U.S. patent application number 11/713982 was filed with the patent office on 2007-09-06 for bag filling and packaging method and bag filling and packaging apparatus.
This patent application is currently assigned to Toyo Jidoki Co., Ltd.. Invention is credited to Hiroyuki Okazaki.
Application Number | 20070204570 11/713982 |
Document ID | / |
Family ID | 37897481 |
Filed Date | 2007-09-06 |
United States Patent
Application |
20070204570 |
Kind Code |
A1 |
Okazaki; Hiroyuki |
September 6, 2007 |
Bag filling and packaging method and bag filling and packaging
apparatus
Abstract
A bag filling and packaging system including gripper pairs
around a rotating table so that the grippers of each gripper pair
grip two side edges of a bag on which various packaging processes
are performed. A gripper distance adjustment auxiliary cam is
provided to ascend and descend relative to a gripper distance
setting cam for setting distance between grippers. A roller rolls
on the two cams as the table rotates, and the distance between the
grippers changes in response to the height of the roller by a
transmission mechanism. An apparent bag width is measured prior to
gripping a bag, the height of the gripper distance adjustment
auxiliary cam is controlled according to this measured value, and
the distance between grippers in a bag supply process is adjusted
accordingly, the amount of part gripped by the grippers at side
edges of a bag thus being constant for all bags.
Inventors: |
Okazaki; Hiroyuki;
(Iwakuni-shi, JP) |
Correspondence
Address: |
KODA & ANDROLIA
2029 CENTURY PARK EAST, SUITE 1140
LOS ANGELES
CA
90067
US
|
Assignee: |
Toyo Jidoki Co., Ltd.
|
Family ID: |
37897481 |
Appl. No.: |
11/713982 |
Filed: |
March 5, 2007 |
Current U.S.
Class: |
53/459 ;
53/570 |
Current CPC
Class: |
B65B 59/02 20130101;
B65B 3/06 20130101; B65B 59/003 20190501; B65B 1/06 20130101; B65B
43/465 20130101; B65B 43/50 20130101; B65B 43/60 20130101; B65B
43/30 20130101; B65B 43/22 20130101 |
Class at
Publication: |
53/459 ;
53/570 |
International
Class: |
B65B 43/26 20060101
B65B043/26 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 6, 2006 |
JP |
2006-60123 |
Nov 30, 2006 |
JP |
2006-322936 |
Claims
1. A bag filling and packaging method, wherein: with a plurality of
gripper pairs, each for gripping left and right side edges of a
bag, being provided at equal distance about a carrying member that
rotates along a circular path, bags are supplied to each gripper
pair so that, while said carrying member makes one revolution, a
bag gripped by said gripper pair is subjected sequentially to
packaging processes including bag mouth opening, contents charging,
and bag mouth sealing; said method comprising the steps of:
measuring an apparent bag width of each one of the bags prior to
gripping the bag with said gripper pair; and adjusting, according
to an obtained measured value, a distance between grippers of said
gripper pair when said gripper pair grips two side edges of a bag,
so that an amount of part gripped by said gripper pair at side
edges of a bag is constant for all of bags.
2. A bag filling and packaging method, wherein: with a plurality of
gripper pairs, each for gripping left and right side edges of a
bag, being provided at equal distance about a carrying member that
rotates along a circular path, bags are supplied to each gripper
pair so that, while said carrying member makes one revolution, a
bag gripped by said gripper pair is subjected sequentially to
packaging processes including bag mouth opening, contents charging,
and bag mouth sealing; in said bag filling and packaging method: a
reference value, based on a nominal bag width value, being set for
a distance between grippers of said gripper pair corresponding to
each one of said packaging processes, and a distance between
grippers of said gripper pair, when said gripper pair grips two
side edges of a bag in a bag supplying process, being adjustable to
a size equal to or below said reference value; and said method
comprising the steps of: measuring an apparent bag width of each
one of the bags prior to gripping the bag with said gripper pair;
and adjusting, according to an obtained measured value, a distance
between grippers of said gripper pair when said gripper pair grips
two side edges of a bag, so that an amount of part gripped by said
gripper pair at side edges of a bag is constant for all of
bags.
3. A bag filling and packaging apparatus, wherein: a plurality of
gripper pairs, each for gripping left and right side edges of a
bag, are provided at equal distance about a carrying member that
rotates along a circular path, and bags are supplied to each
gripper pair so that, while said carrying member makes one
revolution, a bag gripped by said gripper pair is subjected
sequentially to packaging processes including bag mouth opening,
contents charging, and bag mouth sealing; in said bag filling and
packaging apparatus: a reference value, based on a nominal bag
width value, being set for a distance between grippers of said
gripper pair corresponding to each one of said packaging processes,
and a distance between grippers of said gripper pair, when said
gripper pair grips two side edges of a bag in a bag supplying
process, being adjustable to a size equal to or below said
reference value; and said bag filling and packaging apparatus
comprising: a bag width measurement means for measuring an apparent
bag width of each one of the bags prior to gripping the bag with
said gripper pair, a gripper distance adjustment means for
adjusting a distance of grippers of said gripper pair when said
gripper pair grips two side edges of a bag; and a control means for
controlling said gripper distance adjustment means according to bag
width measurement values and adjusting a distance between grippers
to a value equal to or below the reference value, so that an amount
of part gripped by said gripper pair at side edges of a bag is
constant for all of bags.
4. The bag filling and packaging apparatus according to claim 3,
wherein: said carrying member is a revolving table; a gripper
distance setting cam for setting the distance between said grippers
to a reference value is provided to surround a circumference of a
table rotating shaft, an upper surface of said gripper distance
setting cam making a cam surface; said gripper distance adjustment
means is comprised of a gripper distance adjustment auxiliary cam
having a cam surface on an upper surface thereof, said gripper
distance adjustment auxiliary cam being provided at predetermined
positions in a circumferential direction of said gripper distance
setting cam so as to be ascendable and descendable relative to said
gripper distance setting cam, and a drive mechanism for causing
said gripper distance adjustment auxiliary cam to ascend and
descend; an urging means is provided in each one of said gripper
pairs for urging grippers thereof so as to narrow a distance
between said grippers; and a transmission mechanism is provided in
said table for each one of said gripper pairs, said transmission
mechanism comprising a roller that rolls along cam surfaces of said
two cams for, against an urging force of said urging means,
transmitting displacement of said roller to said gripper pair, thus
opening said grippers of said gripper pair to a distance that
corresponds to heights of said cam surfaces.
