Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02295360 2000-O1-13
Herr Helmut Seidel
Fliederstrasse 19
65396 Walluf
Machine for folding a downwardly directed bottom section
of a packing box beneath a product being packaged
D a s c r i p t i o n
There are a number of different ways of packing a product
in a packing box, more particularly in a folding carton.
On the one hand it is possible to first produce the
folding carton and to place the product therein before
proceeding to seal the packing box. Another method is to
use the wrap-around process to enclose the product in the
packing.
Setting the bottom section in position beneath a product
being carried along by a conveyor device and which
accordingly is resting on the conveyor device presents a
special difficulty. Problems arise in particular in
guiding and conveying the packing box in the defined
manner and in folding the bottom section of the packing
box, which in the initial situation is downwardly
directed, beneath the product being packaged.
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For example the product is packed directly into the box or
else it is contained in a separate packaging, for instance
a bag, which is put into the folding carton. An example
of a directly packed product is a pizza, or several pizzas
arranged one above the other. An example of a product in
a bag is cornflakes, where the cardboard packing box is
formed around the bag filled with the cornflakes.
From unexamined German patent application DE-OS 21 58 540
a machine for forming a carrier pack is known, more
particularly one for glasses. Here the packing blank is
placed from above symmetrically around the article to be
packed, with folding rails of different shapes being
provided on both sides to pivot two associated bottom
section elements of the blank against the base of the
article. A driving dog is simultaneously applied against
the blank and against the article. The conveying sections
of the machine do not incorporate functional interspaces,
and instead a feeder belt for the articles is directly
followed by a bracing strut therefor, subordinated
directly to which are the folding rails which are now at
the lower level there.
Against this background it is the object of the present
invention to indicate a folding machine which allows the
downwardly directed bottom section of the packing box to
be folded beneath the product being packed, as the product
and the packing box are being continuously carried along.
The machine is intended to be of a particularly
straightforward constructional design and to allow
continuous packaging of products at a high rate of
throughput. What is meant by a high rate of throughput is
a packaging and product conveying speed that enables at
least 150 packing boxes to be handled per minute. What is
meant by continuous conveying of the product and the
packing box is uninterrupted conveying thereof. The
conveying speeds of the product and the packing box are
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preferably identical, and thus the product and packing box
move along in synchronism.
The invention proposes a machine for folding a downwardly
directed bottom section of a packing box beneath a product
being packaged, with a device holding the packing box and
carrying it along in the conveying direction and a
conveyor device receiving the product, the machine
incorporating the following additional features:
- the conveyor device incorporates a rear and a front
conveyor section,
- there is an interspace disposed between the conveyor
sections,
- in the area of the interspace, beneath the product
conveying plane and at an inclined angle to the
conveying direction, there is disposed a device for
folding the bottom section of the packing box
underneath the product being packed.
The invention is based on recognition of the fact that it
is sufficient for only discrete areas of the product to be
carried by the conveyor device. This state of affairs can
be utilised to fold the bottom section beneath the product
being packed. This is achieved by means of the device for
folding the bottom section, which functions more or less
like a set of points. This means that the downwardly
directed bottom section passes into the zone of the device
for folding the bottom section and on account of the
points function the bottom section is folded inwards by
its leading zone and in one direction beneath the product
being packed. As the product and packing box are conveyed
onward, first that zone of the bottom section which is
folded inwards comes into contact with the front conveying
section, with the result that this packing box zone and
the product are supported there, while as a result of the
product and packing box being conveyed onward, trailing
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sections of the product and packing box are no longer
supported by the conveyor device, thereby enabling the
bottom section to be folded beneath the product in this
zone.
In accordance with one preferred embodiment of the
machine, the front and/or rear conveying section of the
conveyor device are configured as conveyor belts, more
particularly in the manner of toroidal belts. In
particular the front and rear conveying sections are
configured as conveyor belts. It is helpful if each
conveying section has a plurality of conveyor belts, more
particularly toroidal belts.
The interspace provided under the invention can be formed
in a particularly straightforward fashion if the conveyor
belts of the rear conveying section of the conveyor device
and the conveyor belts of the front conveying section of
the conveyor device have different lengths, notably in
such a manner that the interspace formed between the
conveying sections is orientated at an inclined angle to
the conveying direction. In particular it is provided
that the interspace has the shape of a parallelogram, more
particularly the corner of the parallelogram that lies to
the front in the conveying direction encloses an angle of
30 to 60°, preferably 40°, with the conveying direction.
