FIELD AND BACKGROUND OF THE INVENTION
[0001] The invention relates to a method and an apparatus for collating postal items. In
many cases, the automated production of postal items involves collation of a number
of postal items that are to be included in a mail piece. Such postal items may for
instance include postal items, each constituted by one or more sheets, business reply
envelopes, cards on carriers, brochures etc..
[0002] One manner of collating such postal items is to successively stack the items on top
of each other, each sheet being aligned against a common alignment stop as it is positioned
on top of the stack of items. However, a disadvantage of this manner of stacking is,
that each next item that is added to a stack slides over the previous item, which
entails a risk of jams, in particular if the items are to be stacked at high speed.
Moreover, the requirement that postal items can slide over each other reduces the
versatility with respect to the ability to process postal items of various lengths,
friction coefficients and thickness patterns.
[0003] Another manner of collating postal items includes transporting a first postal item
in a transport direction along a transport track, detecting a leading or trailing
edge (the detected edge) of the first postal item in the transport track, and, in
response to the detection of the detected edge of the first postal item, transporting
a second postal item in a feeding direction along a feeding track into a position
collated with the first postal item in the transport track and retaining the second
postal item in that position relative to the first postal item. In such a stacking
process, the postal items in the transport track are merged with postal items fed
from the feeding tracks and the merged postal items are transported further along
the transport track.
[0004] Such a method and such an apparatus are known from
EP-A-1550628.
[0005] However, because the first and second items are retained by the feeding and transport
tracks during stacking without sliding relative to each other and are retained in
mutually fixed positions after having been stacked, tolerances on the precision with
which leading or trailing edges of the stacked postal items are mutually aligned do
in practice result in some misalignment of the leading or trailing edges of many of
the stacks.
[0006] To avoid that such misalignments build up with each next item that is added to a
stack, it is known to deliberately include an offset between the detected edge of
the first postal item and the edge of that next postal item on the same side of the
stack. The size of this offset is selected for all sets, such that the edge of each
further postal item at the side of the detected edge is positioned either slightly
retracted relative to the detected edge of the first postal item or, in the event
this next postal item has ended up in the tolerance range in a position extremely
shifted to the side of the stack of the detected edge, precisely in alignment with
the detected edge.
[0007] To avoid that misalignment causes a next postal item of a length shorter than the
distance between one end and one of the folds to be made in the stack to be improperly
folded along an edge and/or displaced during folding, it is also known to deliberately
include an off-set between a leading or trailing edge of the first postal item and
the edge of that next postal item on the same side of the stack, such that the next
postal item is positioned either with an area along this edge slightly projecting
relative to the first postal item or, in the event this next postal item has ended
up in the tolerance range in a position extremely shifted to the side of the stack
away from this edge, with this edge precisely in alignment with the first postal item.
[0008] However, such deliberate offsets cause misalignments between the postal items of
most stacks, which is disadvantageous for an orderly presentation of the stacks of
postal items.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to provide a solution to reduce misalignment
due to deliberate offsets in the positions of next postal items in stacks.
[0010] According to one aspect of the invention, this object is achieved by providing a
method according to claim 1. The invention may also be embodied in an apparatus according
to claim 9, which is specifically arranged for carrying out the method according to
claim 1.
[0011] Because, the tolerance between nominal relative positions of the first and second
postal items and the actual relative positions of these postal items is determined
on an apparatus, the nominal off-set based on the tolerance for successive sets to
be collated on the same apparatus can, at least in many cases, be set smaller than
a nominal off-set that is selected to take into account a largest tolerance that may
be expected.
[0012] Particular elaborations and embodiments of the invention are set forth in the dependent
claims.
[0013] Further features, effects and details of the invention appear from the detailed description
and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014]
Fig. 1 is a schematic representation in side view of an example of an apparatus according
to the invention;
Fig. 2 is a schematic representation of a stack stacked in accordance with an example
of a method according to the invention; and
Fig. 3 is a schematic representation of another stack stacked in accordance with an
example of a method according to the invention.
DETAILED DESCRIPTION
[0015] In Fig. 1, an example of an apparatus according to the invention for collating postal
items into sets is shown schematically. In this apparatus, a transport track 1 for
transporting postal items in a transport direction (arrow 2) is defined by two upper
conveyor belts 3, 4 and a lower conveyor belt 5 on opposite sides of the transport
track 1. The conveyor belts 3-5 may each include single belts mounted around end rollers.
However, one or more of these conveyor belts may include a plurality of narrow belts
or strings tensioned parallel to each other. The transport track 1 is for transporting
postal items 6-9.
[0016] The postal items 6-9 are generally flat and rectangular items and may for instance
be postal items, each constituted by one or more sheets, business reply envelopes,
cards on carriers, brochures etc., suitable to be inserted and mailed in an envelope.
The postal items 6-8 each have a leading edge 16, 17, 18 and a trailing edge 26, 27,
28 in the transport track 1 and oriented perpendicular to the transport direction
2.
[0017] Along the transport track 1, an edge detector (indicated by opposite arrows) 11 is
located for detecting a leading or trailing edge of each first postal item in the
transport track 1 as it passes the detector 11.
