U.S. patent application number 11/302815 was filed with the patent office on 2007-06-14 for method and device for aligning sheets in a transport module.
This patent application is currently assigned to Pitney Bowes Incorporated. Invention is credited to James A. Fairweather, Thomas M. Lyga, Chiping Sye.
Application Number | 20070132179 11/302815 |
Document ID | / |
Family ID | 38138522 |
Filed Date | 2007-06-14 |
United States Patent
Application |
20070132179 |
Kind Code |
A1 |
Fairweather; James A. ; et
al. |
June 14, 2007 |
Method and device for aligning sheets in a transport module
Abstract
A transport module for deskewing and accumulating sheets of
insert materials before the sheets are inserted into an envelope
for mailing. Retractable gates are used to stop the sheets as they
are separately moved into the transport module by a plurality of
endless belts. Idlers are used to apply normal forces on the belts
at various locations to provide traction between the sheet and the
belts for moving the sheet forward. If a sheet is skewed when it
enters the transport module, one corner on the leading edge of the
sheet encounters one of the side gates and the advancing sheet can
align itself by an angular motion using the contact point as center
of rotation. As such, the leading edge is registered against the
retractable gates at both sides of the leading edge. The transport
module can also be used as a conveyor without the accumulation
function.
Inventors: |
Fairweather; James A.;
(Milford, CT) ; Lyga; Thomas M.; (Southbury,
CT) ; Sye; Chiping; (Stamford, CT) |
Correspondence
Address: |
PITNEY BOWES INC.;35 WATERVIEW DRIVE
P.O. BOX 3000
MSC 26-22
SHELTON
CT
06484-8000
US
|
Assignee: |
Pitney Bowes Incorporated
Stamford
CT
|
Family ID: |
38138522 |
Appl. No.: |
11/302815 |
Filed: |
December 14, 2005 |
Current U.S.
Class: |
271/226 |
Current CPC
Class: |
B65H 9/06 20130101; B65H
2701/1916 20130101; B65H 2404/261 20130101; B65H 39/10 20130101;
B65H 2701/1311 20130101; B65H 2515/34 20130101; B65H 2801/78
20130101; B65H 2301/44316 20130101 |
Class at
Publication: |
271/226 |
International
Class: |
B65H 9/00 20060101
B65H009/00 |
Claims
1. A method to transport mailing materials along a moving direction
by a moving mechanism in a transport module for use in a mailing
machine, the mailing materials including sheets to be accumulated,
wherein each of the sheets is moved into the transport module along
the moving direction, and the transport module comprises a
registration barrier substantially perpendicular to the moving
direction so as to allow a leading edge of each of the sheets to
register against the registration barrier, the leading edge of each
sheet has a first side and an opposing second side, the sheets
including a current sheet and a previous sheet, the current sheet
having a frictional force against the previous sheet, the transport
module at least operable in a first mode to accumulate the sheets,
said method comprising the steps of: providing a moving surface on
the moving mechanism adjacent to the current sheet; and
distributing a plurality of normal forces at a plurality of
locations for urging the moving surface of the moving mechanism
against the current sheet so as to produce a traction between the
moving surface and the current sheet, such that, when the transport
module is operated in the first mode, the traction is able to
overcome the frictional force so as to continue moving the second
side of the leading edge of the current sheet until it contacts the
registration barrier, if the first side of the leading edge of the
current sheet contacts the registration barrier before the second
side.
2. The method of claim 1, further comprising the step of:
retracting the registration barrier after the sheets have been
accumulated so as to allow the accumulated sheets to move further
along the moving direction.
3. The method of claim 1, wherein the registration barrier is
retractable and the mailing materials include mail items, and
wherein the transport module is operable in a second mode, said
method comprising the step of: retracting the registration barrier
when the transport module is operated in the second mode so as to
allow the mail items to move further along the moving direction
separately and sequentially.
