4, characterized in that the air
nozzles (D1, D1', D2, D2') of the additional air blower (3.3) have
an opening diameter equal to or smaller that 0.5 mm, and that the
ratio of the opening diameter of the air nozzles of the additional
air blowers to those of the spreading (3.1) and separating air
blowers (3.2) is equal to or greater than 1:20.
9. Device according to claim 1, characterized in that the air
pressure of the air jet (ST) of the additional air blower (3.30) is
essentially constant during an operating cycle, and that the air
jets (ST) of the additional air blower (3.30) act simultaneously on
the sheets of the upper sheet stack area (SR) with the air jets
(31;32) of the spreading air blowers (3.1) and separating air
blowers (3.2), having a constant air pressure.
10. Device according to claim 9, characterized in that the air
pressure of the air jets (ST) of the additional air blower (3.3) is
pulsating during an operating cycle.
Description
[0001] The invention concerns a device for separating an uppermost
sheet from a supply stack with air blowers in the area of a sheet
transport unit having a sheet bending means operating with a
partial vacuum and feeding to a processing station in a sheet
processing device.
[0002] In the case of known sheet processing devices, such as, for
example, copiers, the first and second air blowers of the sheet
separating device are located downstream in front of the supply
stack transverse to a transport path and act opposite the sheet
transport device, rising at an angle to the horizontal plane of the
sheets, to the upper area of the sheet stack, which may be
positioned to the same predetermined equal height by means of a
controlled lifting device. In this case air jets are generated with
low excess air pressure as well as with different directions and
diameters, on the one hand for spreading by raising several sheets
of the upper sheet stack area, and on the other hand for separating
by raising the uppermost sheet from the stack as well as by holding
back an adhering sheet following the uppermost sheet, by means of
the first air blower supplied from a compressed air source, with an
air nozzle located in the area of a center line of the stack and
the transport path with several air nozzles located on both sides
of the center line and the first air blower.
[0003] A device of the type mentioned initially for separating by
raising an uppermost sheet from a supply stack in a copier is known
from EP-B 1-0 812 680, in the case of which on the one hand there
is a first air blower mounted centrally with respect to the sheet
stack and to the sheet transport path, with an individual air
nozzle having a relatively large trapezoidal opening
(7.62.times.6.35 mm to 15.24.times.19.90 mm) and on the other hand
there is a second air blower offset in the direction of sheet
transport, in each case with three air nozzles, in each case with
relatively large semicircular openings (7.87 to 24.85 m.sup.2),
mounted on both sides of the center line of the transport path. The
alignment of the air jets with the horizontal plane of the sheets
in the direction toward the upper area of the sheet stack is in an
angular range between 35 to 35 degrees for the air jet of the first
air blower and for the air jets of the second air blower. The
excess air pressure of the air jets is around 30 mbar and is
created on the air nozzles of the air blower by one or two
controllable air pressure sources and maintained constant during an
operating cycle.
[0004] In this case it is disadvantageous that, as a result of the
large air nozzle openings and the low excess pressure of the air
jets, an uppermost sheet can be separated, and transported away,
from the stack only with difficulty or even not individually, in
the case of using a sheet of a type of paper which is heavy, thick,
or the sheets of which adhere strongly to one another. Thus the
range of types of sheets of paper for reliable operation, that is,
reliable separation and avoidance of double-sheet transport, is
greatly limited.
[0005] Therefore the object of the invention is to create a device
of the type mentioned initially, which does not have these named
disadvantages, but by means of which sheets of very different types
can be reliably fed from the sheet supply stack to a sheet
processing device one after the other reliably and efficiently.
[0006] The object is achieved according to the invention with a
device according to claim 1, in that an additional air blower
having several nozzles, supplied by a high pressure air source, is
located in the area of the center line of the stack and the
transport path, by means of which air jets with a high excess air
pressure and small diameter can be created, which on the one hand
support the separation of the uppermost sheet from the stack as
well as holding back the adhering sheet following the uppermost
sheet, and on the other hand serve for supporting the spreading of
the sheets in the upper area of the sheet stack.
[0007] Advantageously, air jets with an excess air pressure equal
to or greater than 1.0 bar can be created by means of the high
pressure air source and the air nozzles of the additional air
blower; the pressure ratio of the air jets of the additional air
blower to those of the spreading and separating means is equal to
or greater than 20:1; and the ratio of the air nozzle opening
diameters of the additional air blower to those of the spreading
and separating air blowers is equal to or greater than 1:30. The
air pressure of the air jets of the additional air blower in this
case is essentially constant during an operating cycle, and the air
jets of the additional air blower act on the sheets of the upper
sheet stack area simultaneously with the air jets of the spreading
air blower and separating means having a constant air pressure.
