Note: Descriptions are shown in the official language in which they were submitted.
DC-3089 2~7~1
BAG OPENING MEANS FOR BAGGING MACHINE
The present invention relates to an automatic
bagging machine and the method of operation thereof, and
5 more particularly to a machine capable of bagging
material by placing the material in an open mouth of a
first bag of a plurality of bags, and releasing the
first bag.
Bagging machines for holding, transporting,
lO filling and sealing plastic bags are well known in the
art. An example of such a machine is disclosed in U.S.
Patent 4 253 292 to Arnold Lipes, which issued 1981
September 29. Although such machines have b~en used
successfully for packaging materials such as pluralities
15 of carrots, difficulties are experienced when packaging
materials in wide bags, e.g. 60 cm wide. It is a:
feature of this invention to address these difficulties.
Accordingly the present invention provides a :-~
bagging machine for placing a plurality of objects in a :.:
20 first bag of a plurality o:f juxtaposed, wide bags held
in said machine, said bags having a front wall portion
and a~back wall portion, and having an extended tab
secured~to~the back wall portion thereof, said tab
~: extending above a mouth opening of said bag, said
25 machine comprising:
. a) first holding means for holding said
plural:ity of bags in juxtaposition, said bags being held
by sai~d tabs;~
b) second holding means for transversely
30 securing at least a portion of said extended tab of said
:first bag;
:~ : c) bag opening means for opening said mouth of
said first:bag comprising i~ third holding means to hold :
the front portion~of the bag, at~the mouth, such that a
35 smal~ler mouth~is~formed by the third holding means, ii)
mouth~:opening;means adapted to separate the front wall :
portion of the bag, at the smaller mouth, from the back
wall:~portion, and iii) means to displace the third
holding means, such that a full mouth of the bag is
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formed;
d) mouth clamping means associated with the
mouth opening means, for holding the full bag mouth in
an open position; and
e) sensing and correction means adapted to
sense whather the bag has been clamped by the mouth
clamping means and if not, to cause the bag opening and
bag clamping means to attempt bag opening and clamping
again.
In another embodiment the bag opening means has
an air jet adapted to initially open part of the smaller
bag mouth.
In yet another embodiment the air jet means
comprises an air jet located to blow gas into the centre
15 of the mouth of the first bag.
In yet another embodiment the machine is
adapted to open mouths of bags whose total width is from
about 50 cm to 90 cm.
As will be understood, when the smaller mouth
20 is about half the width of the full bag mouth the bag
mouth will form an approximately square opening when the
bag~mouth is fully opened. The most advantageously
sized smaller mouth can be determined by simple
~ experimentation and often is from 40 to 60% of the full
25 bag opening.
In a ~urther embodiment the machine
additionally has case positioning means for placing and
~holding an open-mouthed case such that the opened full
bag mouth is above mouth of the case.
In one embodiment there is a bar level with or
above the case mouth opening, between the case and the
bag, `said~bar being adapted to permit the bag to slide
thereover.
In another embodiment the bag opening means has
35 an air jet adapted to initiall~ open part of the smaller
bag mouth.
In yet another embodiment the air jet means
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comprises an air jet located to blow gas into the centre
of the mouth of the first bag.
In another embodiment the mouth opening means
comprises a vacuum tube adapted to temporarily secure
5 the front wall to the vacuum tube across the extent of
the small mouth.
In yet another embodiment the machine is
adapted to open mouths of bags from 50 cm to 90 cm wide.
The invention also provides a process for
10 filling a bag with a plurality of objects, on a bagging
machine which is adapted to place said objects in a
first bag of a plurality of juxtaposed, wide bags held
in said machine, said bags having a front portion wall
and a back walI portion, and having an extended tab
15 secured to the back portion thereof, said tab extending
above a mouth opening of said bag, said process
comprising:
a) holding at least a portion of said extended
tab of said first bag;
20~ h~ holding the bag at the mouth such that a
smaller mouth opening is formed thereby;
c) opening the smaller mouth of the first bag
by securing the extremities o the smaller mouth and
pulling the mouth opening means away from the extended
25 tah;
d) holding the full mouth in an open position;
and
e) dropping objects into said bag mouth.