4. The method of claim 1, wherein the transport module is operable
between the first mode and a second mode and the registration
barrier is operable is a first position and a second position, and
wherein the mailing materials also include mail items, said method
further comprising the steps of: maintaining the registration
barrier in the first position when the transport module is operated
in the first mode, such that if the first side of the leading edge
of the current sheet contacts the registration barrier before the
second side, the traction is able to overcome the frictional force
so as to continue moving the second side of the leading edge of the
current sheet until it contacts the registration barrier; and
retracting the registration barrier to the second position after
the sheets have been accumulated so as to allow the accumulated
sheets to move further along the moving direction, and when the
transport module is operated in the second mode so as to allow the
mail items to move further along the moving direction separately
and sequentially.
5. The method of claim 1, wherein the moving surface comprises a
plurality of moving belts and the transport module comprises a
plurality of weighting objects distributed at the plurality of
locations for providing the normal forces to urge the moving belts
against the current sheet.
6. A transport module for use in a mailing machine to move and a
plurality of mailing materials in a moving direction toward a
downstream direction, the transport module at least operable in a
first mode, wherein the mailing materials comprise sheets to be
accumulated, the sheets having a current sheet and a previous
sheet, the current sheet having a frictional force against the
previous sheet, said transport module comprising: a moving
mechanism for moving each of the sheets along the moving direction,
each sheet having a leading edge, the leading edge having a first
side and an opposing second side, the moving mechanism having a
moving surface adjacent to the current sheet; a registration
barrier operable in a first position and in a second position, the
barrier substantially perpendicular to the moving direction so as
to allow the leading edge of each of the sheets to register against
the registration barrier when the transport module is operated in
the first mode and the barrier is operated in the first position,
and a plurality of weighting objects distributed at a plurality of
locations for urging the moving surface of the moving mechanism
against the current sheet so as to produce a traction between the
moving surface and the current sheet, such that if the first side
of the leading edge of the current sheet contacts the registration
barrier before the second side, the traction is able to overcome
the frictional force so as to continue moving the second side of
the leading edge until it contacts the registration barrier.
7. The transport module of claim 6, wherein the registration
barrier is retractable to the second position so as to allow the
sheets to move toward the downstream direction after the sheets
have been accumulated.
8. The transport module of claim 6, wherein the mailing materials
include mail items, and the transport module is also operable in a
second mode so that, when the transport module is operated in the
second mode, the registration barrier is retractable to the second
position so as to allow the mail items to be moved toward the
downstream direction separately and sequentially.
9. The transport module of claim 8, wherein the mailing items
include one or more cards.
10. The transport module of claim 8, wherein the mailing items
include one or more folded sheets.
11. The transport module of claim 12, wherein the mailing items
include one or more booklets.
12. The transport module of claim 7, wherein the mailing materials
include mail items, and the transport module is operable between
the first mode and a second mode such that, when the transport
module is operated in the first mode, the registration barrier is
operated in the first position so as to allow the leading edge of
each of the sheets to register against the registration barrier,
and if the first side of the leading edge of the current sheet
contacts the registration barrier before the second side, the
traction is able to overcome the frictional force so as to continue
moving the second side of the leading edge until it contacts the
registration barrier; and the registration barrier is retracted to
the second position after the sheets have accumulated so as to
allow the accumulated sheets to move further toward the downstream
direction; and when the transport module is operated in the second
mode, the registration barrier is retracted to the second position
so as to allow the mail items to move separately and sequentially
along the moving direction toward the downstream direction.
Description
TECHNICAL FIELD
[0001] The present invention relates generally to a mail inserter
and, more particularly, a device that can selectively transport or
deskew and accumulate elements of a mailpiece.
BACKGROUND OF THE INVENTION
[0002] A typical mailing machine has a mail inserter section 3
where a pack of insert material 20 is inserted into an envelope 30,
as shown in FIG. 1. The mailing machine also has an accumulation
section 1 where a plurality of insert documents 10 are fed and
accumulated into a stack 12. The accumulation section typically has
one or more enclosure feeders to separately release individual
sheets of insert documents into a collection deck to be
accumulated. The accumulated documents may be folded in a
folder/feeder 2. The mailing machine may also have a printing
section for printing the insert documents or the envelopes.
[0003] Before the accumulated documents are folded into a pack or
moved into a receiving envelope, the individual sheets must be
aligned to one another. However, one or more of the sheets may be
skewed when they are released. This means that the leading edge of
one sheet may not be registered to the leading edge of the others.
