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Патент USA US3058284

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Oct. 16, 1962
o. v. CHRISTENSSON
3,058,274
ARRANGEMENT FOR HEAT-SEALING OF PACKAGES
Filed NOV. 9, 1959
3 Sheets-Sheet 1
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INVENTOR
/ 00 wk”; “FEW
cum ""(c/
ATTORNEKS
Oct. 16, 1962
o. v. CHRISTENSSON
3,058,2 74
ARRANGEMENT FOR HEAT-SEALING OF PACKAGES
Filed NOV. 9, 1959
3 Sheets-Sheet 3
IN V EN 1 OR
00 VIM/P
O/F/S 7EK$~9GM
BY
ATTORNEYS
United States Patent 0 " "ice
2
1.
3,058,274
ARRANGEMENT FGR HEAT-SEALWG
'
$358,274
Patented Oct. 16, 1962
0F PACKAGES
0d Vikar Qhristensson, Vikavagen 5, Bromma, Sweden
Filed Nov. 9, 1959, Ser. No. 13,412
Claims priority, application Sweden Mar. 16, 1959
1 Claim. (Cl. 53-112)
means, by which the remaining part is heat-sealed can be
operated by means of one single entering shaft or the like.
The invention will be described below in connection
with the attached drawings, which show a form of execu
tion of the invention. In the drawings FIG. 1 shows a
perspective view of a package which is to be packed
and closed according to this invention, FIG. 2 shows a
schematic view of the packaging machine, in which the
evacuation and closing takes place. FIGS. 3 and 4 show
This invention relates to the packaging of products,
particularly food stuffs easily damaged by the outer at 10 a pair of sectional views according to the lines III—III
and lV-IV, respectively, in FIGS. 5 and 6 of an evacua
mosphere, wherein use is made of packages consisting of
tion pocket, whereas FIGS. 5 and 6‘ show sections along
an outer covering of cardboard or similar material and
the lines V-V and VI-VI, respectively in FIGS. 3 and 4.
an inner lining. The lining is of suitable airtight mate
FIG. 7 ?nally, shows a view of the tool used for the
rial, such as plastic. After ?lling the package with the
heat-sealing.
material to be packed, the mouth of the lining may be
The package, in the chosen form of execution, consists
heat sealed except for a rather small portion thereof,
in an outer package of cardboard, which is rectangular in
where after the package'is introduced into an evacuation
machine. The machine is then supplied with a vacuum
cross-section and has a broad side 10 and a small side 11.
of rather high degree, thereby evacuating the interior of
the package. The package is thereafter heat sealed along
At each broad side there is connected a closing ?ap ‘l2
and 113, respectively, and at each small side there is con
the remaining small part of the mouth. In this manner
the package material is now contained in an atmosphere
of greatly reduced air pressure, e.g., a few millimeters of
mercury, and the package life is greatly increased.
In the execution of this principle of vacuum packing,
nected a closing ?ap 14 and 15, respectively. The lining
has been previously closed at the bottom of the package
according to FIG. 1, and the closing flaps have also been
previously folded inwards and pasted together. At the
top, however, the closing flaps are folded outwards after
the ?nal heat sealing is provided while the package is still
the packed material has been fed to the package, in a
manner that will assist in the continuous handling of the
package in the evacuation machine. In advance of the
evacuation machine, the edge 16 formed at the closing of
in an outer evacuated atmosphere within the evacuation
machine.
To stand the change of shape occurring during the
evacuation the lining must be of a very easily formable
material, having little or no stiffness of its own. The
change of form during the evacuation causes a tendency
of the lining or the bag to assume many different shapes;
and the month, which is to be heat-sealed can at the
the lining has been heat-sealed (welded) along the major
part of its length, but a small unwelded part 17 has been
left at the outmost part at the one edge. The evacuation
of the package then takes place through the unwelded
opening.
When the packages are introduced into the evacuation
and closing machine schematically shown in FIG. 2 the
package is to be vacuum tight, then the heat-sealing must
packages are in the state shown in FIG. 1. This ma
take place with the best possible care, and the heated tools,
chine consists in a carousel 20, which is in continuous
which are to be pressed against the two sides of the mouth
movement in the direction of the arrow 21. In the
for causing the heat-sealing, must contact the mouth along
the whole length of the open part so that continuity is 40 carousel a number of chambers or pockets are provided
separately so that each of them may be evacuated sepa
created between the earlier performed part of the heat
rately. This is done by means of a common evacuation
sealing and the remaining part of the heat-sealing of the
conduit, a valve being provided in the connection conduit
mouth. Further, the mouth must be in a smooth state,
between the vacuum conduit and each pocket for con
because any plait or crease in the mouth may cause leak
trolling the increase of vacuum in the pocket. The
age.
carousel is shown to contain eighteen such pockets 12.
