Self-sealing bag sleeve

In a bag adapted to contain a flowable product therein, the bag having first and second opposed closed ends, one of said ends having a self-sealing sleeve formed therein through which flowable product may be delivered into the bag, an improved self-sealing sleeve comprising a first generally tubular sleeve extending into said bag at one side of said one end, a second generally tubular sleeve located inside of and being attached to first sleeve and extending beyond the first sleeve into the bag and a third generally tubular sleeve located inside of and being attached to the second sleeve and extending beyond the second sleeve into said bag.

BACKGROUND OF THE PRESENT INVENTION 
The present invention relates generally to the packaging art and deals more 
particularly with an improved self-sealing filler sleeve for a flexible 
bag suitable for storing fine powdery materials and small size particle 
and granular products therein, and is of the type provided with a self 
closing sleeve valve to allow filling the bag with product. Heavy weight 
paper bags are frequently employed for containing, storing and shipping 
flowable, fine powdery materials and small sized granular products, such 
as starch, food products, chemicals, cement and the like. By virtue of the 
flowable character of these products, such bags are filled by inserting a 
filler spout of a dispensing machine into an opening of the bag, and the 
product is delivered from a source thereof through the spout into the bag. 
Many types of products packaged in this manner may contain dust, or are 
themselves "dusty" and the dust is easily suspended in the air during 
movement of the product, as during filling of the bag. 
Because the dust from the products is easily suspended within the air, 
filling operations are sometimes messy, and can even present a health 
hazard to personnel due to the ambient air being polluted by the product. 
In addition, when the filled bags are being transported, the vibrations of 
the carrier, which may be a truck, train or the like, cause the fine 
powdery material to sift out through the filler opening part of the bag. 
Consequently, attemps to prevent sifting of the bags' contents through the 
valve have been made and special valves have been devised in the past to 
tightly fasten the filler openings of the bag to the dispensing spout 
during filling operations and to substantially prevent the escape of 
product from the bag once the dispensing spout is removed from the filler 
opening. In order to increase production efficiency, these prior art 
filler valves have been adapted to automatically seal the filler opening 
after the filling process has been completed. 
Prior art bags of the type mentioned above comprise a tubular paper bag 
closed at both ends, at least one end having a plurality of flaps folded 
over to define a passageway in the end of the bag which presents an 
opening at one corner thereof. The flaps are hingedly interconnected to 
permit the bag to be folded into a flat condition wherein the walls 
defining the passageway collapse into a face-to-face abutting 
relationship. A flexible, tubularly shaped sleeve, formed of kraft paper 
and having a one mil, low density polyethylene film sleeve attached to the 
inside thereof and extending beyond said kraft paper sleeve is secured 
within the passageway and extends beyond the latter into the interior of 
the bag. The entire length of the sleeve is secured to, and between, 
overlapping flaps which form the closed end of the bag. The dispenser 
spout is inserted into the sleeve forming the valve and product is 
dispensed into the bag. After the bag is filled, it may or may not be 
inverted and the weight of the product in the bag presses against and 
squeezes the sleeve between opposing flaps thereby closing the sleeve and, 
thus, the valve. 
The primary problem associated with the prior art bags of the type 
described above is related to the fact that the sleeve valve used in such 
bags was not "sift-proof" with respect to the product; i.e. the fine 
powdery material and small sized product within the bag had a tendency to 
sift out around and through the sleeve thereby escaping from the bag. This 
was due in part to the fact that wrinkles in the sides of the plastic 
sleeve were created by the filling operation. These wrinkles formed 
channels on both sides of the walls of the sleeve through which the 
product could escape. 
Accordingly, it is an object of the present invention to provide an 
improved filler sleeve for flexible bags which permits filling of the bag 
with product but which are automatically closable to eliminate the problem 
of sifting of the product through the sleeve after the bag is filled. 
Another object of the present invention is to provide an improved filler 
sleeve having a sleeve through which the bag may be filled with product 
and yet which sleeve completely closes after the filling operation in 
order to positively close the filler passageway through the sleeve and 
prevent sifting of the product through the sleeve after the bag is filled. 
SUMMARY OF THE INVENTION 
Thus, the present invention relates to an improved filler sleeve for a bag 
adapted to contain a flowable product therein, said bag having first and 
second opposed closed ends, one of said ends having a self-sealing sleeve 
formed therein through which flowable product may be delivered into said 
bag, said improved self-sealing filler sleeve comprising a first generally 
tubular sleeve extending into said bag at one side of said one end, a 
second generally tubular sleeve located inside of and being attached to 
said first sleeve and extending beyond said first sleeve into said bag and 
a third generally tubular sleeve located inside of and being attached to 
said second sleeve and extending beyond said second sleeve into said bag.