In one embodiment the smaller bag mouth is
30 opened~by blowing~a jet of gas into the smaller mouth of ,~
the bag sufficient to allow a small mouth securing and
opening means to enter the mouth.
In another embodiment the small mouth securing I
and~opening means are clamps at the extremities of the
35~smal~1 mouth.
In a further embodiment the small mouth is
delineated by two holding means which are adapted to
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rest against the front wall adjacent the mouth.
In yet a further embodiment a sensor senses
whether the front wall of the first bag has been engaged
by the mouth opening means and causes step c) to be
5 reiterated until the mouth opening means has entered the
mouth of the bag and engaged the mouth.
In yet another embodiment the bags are from
about 50 cm to 90 cm wide.
In another embodiment the bags are made of
10 plastic film.
In a further embodiment the plastic film is a
polyethylene having a thickness of from about 20 to
about 50 micrometres.
In another embodiment the bag is made from
15 netting.
In a further embodiment an open-mouthed case is
positioned such that the opened full bag mouth is above
mouth of the case; ob~ects are dropped into said bag
mouth, causing the front bag wall to be pulled into the ;
20 case; and when the desired number of objects are in the
bag, the bag mouth is released.
In one embodiment there is a bar which is
about level with or above the case mouth opening and ~-
~ between the case and the bag, and which permits the bag
25 to slide thereover, thus permitting the objects to pull
the bag into the case.
In another embodiment the bags are made of
plastic film.
In a further embodiment the plastic film is a
30 polyethylene having a thickness of from 20 to 50
micrometres.
In another embodiment the bag is made from
netting.
In yet another embodiment the bar is a roller.
The invention further provides a process for
filling a bag with a plurality of objects and for the
placing the bag in a case, said bags having a ~ront
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portion wall and a back wall portion, sa.id process
comprising:
a) holding the unopened bag such that the bag
hangs down at the side of the case an such that the
5 mouth of the bag is above a plane which passes through
the mouth of the case;
b) opening the mouth of the bag such that the
mouth of the bag is situated above the case and the
front wall of the bag extends from the mouth, over an
10 upper edge of the case, to the bottom of the bag which
is situated at the side of the case; and
c) dropping said objects into the bag through
the open mouth positioning onto the inner surface of the
front wall, ~ausing the front bag wall to be pulled into
15 the case.
In one embodiment there is a bar which is about
level with or above the case mouth opening and between
the case and the bag, and which permits the bag to slide
thereover, thus permitting the objects to pull the bag
20 into the case.
A further aspect of the invention provides an
apparatus for sealing the mouth of a filled bag, which
apparatus comprises a) means to initially hold the bag
mouth open, b) two bars which are adapted to cooperate
25 and gather the bag therebetween, just below the bag
mouth, and c) means release the hold on the bag mouth
simultaneously with the gathering of the bag, and d)
means to squeeze the gathered portion of the bag
together in a direction perpendicular to the length of
30 the cooperating when the bag has been gathered and to
seal the so ga~hered and squeezed bag.
In one embodiment both bars are pivoted such
that they are adapted to swing together in order to
sweep the bag material ahead of each bar and so gather
35 the bag.
In another embodiment one of the bars is
adapted to swing into position, sweeping the bag
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material ahead of it and the other bar is adapted to
move in a direction perpendicular to the bar in order to
sweep bag material towards the position where the bag
material is to be gathered.
In a further embodiment the means to squeeze
the gathered portion is a thermal heat sealer, which is
also adapted to heat seal the squeezed and gathered
portion.
In another embodiment the means to squeeze the
10 gathered portion is a clipping device, which is also
adapted to clip the squeezed and gathered portion.