In prior art accumulators, the sheets are aligned against one or
more side guides parallel to the moving direction of the sheets.
The sheets are typically urged to register against the side guides
by a system of light drive forces. These accumulators are
inadequate when transporting media of variable widths and
thickness. The fixed side guides cannot accommodate variable widths
and the light drive forces may not be sufficient to accelerate
thick materials without slippage.
[0004] It is thus desirable and advantageous to provide a method
and system for aligning the insert materials in an accumulator
where the leading edge of an individual sheet can be aligned
independently of side registration devices.
SUMMARY OF THE INVENTION
[0005] The present invention provides a transport module in a
mailing machine to deskew and accumulate sheets of insert materials
before the sheets are inserted into an envelope for mailing. The
transport module uses a plurality of retractable gates to stop the
insert materials as they are separately moved into the transport
module by a plurality of endless belts. A plurality of idlers are
used to apply normal forces on the belts at various locations to
provide traction between the sheet and the belts for moving the
sheet forward. If a released sheet is skewed when it enters the
transport module, one of the corners on the leading edge of the
sheet encounters one of the side gates in the transport module. The
advancing sheet may be able to align itself by an angular motion
using the contact point as the center of rotation. As such, the
leading edge can be registered against the retractable gates at
both sides of the leading edge. However, this is possible only if
the traction between the sheet and belts is greater than the moment
associated with the friction between the sheet and the existing
stack as the skewed sheet experiences the angular motion. According
to the present invention, the normal forces applied to the
advancing sheet are dependent upon the location of the idlers. In
particular, the normal forces are distributed such that the normal
forces are stronger at locations nearer to the retractable gates
than the normal forces at locations farther from the retractable
gates. Furthermore, a number of pivotable hold-down mechanisms are
disposed near the retractable gates to prevent the leading edge
from buckling up.
[0006] Additionally, the transporting module can be programmed to
selectively skip the accumulation mode so that insert materials can
be moved into the envelope without being stacked up before
insertion. Insert materials such as booklets, folded sheets, cards,
mailpieces or other envelopes can be conveyed through the transport
module to the waiting envelope. These insert materials can be
conveyed through the transport module with or without the sheets to
be accumulated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a schematic representation of a typical mailing
machine.
[0008] FIG. 2a is a schematic representation of a mailing machine,
according to the present invention.
[0009] FIG. 2b is a schematic representation of a different mailing
machine, according to the present invention.
[0010] FIG. 3a is a schematic representation showing a sheet of
insert material being released into an accumulation section of a
mailing machine.
[0011] FIG. 3b is a schematic representation showing the sheet of
insert material aligning itself against a plurality of registration
gates.
[0012] FIG. 3c is a schematic representation showing a sheet of
insert material being released into an accumulation section of a
mailing machine, wherein the sheet is skewed.
[0013] FIG. 3d is a schematic representation showing the skewed
sheet experiencing an angular motion after one of the leading-edge
corners is stopped by one of the side gates.
[0014] FIG. 4 is a schematic representation showing a plurality of
locations where normal forces are provided on a plurality of
driving belts.
[0015] FIG. 5a is a schematic representation showing the normal
forces applied on different locations of a driving belt.
[0016] FIG. 5b is a schematic representation showing a plurality of
idlers being used for providing the normal forces.
[0017] FIG. 6 is a perspective view of the transport module of the
present invention.
[0018] FIG. 7 shows the details of a front portion of the transport
module.
[0019] FIG. 8 is a side view of the transport module showing a
drive belt and a plurality of idlers for applying normal forces on
the belt.
[0020] FIG. 9 is a plan view of the transport module of the present
invention.
[0021] FIG. 10 shows the details of a back portion of the transport
module.
[0022] FIG. 11a shows the transport module being used as a
conveyor.