[0008] Furthermore, the additional blower advantageously has two
nozzle elements with several air nozzles and the nozzle elements
are positioned on both sides of the air blower for spreading, a
first air blower, and outside the inner air nozzles of the air
blower for separation and holding back, a second air blower. The
additional, third air blower here in each case has two air nozzles
in a vertically overlapping arrangement on the two nozzle elements,
the upper air nozzles being directed toward a middle front edge
area of the second and third sheets of the stack for the purpose of
separating and holding back the adhering second sheet following the
first stack sheet, and the lower air nozzles for supporting the
spreading and lifting of the sheets located below are directed
toward the middle front edge area thereof.
[0009] In addition, the air nozzles of the additional air blower,
and thus their air jets, are directed advantageously parallel to
the horizontal plain of the sheets of the stack and parallel to the
central axis of the stack and the sheet transport path.
[0010] Further features and advantages are to be deduced from the
description of the embodiments of the invention shown in the
drawing as well as the further subclaims. In the drawing:
[0011] FIG. 1 shows the device according to the invention, with air
blowers in the area of a sheet supply stack and sheet entrance area
of a sheet processing device, without a sheet transport unit and
without a housing in a three-dimensional representation from
above.
[0012] FIG. 2 shows the device according to the invention shown in
FIG. 1 with air blowers in a magnified three-dimensional partial
representation, as seen in the direction of sheet transport and
with a sheet transport unit.
[0013] FIG. 3 shows the device according to FIG. 2 in a side view
in the section along a section line `A-A` with air jets of the air
blowers acting on a sheet stack.
[0014] FIG. 4 shows the device according to the invention according
to FIG. 2 in a top view without sheet transport unit.
[0015] FIG. 5 shows an air blower of the device according to the
invention according to FIG. 1 to FIG. 4 in a three-dimensional view
(a) and as a side view (b) in the section along a section line
`B-B`.
[0016] The following description according to FIGS. 1 to 5 refers
to a preferred embodiment of the device according to the invention
for separating a topmost sheet from a supply stack with several air
blowers. In this case the device is used in a sheet processing
device of known type, such as, for example, a copier.
[0017] For an expert working in this field it is self-evident here
that the device according to the invention also may be used in
sheet processing devices such as presses, printers, or sheet
sorting devices.
[0018] FIG. 1 shows the separating device 1 according to the
invention in the area of a sheet supply stack 6 held by means of a
magazine 2 and in the sheet intake area 9 of the copier, not shown
otherwise. A sheet transport unit 4 in FIGS. 1 and 4 located above
the sheet supply stack usually used is omitted in order to show the
device according to the invention completely.
[0019] FIGS. 1 and 4 here show air blowers 3.1; 3.2, 3.3 of the
device according to the invention for separating an uppermost sheet
S1 from a supply stack S in the area of the sheet entrance 9 and
below the sheet transport unit 4 of the device shown in FIGS. 2 and
3.
[0020] The first air blower 3.1 for spreading several sheets of an
upper sheet stack area SR and second air blower 3.2 for separating
the uppermost sheet S1 and holding back an adhering sheet S2,
following the uppermost sheet downstream in front of the supply
stack, which act against a sheet transport direction T on the upper
area SR of the sheet stack S, are arranged transverse to a sheet
transport path 12 in an air nozzle holder 10. Different alignments
and diameters may be created by means of the first and second air
blower 3.1, 3.2 supplied in common by an ordinary air pressure
source 6, shown schematically in FIG. 3, having a low excess air
pressure, air jets with low different pressures around 10-50 mbar)
(see FIG. 2 and 4), on the one hand the first air blower 3.1 having
an air nozzle 31 located in the area of a center line Y, Z of the
stack S and the transport path 42, and on the other hand the second
air blower 3.2 having several air nozzles 32 located on both sides
of the center line.
[0021] Moreover, as is shown in FIGS. 1 to 5, an additional third
air blower 3.3, having several air nozzles D1, D1', D2, D2', and
supplied by an ordinary high pressure air source 7, shown
schematically in FIG. 3, is located in the area of the center line
Y, Z of the sheet stack S and the transport path 42 on the air
nozzle holder 10, by means of which air jets ST with a high excess
air pressure and low diameter may be generated, which on the one
hand support the separation of the uppermost sheet S1 of the stack
as well as holding back the adhering sheet S2 following the
uppermost sheet, and on the other hand serve for supporting the
spreading of the sheets in the upper area SR of the sheet stack S,
which makes use of paper sheets of different kinds, thickness, and
weight (e.g. 60-300 g/m.sup.2) in the copy machine.