Preferred embodiments of the invention will now
be described with reference to the accompanying drawings
in which:
Figure 1 is a schematic view illustrating
operation of the bagging machine during opening of a
bag;
Figure 2 is a further schematic view
illustrating a step in the operation of the bagging
20 machine where pouches are dropped into the bag.
Figure 3 i5 a perspective view, partly
fragmented, illustrating a position for blocking a bag
prior to opening the bag mouth.
Figure 4 is a front view of the bag as the
25 smaller mouth is being opened.
Figures 5a and 5h are plan views showing steps
in opening the bag mouth.
Figure 6 is a plan view of a bagging machine
showing the stages of travel of a case and of closing
30 the mouth of a bag.
Referring to the drawings, particularly Figures
1 to 4, there are shown the essential parts of the i7
automatic bagging machine for holding and opening a
~first bag ll of a plurality of bags 11' held in the
35 machine by wicket pins 12. Each of the bags 11 has an
extended tab 13 provided with two spaced apart apertures
14. Apertures 14 allow bags to be slidingly retained on
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the wicket pins 12. Each bag is also provided with a
mouth 15, defined between rear bag wall 16 and front bag
wall 17 (see Figures 2 and 4). Although not shown in
the drawings the bags may have bottom gussets therein at
5 the portions where the front and back walls adjoin.
The machine includes holding means 20 for
engaging at least a portion of the extended tab 13 of
the first bag 11. A displaceable clamp 32 is secured to
the free end of a piston rod 33 of piston 34. The
10 clamping surface of the displaceable clamp 32 is
positioned in alignment with the clamping surface of the
stationary clamp 30 whereby all of the extended tabs 13
are held compressed between the clamping surfaces when
the piston rod 33 is displaced outwardly from the piston
15 cylinder 34.
The bag opening means 21 comprises two
pressure pads 62 and corresponding bag clamps 63, an air
jet 36 and retractor members 38. Pressure pads 62 are
spaced apart and:bear upon the mouth 15 of bag 11, at a
20 position just wider than stationary clamp 30, thus
lightly holding the mouth portion of front bag wall 17.
For a bag~having a 61 cm layflat width and a fllm
thickness of about:25 ~m, typically the distance between
pressure pads 62 would be from about 25 cm to 40 cm.
25 The portion of~the front bag wall between pressure pads
62 forms a smaller bag mouth 15'. Air jet 36 is
positioned above and adjacent the smaller mouth opening
15'`of the bag in order to direct a jet of air into the
smaller mouth;openlng after the bag mouth is engaged by :
30 pressure pads 62. Blowing air through jet 36 causes the
smaller mouth 15' of the bag to open and to permit the
insertion of~bag clamps 63 to be swung inside smaller
mouth 15' and to clamp the film of the mouth between
pressure pads 62 and bag clamps 63.
Pressure pads 62 and bag clamps 63 are on the
same~frame (not shown) so that movement of retractor
~members 38~csuses pressure pads 62 and the corresponding
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bag clamps 63 to mov~ together in the direction of
travel of retractor membe~s 38. This arrangement is
shown in Figure 5a.
As retractor members 38 are moved away from
5 stationary clamp 30, the front wall 17 is pulled away
from the back wall 16. Extended tab 13, which continues
to be held by stationary clamp 30 and displaceable clamp
32, is ripped away from wicket pins 12. As shown in
Figure 5b, pressure pads 62 and corresponding bag clamps
10 63 are moved to their furthest travel position so that
the mouth of the bag consists of the full mouth 15,
which is opened fully above case 61.
As will be seen in Figure 1, as retractor
members 38 are moved away from stationary clamp 30,
15 front wall 17 is pulled over roller 60. It is not
essential that roller 60 be present because the front
wall 17 would be pulled over the upper lip of case 61.
However, in practice the cases are reused and tend to
become damaged, particularly at the lip, causing there
20 to be snags on the lip. Such snags may damage the front
wall 17 as it was pulled over the lip, so roller 60, a
bar or similar is preferred. As indicated hereinabove,
extended tab 13 is pulled off wicket pins 12. To
~facilitate disconnection, a razor edge may be provided
25 along the top of the pins 12. Disconnection can also be
aided by the weight of the product 50 being dropped into
~he bag. In the case of packaging pouches, it is usual
to drop pouches 50 into bag 11 one at a time until a
defined number of pouches are in the bag.