The di?iculties in meeting with these demands are ex
The pockets are provided each with one shutter, cover
pecially important when considering that, at the time of
ing all of the peripheral side of the pocket, the shutter
heat-sealing, the package is in the interior of a closed
time of the heat-sealing be easily displaced. If the
and evacuated chamber. Thus one cannot usually see the
being turned upwardly for opening access to the pocket
package or readily introduce any tools.
Therefore the
by means of a horizontal shaft applied at the upper edge
steps for correcting the position of the mouth of the
package must take place automatically and accurately.
The automatic handling for these steps concerned must
The packages to be evacuated and closed are fed to the
carousel 20 by means of an auxiliary carousel 23, re
further be accomplished by the use of shafts or other con
trolled means entering into the evacuated chamber from
the outside. In order to avoid leakage it is therefore
very important that the number of such controlled means
movement of the carousel 20 in the direction of the ar
be limited.
,
of the pocket.
ceiving the packages from a path 24 and transferring
them into an empty pocket 22. During the continuous
row 21, the shutter is closed about in position 25. About
when the pocket passes the position 26, it is connected to
a low vacuum conduit. The low evacuation is assumed
The invention is based upon the principle that the mouth
of the lining or the bag, in advance, before the package 60 to be completed in the position 27, where the pocket 22
is then connected to a high vacuum conduit and the
is introduced into the evacuation machine, is closed along
vacuum is further increased. The heat-sealing of the
the major part of its length, so that only a rather small
mouth of the lining then takes place in the position 28.
part of the mouth remains open for the evacuation. This
In the position 29 air is introduced into the pocket for two
makes possible the use of special means embracing the
65 different purposes. Firstly the vacuum is released, so
already sealed part of the mouth at the introduction of
that the shutter may be opened for removal of the pack
the package into the evacuation machine and before the
age, and secondly the heat-sealing joint is cooled for ob
commencement of evacuation. Therefore the whole
taining the required rigidity. In the position 30 the
mouth is retained in an exact position relative to the heat
shutter is again opened, and in the position 31 the pack
sealing means. The invention further contemplates a de~ 70 age is removed. For the removal of the package a sec
vice wherein the means which are thus used for em
ond auxiliary carousel is used, transferring the package
bracing the ah'eady sealed part of the mouth, and the
to a conveyor path 33.
3,058,274
4
FIGS. 3 and 4 show a pocket with a package 34 in
troduced therein, as seen in the direction inwardly through
the open shutter. This package has, in a manner de
relation in the pocket 22, and consisting of a border,
for instance of rubber or similar material 41, which is
kept in its place by means of a metal clamp 42. The
clamp 42 is attached to the wall of the pocket 22 by
scribed already, been closed at the bottom, ?lled, and
folded together at the mouth of the lining. The mouth
has been welded together along the major part of the
length, leaving the small part 17 unwelded.
In the pocket the package is retained in correct posi
tion by partly resting on a support 35, which is carried
means of a pair of screws 43. The clamp and the rubber
border, of course, must be attached to each other and
formed in such a Way, that they form an even surface
against the lining edge 16 of the package. FIG. 6 shows
these parts in section.
up in its turn by a guide 36, as seen in FIGS. 5 and 6.
At the left end of the place of the lining edge in the
pocket 22, the inner welding block 44 is provided. In
order to insure good welding this is resiliently geared
The package is also partly embraced by a pair of em
bracer arms 37, 38. The two closing ?aps 13 and 14
at the short sides are folded outwardly, so that they
do not prevent the continuous handling of the package.
about a vertical, spring loaded shaft 45 attached to a
holder 46, which in its turn, by means of screws 47,
The closing ?aps 12, 13 along the long sides of the pack 15 is attached to the wall of the pocket 22. Feed of
age are folded down closely to their respective long sides,
current to the electrically heated welding block takes
as shown in FIGS. 5 and 6. The guide 36- and the func
place by means of a pair of terminals 48. The character
tion of the embracer arms 37, 38 do not form a part
of this welding block will be described in connection with
FIG. 7.
of the present invention, and therefore only a short de
seription thereof is given here.
