Note: Descriptions are shown in the official language in which they were submitted.
CA 02508646 1997-O1-17
TIGHTENING ARRANGEMENT FOR PAPERBOARD WRAP AND TIGHTENING
SECTION FOR APPARATUS FOR APPLYING A WRAP AROUND A PLURALITY
OF ARTICLES
The invention relates to paperboard wraps for retaining a number of
articles.
According to one aspect of the present invention there is provided a
paperboard wrap comprising two panels hingedly connected together along a
fold line and at least one tightening arrangement, each comprising a first cut
being made in one panel which first cut has two ends which are both located at
a hinge line to define a first part and a second cut being made in the second
panel which second cut has two ends which are both located at the hinge line
to
define a tab part which is integrally formed with the first part to constitute
a
hinge panel, at least one of the ends of the second cut being disposed
generally
- between the two ends of the first cut, whereby in use the hinge panel is
pivotted about the hinge line and the parts of the hinge line between adjacent
ends of the cuts provide surfaces for engagement with a tightening edge of a
packing machine.
2 p Preferably both ends of the second cut are disposed between the
ends of the first cut and also the hinge line does not extend across the hinge
panel.
With preferred embodiments the wrap comprises a sleeve for
2 5 retaining a plurality of articles as a multipack. Conveniently said one
panel is
a side wall of said sleeve and the other side wall of the sleeve is also
constituted by a panel similar to said one panel. Each side wall may comprise
a main side panel and a sub-panel adjacent the second panel.
Generally, said second panel is a base wall of said sleeve and
another base wall of the sleeve is also constituted by a panel similar to said
second panel. A further preferred feature is that each pair of first and
second
cuts constitutes an article retaining seat in use. A further feature of such
an
arrangement is that when the hinge panel is rotated about said hinge line, the
first part lies against the associated base wall and constitutes a seat for an
article.
~
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Preferably each article is associated with a hinge panel, the first cut
of which is generally C-shaped and the second cut is angled inwardly from
both ends and joined with a straight central section which is generally
parallel
to the hinge line. The first part of the hinge panel need not extend to the
first
cut in chosen locations such as that part remote from the two ends of the cut.
The two base panels may be connected together using adhesive or
0 interlocking panels or other means.
In some embodiments the hinge line is an extension of said fold line
whereas in other embodiments the hinge line is substantially parallel to but
spaced from the fold line, with the ends of the first cut extending into the
15 second panel.
According to a second aspect of the present invention there is
provided a tightening section for apparatus for applying a paperboard wrap
around a plurality of articles, said tightening section comprising an endless
20 drive member having at least one straight line section and having a
multitude
of elements which project outwardly from the drive member the elements
being such that a number of said elements form a substantially straight edge
in
said straight line section which edge is substantially parallel to the path of
2 5 articles through the tightening section and to the path of the drive
member in
said straight line section.
Preferably, said substantially straight edge is substantially
continuous. Said elements may be in the form of plates attached to the drive
member and also the drive member is in the form of an endless chain
comprising links each having two pivot points by which the link is connected
to a further pair of links.
In a preferred arrangement each plate is pivotally attached to two
successive pivot points provided by adjacent links, all pivot points of the
links
being coupled to a plate. Conveniently the chain is constrained for guided
movement within guide members at least in certain areas of its endless path.
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A further preferred feature is that upstream of the straight line
section is a second straight line section which is angled relative to the
first
straight line section, whereby in use the projecting elements begin to engage
respective formations on the paperboard wrap as the wrap passes said second
straight line.
According to a third aspect of the present invention there is
provided, in combination, a pair of said tightening sections spaced apart one
on
each side of the article path, said straight line sections being located
directly
opposite each other.
Embodiments of the present invention will now be described in
more detail. The description makes reference to the accompanying
diagrammatic drawings in which:
Figure 1 shows a blank incorporating an embodiment of the present
invention, together with an enlarged detail,
Figure 2 is a perspective view of a paperboard wrapping apparatus,
Figure 3 is a sectional view through tightening apparatus operating
on the figure 1 blank,
Figure 4 is a schematic plan view of the figure 3 apparatus,
2 5 Figure 5 is a schematic perspective view of a part of the blank
folding process,
Figure 6 is a schematic perspective view of part of the assembled
blank with two bottles removed, and showing part of the tightening apparatus
on one side,
Figure 7 shows an alternative blank according to the present
invention, together with an enlarged detail,
Figure 8 is a sectional view through tightening apparatus operating
on the figure 7 blank,
Figure 9 is a schematic perspective view similar to figure 6 of part
of the assembled figure 7 blank with two bottles removed,
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Figure 10 is a plan view of part of a prior art tightening section, and
Figure 11 is a plan view of part of a tightening section according to
the present invention, and
Figure 12 is a perspective view of a rotating disc used in the
tightening section.