[0023] FIG. 11b shows the dual-function of the transport module,
according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention provides a transport module 100 for
use in a mailing machine, which allows a sheet of insert material
to align itself when it is released and moved into the transport
module. The transport module, according to the present invention,
can be programmed to function like an accumulator. It can also be
programmed to function like a simple conveyor. These two functions
can exist alternately in a continuous operation. The transport
module 100 is capable of transporting insert materials of various
thickness, lengths and widths. The transport module 100 can be used
to provide insert materials to a mail inserter section 300, with or
without a folder/feeder 200, as shown in FIGS. 2a and 2b. A feeder
90 (see the releasing mechanism 180 in FIG. 10) is used to release
the mailing materials on to the transport module 100.
[0025] When the transport module 100 is used as an accumulator, the
sheets released into the transport module are registered against a
plurality of registration gates so that they form a stack in the
transport module. These registration gates are retractable such
that when the accumulation of a stack is completed, the gates are
retracted to allow the stack of insert material to move forward to
the next section of the mailing machine.
[0026] The movement of a released sheet in the transport module 100
is shown in FIGS. 3a to 3d. As shown in FIG. 3a, a sheet of insert
material 10 is released on top of another sheet 10' already in the
transport module 100. The released sheet 10 moves along a movement
direction 104 until it is registered against the registration gates
110, as shown in FIG. 3b. FIG. 3c shows a sheet of insert material
10 which is skewed when it is moved into the transport module 100.
The skewed sheet moves along the direction 104 until one of the
corners of its leading edge is blocked by one of the registration
gates 110. After the skewed sheet 10 is stopped by the registration
gate at a contact point, as shown in FIG. 3d, it experiences an
angular motion as indicated by an arrow 106, using the contact
point as the center of rotation. This angular motion continues
until the both sides of the leading edge are registered against the
registration gates, as shown in FIG. 3b.
[0027] As shown in FIG. 4, a plurality of driving belts 1201, 1202,
1203 are used to move insert materials, one sheet at a time, into
the transport module along the movement direction 104. In order to
provide sufficient traction between the belts and the sheet 10 (not
shown) so the sheet can be moved into the stacking position, normal
forces are applied at a plurality of locations (xn, ym). Here the
coordinates x, y are relative to a potential contact point (0,0) at
the rightmost registration gate (see FIG. 3d). In this exemplary
embodiment, n=3 and m=5. However, the number of driving belts and
the number of locations where the normal forces applied on each
driving belt can be different from 3 and 5, depending on the size
of the insert materials.
[0028] After one corner of a skewed sheet is stopped by a
registration gate at a contact point as shown in FIG. 3d, the
traction between the belts and the sheet causes the sheet 10 to
rotate along the direction 106. This angular motion, however, is
countered by the frictional force between the sheet 10 and the
sheet 10' below. The action by the traction (deskew moment) and the
counter-action by the frictional force (anti-deskew moment) are
related to the normal forces Fnm applied at point (xn, ym). In
order to allow the sheet to align itself against the registration
gates, the deskew moment must be greater than the anti-deskew
moment.
[0029] Assuming that the frictional coefficient between the belts
and the sheet is ubp and the frictional coefficient between two
sheets of insert material is ubp, self-alignment of the insert
materials in the accumulator is possible if upb .times. m .times. n
.times. F n .times. .times. m .times. x n > upp .times. m
.times. n .times. F n .times. .times. m .times. D .times. n .times.
.times. m ##EQU1## where D.sub.nm is the distance between point
(0,0) and point (xn, ym). As shown in the above equation, the term
F.sub.nm D.sub.nm becomes more dominant when the distance D.sub.nm
becomes greater. In order to reduce the dominant factors
attributable to the normal forces at such locations as (X.sub.n,
y.sub.4) and (x.sub.n, y.sub.5), as shown in FIG. 5a, it is
desirable to have F.sub.n5<<F.sub.n1, for example.
[0030] According to the present invention, normal forces F.sub.nm
are provided by a plurality of idlers 131, 132, 133, 134, 135 at
points (xn, y1), (xn, y2), (xn, y3), (xn, y4), (xn, y5),
respectively, as shown in FIGS. 5b-9. At points (xn, y3), (xn, y4),
(xn, y5), the idlers 133, 134, 135 are allowed to float, or move up
and down freely about their pivot (see FIG. 8). Thus, the normal
forces applied at these locations are mainly determined by the
weight of the idlers and the idler pivot arms. In order to increase
the normal forces at points (xn, y1) and (xn, y2), the idlers 131,
132 are loaded against the driving belts 120n by springs 141 and
142, as shown in FIG. 7.