~ Instead of pressure pads 62 and air jet 36, a
tube which extends the width of smaller mouth 15' may be j-
used. ~The tube has holes in it adjacent the film of the
bag which permit vacuum to secure film thereto. Thus,
the vacuum tube is used to pull smaller mouth 15' away
35 from the back wall 16 of bag 11. The vacuum tube still
has finger~ 63 attached thereto for gripping the film
more positively. For a bag having a 61 cm layflat width
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and a film thickness of about 25 ~m, typically the
length of the tube would be from about 25 cm to 40 cm.
Having given the sequence for opening the bag
mouth, a description of the whole process of placing the
5 bag in a case will now be given. Prior to opening the
bag, a case or box 61 is placed in position adjacent to
bag 11 in readiness for bag mouth 15 to be opened
thereabove. As shown in Figure 6 cases are brought to
the bagging machine along a conveyor 72, in a direction
10 shown by arrow A, and onto platform 73. Once in
position on platform 73, case 61 is pushed, in a
direction shown by arrow B, onto platform 74 by ram 75.
The bag opening sequence described hereinabove
takes place. If there is no~film grasped between
15 pressure pads 62 and bag clamps 63, however, control
circuitry is activated which causes air to continue to
issue from air jet 36 and the bag clamps 63 to open and
reattempt grasping the film again. In this way it is
not possible to drop product, e.g. pouches, into bag 11
20 until~;the mouth of bag 11 is firmly held and open.
Control of the working parts of the apparatus may be
provided pneumatically, e.g. air with suitable valves,
and with a microprocessor.
It has been found that for productivity
25 reasons, it is desirable to continue to keep control of
the mouth of the bag, rather than allow it to be free,
while the filled bag seats itself in case 11 and while
the mouth of the bag is gathered and sealed. Thus,
after the bag 11 has been filled with objects, e.g.
30 pouches 50, the mouth is gathered by arms 64 and 65
which are pivoted on plVOtS 66 and 67 respectively, as
shown in Figure;6. Arms 64 and 65 start in positions
64' and~65' respectively. The arms are then caused to
swing towards one another about pivots 66 and 67. As
35 arms 64 and 65 close together, the mouth 15 of bag 11 is
gathered therebetween, as shown at 68. As arms 64 an
~65 close on the mouth of bag 11, bag 11 is released from
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being held by clamp devices 30 an~ 32 ~y momentarily
withdrawing piston 33, and by opening bag clamps 63, and
allowing the weight of the filled bag to drop the bag to
rest in case 61.
Case 61 and arms 64 and 65 are on a carriage
~not shown). This carriage is pushed in the direction
of arrow C by ram 76 until the carriage is over platform
77. The gathered mouth 68 is then squeezed along the
length of and between arms 64 and 65 by two sealing
10 heads 59 and 70, for example the sealer described in
Canadian Patent No.l 260 884 which issued 1989 September
26 to A. Lipes and G. Soga. After the mouth 15 has thus
been sealed or otherwise secured, e.g with a clip, case
~1 is pushed in direction D by ram 79 onto conveyor 78.
15 While case travels along conveyor 78 in direction E, the
carriage, which is over platform 77 is returned to
position over platform 74 in readiness for filling
another bag and case.
The apparatus described herein is particularly
20 useful for bags made of plastic films such as
polyethylene. Other adaptations, within the skill of
one skilled in the art, may be made for bags of paper,
nettlng or the like. Obviously, when the bag is made of
netting the mouth would not be openable with a vacuum
25 system and this is clear to those skilled in the art.
~ The present invention may be use to bag a
number of products, e.g. carrots, milk pouches. For
;example the~apparatus may be used to package fifty
280 ml~pouches containing milk.
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