Figures 1 to 6 show a paperboard blank 10 for forming into a wrap
around six bottles 11 arranged in two rows of three. The blank 10 has a top
panel 12 hingedly connected to two angled side panels 13 which in turn are
hingedly connected to two main side panels 14. At the lower ends of the side
panels 14 are lower side panels 15 for receiving heel portions 16 of the
bottles
11. Hingedly connected to the lower side panels 15 are base panels 17 which
incorporate formations 18 which interlock to close the blank 10 around the six
bottles 11. The blank 10 also has top openings 19 for receiving the tops 20 of
the bottles 11 and finger holes 21 in the top panel 12 to enable the pack to
be
2 p easily carried.
With the type of blank shown, and indeed many other types of
blank, the blank has to be tightened around the articles being held before and
during the securing together of the ends of the blank by interlocking
2 5 formations or other suitable means such as adhesive. In the heel receiving
areas of the blank 10, heel receiving apertures are provided. Each heel
receiving aperture is formed primarily by two cuts 22, 23. The first cut 22 is
generally arcuate, starting and finishing on the hinge line between the lower
side panel 15 and its associated base panel 17. The second cut 23 also starts
and finishes on the hinge line between the lower side panel 15 and its base
panel 17, but within the ends of the first cut.
The two cuts 22, 23 define, with the hinge portions 24 between the
ends of the cuts a hinge panel 25 having a first part 26 defined by the first
cut
22 and a tab part 27 adjacent the second cut 23. The hinge between the lower
side panel 15 and its base panel 17 does not extend across the hinge panel 25.
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It will be appreciated that six such hinge panels 25 are provided on
the blank 10 but the number will vary depending on the intended number and
arrangement of the articles.
When applying the blank 10 around the bottles 11, much existing
equipment can be used as illustrated in figure 2 which shows a product
metering section 100, a magazine 1 O1 for a number of blanks 10, a pick device
102 for picking a blank from the magazine l O1 and placing it on the next
group
of articles which are bottles 103 in this illustrated arrangement. The side
panels 14 are then swept down towards the sides of the bottles. The blanks are
then folded around the cans and are then tightened and secured in the
tightening section 104.
At present a typical tightening section would be pitched and
comprise a number of small fingers 71 mounted in groups at regular spaced
intervals on a pair of oppositely disposed, side running chains ?2. A part of
such a tightening section is shown in figure 10. These fingers engage in small
cut outs in the side panels of the blanks adjacent the base panels. The
relationship between the fingers and the cut outs is critical and requires
accurate setting. If a different product is to be used on the packing machine
it
2 5 is quite often the case that the positions of the fingers needs to be
changed.
This is very time consuming and results in increased costs and reduced
production.
Just prior to the tightening section of the present arrangement, there
is a rotating disc 70 provided on each side of the apparatus. One of these
discs
70 is visible in figure 2 and is mounted for rotation in a generally
horizontal
plane about central axis 72. Each disc 70 has a number of lugs 71 which
engage the successive first parts 26 of the hinge panels 25 and move them
inwardly whilst the tab parts 27 move outwardly thereby to cooperate with the
tightening section 104.
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The discs may be coated with a suitable friction reducing material
and the form of the lugs may vary depending on the form of the hinge panels
25.
In the present arrangement the tightening section includes a pair of
oppositely disposed, endless chains 50 which approach the bottles 11 in an
angled section 60 as they pass along a conveyor in direction 51, the chains
continuing in a straight section 61. Attached to the chains 50 are carton
engaging members 52 in the form of substantially flat plates. Each pair of
adjacent links 53 of the chain 50 have attached to them, in a pivotal fashion
on
the pivots of the links, an engaging member 52. Each member 52 has a
straight active edge 54 which remains generally parallel to the direction of
movement of the chain 50 as it passes adjacent the conveyor in straight
section
61. The chains 50 are retained in guides 55 which ensure the accurate passage
of the chains 50 in the angled and straight sections 60, 61 alongside the
2 0 conveyor. When the chains are travelling in straight lines, as illustrated
in
figure 11, it will be seen that the edges 54 provide a combined active edge
which is substantially straight and continuous in that it is broken only by
small
gaps. In practise, these gaps can be negligible if the engaging members 52 are
2 5 ~e~ioned accurately.
