Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF TI-IE INVENTION
l~ield of the Invention
The present invention is directed to plastic bags for
receiving bulk products and more specifically to a closable filling valve
disposed in one corner of the bag which is otherwise completely closed
prior to filling.
Pr io r A r t
In the past, most plastic bags used for the packaging of
bulk products were completely open at one end during the filling of the
bag and the top edges of the bag would subsequently be secured together
by heat sealing means or the like. Other bags would be partially closed
along their top edges leaving only a srrmall opening through which a filler
tube would extend and upon the withdrawal of the filler tube the upper
edges of the bag would be completely sealed together. In both of these
prior art arrangements a certain amount of air would be trapped within
the bag after the edges were sealed so that when a plurality of bags were
stacked l~allooning of the plastic bags would occur. Such baliooning was
considered to be undesirable since under extreme circumstances the
force of the air pressure could possibly rupture the pla9tic bag, especiauy
at the closure thereof. If the bulk lnaterial had a substantial grain size
such as pine bark chips or the like the bag coulcl be provided with perfora-
tions which would be either spaced over the entire surface of the bag or
along the closure line to allow air to escape from the interior of the bag.
I-Iowever, finely divided bulk products such as powdered
fertilizer or the like could not be placed in a bag having any perforations
since a substantial amount of the bulk product would be lost through the
perforations durlng handling. Therefore, such finely divided bulk products
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¦ always hacl to be packaged heretofor in a completely sealed bag which
resulted in the aIorementioned cletrimental ballooning of the bags during
~; handling and stacking. Various schemes have been devised for trying to
evacuvate n~ost of the air from the bag prior to sealing the filled bag but
none of these have proven to be very successful.
SUMMARY OF Tl-IE INVENTION
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The present invelltion provides a bag which is extremely
suital~le for the packaging of practically every conceivable type of bulk
proclucts, especially finely divided, powder-like material. The bag i9
provided with a closable filling spout which will permit the escape of
excess air without any substantial loss of the powder product.
1~ The present invention provides a bag having a corner valve
', into which a conventional horizontally disposed bag filling spout may be
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inserted and which is provided with a closure flap which may be manually
folded over the top of the bag to close the valve subsequent to the filling
of the bag and the withdrawal of the spout.
The present invention provides a corner valve for a plastic
bag which is comprised of a rectangular sheet of plastic material having
a reverse fold along one edge thereof and which is secured in superposed
relation to an inwardly folded triangular bag corner vith the side edge~
of the insf rt perpendicular to the reverse fold being flush with the top
edges of the bag. When the top edges of the bag and the side edges of the
insert are sealed together the insert will define a filling sleeve adapted to
fit over the encl of a conventional horizontally disposed filling spout,
After the bag is filled and the spout ren~oved the top portion of the bag
will be flattened out in a substantially horizontal disposition and the revers
fold on the insert may be pulled out and folded back over the top of the bag
to effectively close the sleeve to prevent the loss of material from the
bag while permittillg the escape of air th!erefrom.
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The present invention provides a corner valve which is
equally compatible with bags having single folded side edges as
well as with bags having gusseted side edges.
These objects are attached by the present invention which
specifically provides a corner valve for a bag of the type having
two sidewalls joined together along the bottom and two side edges
comprising an inwardly folded triangular flap at a top corner of
the bag, an insert having a reversely folded flap along one edge
thereof, first securing means for holding the reversely folded
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flap in the folded position with the center portion thereof left
free, second securing means for connecting said insert to said
triangular flap along a line parallel to and spaced from said --~
reversely folded flap, said reversely folded flap being disposed
in face-to-face relation with said triangular flap between said
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second securing means and the adjacent side edge of said bag, the ~
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side edges of said insert perpendicular to the reversely folded
flap being disposed flush with the top edges of the bag and third ;
securing means for sealing the top edges oE the bag and the side
edges of the insert together whereby said insert defines a valve
filling sleeve adapted to be closed by pulling out said reversely
folded flap and re-folding it over the sealed side edges of the
insert after the bag is folded.