DETAILED DESCRIPTION OF THE INVENTION 
FIG. 1A is a partial side view of the corner of a bag generally denoted as 
10 in its folded state with a first generally tubular sleeve 12 extending 
into said bag at one side of said one end. Tubular sleeve 12 is formed by 
folding the side flaps 14 (shown in dotted lines) inwardly about fold line 
17 until they are lying inside the bag. Thus top side 16 becomes the inner 
end 18 of the first tubular sleeve 12 when it is tucked inside the bag. 
Outer edge 20 becomes bottom edge 22 when the sleeve is formed inside the 
bag. Outer flap 24 is folded about fold line 26 to form the overlapping 
flap 28 which is glued to hold the bag sealed in the position shown in 
FIG. 1A. Strip 30 indicates the area for a glue strip on tubular sleeve 12 
to which the second generally tubular sleeve 34 shown in FIG. 2 will be 
glued to hold the second tubular sleeve 34 in place. Thus by folding outer 
edge 20 of one side of one end of the bag 10 inwardly about hinge line 17, 
a first generally tubular sleeve 12 is formed. It is, of course, open at 
the top 32 but that opening will be closed when the second generally 
tubular sleeve 34 shown in FIG. 2 is attached to sleeve 12 as hereinafter 
described. FIG. 1B is an isometric view of the partial corner of bag 10 
shown in FIG. 1A better illustrating the first generally tubular sleeve 
formed when the outer edge 20 is folded inwardly about fold line 17 as 
previously described. 
FIG. 2A is a side view of the second generally tubular sleeve indicated 
generally by the numeral 34 which comprises a cylinder 36 preferably made 
from kraft paper with one end 38 folded back on itself to form a U-shape 
40 into which the first tubular sleeve 12 shown in FIG. 1 may be placed 
and glued. Thus glue strip 42 which is placed on the inside of the U-shape 
40 mates with glue strip 30 in FIG. 1 as end 18 of first tubular sleeve 12 
slides over outer end 44 of second tubular sleeve 34 and into the U-shaped 
portion 40 thereof. Outer surface 46 of the U-shaped portion 40 covers the 
open area 32 on first tubular sleeve 12. Folded back end portion 38 of 
sleeve 34 extends inside the bag as shown in FIG. 4. Areas 48 and 50 
represent the areas on which glue may be placed inside of second generally 
tubular sleeve 34 and by which the third tubular sleeve 52 shown in FIG. 3 
will be attached thereto. 
FIG. 2B is an isometric view of the second generally tubular sleeve 34 
showing more clearly how lower end 38 is folded back on itself to form a 
U-shaped section 40. 
FIG. 3A is a side view of the third generally tubular sleeve 52 which is 
preferably made of polyethylene having a thickness of approximately 1 mil 
or less and which has thereon areas 54 and 56 for receiving a glue whereby 
third tubular sleeve 52 may be placed inside of and attached to second 
tubular sleeve 34 shown in FIG. 2 at glue strips 48 and 50. 
FIG. 3B is an isometric view of the third tubular sleeve 52 illustrating 
the glue strip 54 and 56 where the sleeve 52 would be attached to second 
tubular sleeve 34 at glue strips 48 and 50 as shown in FIG. 2. 
A partial isometric view showing the entire assembled sleeve with parts 
thereof exposed is illustrated in FIG. 5. Thus the end 18 of first 
generally tubular sleeve 12 is placed in U-shaped portion 40 of second 
generally tubular shaped sleeve 34 and glued at strips 30 and 42 which 
overlap each other. Third generally tubular shaped sleeve 52 is then 
placed inside of second generally tubular shaped sleeve 34 and is glued 
thereto at overlapping strips 48 and 54 and 50 and 56. It will be noted 
that end 58 of third generally tubular shaped sleeve 52 extends beyond the 
end 60 of second tubular shaped sleeve 34 and well into the bag. 
One method of constructing the novel sift proof sleeve is illustrated in 
FIGS. 5 and 6. As can be seen in FIG. 5, the bag 11, in its opened 
condition, may have one corner folded inwardly about line 17 to form flaps 
12 and 12' projecting inwardly into the bag. Next, the polyethylene sheet 
52 which will finally result in third generally tubular sleeve 52 may be 
folded and placed inside of kraft paper sheet 34 which is folded about 
line 44 and which also has one end 38 folded backwards on itself about 
line 60. By having one end 38 folded back on itself about line 60, a 
U-shaped channel 40 is formed which slides over both sides of panels 12 
which are folded inwardly about line 17 of bag 10. By folding flap 28 of 
bag 10 and the upper edges of kraft paper sheet 34 and polyethylene sheet 
52 over the upper edge 62 of the other side of bag 10 and have the flap 28 
glued to upper edge 62 of bag 10, the entire sleeve is formed in the bag 
10 during construction of bag 10 and sealing of the end thereof. 
FIG. 6 illustrates a cross-sectional view of the upper edge 28 of bag 10 
folded over with the kraft sheet 34 and the polyethylene sheet 52 folded 
under it. Edge 28 may then be glued to bag 10 to hold the entire 
construction in place. 
From the foregoing, it is apparent that the improved sleeve of the present 
invention not only provides for the reliable accomplishment of the objects 
of the invention but does so in a particularly effective and economical 
manner. It is recognized, of course, that those skilled in the art may 
make various modifications or additions to the preferred embodiment chosen 
to illustrate the invention without departing from the spirt and scope 
thereof. Accordingly, it is to be understood that the protection sought 
and to be afforded hereby should be deemed to extend to the subject matter 
claimed and all equivalents thereof within the scope of the invention.