Particularly in the case of such an acute angle of 40 ° ,
the configuration of the interspace is such that the
extension thereof in the conveying direction is very
large, thereby enabling the downwardly directed bottom
section to be folded beneath the product over a great
conveying length of the product and packing box.
In order to achieve accurate folding of the downwardly
directed bottom section of the packing box beneath the
product being packed, it is essential that the packing box
is held in a precise manner and moved in a precise manner
CA 02295360 2000-O1-13
relative to the product. In this context the packing box
is provided to have a lid section and two side wall
sections folded downwards perpendicularly to said lid
section, with the bottom section being hinged to one of
the side wall sections and the device for holding the
packing box adequately gripping the latter in the region
of the opposing end edges of the respective side wall
section. The packing box is consequently held in position
in the region of the side wall sections so that,
regardless of the fact that the packing box is being
continuously carried along, the packing box blank is
guaranteed to be retained in an exact manner, separate
from the bottom section that is to be folded. One
special design variant provides for the device to
incorporate driving dogs for holding the packing box.
Each side wall is held in position in the region of the
opposing end faces by means of driving dogs which are held
in different conveyor chains.
The device for folding the bottom section of the packing
box may be configured in various ways. The essential
thing is that this device operates like a set of points.
One particularly simple design in constructional terms
provides for the device for folding the bottom section to
be in the form of a strut which juts out into the path of
the bottom section. This folding device is basically
competent to fold the bottom section so far towards the
product that is being packed that, as the leading edge ( in
the conveying direction ) of the bottom section strikes the
front conveying section of the conveyor device, this
conveying section causes the bottom section to swing right
up beneath the product being packed, thereby enabling the
bottom section to be glued by, for example, a tab portion
disposed on the opposite side wall section. To help to
fold up the bottom section, one refinement of the
invention provides for a device for folding up the bottom
section of the packing box to be disposed in the region of
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the interspace below the conveying plane of the product.
The device for folding up the bottom section is for
example configured as a revolving belt orientated in the
conveying direction, whose rear section is disposed ahead
of the front line of the front conveying section and
converges in the conveying direction towards the conveying
plane of the conveying device for the product. In this
way the bottom section that is folded at least partly
upwards by means of the strut is obliged to run up against
the revolving belt, which, due to the fact that its
conveying plane is inclined to the conveying plane of the
product, causes the bottom section of the packing box to
be folded right up against the product being packed, as
the product and the packing box continue to be carried
along.
The above-mentioned device for folding up the bottom
section of the packing box is preferably configured as a
device that accelerates the bottom section. In particular
this is the above-mentioned revolving belt, which in
particular is configured as an accelerating belt. The
accelerating device is used for the purpose of
accelerating the bottom section in order to prevent
crooked packing boxes and to ensure that one or more
driving dogs used to convey the packing box onward can be
placed accurately against the packing box. The forwardly
accelerated bottom section should thus spring back against
the driving dog or dogs.
Further features of the invention are described in the
Claims, the Description of the Figures, and in the Figures
themselves, it being noted that all the features and
individual features are essential to the invention.
The invention is represented by means of an exemplifying
embodiment, though without being confined thereto, in the
Figures, wherein:
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Fig. shows a side view of a packaging machine
1
equipped with the folding apparatus according
to the invention, with the individual stations
of the folding machine being represented in a
highly simplified form;
Fig. shows a plan view of the packaging machine
2
represented in Fig. 1, with the folding
apparatus according to the invention
essentially depicted in a schematised form;
Fig. shows an unfolded blank at the incoming end of
3
the packaging machine, at the same time as
illustrating the product to be packed, in this
case a pizza;
Fig. shows the blank seen in Fig. 1 in a partly
4
folded state, as it appears before it enters
the folding apparatus of the invention;
Fig. shows the blank in the folding apparatus
according to the invention, between the rear
and the front conveying sections;
Fig. shows the blank after the conclusion of the
6
folding operation carried out in the region of
the folding station;
Fig. shows the folding station in a side view as
?
seen in excerpt VII in Fig. 1; and
Fig. shows a plan view of the folding station in the
8
arrowed direction VIII in Fig. 7.