[0018] A feeding track 12 for feeding second postal items 7, 9 extends in a feeding direction
(arrow 13). The feeding track 12 is defined between upper and lower conveyor belts
14, 15 on opposite sides of the feeding track 12. Also these conveyor belts 14, 15
may each include single belts mounted around end rollers or one or more of these conveyor
belts may include a plurality of narrow belts or strings tensioned parallel to each
other. In Fig, 1, a second postal item 9 having a leading edge 19 and a trailing edge
29 in the feeding track 12 and oriented perpendicular to the feeding direction 13
is shown. The feeding track 12 merges with the transport track 1 downstream of the
detector 11, for collating each of the second postal items 9 with one of the first
postal items 8 transported in the transport track 1.
[0019] In Fig. 1, the postal item 7 is a second postal item that has been fed via the feeding
track and collated onto one of the first postal items 6 being transported along the
transport track 1. After having been collated, the collated first and second postal
items 6, 7 are transported further in the transport direction 2 along the transport
track 1. In the present example, the transport track 1 leads to a folding station
20.
[0020] With respect to the representation in Fig. 1, it is noted that a small gap is shown
between the belts 3-5, 14, 15 and the postal items 6-9 to facilitate distinguishing
these distinct items from each other in the drawing, but that, in practice, the directly
adjacent portions of these items on diametrically opposite sides of the respective
gap are generally in contact with each other for engaging postal items between opposite
belt sections and for retaining collated postal items 6-8 in the transport track 1
in positions that are fixed relative to each other.
[0021] The apparatus further includes a sensor structure for measuring the actual relative
positions of the collated first and second postal items of the sets of collated postal
items (in the example shown in Fig. 1 the items 6, 7). This sensor structure is formed
by a combination of an edge detector (indicated by opposite arrows) 21 located downstream
of a point where the feeding track 12 meets the transport track 1, for detecting a
leading and trailing edge of each collated sets of postal items in the transport track
1 as it passes the detector 21, a pulse disk unit 22 (including a disk and a pulse
detector) coupled to a drive of the lower conveyor belt 5 and a control system 23
to which the edge detector (indicated by opposite arrows) 21 and the pulse disk unit
22 are connected. The control unit 23 is arranged for counting the number of pulses
between detection of a leading and a trailing edge of a set of collated postal items,
thereby obtaining a signal that is a measure of the length in transport direction
2 of the set of postal items 6, 7.
[0022] Thus, the actual relative positions of the collated first and second postal items
6, 7 can be measured in a relatively simple manner by measuring the length of the
sets of collated postal items 6, 7.
[0023] For driving the conveyor belts 3-5, a central motor 24 is provided, which can be
coupled to and uncoupled from end rollers of the conveyor belts 5, 14 by clutches
30 and 33 respectively. The clutches 30 and 33 are arranged for stopping the belts
5, 14 and the belts coupled thereto within a predetermined stopping distance when
disconnected from the drive. The upper conveyor belts 3, 4 of the transport track
1 are permanently coupled to the lower conveyor belt 5 for circulation at the same
velocity as the lower conveyor belt 5.
[0024] Along the feeding track 12, an edge detector (indicated by opposite arrows) 31 is
located for detecting leading and trailing edges 19, 29 of each second postal item
9 in the feeding track 12 as it passes the detector 31. A pulse disk unit 32 is coupled
to the conveyor belt 14 of the feeding track 12 and connected to the control system
23 for signaling displacement of items in the feeding track 12 in terms of counted
pulses to the control system 23. The control system is arranged for controlling the
clutch 33 for stopping the conveyor belts 14, 15 of the feeding track 12 within a
predetermined distance counted by the pulse disk unit 32 after the detection of the
leading edge 19 of a postal item 9 has been signaled by the edge detector 31 to the
control system 23. Thus, a postal item 9 can be reliably stopped in a waiting position
in the feeding track 12.
[0025] The control system 23 is connected to the clutches 30, 33 for each time transporting
one of the second postal items 7, 9 from its waiting position in the feeding track
12 in the feeding direction 13 along the feeding track 12 in response to the detection
of the trailing edge 28 of the first postal item 6 resp. 8 by the detector 11, into
a position collated with one of the first postal items 6, 8 in the transport track
1. Thus, the postal item 9 is ready waiting between the conveyors 14, 15 of the feeding
track and on the transport track 1 a postal item 8 is transported from an upstream
feeder. Based upon the passing of the trailing edge 28 at a photocell of the edge
detector 11, the conveyors 14, 15 are started, so as to add the second postal item
9 in an accurately stacked position on top of postal item 8. The conveyors 14, 15
of the feeding track 14 are stopped as soon as the trailing edge of second postal
item has passed a photocell of the edge detector 21.
[0026] As will be explained in more detail with reference to Figs. 2 and 3, because the
first and second items 6-9 are retained by the feeding and transport tracks 1, 12
during stacking without sliding relative to each other and are retained in mutually
fixed positions after having been stacked, tolerances on the precision with which
leading or trailing edges 26-29 of the stacked postal items 6-9 are mutually aligned
do in practice result in some misalignment of the leading or trailing edges of many
of the stacks.
[0027] One situation in which such misalignments can lead to a particularly large increase
of the length of a stack, which becomes irreversible if the stack is folded, is when
a succession of feeding tracks, such as the feeding track 12, merges with a transport
track, such as the transport track 1, in a succession of positions along the transport
track. In some stacks, a number of postal items may each become positioned in a position
in which the aligned edge projects slightly from all other aligned edges. In such
a situation, the length of the stack may be increased by an amount that hampers reliable
processing and particularly insertion of the stack of postal items.