5. A bag filling and packaging method, wherein: with a plurality of
gripper pairs, each for gripping left and right side edges of a
bag, being provided at equal distance about a carrying member that
rotates along a circular path, bags are supplied to each gripper
pair so that, while said carrying member makes one revolution, a
bag gripped by said gripper pair is subjected sequentially to
packaging processes including bag mouth opening, contents charging,
and bag mouth sealing; said method comprising the steps of:
measuring an apparent bag width of each one of the bags and
adjusting said distance between said grippers, according to a
measured value of the apparent bag width, when, in one or more
processes after a bag supplying process, said distance between said
grippers is widened greater than a distance between grippers in
said bag supplying process so that a degree of bag tension in said
one or more processes after said bag supplying process is constant
for all of bags.
6. A bag filling and packaging method, wherein: with a plurality of
gripper pairs, each for gripping left and right side edges of a
bag, being provided at equal distance about a carrying member that
rotates along a circular path, bags are supplied to each gripper
pair so that, while said carrying member makes one revolution, a
bag gripped by said gripper pair is subjected sequentially to
packaging processes including bag mouth opening, contents charging,
and bag mouth sealing; in said bag filling and packaging method: a
reference value, based on a nominal bag width value, being set for
a distance between grippers corresponding to each one of said
packaging processes; and a distance between grippers of said
gripper pair in one or more processes, for which a reference value
greater than a reference value in a bag supplying process is set,
being able to be set to be a size equal to or greater than a
reference value in said one or more processes; and said method
comprising the steps of: measuring an apparent bag width of each
one of the bags and adjusting a distance between grippers of said
gripper pair, according to a measured value of the apparent bag
width in said one or more processes after said bag supplying
process, to a size equal to or greater than a reference value in
said one or more processes, so that a degree of bag tension in said
one or more processes after said bag supplying process is constant
for all of bags.
7. A bag filling and packaging apparatus, wherein: a plurality of
gripper pairs, each for gripping left and right side edges of a
bag, are provided at equal distance about a carrying member that
rotates along a circular path, and bags are supplied to each
gripper pair so that, while said carrying member makes one
revolution, a bag gripped by said gripper pair is subjected
sequentially to packaging processes including bag mouth opening,
contents charging, and bag mouth sealing; in said bag filling and
packaging apparatus: a reference value, based on a nominal bag
width value, being set for a distance between grippers
corresponding to each one of said packaging processes, and a
distance between grippers of said gripper pair in one or more
processes, for which a reference value greater than a reference
value in a bag supplying process is set, being able to be set to be
a size equal to or greater than a reference value in said one or
more processes; and said bag filling and packaging apparatus
comprising: a bag width measurement means for measuring an apparent
bag width of each one of the bags; a gripper distance adjustment
means for adjusting said distance between said grippers in said one
or more processes after said bag supplying process; and a control
means for controlling said gripper distance adjustment means
according to a bag width measurement value and for adjusting said
distance between grippers in said one or more processes after said
bag supplying process to a value that is greater than said
reference value by a difference between said nominal value and said
measured value.
8. The bag filling and packaging apparatus according to claim 7,
wherein: said carrying member is a revolving table; a gripper
distance setting cam for setting the distance between said grippers
to a reference value is provided to surround a circumference of a
table rotating shaft, an upper surface of said gripper distance
setting cam being a cam surface; said gripper distance adjustment
means is comprised of a gripper distance adjustment auxiliary cam
having a cam surface on an upper surface thereof, said gripper
distance adjustment auxiliary cam being provided at predetermined
positions in a circumferential direction of said gripper distance
setting cam so as to be ascendable and descendable relative to said
gripper distance setting cam, and a drive mechanism for causing
said gripper distance adjustment auxiliary cam to ascend and
descend; an urging means is provided in each one of said gripper
pairs for urging grippers thereof so as to narrow a distance
between said grippers; and a transmission mechanism is provided in
said table for each one of said gripper pairs, said transmission
mechanism comprising a roller that rolls along cam surfaces of said
two cams for, against an urging force of said urging means,
transmitting displacement of said roller to said gripper pair, thus
opening said grippers of said gripper pair to a distance that
corresponds to heights of said cam surfaces.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a bag filling and packaging
apparatus including a plurality of gripper pairs, which are
provided at equal distance about a carrying member (table or chain)
that rotates continuously or intermittently along a circular path,
for gripping both (left and right) side edges of a bag, wherein
bags are supplied to the gripper pairs while the carrying member
makes one revolution, and the bags gripped by the gripper pairs are
sequentially subjected to such packaging processes as bag mouth
opening, contents charging, and bag mouth sealing.
[0003] 2. Description of the Related Art
[0004] A typical bag filling and packaging apparatus includes a
table that has a plurality of gripper pairs provided about the
circumference and rotates intermittently; and in this bag filling
and packaging apparatus, various packaging processes are
sequentially performed at various stop positions. Such processes
include supplying of bags to the gripper pairs, printing on the bag
surface(s) gripped by a gripper pair, bag mouth opening, contents
charging, air removal or gas exchange, and bag mouth sealing.
[0005] In this bag filling and packaging apparatus, while the table
is making one revolution, the degree of opening (or the distance)
in the grippers of each one of the gripper pairs varies within some
range. Generally, in the bag supply process, a distance X.sub.0
(see FIG. 11) between two grippers is effected which is slightly
narrower (smaller) than the widest distance; in the printing
process, the widest distance X.sub.0+.alpha. is effected between
two grippers; in the mouth opening process and charging process,
the two grippers making the gripper pair are moved closer to each
other and the distance in between is made narrowed to be
X.sub.0-.beta.; and, thereafter, the widest distance which is
X.sub.0+.alpha. is again effected for the two grippers. In the
above description, .alpha. is generally a small positive number and
is smaller than .beta. (.alpha.<.beta.). The distance between
the two grippers of the gripper pair is widened so that tensions
are applied to the bag mouth to effect a condition of no looseness
or wrinkle in the bag. On the other hand, the gripper pair is (or
the two grippers thereof are) moved closer to each other, narrowing
the distance so as to open the bag mouth. The distance between the
grippers is set slightly narrower in the bag supply process,
because, generally, the bags supplied to the gripper pair in the
bag supply process are slightly loose and not in a condition that
they are tensioned tightly in the width direction.
[0006] In this type of bag filling and packaging apparatus, as
described in Japanese Patent Application Laid-Open (Kokai) No.