[0022] Both air pressure sources 6, 7 are, as shown in FIG. 3,
coupled by means of control lines 80, 81, with an air control unit
8 which is connected via a control line 82 with an ordinary
microprocessor unit of the device, not shown, and may be controlled
according to a control program. The first and second air blower
3.1, 3.2 are connected via an air line 60 with the low pressure air
source 6 and the third, additional air blower 3.3 is connected via
its connections 34.1, 34.2 (see FIG. 5) and air line 70 with the
high pressure air source 7. By means of the high pressure air
source 7 and the air nozzles D1, D1', D2, D2' of the third,
additional air blower 3.3 air jets ST may be generated with an
excess air pressure equal to or greater than 1.0 bar, and the ratio
of the first spreading and second separating air blowers 3.1, 3.2
air jets of the additional air blower 3.3 to those of the first
spreading and second separating air blowers 3.1, 3.2 is equal to or
greater than 20:1.
[0023] The sheet stack S in magazine 2 is, as shown in FIG. 1,
located on a lifting platform 50 of an ordinary sensor-controlled
lifting device 5 not shown further, and with its upper sheet stack
area SR automatically capable of being positioned by means of the
lifting device 5 to a predetermined height equal to the blowers
3.1, 3.2, 3.3. The sheet stack magazine 7 has a front stop 20, a
back stop 21, and two side stops 22 for centering and lateral
guiding of the sheet stack S during its lifting motion,
interruptions being located on the front stop 20 in the upper area
of the sheet stack SR as passages for the air jets of the air
blower 3.1, 3.2, 3.3, and the height of all stops is predetermined
(see FIGS. 3 and 4).
[0024] The generally known sheet transport device 4 shown in FIGS.
2 and 3 on the one hand has conveyor belts 40, revolving in the
direction of transport T and perforated with air passage holes 43,
with an integrated suction device 46 made as suction holders 46,
operating with a partial vacuum, and on the other hand has sheet
bending means 41 in the area of the middle axis of the sheet
transport means, respectively the center line Z of the sheet
transport path 42. The sheet bending means 41 in this case are
located axially central on the outer circumference of drive roller
44 and guide roller 45 of the sheet conveyor belt 40 as a bead 41
projecting radially outward in the direction of the upper side of
the sheet stack. The sheet transport device 4 is, as known from the
prior art, spaced from the upper side of the sheet stack with the
underside of its sheet bending means 41, respectively its sheet
conveyor belt, in the known way.
[0025] Lower and upper sheet transport rollers 91, 92 are connected
downstream with the sheet transport device 4 and the air blower
3.1, 3.2, 3.3, as shown in FIGS. 1, 2, and 4, the lower transport
roller 91 being mounted on the air nozzle holder 10.
[0026] The first air blower 3.1 for spreading the sheet stack S
contains, as shown in FIGS. 1 to 4, an air nozzle piece 30 with an
air nozzle 31 with a relatively large trapezoidal opening 31,
located centered onto the center line Z. The second air blower 3.2
for separating an uppermost sheet S1 from the sheet stack S has air
nozzles 32 with relatively large semicircular/D-shaped air nozzle
openings 32 lying on the back, which are mounted in a horizontal
arrangement, aligned plane-parallel to the plane of the stack
sheets and at a right angle to the sheet transport path 42, in each
case three air nozzles 32 separated from one another are mounted
directed in a line on both sides of the first air blower 3.1.
[0027] The air nozzles 31, 32 of the first and second air blower
3.1, 3.2, and thus their air jets, on the one hand, in a top view
according to FIG. 4, are oriented parallel to the center line Z of
the sheet transport path 42, respectively perpendicular to the
front side of the sheet stack, and on the other hand, in a side
view according to FIG. 3, are oriented at an angle of 20-36.degree.
to the horizontal plane of the stack sheets S rising to the upper
area SR of the sheet stack S.
[0028] The third, additional air blower 3.3 has, as shown in FIG.
1, two nozzle elements 33.1, 33.2 with several air nozzles D1, D1',
D2, D2', which are positioned on both sides of the first
(spreading) air blower in a vertically overlapping arrangement, the
upper air nozzles D1, D1' with their air jets are directed toward a
central front edge area of the second and third sheets of the sheet
stack S for the purpose of separating and holding back the adhering
second sheet S2 following the uppermost stack sheet S1, and the
lower air nozzles D2, D2' with their air jets for supporting the
spreading and lifting of the sheets located thereunder are directed
toward the central front edge area thereof Y, Z.
[0029] The upper air nozzles D1, D1' of the two nozzle elements
33.1, 33.2 here are, as shown in FIGS. 2 and 3, arranged
approximately at the height of the upper edge of air nozzle
openings 32 of the air blower 3.2 for separation and above the
upper edge of the air nozzle opening 31 of the air blower 3.1 for
spreading, and the two lower air nozzles D2, D2' of the two nozzle
elements 33.1, 33.2 are located at approximately the level of the
middle of the air nozzle opening 31 of the air blower 3.1 for
spreading.