[0028] As is illustrated by Fig. 2, to avoid that such misalignments due to a possible tolerance
range 2t (tolerance = ± t) build up with several or even all next items 52, 53, 54,
55 that are added to a first postal item 51 of a stack 50 from a next feeding track
merging with the transport track 1 in positions downstream of the position where the
feeding track 12 merges with the transport track, a nominal off-set o
nom ≥ t in transport direction (arrow 2) between the detected edge 56 of the first postal
item 51 and the edge 57 of the next postal item 52 on the same side of the stack 50
is applied. The size of this offset O
nom ensures that the edge 57-60 of each further postal item 52-55 at the side of the
detected edge 51 is positioned either slightly retracted relative to the detected
edge 56 of the first postal item 51 or, if the next postal item 52-55 has ended up
extremely to the right in the tolerance range 2t, possibly in alignment with the detected
edge 56. Thus, it is ensured that an edge 57-60 of a next postal item 52-55 does not
project beyond the first postal item 51 and thereby becomes the new edge that is detected
and triggers the feeding of a next postal item 53-55 from a next insert feeding track
to the postal items 51-54 arriving along the transport track..
[0029] If, as a variant on the example illustrated by Fig. 2, instead of the passage of
the trailing edge of the postal item in the transport track, each time the passage
of the leading edge of the postal item in the transport track triggers the feeding
of a second postal item and the leading edges are aligned relative to each other,
to avoid a build up of misalignments of stacked postal items fed from successive feeding
tracks, the nominal off-set of the leading edge of the second postal item relative
to the leading edge of the first postal item should each time be in a direction opposite
to the transport direction 2.
[0030] As is illustrated by Fig. 3, if each time a next postal item 102 is added to a first
postal item 101 to form a stack 100 and the next postal items 102 each have a length
l
2 measured from the leading edge 105 to the trailing edge 104 that is shorter than
the length of each of the first postal items 101 from the leading edge 106 to the
trailing edge 103 and shorter than or equal to the length l
f measured from the trailing edge 103 to the envisaged position f of a fold to be made
in the first postal item 101, it should be avoided that misalignment causes the next
postal 102 to interfere with the folding of the first postal item 101, for instance,
because only a small edge portion of the next postal item 102 projects beyond the
envisaged position f of the fold. To achieve this, a deliberate nominal off-set O
nom between the edge 103 of the first postal item 101 and the adjacent parallel edge
104 of the next postal item 102 may be provided, such that the next postal item 102
is positioned either with its edge 104 along the edge 103 of the first postal item
101 slightly projecting in a direction opposite to the transport direction (arrow
2) relative to the first postal item 101 or, in the event this next postal 102 item
has ended up in the tolerance range 2t (tolerance = ± t) in a position extremely shifted
to the side of the stack 100 away from the edges 103, 104, possibly with the edges
103, 104 precisely in alignment with each other. It is thus ensured, that the opposite
edge 105 of the second postal item 102 stays clear of the fold, when the fold is made
in the envisaged position f.
[0031] If, as a variant on the example illustrated by Fig. 2, instead of the passage of
the trailing edge of the postal item in the transport track, each time the passage
of the leading edge of the postal item in the transport track triggers the feeding
of a second postal item and the leading edges are aligned relative to each other,
to reduce the risk of interference of the second postal item with the folding of the
first postal item, the nominal off-set of the leading edge of the second postal item
relative to the leading edge of the first postal item should be in the transport direction.
[0032] In the apparatus according to the example shown in Fig. 1, the control system 23
is arranged for determining the tolerance t between nominal relative positions of
the first and second postal items 6, 8 and, respectively 7, 9 and the actual relative
positions of the collated first and second postal items 6, 8 and, respectively 7,
9 of each of a first plurality of the stacked sets. The control system 23 is moreover
arranged for, for at least one of the sets after the first plurality of the sets,
controlling the transport of the second postal items for bringing the leading or trailing
edge of the second postal item into a nominal off-set O
nom relative to the trailing edge of the first postal item, which nominal off-set O
nom is larger than or equal to the determined tolerance t.
[0033] Because, the tolerance t between nominal relative positions of the first and second
postal items and the actual relative positions of these postal items is determined,
the nominal off-set can, at least in many cases, be set smaller than a nominal off-set
that is selected to take into account a largest tolerance that may be expected. For
instance, since the tolerance t is determined using the apparatus on which collation
is subsequently carried out in the production mode, the tolerance is determined for
the individual apparatus at hand. The tolerance may also be determined for the prevailing
operating conditions and for, or even during, processing postal items of a given type.
This more individualized and preferably condition based determination of the prevailing
tolerance in the situation at hand allows the applicable tolerance to be determined
more accurately and to select a smaller nominal off-set without adverse effects on
reliability. In practice, the tolerance t is generally partly machine dependent and
partly material dependent.
[0034] The applicable tolerance t may for instance be determined at installation or during
a setting phase prior to operation in a production mode by loading all the downstream
insert feeding stations each with at least 10 sheets or other postal items and by
loading a most upstream feeding station with at least a number of sheets or other
postal items equal to 10 times the number of feeding stations.
[0035] Then, sheets or other postal items are fed from the most upstream feeder and the
next downstream feeder and collated with a nominal off-set O
nom that is larger than the largest tolerance t that may be expected, for instance a
nominal off-set o
nom of -5 mm (i.e., in the example shown in Fig. 1, the trailing edge 27, 29 of the postal
item 7, 9 fed from the downstream feeder along the feeding track 12 would end up 5
mm in advance of the trailing edge 26, 28 of the postal item 6, 8 supplied along the
transport track 1). This is repeated 10 times. By measuring the overall length l
tot of the stack, which should be equal to the item length plus 5 mm if the tolerance
t would be zero, larger than the item length plus 5 mm if the second postal item ends
up too far upstream of the nominal position relative to the first postal item and
smaller than the item length plus 5 mm if the second postal item ends up too far downstream
of the nominal position relative to the first postal item.