H09-95318, a full-circumference cam (gripper distance setting cam)
for adjusting the distance between two grippers of a gripper pair
is provided, with its cam face oriented upward, about the
circumference of the rotary shaft of the table so as to be
ascendable and descendable. The full-circumference cam (gripper
distance setting cam) rotates together with the table when the
table rotates, and it rotates backward to its original position
when the table stops. A spring is provided for each gripper pair so
that the spring urges two grippers of the gripper pair in a
direction that narrows the distance between the grippers. In
addition, a transmission mechanism having a roller at its end is
provided for each gripper pair. The roller is pushed against the
cam surface by the urging force of the spring and rotates on the
cam surface when the cam makes the backward rotation. Accordingly,
the distance between the grippers (distance between the two
grippers of each of the gripper pairs) is set, against the urging
force of the springs, to be a distance that accords with the height
of the cam surface in the sequence of X.sub.0 (slightly narrower
(smaller) than largest distance).fwdarw.X.sub.0+.alpha.(largest
distance).fwdarw.X.sub.0-.beta.(narrower (smaller) than the largest
distance).fwdarw.X.sub.0+.alpha.(largest distance).
[0007] As described in the above-described Japanese Patent
Application Laid-Open (Kokai) No. H09-95318, the height of the
gripper distance setting cam is adjustable, so that, when the bag
size (bag width) varies, the cam height is adjusted accordingly,
and the distance between the grippers is changed to one that
corresponds to the bag width to be worked. The numerical value of
this bag width is generally the width of the bag mouth when the bag
is substantially flat (such is called a "nominal value" of bag
width in the present invention), and the distance between grippers
for each process is set on the basis of this nominal value. In the
present invention, the distance between grippers set on the basis
of the nominal value is called a "reference value."
[0008] The distance between grippers (reference value) set for a
particular bag width (nominal value) is generally not changed so
long as bags having such a bag width are processed.
[0009] If the bags that are worked are ordinary flat bags, then the
bag width of the bags, when they are actually supplied to the
gripper pairs, takes substantially the nominal value. However,
depending on the types of bags, some have bag surfaces that are
warped or distorted (such warping or distortion often occurring in
spout-equipped bags and zipper-equipped bags). In such bags, the
apparent bag width (the bag width measured without correcting the
warping or distortion) is narrower than the actual width, even if
the nominal value of the bag width is the same, and there are
differences in apparent bag widths. When such bags are used in
packaging, problems would arise. Since the amount of parts gripped
by grippers (a width of a bag edge that is gripped) is small, it is
difficult to sufficiently tension the bag mouth when, for instance,
sealing the bag (the bag mouth will not be sufficiently tensioned
even when the distance between the grippers (of a gripper pair) is
widened to the reference value).
[0010] This matter will be described below with reference to FIGS.
11 and 12.
[0011] FIG. 11 shows a gripper pair stopped at a bag supply
position. The reference numeral 1 is a table that rotates
intermittently, and a pair of grippers 2 and 3 are supported by
pins 4 so that they pivot horizontally. The reference numerals 5
are chucks for holding bags, and 6 refers to a spring that urges
the pair of grippers 2 and 3 inwardly (or urges toward each other).
A latching pin 7 secured to the back end of the gripper 2 mates in
a long hole 8 formed in the back end of the gripper 3, so that two
(or the pair of) grippers 2 and 3 pivot simultaneously. This
structure is known conventionally.
[0012] For the pair of grippers 2 and 3, a bag 9 (a bag prior to
being gripped is referred to by 9a) is supplied by a bag feeder
(not shown) to the chucks 5 and 5 that are open as indicated by
dashed lines, and the bag 9 is gripped by the chucks 5 and 5 as
shown by solid lines. The bag mouth of the bag 9a is flat, and its
bag width is W.sub.0 (identical with the nominal value); and thus
the bag is gripped by the chucks 5 and 5, keeping the bag width
W.sub.0 "as is." The distance between the grippers 2 and 3 in this
process is set to be the reference value X.sub.0, and thus the
amount S.sub.0 of the part gripped is basically W.sub.0-X.sub.0)/2.
When the grippers 2 and 3 move to the printing process or sealing
process, and the distance between the grippers 2 and 3 widens to be
the reference value X.sub.0+.alpha., the mouth of the bag 9 is
tensioned or pulled sideways.
[0013] FIG. 12 shows the manner of gripping for the case where
warping or distortion exists in the bag 9 (the bag prior to being
gripped is referred to by 9a) supplied to the pair of grippers 2
and 3 for which the bag width for the bag supply process is set to
be the same reference value X.sub.0. The apparent bag width W of
the bag 9a having warping or distortion is equal to or below the
nominal value W.sub.0, and the bag 9a is gripped by the chucks 5
and 5 keeping the bag width W; accordingly, in this case, the
amount S of the part gripped which are at side edges of the bag is
smaller (S<S.sub.0). Furthermore, when this pair of grippers 2
and 3 next moves to the printing process or sealing process, even
if the distance between the (pair of) grippers 2 and 3 widens to
the reference value X.sub.0+.alpha. in such printing process or
sealing process, depending on the size of the apparent bag width W,
it may be impossible to sufficiently tension the bag mouth of the
bag 9, and the bag mouth would remain loose.
[0014] When the amount of part gripped by grippers is small, the
gripping force is weak, and there is a danger that the bag comes
away from the grippers when contents are charged therein.
Furthermore, when the bag mouth is not sufficiently tensioned, the
bag mouth will not be closed sufficiently, making air removal and
gas replacement defective, and causing sealing defects.
SUMMARY OF THE INVENTION
[0015] Accordingly, the object of the present invention is to solve
the above-described problems with the conventional art conventional
art, and the present invention provides a bag filling and packaging
method and apparatus which is free of the problems of the
conventional art, even in cases that bags having warping or
distortion in the bag surfaces and having bag width of below the
nominal value are involved.
[0016] More specifically, the present invention is for a bag
filling and packaging method and apparatus in which a plurality of
gripper pairs, for gripping the left and right side edges of bags,
are provided at equal distance about a carrying member that rotates
continuously or intermittently along a circular path, and while the
carrying member makes one revolution, bags are supplied to the
gripper pairs, the bags gripped by the gripper pairs are subjected
sequentially to such packaging processes as bag mouth opening,
contents charging, and bag mouth sealing; and the present invention
can be categorized into four: a bag filling and packaging method
(1) and apparatus (2) that maintains the amount of part gripped by
a gripper pair at bag side edges constant, and a bag filling and
packaging method (3) and apparatus (4) that, when the distance of
two grippers (of a gripper pair) is widened and the bag mouth is
thus tensioned, maintains the degree of tension in the bags
constant.