[0030] Moreover, the two nozzle elements 33.1, 33.2 with their air
nozzle openings D1, D1', D2, D2' are arranged along the direction
of transport T of the sheet transport path 42 between the air
nozzle openings of the spreading air blower 3.1 and the separating
air blower 3.2, all three air blowers 3.1, 3.2, 3.3 being located
at a predetermined distance from the front side of the sheet stack,
set for optimized operation.
[0031] As shown in FIGS. 1 to 4, the air nozzles of the additional
air blower 3.3, and thus their air jets ST are directed parallel to
the horizontal plane of the sheets of stack S (FIG. 3) and parallel
to the center line Y, Z of the stack and the sheet transport path
42. (FIG. 4) The air nozzles D1, D1', D2, D2' of the additional
third air blower 3.3 on the one hand have an opening diameter equal
to or greater than 0.5 mm, and on the other hand the ratio of the
air nozzles of the additional air blower to those of the spreading
3.1 and separating air blower is equal to or greater than 1:20 (see
FIG. 3 to 5).
[0032] In the device 1 according to the invention the pressure of
the air jets ST of the additional, third air blower 3.3 is
essentially constant during an operating cycle controlled by means
of the control unit 8. The air jets ST of the additional air blower
3.3 here act on the sheets of the upper sheet stack area SR
simultaneously with air jets 31, 32 of the spreading air blower 3.1
and separating air blower 3.2, also having a constant air
pressure.
[0033] In an alternative embodiment of device 1, the air pressure
of the air jets ST of the additional air blower 3.3 may be made to
pulsate during the operating cycle.
[0034] The device according to the invention operates as
follows:
[0035] Starting from a sheet supply stack S in magazine S, the
upper edge of the stack of which has been brought to a
predetermined height, the removal position, by means of the lifting
device 5, the copier is switched to an operating mode for an
operator to carry out a coping order.
[0036] In this case first the compressed air feed 6, 7 to the two
low pressure air blower 3.1, 3.2 and to the high pressure air
blower 3.3 is switched on by means of the central unit 8, and air
jets, which strike the front, upper area SR of the sheet stack S
with constant low and high excess air pressure (see FIG. 3), are
produced.
[0037] Then the sheets are raised somewhat and spread apart in the
upper sheet stack area SR in the vertical direction Y, these
spread-apart sheets being supported on the rear stop 21 of the
magazine 2 (see FIG. 1). The upper two sheets of the sheet stack SI
and S2 in this case are raised or spread apart somewhat more in
comparison with the following ones (see FIG. 3).
[0038] Then the sheet transport unit 4 is switched on by means of
the microprocessor unit of the device or by the control program
thereof, that is, an ordinary vacuum generator of the sheet suction
device 46 and an ordinary drive unit, not shown, on the drive
roller 44 of the conveyor belt 40 are switched on.
[0039] Now the uppermost raised sheet S1, separated by the device
1, is sucked from the sheet stack S on the underside of the
conveyor belt by the partial vacuum arising on the underside of the
perforated conveyor belt 40 of the transport unit 4 and transported
by the conveyor belt 40, revolving in the direction of transport,
in the direction of the sheet entrance area 9, or to a first
processing station, not shown, (e.g. an image transfer station) of
the device, while the second uppermost sheet S2 and following
sheets are held back by the air jets of the second and third air
blowers 3.2 and 3.3 (see FIGS. 1 and 3).
[0040] As soon as the first sheet S1 has arrived with its front
edge between the also driven lower and upper sheet transport
rollers 91, 92, the sheet suction device 46, and the conveyor belt
drive unit of the sheet transport unit 4 is switched off
sensor-controlled (sensor of known type in the area of the
transport rollers, not shown), and the further transport of the
first sheet S1 into the interior of the device is taken over by the
transport rollers 91, 92 in the entrance area 9 of the device.
[0041] After the first sheet S1 has passed the transport rollers
91, 92, the sheet suction device 46 and the conveyor belt drive
unit of the sheet transport unit 4 is switched on again
sensor-controlled, and the now uppermost, second raised sheet S2 of
the sheet stack S is sucked to the underside of the conveyor belt
and transported in the direction to the interior of the device.
[0042] This process is repeated now until a copy order entered by
the operator via a control panel of the device is completed,
whereby the sheet stack s is raised sensor-controlled with its
upper edge into the predetermined same sheet removal position or
height by means of the lifting platform 50 according to the sheet
removal.
* * * * *