[0036] Thus, the average bias between the intended nominal position of the second postal
item relative to the first postal item can be calculated and compensated for during
stacking of next sets of postal items and the applicable bandwidth or tolerance t
about the average value can be determined as well. On the basis of the determined
tolerance t, a nominal off-set O
nom larger than or equal to the determined tolerance t, but generally significantly smaller
than an off-set, which would have been based on the largest tolerance t that may be
expected, can be selected and applied during operation in a production mode.
[0037] This procedure is then repeated for each feeding station coupled to the transport
track via a feeding track and for each feeding track meeting the transport track,
an individual nominal off-set o
nom larger than or equal to the determined tolerance t for that feeding track can be
selected and applied during operation in the production mode.
[0038] If, as in the example shown in Fig. 3, the nominal off-set is set at a positive value,
for instance a nominal off-set o
nom of +5 mm (i.e., in the example shown in Fig. 1, the trailing edge 27, 29 of the postal
item 7, 9 fed from the downstream feeder along the feeding track 12 would end up 5
mm trailing the trailing edge 26, 28 of the postal item 6, 8 supplied along the transport
track 1), the overall length l
tot of the stack will be smaller than the item length plus the nominal off-set if the
second postal item ends up too far upstream of the nominal position relative to the
first postal item and larger than the item length plus the nominal off-set if the
second postal item ends up too far downstream of the nominal position relative to
the first postal item.
[0039] It is observed that, within the framework of the present invention, the tolerance
t may also be determined from the length of the stacked sets without applying a nominal
off-set larger than the tolerance range. If the stacked postal items are of the same
length, every misalignment between the first and second postal items results in a
change of the length l
tot of the stack, but information regarding the bias between the nominal position of
the added postal item and the actual position where the added postal item is positioned
is, at least to some extent, not available. If one of the postal items is of a shorter
length than the other, misalignments causing one of the postal items to be fully inside
the contour of the larger postal items cannot be determined from the length of the
stacked set. However, such measurements may nevertheless be useful, for instance during
operation in a production mode, to monitor whether the frequency of sets of postal
items with a length equal to the length of the largest postal item stays below a certain
threshold value and whether the nominal off-set is not larger than necessary.
[0040] To further reduce the risk of the build-up of misalignments between successively
fed postal items that are collated into a stack or the risk of a second or further
postal item interfering with the folding of a longer postal item, the nominal off-set
may be selected to be equal to the sum of the determined tolerance and a safety margin.
[0041] While the invention has been illustrated and described in detail in the drawings
and foregoing description, such illustration and description are to be considered
illustrative or exemplary and not restrictive; the invention is not limited to the
disclosed embodiments.
[0042] For example, it is possible to provide that the feeding and/or transport tracks are
partially or completely and on one or both sides defined by a plurality of rollers
and/or stationary guide surfaces forming a succession in transport direction.
[0043] Furthermore, the distance traveled of a set of postal items between detection of
the leading and trailing edges may also be measured in other manners, for instance
by counting pulse commands sent to a stepper motor or to a brushless DC motor or by
counting indicia provided on rollers or belts of the transport track.
[0044] The edge detectors may be positioned for detecting leading edges instead of trailing
edges or vice versa.
[0045] In particular during operation in a production mode, it is advantageous to measure
the relative positions of the collated first and second postal items by monitoring
when the trailing edge of a second postal item passes an edge detector, for instance
as the edge detector 31, along the feeding track. Once the second postal item is traveling,
a quite accurate estimate of what its actual position relative to the first postal
item will be, once stacked, can be obtained from the determination when, in relation
to the progress of the first postal item after its trailing edge had been detected,
the trailing edge of the second postal item passes a given position.
1. A method for collating postal items into sets, comprising:
a) for each of the sets:
transporting a first postal item (6, 8) in a transport direction (2) along a transport
track (1), the first postal item (6, 8) being transported having a leading edge (16,
18) and a trailing edge (26, 28) in the transport track (1) and perpendicular to the
transport direction (2);
detecting a leading or trailing edge (16, 18) of the first postal item (6, 8) in the
transport track (1); and
in response to said detection of the leading or trailing edge (16, 18) of the first
postal item (6, 8), transporting a second postal item (7, 9) in a feeding direction
(13), with a leading edge (17, 19) and a trailing edge (27, 29) in a feeding track
(12) and perpendicular to the feeding direction (13), along the feeding track (12)
into a position collated with the first postal item (6, 8) in the transport track
(1) and retaining the second postal item (7, 9) in said position relative to the first
postal item (6, 8);
b) measuring the actual relative positions of the collated first and second postal
items (6-9); and
c) determining a tolerance between nominal relative positions of the first and second
postal items (6-9) and the actual relative positions of the collated first and second
postal items (6-9) of each of a first plurality of said sets;
d) wherein, for at least one of said sets after said first plurality of said sets,
the feeding of the second postal item (7, 9, 52-55; 102) is controlled for bringing
the leading (17, 19) or trailing edge (27, 29; 57-60; 104) of the second postal item
(7, 9, 52-55; 102) into a nominal off-set relative to the leading or, respectively,
the trailing edge (26, 28; 56; 103) of the first postal item (6, 8; 51; 101), said
nominal off-set being larger than or equal to said determined tolerance.