The foregoing and other object features and advantages
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of the invention will be apparent from the following more parti-
cular description of preferred embodiments of the invention as
illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS `
Figure 1 is a perspective view of one corner of a
plastic bag showing the corner valve in the open condition for the
reception of a cylindrical filling spout.
Figure 2 is a side elevation view of the bag corner in
Figure 1 taken in the direction of the line 2-2 with portions of
the bag and valve broken away for purposes of illustration.
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Figure 3 is a view similar to Figure 2 but showing
the bag in the filled condition with the closure flap in the process
of being folded out in the direction of the arrow.
Figure 4 is a view similar to Figure 3 showing the flap
being folded over the top of the bag in the direction of the
arrow.
Figure 5 is a perspective view of the top corner of the
bag showing the corner valve in the closed position.
Figure 5a is a top plane view of the bag corner shown
in Figure 5.
Figure 6 is an exploded view of the top portion of a
bag and the valve insert prior to secure them together.
Figure 6a is a top plane view of the arrangement shown -`
in Figure 6.
Figure 7 is a perspective view similar to Figure 6 but
showing the valve insert secured to the top corner of the bag. ~-
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Fi~ure 7a is a top plane view of the arrangement shown in
Fig. 7.
Figure 8 is a perspective view of the corner valve arrange-
n~ent of l~ig. 7 as the top edges of the bag and the insert are being
secured together.
Figure 8a is a-side elevation view of the finished corner
valve arrangement of Fig. ~ prior to filling.
Figure 9 is a side elevation view of the finished corner
valve as used in conjullction with a bag having gusseted side edges.
D~:TAILED DEISCRIPTION Ol~ TIIE INVENTION
The plastic bag to which the corner valve of the present
application may be fitted is a standard type of plastic bag utilized for
packagin~ ferl~ ers, peat moss, rnulches, poltin~ soils, powdered or
granulated products and the lilce. The si~e of the bag may vary consi-
derably and the si~e of the corner valve can also be varied depending upon
the type of filling equipment which will be used to fill the bags. The
material ancl construction of the bag may also vary widely but, for example
in the present application the bag will be constructed from a flattened
tubular length of polyethylene filr~ which is heat sealed at one end thereof
to clefine an open ended bag.
The bag l0 shown in Fig. l i9 provided with a c.orner valve
g~enerally designated at 12 and the uppermost edges 14 of the bag have been
heat sealed together and covered by in inverted U-shaped sealing strip 16
as i9 conventional in the bag art. The corner valve 12 of the emptybag 10
in Fi~. l is spread open to define a cylindrical passage 18 which is adapte
to slide over a cylindrical filling~ spout of a conventional bag filling
apparatus. The bag filling apparatus has not been illustrated since it is
not a part of the present invention but the filling spout referred to is genera~
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horizontally disposed at the bottom of a hopper and is comprised of
an elongated cylindrical tube utilizing a forced air flow or having a
screw type feed mechanism therein for forcing the bulk products into
the bag. A conventional air vent or passage may be provided in
conJunction with the filling spout since it is customary to clamp the valve
12 to the cylindrical filling spout during the filling operation thereby
preventing the escape of air between the sleeve and spout.
The corner of the bag to which the valve 12 is applied is
folded inwardly to define a triangular flap 20 and the valve 12 is secured
partially within the triangular flap with the~innermost end thereof extending
into the interior of the bag. The dimensions of the flap valve will vary
depending upon the diameter and length of the filling spout which is to be
used.
The sequence of steps involved in the formation of the corner
valve in the plastic bag is best shown~in Figs. 6-8a. In Fig. 6 the tubular
plastic bag 10 is folded inwardly at one corner to define the triangular
flap 20 which is disposed and supported in a substantially horizontal
position by a suitable anvil or support surface (not shown). The valve 12
is comprised of a rectangular piece of plastic material 22 which is provided
with a reversely folded flap 24 along one edge thereof. The flap 24 is then ,-
secured bo the main sheet 22 by two spaced apart heat seals 26 and 28.