[0017] The above described bag filling and packaging method (1)
that maintains the amount of part gripped by a gripper pair at bag
side edges constant is characterized in that the apparent bag width
of each one of the bags supplied to a gripper pair in the bag
supply process is measured prior to the gripping action on the bag
by a gripper pair; the distance between two grippers (of the
gripper pair) when the gripper pair grips the two side edges of a
bag is adjusted according to the measured value; so that the amount
of part gripped by grippers at the side edges of a bag is constant
for all the bags to be processed.
[0018] In this bag filling and packaging method, for example, based
on a nominal bag width value, a reference value is set for the
distance between the grippers for each one of the processes; and
the distance between the grippers, when the gripper pair grips the
two side edges of a bag in a bag supplying process, is set to be
adjustable to a size equal to or below the reference value.
[0019] The above-described bag filling and packaging apparatus (2)
that executes the method (1) described above is characterized in
that [0020] a reference value, based on the nominal bag width
value, is set for the distance between grippers of each gripper
pair corresponding to each one of the processes, and [0021] it is
made possible to adjust the distance between the grippers, when the
gripper pair grips the two side edges of a bag in a bag supplying
process, to a size equal to or below the reference value; and
[0022] this bag filling and packaging apparatus (2) includes:
[0023] a bag width measurement means for measuring the apparent bag
width of each one of the bags supplied to gripper pair in the bag
supply process prior to gripping the bag by the gripper pair,
[0024] a gripper distance adjustment means for adjusting the
distance between the grippers of the gripper pair when the gripper
pair grips the two side edges of a bag, and [0025] a control means
for controlling the gripper distance adjustment means according to
the bag width measurement values and adjusting the distance between
the grippers to a value equal to or below the reference value so
that the amount of part gripped by gripper pairs at side edges of a
bag becomes a prescribed value.
[0026] In this apparatus, for example, [0027] the carrying member
is a revolving table; [0028] a gripper distance setting cam for
setting the distance between the grippers to a reference value is
provided to surround the circumference of a table rotating shaft,
the upper surface of the gripper distance setting cam making a cam
surface; [0029] as the above-described gripper distance adjustment
means, a gripper distance adjustment auxiliary cam and a drive
mechanism are provided, wherein the gripper distance adjustment
auxiliary cam has on its upper surface a cam surface and is
provided so as to be ascendable and descendable relative to the
gripper distance setting cam at predetermined positions in the
circumferential direction of the gripper distance setting cam, and
the drive mechanism causes the gripper distance adjustment
auxiliary cam to ascend and descend; [0030] an urging means is
provided in each gripper pair for urging the grippers so as to
narrow the distance between the grippers; and [0031] a transmission
mechanism is provided in the above-described table, for each
gripper pair, so that the transmission mechanism, including a
roller that rolls along the cam surfaces of the above-described two
types of cams, transmits the displacement of the roller, against
the urging force, to the gripper pair and opens the grippers to a
distance that corresponds to the heights of the cam surfaces.
[0032] The bag filling and packaging method (3) that, when the
distance of a gripper pair is widened and the bag mouth is thus
tensioned, maintains the degree of tension constant is
characterized in that the apparent bag width of each one of the
bags is measured and the distance between grippers of a gripper
pair is adjusted, according to the measured value, when, in one or
more processes after the bag supplying process, the distance
between the grippers is widened to be greater than the distance of
grippers in the bag supplying process so that the degree of bag
tension at that time is constant for all of the bags.
[0033] In this bag filling and packaging method, the apparent bag
width can be measured any time so long as it is a timing wherein
the apparent bag width for individual bags can be properly
measured. Such a timing is, for example, before a bag supplied to a
gripper pair in the bag supply process is gripped or after it is
gripped, or prior to widening the gripper distance in a process
(the printing process, for example) following the bag supply
process, or, if the gripper distance is maintained without widening
it in the process following the bag supply process, then the time
period of such process. In other words, such a timing is a time
period extending from prior to a bag being supplied to a gripper
pair until the space distance of a gripper pair gripping a bag is
changed from the initial distance (the point in time when the bag
is gripped in the bag supply process).
[0034] In the method described above, for example, a reference
value, based on the nominal bag width value, is set for a distance
between grippers corresponding to each one of the packaging
processes, and a distance between grippers of the gripper pair in
one or more processes, for which a reference value greater than the
reference value in the bag supplying process is set, is able to be
set to be the size equal to or greater than the reference value in
the one or more processes; and the apparent bag width of each one
of the bags is measured, and a distance between grippers of the
gripper pair is adjusted, according to the measured value of the
apparent bag width in the one or more processes after the bag
supplying process, to a size equal to or greater than the reference
value in the one or more processes, so that the degree of bag
tension in the one or more processes after the bag supplying
process is constant for all of bags.
[0035] The above-described bag filling and packaging apparatus (4)
is an apparatus that executes the above-described method (3); and
this bag filling and packaging apparatus (4) is characterized in
that [0036] a reference value, based on a nominal bag width value,
is set for the distance between grippers corresponding to each one
of the processes, and [0037] it is made possible to adjust the
distance between grippers in one or more processes for which a
reference value greater than the reference value in the bag
supplying process is set to be a size equal to or greater than the
reference value in that process or those processes; and [0038] this
bag filling and packaging apparatus (4) includes: [0039] a bag
width measurement means for measuring the apparent bag width of
each one of the bags, [0040] a gripper distance adjustment means
for adjusting the distance between the grippers in the
above-described one or more processes after the bag supplying
process, and [0041] a control means for controlling the gripper
distance adjustment means, according to the bag width measurement
value, and for adjusting the distance between the grippers, in the
above-described one or more processes after the bag supplying
process, to a value that is greater than the above-described
reference value by the difference between the nominal value and the
measured value.
[0042] In this apparatus, for example, [0043] the carrying member
is a revolving table; [0044] a gripper distance setting cam for
setting the distance between the grippers to a reference value is
provided to surround the circumference of a table rotating shaft,
the upper surface of the gripper distance setting cam making a cam
surface; [0045] as the above-described gripper distance adjustment
means, a gripper distance adjustment auxiliary cam and a drive
mechanism are provided, wherein the gripper distance adjustment
auxiliary cam has on its upper surface a cam surface and is
provided so as to be ascendable and descendable relative to the
gripper distance setting cam at predetermined positions in the
circumferential direction of the gripper distance setting cam, and
the drive mechanism causes the gripper distance adjustment
auxiliary cam to ascend and descend; [0046] an urging means is
provided in each gripper pair for urging the grippers so as to
narrow the distance between the grippers; and [0047] a transmission
mechanism is provided in the above-described table, for each
gripper pair, so that the transmission mechanism, including a
roller that rolls along the cam surfaces of the above-described two
types of cams, transmits the displacement of the roller, against
the urging force, to the gripper pair and opens the grippers to a
distance that corresponds to the heights of the cam surfaces.