2. A method according to claim 1, wherein the actual relative positions of the collated
first and second postal items (6-9) of a first plurality of said sets of collated
postal items is measured by measuring the length of each of said first plurality of
said sets of collated postal items (6-9).
3. A method according to claim 1 or 2, further comprising determining a bias between
nominal relative positions of the first and second postal items (6-9) and the measured
actual relative positions of the collated postal items (6-9) of said first plurality
of said sets.
4. A method according to claims 2 and 3, wherein, for each of a first plurality of said
sets of collated postal items (6-9), the feeding of the second postal item (7, 9)
is controlled for bringing the leading or trailing edge of the second postal item
(7, 9) into a nominal off-set relative to the leading or, respectively, the trailing
edge of the first postal item (6, 8), said nominal off-set being larger than the largest
expectable tolerance between the nominal relative positions of the first and second
postal items (6-9) and the actual relative positions of the collated postal items
(6-9).
5. A method according to any one of the preceding claims, wherein said sets of said first
plurality of said sets of collated postal items (6-9) are collated during a setting
phase and wherein said at least one of said sets after said first plurality of said
sets are collated during a production phase and processed into mail pieces.
6. A method according to any one of the preceding claims, wherein, for at least one of
said sets after said first plurality of said sets, either the nominal off-set of the
trailing edge (57-60) of the second postal item (52-55) relative to the trailing edge
(56) of the first postal item (51) is in transport direction (2) or the nominal off-set
of the leading edge of the second postal item relative to the leading edge of the
first postal item is in a direction opposite to the transport direction.
7. A method according to any one of the claims 1-5, wherein at least one of said sets
after said first plurality of said sets is folded after collating, the second postal
items (102) each have a length measured from the leading edge (105) to the trailing
edge (104) that is shorter than the length of each of the first postal items (101)
from the leading edge (106) to the trailing edge (103) thereof and shorter than or
equal to the length measured from the leading or trailing edge (103) to the envisaged
position (f) of a fold to be made in the first postal item (101), and wherein, for
at least one of said sets after said first plurality of said sets, either the nominal
off-set of the trailing edge (104) of the second postal item (102) relative to the
trailing edge (103) of the first postal item (101) is in a direction opposite to the
transport direction (2) or the nominal off-set of the leading edge of the second postal
item relative to the leading edge of the first postal item is in the transport direction.
8. A method according to any one of the preceding claims, wherein said nominal offset
is equal to the sum of said determined tolerance and a safety margin.
9. An apparatus for collating postal items into sets comprising:
a transport track (1) for transporting postal items (6-9) in a transport direction
(2) with a leading edge (16-19) and a trailing edge (26-29) in the transport track
(1) and oriented perpendicular to the transport direction (2) and for retaining collated
postal items (6, 7) in the transport track (1) fixedly positioned relative to each
other;
a detector (11) along the transport track (1) for detecting a leading or trailing
edge (26, 28) of each first postal item (6, 8) in the transport track (1);
a feeding track (12) for feeding second postal items (7, 9) in a feeding direction
(13), the second postal items (7, 9) each having a leading edge (17; 19) and a trailing
edge (27, 29) in the feeding track (12) and oriented perpendicular to the feeding
direction (12), the feeding track (12) merging with the transport track (1) downstream
of the detector (11), for collating each of the second postal items (7, 9) with one
of the first postal items (6, 8) transported in the transport track (1);
a sensor structure (21, 22, 23) for measuring the actual relative positions of the
collated first and second postal items (6-9) of said sets of collated postal items
(6-9);
a control system (23) for each time causing the feeding of one of the second postal
items (7, 9) in the feeding direction (13) along the feeding track (12) in response
to said detection of the leading or trailing edge (26, 28) of the first postal item
(6, 8) by the detector (11), into a position collated with one of the first postal
items (6, 8) in the transport track (1);
wherein the control system (23) is arranged for:
determining a tolerance between nominal relative positions of the first and second
postal items (6-9) and the actual relative positions of the collated first and second
postal items (6-9) of each of a first plurality of said sets; and
for at least one of said sets after said first plurality of said sets, controlling
the transport of the second postal item (7, 9, 52-55; 102) for bringing the leading
(17, 19) or trailing edge (27, 29; 57-60; 104) of the second postal item (7, 9, 52-55;
102) into a nominal off-set relative to the leading or, respectively, the trailing
edge (26, 28; 56; 103) of the first postal item (6, 8; 51; 101), said nominal off-set
being larger than or equal to said determined tolerance.