In the upper part of the pocket 22, a four-edge-shaft
When the package passes from the position 30 into the
50 is provided for controlling the movable tightening
position 31 in FIG. 2, the guide 36, under the in?uence of
means and the movable welding block, respectively. This
means not shown in the drawing, moves outwardly, out
four-edge-shaft is in rounded form carried through the
of the open pocket 22, so that the support 35 together
wall of the pocket 22 as will be seen from FIG. 3,
with the package 34 are displaced out of the pocket. 25 and outside of the pocket it is connected to a hub 51,
During the later part of this movement, simultaneously
with the package arriving at the position 31, FIG. 2,
which carries an arm 52, FIG. 6.
This arm, which is
only in part visible in the drawing, carries at its end,
the embracer arms are opened for freeing the package.
turned onto the interior of the carousel 20, a follower
The package simultaneously embraced by a pair of corre
pulley in cooperation with a curve or cam disc, not shown
sponding embracer arms on the carousel 32, which there 30 in the drawing, by which the turning movement of the
after moves the completed package along the path 33.
shaft in a given time will take place.
During the movement of the carousel 20 from the posi
The curve or cam disc is formed in such a way, that
tion 31 to the position opposite to the carousel 23, the
its turning will take place in two different times. Im
pocket 22 is aired for receipt of a new package when
mediately after the package has been introduced into the
it passes the carousel 23. This new package has been
pocket 22, the shaft 50 is ?rst turned an amount such
brought forward to the exchange position by ?rst pass
that a rubber border 55 will attack the edge 16- of the
ing along the path 24 and thereafter being turned around
lining from the outside, the edge 16 of the lining being
by the carousel 23, in which it has been caught by a
clamped between the two rubber borders 41 and 55.
pair of embracer arms. The package is then caught by
At a later time, after the evacuation is ful?lled, and the
the embracer arms 37, 38, simultaneously as the embracer 40 remaining part 17 of the edge 16 of the lining shall be
arms in the carousel 23 release the package, and im
heat-sealed, the shaft 50 is turned somewhat further,
mediately the support 35 is again displaced inwardly to
whereby a movable welding block 56 attacks the con
gether with the guide 36. Thereafter the shutter 39 is
cerned part of the edge of the lining, and heat-sealing is
provided.
closed for covering the opening of the pocket 22.
At this time the package assumes a position, in which
The rubber border 55 is attached to the one arm 57
the mouth is somewhat erected after the initial closing,
of double armed lever 57—58, geared on a pin 59 in an
arm 60, mounted on the shaft 50. At the outer end
as shown by 40, and the welded part is mainly upright.
When the package is later subjected to evacuation by
of the arm 60, a spring ?xture 61 is provided, attached
by means of a screw spring 62 to a pin 63 on the arm
all of the pocket being evacuated, and gas or air leaves
58. Through a hole in the arm 60 a setting screw 64
the package, and change of form takes place. Since the
runs, which is limiting by means of its head the mutual
evacuation takes place primarily from the pocket, the air
movement between the arms 57 and 60'.
from the package escapes into the pocket through the
It will be evident from the above description, that when
opening 17, FIG. 1. In order that the packed material
the edge 16 of the lining is not clamped, for instance dur
does not escape together with the air, the opening 17
ing the introduction of the package 34 into the pocket 22,
is rather small, and the consequence is that during the
proper progress of the evacuation an overpressure, rela
the arm construction 5“7—-58—-6t) is turned in such a way
tive to the pressure in the pocket 22, will exist in the
that the arms 57 and 69 stand right out in horizontal di
rection, whereas the arm 58 is directed upwardly, and
consequently the now described arrangement will not act
interior of the package.
This over-pressure can cause a
change of shape in the package, particularly in the soft
lining, thereby displacing the partly Welded mouth 17
60
from its proper welding position. Added to this is the
fact that, when air is again let into the pocket 22, the
pressure in the pocket will suddenly increase, thereby a
practically explosive shrinking together of the lining to!
gether with its contents into a minimum volume. The a C11
packed material is now compressed so strongly, that it has
a rather woodli'ke consistency.
With regard to these movements of the lining in the
preventing for the introduction of the package 34 into
the pocket 22. After the package has been introduced
into the pocket 22, however, so that the edge 16—17
of the lining is contacting the rubber border 41 and the
welding block 42, a turning of the shaft 50 shall im
mediately take place, whereby the edge 16 of the lining
is clamped. This turning, however, does not comprise
full 90° but is stopped due to the form of the cam disc
causing a turning movement of about 75°. Thereby the
spring 62 has moved the pin 63 and the spring ?xture
package it is utterly important, that the mouth of the
lining is kept in an exact position relative to the weld 70 61 together, so that the arm 57 has been removed from
ing blocks heat-sealing of the remaining mouth part 17.