The thus formed insert is then placed upon the inwardly folded triangular
flap 20 with the flap 24 between the flap 20 and the sheet 22 as best '~
illustrated in Figs. 6 and 7. The free edge 30 of the flap 24 is spaced
outwardly of the free edge 32 of the triangular flap 20 so that when the
sheet 22'is secured to the flap 20 ad~acent the edge 32 by means of the
transverse heat seal 34 the edge 30 of the flap 24 will remain free. The
end edges 36 and 38 of the sheet 22 are secured to the edges 14 of the
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tubular bag 10 by nleans of heat seals 40 and 42 The heat seals 40 and
42 also secure the end edges of the flap 24 to the cdges 36 and 38 of the
main sheet 2Z. The sheet 2Z is further secured to the bag 10 by means
of heat seals 44 and 46 which are parallel to the end heat seals 40 and 42
j~ and perpendicular to the transverse seal 34. The heat seals 44 and 46
are gencrally aligned with the ileat seals 26 and 28 on the flap but are
!, spaced ~herefrom. The heat seals 34 40, 42, 44 and 46 may be performe I -
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simultaneously or separatcly del~endin~ upon the heat 5ealing equipment
available .
The sides of the bag 10 are then folded back up into fact-to-
face relation best shown in Fig. 8 and the flap 20 and the sheet 22 will be
'I folded about the line 45~. The uppermost edges 14 of the bag and the edges
36 and 3S of the valve insert lZ are then secured together by any conven-
tional heat sealing equipment~ In the present c lse the heat sealing
equipment includes the use of a sealing strip 16 which is folded over the
top edges of the bag and valve insert and the entire assembly is secured
Il together by heat seal 50 best shown in Fig. 8a. The bag with the corner
valve is llOW completed and ready for filling.
In order to fill the bag the valve insert 12 is formed into a
tubular sleeve as best shown in Fig. 1 and placed over the end of a filling
il~ spout. When the bag is filled as shown in Fig. 3 with the bulk material
50 the spout is withdrawn and the upper portion of the bag is substantially
! flattened in a hori~ontal plane as best shown in Fig. 5. An operator may
then reach under the protruding portion of the valve insert 12 and grasp
the free ecl"e 30 of the flap 24 between the heat seals 26 and 28 pull the
flap outwaldly in a direction of the arrow 52. With the upper portion of
the bag flattened out as shown in Fig. 5 the flap 24 can readily be folded
over the top edge of the bag in the direction of the arrow 54 in Fig. 4 to
close the valve The filled and closed bag and valve assembly will then
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appear as shown in Fig. 5. The flap 24 is securely held in place so that
it is next to impossible to accidentally open the valve. The flap will
substantially prevent the leakage of any of the bulk material from the
bag and still provide a vent passage to the interior of the bag. When the
filled bags are stacked on their sides the internal pressure of the material
on the sheet 22 of the valve 12 will press the sheet 22 against the top of
the bag to further close the valve and make it more difficult for the
lealcage of bulk materials to occur.
The valve construction described above is equally suitable
for use with a gussetted bag as shown in Fig. 9. The only difference
between the bag 60 in Fig. 9 and the bag 10 described above resides in
the fact that the entire edge 62 of the bag is tucked inwardly along the
entire length of the bag prior to the closing tlle botton~ of the bag with a
heat seal, In this embodiment the edge 64 of the valve assembly 12' will
be substantially co-extensive with the edge 66 of the bag rather than
recessed as in the previous embodin~ent.
While the invention has been particularly shown and describe
with reference to the preferred embodiments thereof it will be understood
by those skilled in the art that various changes in form and detail may be
made therein without departing the spirit or scope of the invention.
WIIAT 15 CLAIMI;:D 15:
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