1. Verfahren zum Zusammenführen von Poststücken zu Sets, umfassend:
a) für jedes der Sets:
das Transportieren eines ersten Poststücks (6, 8) in einer Transportrichtung (2) entlang
einer Transportbahn (1), wobei das erste Poststücks (6, 8) mit einer Vorderkante (16,18)
und einer Hinterkante (26, 28) auf der Transportbahn und senkrecht zur Transportrichtung
transportiert wird;
das Erfassen einer Vorderkante oder Hinterkante (16,18) des ersten Poststücks (6,
8) auf der Transportbahn (1); und,
in Reaktion auf die Erfassung der Vorderkante oder Hinterkante (16, 18) des ersten
Poststücks (6, 8), das Transportieren eines zweiten Poststücks (7, 9) mit einer Vorderkante
(17,19) und einer Hinterkante (27, zu) auf einer Vorschubbahn (12) und senkrecht zur
Transportrichtung in einer Vorschubrichtung (13) entlang der Vorschubbahn (12) in
eine mit dem ersten Poststück (6,8) vereinigte Position auf der Transportbahn (1)
und das Halten des zweiten Poststücks (7, 9) in dieser Position relativ zu dem ersten
Poststück (6, 8);
b) das Messen der tatsächlichen relativen Positionen der zusammengeführten ersten
und zweiten Poststücke (6-9); und
c) das Bestimmen einer Toleranz zwischen den nominalen relativen Positionen der ersten
und der zweiten Poststücke (6-9) und den tatsächlichen relativen Positionen der zusammengeführten
ersten und zweiten Poststücke (6-9) jedes einer ersten Mehrzahl von Sets;
d) wobei für mindestens eines der Sets nach der ersten Mehrzahl von Sets der Vorschub
des zweiten Poststücks (7, 9, 52-55; 102) gesteuert wird, um die Vorderkante (17,
19) oder Hinterkante (27, 29; 57-60; 104) des zweiten Poststücks (7, 9, 52-55; 102)
in einen nominalen Versatz relativ zur Vorderkante bzw. Hinterkante (26, 28; 56, 103)
des ersten Poststücks (6, 8; 51; 101) zu bringen, wobei der nominale Versatz größer
als die oder gleich der bestimmten Toleranz ist.
2. Verfahren nach Anspruch 1, wobei die tatsächlichen relativen Positionen der zusammengeführten
ersten und zweiten Poststücke (6-9) einer ersten Mehrzahl der Sets von zusammengeführten
Poststücken durch Messen der Länge jedes der ersten Mehrzahl von Sets von zusammengeführten
Poststücken (6-8) gemessen werden.
3. Verfahren nach Anspruch 1 oder 2, ferner umfassend das Bestimmen einer Symmetrie zwischen
nominalen relativen Positionen der ersten und der zweiten Poststücke (6-9) und den
gemessenen tatsächlichen relativen Positionen der zusammengeführten Poststücke (6-9)
der ersten Mehrzahl von Sets.
4. Verfahren nach den Ansprüchen 2 und 3, wobei für jedes einer ersten Mehrzahl der Sets
von zusammengeführten Poststücken (6-9) der Vorschub des zweiten Poststücks (7,9)
gesteuert wird, um die Vorderkante oder Hinterkante des zweiten Poststücks (7, 9)
relativ zu der Vorderkante bzw. Hinterkante des ersten Poststücks (6,8) in einen nominalen
Versatz zu bringen, wobei der nominale Versatz größer ist als die größte zu erwartende
Toleranz zwischen den nominalen relativen Positionen der ersten und der zweiten Poststücke
(6-9) und den tatsächlichen relativen Positionen der zusammengeführten Poststücke
(6-9).
5. Verfahren nach einem der vorhergehenden Ansprüche, wobei die Sets der ersten Mehrzahl
von Sets von zusammengeführten Poststücken (6-9) während einer Set-Bildungsphase zusammengeführt
werden und wobei wenigstens eines der Sets nach der ersten Mehrzahl von Sets während
einer Produktionsphase zusammengestellt und zu Postsendungen verarbeitet wird.
6. Verfahren nach einem der vorhergehenden Ansprüche, wobei für wenigstens eines der
Sets nach der ersten Mehrzahl von Sets entweder der nominale Versatz der Hinterkante
(57-60) des zweiten Poststücks (52-55) relativ zur Hinterkante (56) des ersten Poststücks
(51) in Transportrichtung (2) liegt oder der nominale Versatz der Vorderkante des
zweiten Poststücks relativ zu der Vorderkante des ersten Poststücks in einer zur Transportrichtung
entgegengesetzten Richtung liegt.
7. Verfahren nach einem der Ansprüche 1 bis 5, wobei zumindest eines der Sets nach der
ersten Mehrzahl von Sets nach dem Zusammenführen gefaltet wird, wobei die zweiten
Poststücke (102) gemessen von der Vorderkante (105) zur Hinterkante (104) jeweils
eine Länge haben, die kürzer ist als die Länge jedes der ersten Poststücke (101) von
ihrer Vorderkante (106) zu ihrer Hinterkante (103) oder gleich der von der Vorderkante
oder Hinterkante (103) zu der angestrebten Position (f) einer in dem ersten Poststück
(101) herzustellenden Faltung gemessenen Länge und wobei für wenigstens eines der
Sets nach der ersten Mehrzahl von Sets entweder der nominale Versatz der Vorderkante
(104) des zweiten Poststücks (102) relativ zu der Hinterkante (103) des ersten Poststücks
(101) in einer zur Transportrichtung (2) entgegengesetzten Richtung liegt oder der
nominale Versatz der Vorderkante des zweiten Poststücks relative zu der Vorderkante
des ersten Poststücks in Transportrichtung liegt.
8. Verfahren nach einem der vorhergehenden Ansprüche, wobei der nominale Versatz gleich
der Summe der bestimmten Toleranz und einer Sicherheitsspanne ist.