The packaging machine shown in Figs. 1 and 2 has a double
incoming chain 1 with driving dogs 2 which engage between
mounting rails disposed parallel to one another, upon
which rest pizzas 3. The respective pizza 3 is shifted in
the conveying direction 4 by means of two driving dogs 2
which form a pair. Provided in the entrance zone of the
double incoming chain 1 is a height guard 5, and
downstream of the latter is an explusion unit 6 which is
activated whenever the double incoming chain 1 is loaded
with too high a pizza 3. Arranged above the entrance zone
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of the double chain 1 is a magazine 7 which is used to
accommodate a large number of blanks 8, with one blank 8
in each case being used to package a pizza 3. Based on
its longitudinal extension, the respective blank 8 is
orientated perpendicularly to the plane of the drawing,
with the pizzas being fed through under the lid section of
the blank 8. Positioned ahead of the magazine 7 in the
conveying direction is a rotary placement device 9
equipped with suckers, which enables whichever blank 8 is
at the front to be removed from the magazine 7 and
deposited over the respective pizza 3. Not shown, but
sufficiently well-known from the prior art, are lateral
supports for the respective blank 8 which extend in the
conveying direction of the pizzas 3 in the region of the
opposing narrow sides of the blank 8. The respective
blank 8 is carried along in the conveying direction by
means of a conveyor 10 consisting of a plurality of
circular belts which are in contact with the upper side of
the blank 8. The conveying speed of the blank 8 and the
associated pizza 3 is selected so as to enable the pizza
3 to be moved at the same speed, that is to say in
synchronism. The blank 8 does not rest on the pizza 3,
but is positioned a short distance therefrom. The double
incoming chain 1 is followed in the conveying direction 4
by the folding apparatus according to the invention, which
apparatus has a rear conveying section 11 and a front
conveying section 12 and an interspace 13 disposed
therebetween. In the region of the folding apparatus
according to the invention the blank 8 is no longer
conveyed by means of the circular belt conveyor 10, but
driving dogs (which will be detailed below) are provided
which hold the already partly folded blank 8. Provided in
the packaging machine so as to follow on from the folding
station according to the invention is a rotation device 14
by means of which the packing box, which by now is only
open in the area of the opposing end faces, and which is
loaded with the pizza 3, is rotated through 90° in order
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in the next zone 15 of the packaging machine to close the
packing box in these areas too. This is followed by a
discharging conveyor 16 which conveys the packaged pizza
out of the packaging machine.
Fig. 3 shows the unfolded blank 8 in the state in which it
is removed by the rotary placement device 9. The blank 8
incorporates a bottom section 17, a lid section 18, and a
first side wall section 19 which is joined to the bottom
section 17 and lid section 18 via fold lines 20. On the
side furthest from the side wall section 19 the lid
section 18 has an additional side wall section 21 which is
configured in corresponding manner to side wall section 19
and is joined to the lid section 16 via a fold line 22.
On the side furthest from the lid section 18 a tab portion
23 is joined to the side wall section 21 via a fold line
24. In the region of the narrow sides the two side wall
sections 19 and 21 are joined via fold lines 25 to dust
flaps 26. In the region of the sides joined to the dust
flaps 26 the bottom section 17 and the lid section 18 are
lastly joined via fold lines 27 to end wall sections 28.
The blank 8, in a form as shown in Fig. 3, is placed by
means of the rotary placement device 9 onto the
longitudinal guides (not shown) of the packaging machine
and conveyed onward by means of the circular belt conveyor
10, the dimensions of the blank 8 in the conveying
direction being such that with the blank 8 correspondingly
positioned the pair of end wall sections 28 associated
with the lid section 18 is positioned above adjacent
transverse dividers 2 of the double incoming chain 1. The
centre of the pizza 3 being transported by the double
incoming chain 1 thus coincides with the diagonal point of
intersection of the lid section 18, with its square
surface. The bottom section 17 has a matching square
surface, just as the side wall sections 19 and 21 and the
end wall sections 28 are identical in their construction.
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In the region of the circular belt conveyor 10, lateral
applicators (which are known from the prior art and
therefore not illustrated) firstly fold tab portion 23
downwards through 90° along the fold line 24, following
which side wall section 21 is folded downwards through 90 °
around the fold line 22 and side wall section 19 around
the fold line 20 of the lid section 18. Except for the
position of the dust flaps 26, this therefore results in
the blank 8 being folded as shown in Fig. 4. Via the
front and rear driving dog 29, 30 shown in Fig. 8, which
will described in more detail below, the blank 8 as seen
in Fig. 4 is conveyed onward, with the front driving dogs
29 respectively locking the side wall sections 19 and 21
between them in the region of the fold lines 25 thereof,
and the rear driving dogs 30 locking these side walls 19
and 21 between them in the region of the fold lines 25
thereof. The pizza 3 is carried along in this zone by
means of the rear and front conveying sections 11 and 12.