[0048] As seen from the above, according to the present invention,
even a case that there is warping or distortion in the bag surface,
and even when there are bags that have an apparent bag width which
is smaller than the nominal value, a danger that a bag comes away
from the grippers when the amount of part gripped by grippers is
small and contents are charged is prevented; and further, such
problems as defective printing, defective air removal, defective
gas replacement, and defective seals, that are caused when bag
mouth tension is not sufficiently obtained, is also prevented.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0049] FIG. 1 is a perspective view of a bag filling and packaging
apparatus according to the present invention;
[0050] FIG. 2 shows in cross section the gripper distance setting
cam and a gripper distance adjustment auxiliary cam, as well as a
drive means for the gripper distance adjustment auxiliary cam in
the bag filling and packaging apparatus of the present
invention;
[0051] FIG. 3 is a side elevation thereof;
[0052] FIG. 4 shows in cross section the gripper distance adjusting
mechanism in the bag filling and packaging apparatus of the present
invention;
[0053] FIG. 5 is an expanded diagram of the gripper distance
setting cam and gripper distance adjustment auxiliary cam according
to the first embodiment of the present invention, FIG. 5 showing
also the positions of various processes;
[0054] FIG. 6 is an expanded diagram of the gripper distance
setting cam and gripper distance adjustment auxiliary cam according
to the first embodiment of the present invention, FIG. 6 showing
also the positions of various processes;
[0055] FIG. 7 is a top view showing the distance between grippers
(in a bag supply process) according to the first embodiment of the
present invention;
[0056] FIG. 8 is an expanded diagram of the gripper distance
setting cam and gripper distance adjustment auxiliary cam according
to the second embodiment of the present invention, FIG. 8 showing
also the positions of various processes;
[0057] FIG. 9 is an expanded diagram of the gripper distance
setting cam and gripper distance adjustment auxiliary cam according
to the second embodiment of the present invention, FIG. 9 showing
also the positions of various processes;
[0058] FIG. 10 is a top view showing the distance between grippers
(in a steam blowing process) according to the second embodiment of
the present invention;
[0059] FIG. 11 illustrates, using a top view of a gripper pair,
problems, in a conventional bag filling and packaging apparatus,
when the apparent bag width of a bag differs from a nominal
value;
[0060] FIG. 12 illustrates, using a top view of a gripper pair,
problems, in a conventional bag filling and packaging apparatus,
when the apparent bag width of a bag differs from a nominal
value;
[0061] FIG. 13 is an expanded diagram of a gripper distance setting
cam and gripper distance adjustment auxiliary cam of a conventional
bag filling and packaging apparatus, FIG. 13 showing also the
positions of various processes.
DETAILED DESCRIPTION OF THE INVENTION
[0062] The bag filling and packaging methods and packaging
apparatus according to the present invention will be described
below specifically with reference to FIGS. 1 to 10.
First Embodiment
[0063] First, the packaging method and packaging apparatus that
maintains the amount of part gripped by a gripper pair at bag side
edges constant for all bags will be described.
[0064] Overall Configuration of Rotary Type Bag Filling and
Packaging Apparatus
[0065] In the rotary type bag filling and packaging apparatus shown
in FIG. 1, a plurality of pairs of grippers 2 and 3 (only the
chucks 5 and 5 thereof being shown in FIG. 1) for gripping the left
and right side edges of each one of the bags 9 and suspending such
bags are provided at equal distance along the circumference of a
table 1 that intermittently or continuously rotates (in the
rotating direction being shown by arrow).
[0066] At the various process positions A to J along the
circumference of the table 1, various devices are provided. A
conveyor magazine type bag feeder 11 is provided at position A, a
printer (not shown) is provided at position B, a bag mouth opening
device (only a pair of suction plates 12 thereof being shown) and a
guide device (only guide members 13 thereof being shown) for
holding the bag mouth in an opened state are provided at position
C. A solid material feeder (only a hopper 14 thereof being shown)
is provided at position D, a liquid material feeder (only a
charging nozzle 15 thereof being shown) is provided at position E,
and a steam blower (only a blower nozzle 16 thereof being shown) is
provided at position F. Furthermore, a bag mouth initial sealing
device (only hot plates 17 thereof being shown) is provided at
position G, a bag mouth second sealing device (only hot plates 18
thereof being shown) is provided at position H, and a cool sealing
device (only cooling plates 19 thereof being shown) and a product
discharge chute 21 are provided at position I. Defective bags are
discharged at position J.
[0067] In operation of this bag filling and packaging apparatus, at
position A, a bag 9 is supplied from the conveyor magazine type bag
feeder 11 to a pair of grippers 2 and 3 (chucks 5), which are not
in motion, so that the bag 9 is chuck-held by the grippers 2 and 3
having the bag 9, and, at position B after the grippers 2 and 3
(chucks 5) have moved thereto, printing is done on the bag surface
of the bag 9 by a printer (not shown).
[0068] At position C, after the grippers 2 and 3 (chucks 5) have
moved thereto, the bag 9 is opened by the pair of suction plates
12. Then, the guide members 13 that until then were in an upper
(raised) position (withdrawn position) pivot down and enter the bag
9. The guide members 13 are then moved in mutually opposite
directions or in substantially the radial direction of the table 1,
so that the opened state of the bag mouth opened by the pair of
suction plates 12 is maintained. Following this opening action, the
suction of the pair of suction plates 12 is stopped, and the
suction plates 12 are withdrawn from the bag surface of the bag
9.
[0069] When the table 1, next, rotates, the guide members 13 also
rotate to follow the rotation of the table 1, thus moving to
position D.
[0070] At position D, a hopper 14 descends from above toward the
bag mouth held in the opened state by the guide members 13, the
lower end of the hopper 14 is brought into the bag mouth, solid
material 22 is then introduced into the hopper 14, and the interior
of the bag 9 is charged with the solid material 22. During this
operation, the guide members 13 ascend, being pulled out of the bag
9, and make a rotational movement back to position C for the next
bag.