The generally continuous nature of the active edges 54 of the
engaging members 52 enables such equipment to be used on unpitched
packaging lines as well as pitched ones.
30 In use the blank 10 is placed bythe pick device 102 over the bottles
11 as they move along the conveyor. Guide means fold down the side panels
13, 14 and also guide inwardly the lower side panels 15 and the base panels
17.
The rotating discs 70 push the first part 26 of the hinge panels 25 inwardly
and
this enables the first parts 26 to be folded under the bottles 11 and the
tightening section 104 to cooperate with the tab part 27 of the hinge panel
25.
The blank is then guided such that the hinge portions 24 are engaged by the
CA 02508646 1997-O1-17
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active edges 54 of the carton engaging members 52. This position is shown
clearly in figure 3.
As the bottles and blank move further along the conveyor, the blank
is tightened around the bottles because the distance between the opposite
active
edges 54 reduces due to the angled sections 60. Whilst in the straight section
61 the active edges 54 press tightly against the fold line 24 on the lower
side
panel 15 until the base panels 17 are secured together. The tightening process
in this arrangement can be particularly strong because the active edges 54
operate on a section of the blank which is effectively of double thickness
during the tightening process. This double thickness is a result of the first
part
26 of the hinge panel 25 lying against the base panel 17.
When the blank 10 is secured around the bottles 11 it will be
appreciated that the first parts 26 of the hinge panel 25 also result in a
double
layer of board for cushioning the bottoms of the bottles. Normally the outer
2 p side of the bottle bottoms will rest on a single thickness of paperboard.
In
addition the tab parts 27 can protect the exposed bottle bottom from
accidental
damage. A better view of the base area of the finished wrap is clearly shown
in figure 6.
2 5 It is not, however, necessary that the first part 26 of the hinge panel
extends all the way to the first cut 22. The first part 26 could in fact be
truncated so that in the initial blank 10 an aperture is already visible. It
is,
however, essential that some of the first part 26 remains, especially in the
area
adjacent the hinge portions 24.
In figures 7 to 9 there is shown an alternative blank 110 and its
application to six bottles 11. Parts of the blank 110 which are similar to the
blank 10 have been given similar numbers prefixed with an additional 1. The
principal difference between the two blanks 10, 110 is that in blank 10 the
hinge portions 24 about which the hinge panel rotates coincide with the fold
between the lower side panel 15 and its associated base panel 17. In blank I
10
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this is not the case, with the hinge portions 124 being parallel to the fold
lines
between the lower side panels 115 and the associated base panels 117, but
being located in the base panels 117 themselves.
The principal reason for this is the desire to minimise size .changing
requirements in the tightening section 104 of a wrapping apparatus. The
spacing of the hinge portions 124 relative to the base fold lines can be
varied
dependent on the container diameter and its heel profile which may result in a
variety of angles of the lower side panels 15, 11 S relative to the base
panels
and side panels.
The action of the tightening mechanism 104 on a blank 110 having
15 a spacing between the hinges is almost identical as for the coinciding
folds
except that the plate-like carton engaging members 52 have portions adjacent
the active edges 54 which are located directly below the base panels 117 in
the
straight section 61. This, coupled with other portions adjacent the active
edges
2 a 54 being located directly above the tab parts 127 improves the location of
the
active edge against the hinge portions 124 during tightening.
It will be appreciated that the principle described above can be
applied to any blank for wrapping a plurality of articles, such as bottles or
2 5 cans, in a great variety of arrays such as single or double row. Also, the
base
panels may be secured together by interlocking formations, adhesive or any
other suitable method. Although the carton engaging members 52 are shown
attached to chains 50, other suitable transport means are possible. Also the
size and profile of the members 52 may alter depending on the profile of the
product being wrapped.
In other embodiments the angled section 60 could in fact be slightly
curved.