9. Vorrichtung zum Zusammenführen von Poststücken zu Sets, umfassend:
eine Transportbahn (1) für den Transport von Poststücken (6-9) in einer Transportrichtung
(2), mit einer Vorderkante (16-19) und einer Hinterkante (26-29) auf der Transportbahn
(1) und senkrecht zur Transportrichtung (2) orientiert, und zum Halten von zusammengeführten
Poststücken (6, 7) auf der Transportbahn (1) in einer festgelegten Position relativ
zueinander;
einen Detektor (11) entlang der Transportbahn (1) zum Erfassen einer Vorderkante oder
Hinterkante (26, 28) jedes ersten Poststücks (6, 8) auf der Transportbahn (1);
eine Vorschubbahn (12) für den Vorschub von zweiten Poststücken (7, 9) in einer Vorschubrichtung
(13), wobei die zweiten Poststücke (7, 9) jeweils eine Vorderkante (17; 19) und eine
Hinterkante (27, 29) auf der Vorschubbahn (12) und in senkrechter Orientierung zur
Vorschubrichtung (12) aufweisen, wobei die Vorschubbahn (12) auf der stromabwärtigen
Seite des Detektors (11) mit der Transportbahn (1) zusemmenläuft, um jedes der zweiten
Poststücke (7, 9) mit einem der auf der Transportbahn (1) transportierten ersten Poststücke
(6, 8) zusammenzuführen;
eine Sensorkonstruktion (21, 22, 23) zum Messen der tatsächlichen relativen Positionen
der zusammengeführten ersten und zweiten Poststücke (6-9) der Sets von zusammengeführten
Poststücken (6-9);
ein Steuersystem (23) für die jeweilige Veranlassung des Vorschubs eines der zweiten
Poststücke (7, 9) in der Vorschubrichtung (18) entlang der Vorschubbahn in eine mit
einem der ersten Poststücke (6, 8) auf der Transportbahn (1) zusammengeführten Position,
in Reaktion auf die Erfassung der Vorderkante oder Hinterkante (26, 28) des ersten
Poststücks (6, 8) durch den Detektor (11);
wobei das Steuersystem (23) ausgebindet ist für:
die Bestimmung einer Toleranz zwischen nominalen relativen Positionen der ersten und
der zweiten Poststücke (6-9) und tatsächlichen relativen Positionen der zusammengeführten
ersten und zweiten Poststücke (6-9) jedes einer ersten Mehrzahl der Sets; und
für die Steuerung des Transports der zweiten Poststücke (7, 9, 52-55; 102) für mindestens
eines der Sets nach der ersten Mehrzahl der Sets, um die Vorderkante (17,19) oder
Hinterkante (27, 29; 57-60; 104) des zweiten Poststücks (7, 9, 52-55; 102) in einen
nominalen Versatz relativ zu der Vorderkante bzw. Hinterkante (26,28; zu 103) des
ersten Poststücks (6, 8; 51; 101) zu bringen, wobei der nominalen Versatz größer als
die oder gleich der bestimmten Toleranz ist.
1. Procédé pour collationner des articles postaux en groupes, comprenant :
a) pour chacun des groupes, les étapes consistant à :
transporter un premier article postal (6, 8) dans une direction de transport (2) le
long d'une piste de transport (1), le premier article postal (6, 8) transporté ayant
un bord d'attaque (16, 18) et un bord de fuite (26, 28) dans la piste de transport
(1) et étant perpendiculaire à la direction de transport (2) ;
détecter un bord d'attaque ou de fuite (16, 18) du premier article postal (6, 8) dans
la piste de transport (1) ; et,
en réponse à ladite détection du bord d'attaque ou de fuite (16, 18) du premier article
postal (6, 8), transporter un deuxième article postal (7, 9) dans une direction d'acheminement
(13), avec un bord d'attaque (18, 19) et un bord de fuite (27, 29) dans une piste
d'acheminement (12) et perpendiculaire à la direction d'acheminement (18) le long
de la piste d'acheminement (12) dans une position de collationnement avec le premier
article postal (6, 8) dans la piste de transport (1) et retenir le deuxième article
postal (7, 9) dans ladite position par rapport au premier article postal (6, 8) ;
b) mesurer les positions relatives réelles des premier et deuxième articles postaux
(6 à , 9) collationnés ; et
c) déterminer une tolérance entre des positions nominales relatives des premier et
deuxième articles postaux (6 à 9) et les positions relatives réelles des premier et
deuxième articles postaux collationnés (6 à 9) de chacun d'une pluralité desdits groupes
;
d) dans lequel, pour au moins l'un desdits groupes, après ladite première pluralité
desdits groupes, l'acheminement du deuxième article postal (7, 9, 52 à 55 ; 102) est
commandé pour amener le bord d'attaque ou de fuite (27, 29 ; 57 à 60 ; 104) du deuxième
article postal (7, 9, 52 à 55 ; 102) dans un décalage nominal par rapport au bord
d'attaque ou, respectivement, au bord de fuite (26, 28 ; 56 ; 103) du premier article
postal (6, 8 ; 51 ; 101), ledit décalage nominal étant supérieur ou égal à ladite
tolérance déterminée.
2. Procédé selon la revendication 1, dans lequel les positions relatives réelles des
premier et deuxième articles postaux collationnés (6 à 9) d'une première pluralité
desdits groupes d'articles postaux collationnés sont mesurées en mesurant la longueur
de chacun de ladite première pluralité desdits groupes d'articles postaux collationnés
(6 à 9).
3. Procédé selon la revendication 1 ou 2, comprenant en outre l'étape de détermination
d'une erreur entre les positions relatives nominales des premier et deuxième articles
postaux (6 à 9) et les positions relatives réelles mesurées des articles postaux collationnés
(6 à 9) de ladite première pluralité desdits groupes.