The principle of this detail and hence of the folding
apparatus in accordance with the invention is clearly
shown in Fig. 5. It is shown that the rear section 11 of
the conveyor belt consists of three toroidal belts lla,
llb and llc and the front conveyor section 12 of three
toroidal belts 12a, 12b and 12c. Toroidal belt llb
extends further in the conveying direction than toroidal
belt lla, and toroidal belt llc further than toroidal belt
llb. Correspondingly, toroidal belt 12a extends further
away from the conveying direction than toroidal belt 12b,
and the latter in turn extends further than toroidal belt
12c. This arrangement means that the interspace 13 is
configured in the shape of a parallelogram, and the corner
of the parallelogram lying at the front in the conveying
direction encloses an angle a of around 30° with the
conveying direction 4. From the view shown in Fig. 5 it
can be seen that the long toroidal belts llc and 12a do
not overlap and when the perpendicularly projected
circular surface of the pizza 3 is virtually in contact
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with toroidal belt 12a, said surface is arranged
exclusively in the region of the front section of toroidal
belt 11c. A strut 31 is provided beneath the conveying
plane of the toroidal belts lla to llc, 12a to 12c, at an
inclined angle to the conveying direction, for folding the
downwardly directed bottom section 17 up under the pizza
3 from the position shown in Fig. 4. The extension of the
strut 31 transversely to the conveying direction is
greater than the distance between the outer toroidal belts
lla and llc, and 12a and 12c, respectively, which means
that in particular the zone 31a of the strut that is
directed away from the conveying direction stretches
externally out beyond the plane of the downwardly directed
bottom section 17 of the blank 8. If the blank 8 is
transported by means of driving dogs 29 and 30, and the
pizza by means of the rear conveying section 11 of the
conveyor device, the leading end wall section 28 of the
botom section 17 makes contact with the strut 31 and the
bottom section 17 is folded in accordance with the
inclined arrangement of the strut 31 towards the
underneath of the pizza 3 along the fold line 20 situated
between the bottom section 17 and the side wall section
19. During this operation the strut 31 supports the
bottom section 17, with the result that the pizza 3 cannot
fall down even though the bottom section 17 is not yet
resting on the toroidal belt 12a of the front conveying
section 12. The rear deflection point of the toroidal
belt 12a ensures that the bottom section 17, which as Fig.
makes evident is largely folded up and which in the
region of its fold line 20 is positioned very close to the
pizza 3, is able to roll up onto toroidal belt 12a. Along
with the strut 31, the latter causes bottom section 17 to
continue to be folded up, thereby readily enabling the
bottom section 17 to proceed to be fully folded up so that
it rests against the tab portion 23 in the region of its
front end by the action of the strut 31 and of the other
toroidal belts 12b and 12c. However, to complete the
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picture it should be noted that between the toroidal belts
12b and 12c there is provided a further toroidal belt 32,
inter alia accelerating the bottom section 17, as seen in
Figs. 7 and 8, the rear deflection roller 33 of which is
disposed ahead of the front line 34 of the front conveying
section 12, and the conveying plane 35 of the toroidal
belt 32 which extends perpendicularly to the plane of the
sheet converges in the conveying direction with the
conveying plane of the pizza 3. In consequence of this,
the front end wall section 28 which is associated with the
bottom section 17 comes into contact with the toroidal
belt 32 before the middle toroidal belt 12b of the front
conveying section 12 of the conveyor device becomes
operative and toroidal belt 32 accelerates the end wall
section 28 and the bottom section 17 upwards, thereby
enabling the fully upwardly folded bottom section 17, i.e.
folded through 90°, to also be grasped in a trouble-free
manner from below by toroidal belt 12c. Before the bottom
section 17 is placed against the tab portion 23, glue is
applied to the underside thereof, with the result that
once the folding operation has finished, as depicted in
Fig. 6, it now only remains to close the end wall sections
located in the region of the opposing sides of the packing
box.
Fig. 2 shows conveyor chains 32 disposed on either side of
the folding station according to the invention, which are
used to receive the driving dogs 29 and 30. Fig. 2 and
Fig. 8 do not show that the driving dogs 29 and 30 are
held in different conveyor chains 36. Thanks to a special
method of mounting the respective trailing driving dog 30
in the conveyor chain associated therewith, it is possible
to introduce and fix in position the side wall sections 19
and 21 of the respective blank 8 between the driving dogs
29 and 30.