[0031] The retractable gates 110 that are used for leading edge
registration are shown in FIG. 7. In a mailing machine wherein the
sheets are released and moved into the transport module at high
speed, it is desirable to protect the leading edge of the sheets
when it is blocked by the registration gates. According to the
present invention, at least one hold-down ski 150 is used to
hold-down the leading edge of the stack. As shown in FIG. 7, the
hold-down ski 150 is supported by a freely pivotable arm 154 in
order to reduce the friction between the ski and the sheet below.
The forward edge 152 of the hold-down ski 150 is adjacent to the
retractable gates. A plurality of ski fingers 156 are provided on
the forward edge 152 between the retractable gates. The forward
edge 152 and the ski fingers 156 prevent the leading edge of the
accumulated sheets to buck up and damage.
[0032] As shown in FIG. 8, the belts 120n are driven by rollers 160
and 162. FIG. 9 is a plan view of the accumulator without the
driving belts. FIG. 10 depicts the details of the back section of
the transport module, showing how the trailing edge of a sheet 10
is positioned so that the leading edge of a subsequent sheet 10''
is prevented from hitting the trailing edge of the previous sheet
10. As shown in FIG. 10, the trailing edge 17 of the previous sheet
10 is biased downward by the arrangement of the driving roller 160
and a supporting idler 170. By offsetting the contact point 172 of
the support idler 170 from the center line 164 of the driving
roller 164, the nip 176 formed by the driving roller 164 and the
support idler 170 bends the trailing edge 17 of the sheet 10
downward. Along with the precise start stop aspect of the releasing
mechanism 180 and the driving belts 120n, the subsequent sheet 10''
is always positioned above the trailing edge 17 of the previous
sheet 10'' when the subsequent sheet 10'' is released toward the
nip 176.
[0033] When the transport module 100 is used as a conveyor, it
typically allows insert materials to be conveyed from the upstream
direction to the inserting station where the insert materials are
inserted into a waiting envelope. As shown in FIG. 11a, the feeder
90 located upstream from the transport module 100 is used to
release the insert materials. The insert materials, as shown in
FIG. 11a, may include a card 6, a booklet 7, a folded sheet 8, and
a regular sheet 10. Some of these insert materials are moved by the
transport module 100 into the envelope 30 while some will be moved
into the next envelope (not shown). In this operation mode, the
registration gates 110 (see FIG. 7) are always in a retracted
position. Other materials such as envelopes can also be moved to
the inserting section 300 by the transport module 100. These
materials can have different thickness, length and width. For
example, the transport module can transport sheets about 0.004''
(about 0.01 cm) thick, having a width from 5'' to 10'' (about 12.7
to 25.4 cm) and a length from 5'' to 14'' (about 12.7 to 35.6 cm);
booklets up to 0.16'' (about 0.4 cm), tri-folds having a length
from about 2.8'' to 11.8'' (7.2 cm to 30 cm), etc. So long as the
width of the mailing items to be transported falls within a
predetermined range, the transport module can accommodate those
mailing items without the need of adjustment.
[0034] FIG. 11b illustrates the dual-nature of the transport
module, according to the present invention. As shown, the upstream
feeder 90 delivers a plurality of sheets 10 to be accumulated, a
folded sheet 8 and a booklet 7 to the transport module 100. The
transport module 100 is programmed to accumulate all the sheets 10
into a stack 12 before inserting the stack 12 into the envelope 30.
However, the folded sheet 8 and the booklet 7 are separately and
sequentially moved by the transport module 100 into the envelope 30
after the stack 12 has been inserted.
[0035] It is understood that the range of thickness, widths and
lengths of the insert material is dependent upon the dimensions and
design of the transport module and the dimensions of the envelope
30. One skilled in the art can reduce or increase the number of
belts, the number of idlers to suit the need. Thus, although the
invention has been described with respect to one or more
embodiments thereof, it will be understood by those skilled in the
art that the foregoing and various other changes, omissions and
deviations in the form and detail thereof may be made without
departing from the scope of this invention.
* * * * *