The character of the means provided for this purpose
forms the object of the present invention.
the arms 60 as far as allowed by the setting screw 64.
The consequence is that in this position, the
border 41 will attack the ridge 16 of the border,
The part of the mouth 16 shown at the right in FIGS.
movable welding block 44 still is placed at a
1, 3 and 4 is supported by a support, applied in ?xed 75 distance from the ridge of the border. Due to
rubber
but the
certain
this no
3,058,274
5
pressure will be applied against the part of the ridge of
dicular to each other by means of the pins 79 and 81,
the border at 17, not yet closed. Thus there is a pos
sibility for air to escape, so that when vacuum is created
in the pocket 22, air will escape, and the package can
be evacuated.
the welding block will obtain a setting of its own, so
that a good surface contact and heating with the mouth
After evacuation heat-sealing takes place by plastic
welding at the place 17 of the ridge of the border. The
cam disc, controlling the turning movement of the shaft
of the lining will result, when electrical current is fed
to the resistance band.
What I claim is:
In a means for heat sealing an edge of a substantially
closed liner comprising a pocket, means for opening said
pocket and inserting the liner to be evacuated and heat
time, this shaft will describe the remaining part of its 10 sealed, means for closing said pocket, means for evacuat
turning movement from the above indicated angular
ing said pocket when closed, and means for holding and
50, thereby is formed in such a way that, at a suitable
position of approximately 75° to fully 90°. Thereby the
welding block 56 is brought into contact with the mouth
heat sealing said liner in the pocket while said pocket
is closed and evacuated, the improvement wherein said
holding and heat sealing means comprises opposed sup
of the lining, but the rubber border 55 will not change
its position in relation to the mouth of the lining, be 15 port jaws pivotably movable between open and clamping
positions disposed in said pocket at a position to receive
cause the movement is received by the spring 62. Simul
between said jaws in their open position a previously
taneously electric current is fed to the two welding blocks
sealed length of one edge of the liner, opposed welding
44 and 56, so that the mouth of the lining is closed along
blocks pivotably movable between open and clamping
all of its length.
For securing good contact between the welding blocks 20 positions and disposed in said pocket in line with said
support jaws at a position to receive between said weld
44 and 56 and the intermediate part of the ridge 16 of
the lining, the outer welding block is mounted resiliently
ing blocks an open portion of said one edge of the liner,
a common shaft on which at least one of said support
about a spring loaded pin 66. This pin 66 is geared in
jaws and at least one of said welding ‘blocks are mounted
69, attached to the shaft 50.
25 in axial alignment, said shaft being rotatable through a
predetermined number of degrees, and operating means
The shaft 50 is geared in ball bearings 70, 71. The
a holder 67 on an arm 68, which is, by means of a screw
bearing 70 is tightened against air entering from outside
for sequentially closing said support jaws and said weld
by means of a plate 72. A cuff-tightening 73 is provided
ing blocks while said pocket is closed operable to ?rst
close said support jaws before the pocket is evacuated
inside of the ball bearing 71, for providing a correspond
ing tightening at the outside shaft end to the hub 51 30 by rotation of the shaft through a portion of the pre
determined number of degrees and then to close said
and the arm 52.
welding blocks at the edge after the pocket is evacuated
The welding blocks 44 and 56 are made in a manner
by rotation of said shaft through the remainder of said
shown in FIG. 7. The active part of the welding block
number of degrees, and heating means for heating at least
consists of a resistance band 76, running partly on the
attacking side of the welding block and partly around 35 one of said opposed welding blocks.
its edge sides. The resistance band, at its one end, is
References Cited in the ?le of this patent
attached to a terminal 77, which is carried by the piece
78 made of insulating material, and at its other end is
UNITED STATES PATENTS
carried by a part 80, which is attached to the piece 78
Bower ______________ __ Mar. 16, 1954
and hinged by means of the pin 79. Part 80 is in turn 40 2,672,268
2,676,440
Campbell ___________ __ Apr. 27, 1954
hinged on the pin 81. The part 80 in its interior, is pro
2,692,074
Mueller et al. _________ __ Oct. 19, 1954
vided with a conductor not visible in the drawing, con
2,778,177
Maha?ey et al _________ __ Jan. 22, 1957
necting the end of the resistance tape 76 with the terminal
2,889,673
Rockland et a1. _______ __ June 9, 1959
82.
Due to the resistance band 76 resting along the major 45 2,933,868
2,966,019
part of its length against the insulation piece 78, and
this is carried in a hiugeable way into directions perpen
Grae?ngholt _________ __ Apr. 26, 1960
Grae?ngholt __________ __ Dec. 27, 1960
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