[0071] At position E, a charging nozzle 15 is inserted into the bag
mouth of the bag 9, steam is blown into the bag interior, and the
air inside the bag 9 is replaced therewith.
[0072] At positions G and H, bag mouth sealing is performed by the
hot plates 17 at position G and by the hot plates 18 at position H.
At position I, the sealed bag mouth is cooled by cooling plates 19.
Next, the finished bag 9A is released from the pair of grippers 2
and 3, dropped onto the product discharge chute 21, and discharged
out from the packaging apparatus.
[0073] At position J, defective bags (no charging or the like being
performed for bags detected to be defective bags) are released from
the pair of grippers 2 and 3 and dropped.
[0074] The configuration and functions of the bag filling and
packaging apparatus described above are the same as those of a
conventional apparatus.
[0075] Distance Setting and Adjusting Mechanism for Grippers
[0076] As shown in FIGS. 2 to 4, a hub 23 is provided to stand on a
machine base (not shown), a follower shaft 24 is provided in the
hub 23 so that the follower shaft 24 rotates on the inner
circumferential side of the hub 23. A rotary shaft 25 for rotating
the table 1 is provided in the follower shaft 24 so that the rotary
shaft 25 rotates relative to the follower shaft 24 on the inner
circumferential side of the follower shaft 24.
[0077] On the outer circumference of the follower shaft 24, a cam
receiver 26 is attached so that it can freely slide, only in the
up-and-down direction, by a rotating-prevention key 27. On the
outer circumferential side of the cam receiver 26, a gripper
distance setting cam 28 is secured; and, at a predetermined
position in the circumferential direction of the gripper distance
setting cam 28, a gripper distance adjustment auxiliary cam 29 is
provided so that it is movable up and down in a vertical direction.
The gripper distance adjustment auxiliary cam 29 is driven so as to
ascend and descend along guide rods 30 erected on the cam receiver
26 by a servo motor 31, which is secured to the cam receiver 26,
and by a threaded shaft 32, which is secured to the rotary shaft of
the servo motor 31 and is screwed into a base 29a of the gripper
distance adjustment auxiliary cam 29. The cam receiver 26 can
ascend and descend by an elevator means (not shown).
[0078] The follower shaft 24 (and the gripper distance setting cam
28 attached to the follower shaft 24 and the gripper distance
adjustment auxiliary cam 29 as well) rotates to follow the rotation
of the table 1, and it rotates backward to its original position
when the table 1 is stopped.
[0079] In the table 1, a transmission mechanism 33 is provided for
each pair of grippers 2 and 3 (see FIG. 4). This transmission
mechanism 33 is comprised of, similar to that of the
above-described Japanese Patent Application Laid-Open (Kokai) No.
H09-95318, an L-shaped lever 34 and rollers 35 and 36. The L-shaped
lever 34 is axially supported at its bent part in the table 1, and
the rollers 35 and 36 are attached to the upper and lower ends
thereof, respectively. The roller 35 is in contact with a tail end
2a of the gripper 2 (see FIG. 11), while the roller 36 rolls along
the cam surfaces of the gripper distance setting cam 28 and gripper
distance adjustment auxiliary cam 29. When the roller 36 is
displaced in the height direction on the cam surfaces of the
gripper distance setting cam 28 and gripper distance adjustment
auxiliary cam 29, this displacement is transmitted through the
L-shaped lever 34 and the roller 35 to the pair of grippers 2 and
3, and the grippers 2 and 3 are opened (or separated from each
other), against the urging (spring) force of the spring 6 (see FIG.
11), to a distance that is in accordance with the height of the
roller 36 (such "height" being the above-described cam surface
height). More specifically, the apparatus is set so that the higher
the cam surface height, the wider (lager) the distance between the
grippers 2 and 3 becomes.
[0080] Function of Conventional Distance Setting Mechanism
[0081] Before describing the function of the above-described
gripper distance setting cam 28 and gripper distance adjustment
auxiliary cam 29 employed in the bag filling and packaging
apparatus of the present invention, a conventional gripper distance
setting cam (the gripper distance adjustment auxiliary cam 29 not
being employed conventionally) will be described with reference to
FIG. 13 (and FIG. 1), using the reference numbers and symbols of
FIG. 1 without alteration.
[0082] The conventional gripper distance setting cam 28A, similar
to the gripper distance setting cam 28 of the present invention, is
secured to a cam receiver 26 that is attached, so as to ascend and
descend, to a follower shaft 24 provided on the circumference of
the rotary shaft 25 of a table 1; and it rotates so as to follow
the rotation of and together with the table 1 and rotates backward
to its original position when the table 1 stops. The height of the
gripper distance setting cam 28A is set on the basis of the width
of the bag processed.
[0083] FIG. 13 shows the gripper distance setting cam 28A extended,
and it also shows the position of the roller 36 at each one of the
above-described processes A to J.
[0084] In FIG. 13, the positions of the gripper distance setting
cam 28A and roller 36 when the rotation of the rotary shaft 25 of
the table 1 has just stopped and the roller 36 has stopped
simultaneously are shown in (a); and in (b), the positions of the
gripper distance setting cam 28A and roller 36 when, continued from
(a), the follower shaft 24 has rotated backward are shown. As seen
from FIG. 13, the gripper distance setting cam 28A has a slightly
lower recess (first or shallow recess) 28Aa and a much lower recess
(second or deep recess) 28Ab.
[0085] At the point in time when the pair of grippers 2 and 3 stop
at the bag supply process position A, the distance between the
grippers 2 and 3 is X.sub.0+.alpha. (see the description in above
"Background of the Invention"). Then, when the gripper distance
setting cam 28A rotates backward, the roller 36 rolls into the
first (shallow) recess 28Aa, and the distance between the pair of
grippers 2 and 3, as a result, becomes X.sub.0; and, at this point
in time, a bag is supplied to the pair of grippers 2 and 3 and held
thereby.
[0086] Next, the table 1 rotates, and when the pair of grippers 2
and 3 stop at the printing process position B, the distance between
the pair of grippers 2 and 3 is still X.sub.0; however, when the
gripper distance setting cam 28A then rotates backward, the roller
36 comes out of the first (shallow) recess 28Aa, and the distance
between the grippers 2 and 3 becomes X.sub.0+.alpha., so that the
bag gripped by the pair of grippers 2 and 3 attains a tensioned
condition and the bag mouth is pulled tight.