4. Procédé selon les revendications 2 et 3, dans lequel, pour chacun d'une première pluralité
desdits groupes d'articles postaux collationnés (6 à 9), l'acheminement du deuxième
article postal (7, 9) est commandé pour amener le bord d'attaque ou de fuite du deuxième
article postal (7, 9) dans un décalage nominal par rapport au bord d'attaque ou, respectivement,
au bord de fuite du premier article postal (6, 8), ledit décalage nominal étant plus
grand que la tolérance la plus grande que l'on peut attendre entre les positions relatives
nominales des premier et deuxième articles postaux (6 à 9) et les positions relatives
réelles des articles postaux collationnés (6 à 9).
5. Procédé selon l'une quelconque des revendications précédentes, dans lequel lesdits
groupes de ladite première pluralité desdits groupes d'articles postaux collationnés
(6 à 9) sont collationnés pendant une phase de réglage et dans lequel ledit au moins
un desdits groupes après ladite première pluralité desdits groupes est collationné
pendant une phase de production et traité en courriers.
6. Procédé selon l'une quelconque des revendications précédentes, dans lequel, pour au
moins un desdits groupes après ladite première pluralité desdits groupes, soit le
décalage nominal du bord de fuite (57 à 60) du deuxième article postal (52 à 55) par
rapport au bord de fuite (56) du premier article postal (51) se situe dans le sens
de transport (2), soit le décalage nominal du bord d'attaque du deuxième article postal
par rapport au bord d'attaque du premier article postal se situe dans un sens opposé
au sens de transport.
7. Procédé selon l'une quelconque des revendications 1 à 5, dans lequel au moins l'un
desdits groupes après ladite première pluralité desdits groupes est plié après collationnement,
les deuxièmes articles postaux (102) ont chacun une longueur mesurée du bord d'attaque
(105) au bord de fuite (104) qui est plus courte que la longueur de chacun des premiers
articles postaux (101) du bord d'attaque (106) au bord de fuite (103) de ceux-ci et
plus courte ou égale à la longueur mesurée du bord d'attaque ou de fuite (103) à la
position envisagée (f) d'un pli à effectuer dans le premier article postal (101) et
dans lequel, pour au moins un desdits groupes après ladite première pluralité desdits
groupes, soit le décalage nominal du bord de fuite (104) du deuxième article postal
(102) par rapport au bord de fuite (103) du premier article postal (101) est dans
un sens opposé au sens de transport (2), soit le décalage nominal du bord d'attaque
du deuxième article postal par rapport au bord d'attaque du premier groupe postal
se situe dans le sens de transport.
8. Procédé selon l'une quelconque des revendications précédentes, dans lequel ledit décalage
nominal est égal à la somme de ladite tolérance déterminée et d'une marge de sécurité.
9. Appareil pour collationner des articles postaux en groupes comprenant :
une piste de transport (1) pour transporter des articles postaux (6 à 9) dans un sens
de transport (2) avec un bord d'attaque (16 à 19) et un bord de fuite (26 à 29) dans
la piste de transport (1) et orientés perpendiculairement à la direction de transport
(2) et pour retenir les articles postaux collationnés (6, 7) dans la piste de transport
(1) positionnés de manière fixe l'un par rapport à l'autre ;
un détecteur (11) le long de la piste de transport (1) pour détecter un bord d'attaque
ou de fuite (26, 28) de chaque premier article postal (6, 8) dans la piste de transport
(1) ;
une piste d'acheminement (12) pour acheminer des deuxièmes articles postaux (7, 9)
dans un sens d'acheminement (13) les deuxièmes articles postaux (7, 9) ayant chacun
un bord d'attaque (17 ; 19) et un bord de fuite (27, 29) dans la piste d'acheminement
(12) et orienté perpendiculairement à la direction d'acheminement (12), la piste d'acheminement
(12) fusionnant avec la piste de transport (1) en aval du détecteur (11) pour collationner
chacun desdits deuxièmes articles postaux (7, 9) avec l'un des premiers articles postaux
(6, 8) transportés dans la piste de transport (1) ;
une structure de capteur (21, 22, 23) pour mesurer les positions relatives réelles
des premiers et deuxièmes articles postaux (6 à 9) desdits groupes d'articles postaux
collationnés (6 à 9) ;
un système de commande (23) pour provoquer chaque fois l'acheminement d'un des deuxièmes
articles postaux (7, 9) dans le sens d'acheminement (18) le long de la piste d'acheminement
(12) en réponse à ladite détection du bord d'attaque ou de fuite (26, 28) du premier
article postal (6, 8) par le détecteur (11), dans une position collationnées avec
l'un des premier articles postaux (6, 8) dans la piste de transport (1) ;
dans lequel le système de commande (23) est aménagé pour :
déterminer une tolérance entre les positions relatives nominales des premier et deuxième
articles postaux (6 à 9) et les positions relatives réelles des premier et deuxième
articles postaux collationnés (6 à 9) de chacun d'une première pluralité desdits groupes
; et,
pour au moins l'un desdits groupes après ladite première pluralité desdits groupes,
commander le transport du deuxième article postal (7, 9, 52 à 55 ; 102) pour amener
le bord d'attaque (17, 19) ou de fuite (27, 29 ; 57 à 60 ; 104) du deuxième article
postal (7, 9, 52 à 55 ; 102) dans un décalage nominal par rapport au bord d'attaque
ou, respectivement, au bord de fuite (26, 28 ; 56 103) du premier article postal (6,
8 ;51 ;101), ledit décalage nominal étant supérieur ou égal à ladite tolérance déterminée.