[0087] The table 1 further rotates, and when the pair of grippers 2
and 3 stop at the bag mouth opening process position C, the
distance between the grippers 2 and 3 is still X.sub.0+.alpha.;
however, when the gripper distance setting cam 28A rotates
backward, the roller 36 rolls into the second (deep) recess 28Ab.
As a result, the distance between the grippers 2 and 3 narrows to
be X.sub.0-.beta., and the bag gripped by the pair of grippers 2
and 3 attains a condition that the bag mouth is loose.
[0088] To briefly describe the distance between the pair of
grippers 2 and 3 at positions D to J (after the gripper distance
setting cam 28A making the backward rotation), the distance
X.sub.0-.beta. is kept up to position E, and then the distance
becomes to be X.sub.0+.alpha. at position F, and the distance
X.sub.0+.alpha. is kept up to position J.
[0089] When the distance described above for the pair of grippers 2
and 3 in the various process is set appropriately based on the bag
width (nominal value) of the bags processed, this distance is
basically not changed so long as those (same size) bags continue to
be processed. Accordingly, in the present invention, this distance
is called the "reference value."
[0090] Function of Distance Setting and Distance Adjusting
Mechanism in the Present Invention
[0091] The gripper distance setting cam 28 and the gripper distance
adjustment auxiliary cam 29, which is provided at predetermined
positions in the circumferential direction of the gripper distance
setting cam 28 so as to be ascendable and descendable relative to
the gripper distance setting cam 28, employed in the bag filling
and packaging apparatus of the present invention will be described
with reference to FIGS. 5 to 7 and FIGS. 1 to 4.
[0092] In the processes at positions B to J, the distance between
the grippers 2 and 3 is set by the gripper distance setting cam 28
so as to be the reference value based on the nominal value of the
bag width. In the bag supply process at position A, the distance
between the grippers 2 and 3 is adjusted, by the gripper distance
adjustment auxiliary cam 29 and drive means therefor, to an
appropriate value equal to or below the reference value according
to the apparent bag width (measured value) measured bag by bag.
[0093] Furthermore, as shown in FIGS. 1 and 4, in the bag filling
and packaging apparatus of the present invention, a camera 38 is
provided at the bag supply process position A. This camera 38
detects, one bag at a time, the apparent bag width of the bags 9
that are suction-held by the bag-feeding suction device 37 of the
bag feeder 11 and supplied to the pair of grippers 2 and 3. An
image captured by the camera 38 is sent to a controller 39 (see
FIG. 4), and the apparent bag width is measured by way of image
processing. The controller 39 controls the drive of the servo motor
31 pursuant to this measured value, so that the gripper distance
adjustment auxiliary cam 29 is made to ascend or descend, and the
distance between the grippers 2 and 3 is adjusted (widened or
narrowed) to be an appropriate value.
[0094] FIGS. 5 and 6 shows the expanded gripper distance setting
cam 28 and gripper distance adjustment auxiliary cam 29, as well as
showing the positions of the roller 36 in the various process
positions. The gripper distance adjustment auxiliary cam 29 is
positioned at the bag supply process position A (and reciprocates
between the positions A and B).
[0095] In FIGS. 5 and 6, respectively, (a) shows the positions of
the two cams 28 and 29 and the roller 36 when the rotation of the
rotary shaft 25 of the table 1 has just stopped and the roller 36
has also stopped simultaneously; and (b), continued from (a), shows
the positions of the two cams 28 and 29 and the roller 36 when the
follower shaft 24 has rotated backward. In most of the processes,
the roller 36 is positioned on the gripper distance setting cam 28;
however, in the bag supply process (position A), the roller 36 is
positioned on the gripper distance adjustment auxiliary cam 29. As
shown in FIGS. 5 and 6, the gripper distance setting cam 28 has a
lower recess (first or shallow recess) 28a and a much lower recess
(second or deep recess) 28b. The gripper distance adjustment
auxiliary cam 29 is provided in parallel at the position of the
recess 28a. Compared to the recesses 28Aa and 28Ab of the gripper
distance setting cam 28A (see FIG. 13), the first (or shallow)
recess 28a of the gripper distance setting cam 28 is considerably
deeper than the first (or shallow) recess 28Aa of the gripper
distance setting cam 28A, and the second (or deep) recess 28b of
the gripper distance setting cam 28 is formed to have the same
depth as the second (or deep) recess 28Ab of the gripper distance
setting cam 28A.
[0096] Now, the nominal value of the bag width of the bags 9 is
W.sub.0, the amount of part gripped by the pair of grippers 2 and 3
is set to be S.sub.0 (so that it is constant for any and all bags),
and the reference value for the distance between the grippers 2 and
3 in the bag supply process is set to be X.sub.0. Here,
X.sub.0=W.sub.0-2S.sub.0.
[0097] When the bag 9 is flat and the measured value of the bag
width (the apparent bag width) is W.sub.0 as the nominal value
indicates, then the controller 39 controls the servo motor 31 to
adjust the height of the gripper distance adjustment auxiliary cam
29, making adjustment so that the distance between the grippers 2
and 3 becomes the reference value X.sub.0. FIG. 5 shows this
situation, in which the height of the cam surface of the gripper
distance adjustment auxiliary cam 29 is the same height as the
first (shallow) recess 28Aa in FIG. 13.
[0098] As shown in FIG. 7, on the other hand, when there is warping
or distortion in the bag 9, and the measured value of the bag width
(the apparent bag width) is W (where W<W.sub.0), in order to
make the amount of part gripped by the grippers 2 and 3 to be
S.sub.0, the distance between the grippers 2 and 3 must be adjusted
to be X.sub.0-(W.sub.0-W), narrower than the reference value
X.sub.0. Dashed lines in FIG. 7 indicate the positions of the
grippers 2 and 3 when the grippers 2 and 3 are opened (moved away
from each other) to the reference value X.sub.0. The controller 39
controls the servo motor 31, based on the measured value, to adjust
the height of the gripper distance adjustment auxiliary cam 29,
making adjustment so that the distance between the grippers 2 and 3
becomes X.sub.0-(W.sub.0-W). This condition is shown in FIG. 6. As
seen from FIG. 6, the height of the cam surface of the gripper
distance adjustment auxiliary cam 29 is slightly lower than the
height of the cam surface of the gripper distance adjustment
auxiliary cam 29 shown in FIG. 5.
[0099] As a result, even if the apparent bag width W differs from
the nominal value W.sub.0, or even if the apparent bag width W is
different for each bag, the bags can always be gripped with the
same (gripped) amount S.sub.0.
Second Embodiment
[0100] Next, in the bag filling and packaging method and packaging
apparatus according to the present invention, a packaging method
and packaging apparatus in which when the bag mouth of a bag
gripped by a gripper pair is tensioned by widening the gripper
distance for the gripper pair, such tension is kept constant for
(or applicable to) any and all bags will be described.
[0101] Distance Setting and Distance Adjusting Mechanism
[0102] As shown in FIG. 8, in a predetermined position in the
circumferential direction of the gripper distance setting cam 28, a
gripper distance adjustment auxiliary cam 41 is provided so as to
be movable up and down in a configuration similar to the gripper
distance adjustment auxiliary cam 29 in FIGS. 5 and 6. The position
where the gripper distance adjustment auxiliary cam 41 is provided,
however, differs from that of the gripper distance adjustment
auxiliary cam 29. The drive mechanism for moving the gripper
distance adjustment auxiliary cam 41 up and down is the same as
that for the gripper distance adjustment auxiliary cam 29.
Accordingly, if, in FIGS. 2 to 4, the gripper distance adjustment
auxiliary cam 29 is replaced by the gripper distance adjustment
auxiliary cam 41, FIGS. 2 to 4 can be referred to in describing the
second embodiment.
[0103] FIGS. 8 and 9 show the expanded gripper distance setting cam
28 and gripper distance adjustment auxiliary cam 41, wherein the
positions of the roller 36 at the various process positions are
shown as well. The gripper distance adjustment auxiliary cam 41 is
provided at the first sealing process position G (and reciprocates
between the position G and position H).
[0104] Function of Distance Setting and Distance Adjusting
Mechanism in the Present Invention
[0105] In the processes at the positions A to F and positions H to
J, the distance between the grippers 2 and 3 is set to be the
reference value based on the nominal value W.sub.0 for the bag
width; and in the first sealing process at position G, the distance
between the grippers 2 and 3 is adjusted, by the gripper distance
adjustment auxiliary cam 41 and the drive means therefor, to an
appropriate value equal to or greater than the reference value, one
bag at a time, according to the apparent bag width W (measured
value) measured for each bag.
[0106] In FIGS. 8 and 9, respectively, the positions of the two
cams 28 and 41 and the roller 36 when the rotation of the rotary
shaft 25 of the table 1 has just stopped and the roller 36 has
stopped simultaneously are shown in (a), and, in (b), the positions
of the two cams 28 and 41 and the roller 36 when, continued from
(a), the follower shaft 24 has rotated backward are shown. In most
of the processes, the roller 36 is positioned on the gripper
distance setting cam 28; however, in the first sealing process
(position G), the roller 36 is on the gripper distance adjustment
auxiliary cam 41. The shape of the gripper distance setting cam 28
is the same as that of the conventional gripper distance setting
cam 28A.
[0107] Now, the nominal value of the bag width of the bags 9 is set
to be W.sub.0, the reference value for the distance between the
grippers 2 and 3 in the bag supply process is set to be X.sub.0,
the amount of part gripped by the pair of grippers 2 and 3 when the
apparent bag width W of the bag 9 coincides with the nominal value
W.sub.0 is set to be S.sub.0, and the reference value for the
distance between the grippers 2 and 3 in the first sealing process
(position G) is set to be X.sub.0+.alpha.. Here, X.sub.0=W.sub.0-2
S.sub.0.
[0108] When the bag 9 is flat and the measured value of the bag
width W (the apparent bag width) measured by the camera 38 is
W.sub.0 as the nominal value indicates, then the controller 39
controls the servo motor 31 to adjust the height of the gripper
distance adjustment auxiliary cam 41, so that the cam surface of
the gripper distance adjustment auxiliary cam 41 coincides with the
cam surface of the gripper distance setting cam 28, thus making
adjustment that the distance between the grippers 2 and 3 becomes
the reference value X.sub.0+.alpha.. This situation is shown in
FIG. 8.
[0109] When, on the other hand, there is warping or distortion in
the bag 9, and the measured value W (apparent bag width) measured
by the camera 38 is less than the nominal value (W<W.sub.0), if
the distance between the grippers 2 and 3 in the first sealing
process (position G) is still the reference value X.sub.0+.alpha.
as indicated by dashed lines in FIG. 10, then the bag mouth tension
is insufficient. Thus, in order to apply tensions to the bag mouth
of the bag having the apparent bag width W (where W<W.sub.0), in
the first sealing process, as the same degree of tension as for a
bag having a bag width of the nominal value W.sub.0, the distance
between the grippers 2 and 3 must be adjusted so as to be
X.sub.0+.alpha.+(W.sub.0-W), which is wider than the reference
value X.sub.0+.alpha.. As a result, the controller 39 controls the
servo motor 31 based on the above-described measured value and
adjusts the height of the gripper distance adjustment auxiliary cam
41 so that the distance between the grippers 2 and 3 is
X.sub.0+.alpha.+(W.sub.0-W) as indicated by the solid lines in FIG.
10. FIG. 9 shows the gripper distance adjustment auxiliary cam 41
after this height adjustment is completed.
[0110] In this manner, in the first sealing process at position G,
the roller 36 rides on the gripper distance adjustment auxiliary
cam 41 from the gripper distance setting cam 28, and the distance
between the grippers 2 and 3 is adjusted so as to be the
above-described appropriate value.
[0111] In the second embodiment described above, the camera 38
detects the apparent bag width W of the bag 9 before this bag is
suction-held by the bag-feeding suction device 37 of the bag feeder
11 and supplied to and gripped by the pair of grippers 2 and 3.
However, this detection by the camera can be done after the bag is
supplied to and gripped by the pair of grippers 2 and 3. Such
detection can also be done, furthermore, immediately after the pair
of grippers 2 and 3 stop at position B (prior to when the gripper
distance setting cam 28 and the gripper distance adjustment
auxiliary cam 41 make the backward rotations and the distance
between the grippers 2 and 3 widens).
[0112] The detection means is not limited to a camera, and a laser
sensor or the like, for example, can be used instead.
[0113] In the second embodiment described above, moreover, the
gripper distance adjustment auxiliary cam 41 is used for adjusting
the distance between the grippers 2 and 3 in the first sealing
process. However, the gripper distance adjustment auxiliary cam 41
can also be used for other processes where it is preferable to
apply tensions to the bag mouth uniformly and sufficiently, such
other processes, for example, being a steam blowing process, a
second sealing process, and a cool sealing process; and it can also
be used, respectively, to two or more processes, such as a first
sealing process and a second sealing process, for example.
* * * * *