CA1079231A - Flexible collapsible container defining relatively rigid shoulder and base at opposite end - Google Patents

Abstract

FLEXIBLE COLLAPSIBLE CONTAINER
DEFINING RELATIVELY RIGID
SHOULDER AND BASE AT OPPOSITE END

Inventor; Joe A. Miller ABSTRACT OF THE DISCLOSURE

A flexible, collapsible container defining a relatively rigid shoulder and neck portion at one end and a relatively rigid base at the other end, and having a flexible tubular wall between the shoulder and the base, utilizes first and second pairs of oppositely-disposed gus-set portions defined in the flexible walls and positioned respectively adjacent the shoulder and the base. The gus-sets are adapted to fold outwardly from the shoulder and base as the container collapses.

Description

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BACKGROUND OF THE I~VENTION

Containers which are made o~ flexible material, so that they can easily collapse upon draining to a residual volume which is a very small percentage of the original filled volume, find particular use in the area of parenteral ..
solution administration. Also, these containers can be put to any other use, particularly those uses where the venting :~
of air into the container as it is emptied is considered not :-to be desirable.
In Grosjean U.S. patent Number 3,595,441, a col~
lapsible tubular container of square cross section is dis- :
closed utilizing a relatively rigid shoulder at one end, and a base at the other, about which the remainder of the container collapses through the infolding of gussets simi-lar to those found in a paper bag. ~:
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The container of the Grosjean patent shares the -characteristic with many other collapsible containers in that it is difficult to ascertain how much solution has been :~
administered from the container, which is of course important ., :

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'` 1~79Z31 to know in the field of administration of parenteral solutions.
Furthermore, the Grosjean container is very complex and is subject to malfunction, since each gusset includes seven ~; individual fold lines which must all function as intended in order to obtain the desired folding results. Added to the total of twenty-eight fold lines in the four gussets are three fold lines on each of the sides of the container, to permit the achievement of the inward folding structure, in the manner of a paper bag having double, opposed bottom ends, as shown in the drawings of the Grosejean patent.
;! It is sometimes deemed desirable to have a flexible, ... .
collapsible container which, nevertheless, can stand up on a -i relatively rigid base while it is full. Furthermore, it is desirable to provide a structure having fewer fold lines, so that there is less chance that a failing fold line will interfere with the collapse of the container. -DESCRIPTION OF THE INVENTION
`1 In its broadest form the present invention provides, -1 in a flexible, collapsible container defining a relatively -.~j .
~', 20 rigid shoulder and neck portion at one end, a relatively rigid ~1 base at the other end, and a flexible, tubular wall between !~~ the shoulder and base, the improvement comprising, in combin-ation, the container defining, in its original, unstressed condition, first and second pairs of oppositely-disposed gussets defined in the flexible wall and positioned respectively adjacent the shoulder and the base, the first pair of gussets I each defining in the wall a recessed, fold line positioned s adjacent to and generally parallel with the adjacent edge of the shoulder, the second pair of gussets each defining a recessed, fold line positioned adjacent to and generally parallel with the adjacent edge of the base, each gusset portion , :;~ ' ' ' ' ' ' ' , ~ 1079Z31 also defining in the walls a pair of lines of folding weakness which join together in angular relationship to define an apex, the lines of weakness extending toward respective ends of their associated recessed, fold line to define a generally triangular arrangement, whereby, upon collapse of the container the gussets fold outwardly respectively from the shoulder and base.
DESCRIPTION OF THE INVENTION
This simpler folding arrangement provides for threè :
fold lines per gusset and only one fold line on each longi-tudinal edge of the container. Furthermore, the outward folding of the gussets prevents the entrapment of the last amounts of the container's contents as it collapses. .
The gussets which are adjacent the base of the :
container of this invention may optionally be smaller or at least of less triangular elevation than the gussets adjacent the shoulder portion. Accordingly, the collapse of ~ :-the .

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. - . - , . ~ ~ .. . . :~ . , 1~79Z31 container, as the contents are withdrawn, takes place first directly adjacent to the base, and thereafter progressively ` from the area o the base towards the shoulder, culminating in the outward collapse of the gussets next to the shoul-der and inward collapse of the remaining portions of the container. The container folds up about the inner surfaces of the shoulder and base to create a very small residual volume when based upon the original volume of the container.
Because of the progressive tail-to-head collapse of the conta1ner when held in inverted position, it becomes feasible to make a reasonably accurate determinati~n of the amount of contents of the container which have been expended, which is particularly important when the container is a parenteral solution administration container or other medi-;. .
cal liquid container. However, simultaneously with this, the container of this invention is capable of standing on its base while full, and also collapsing down to a residual vol-ume which may be about five percent of its original volume.
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Preferably, the shoulder and base of the container of this invention are generally oval in shape, but preferably with truncated ends, the gussets being positioned adjacent the ends of the major axes of the shoulder and base.
It is also contemplated that, optionally, the cir-cumference of the tubular wall between the shoulder and base may increase in the direction of said base so that the ~ `
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i container exhibits a tapered or frustoconical aspect.
Referring to the drawings, Figure 1 is an elevational view, with parts broken away, of the container of this invention, shown lying in a mold half used for manufacture of the container by blow molding.
Figure 2 is a plan view of the container of this invention from the shoulder end.
Figure 3 is an elevational view of the container of -this invention, rotated 90 about its longitudinal axis from the aspect shown in Figure 1, also showing the molds used to ;`
manufacture the container.
Figure 4 is an elevational view of the container of ~
Figures 1 through 3 in the condition of having its contents ~ `
partially withdrawn, and the wall portion adjacent to the base being folded up.
Figure 5 is an elevational view similar to Figure 4, showing the essentially completely collapsed container after virtually all of the contents have been expelled.
Figure 6 is an elevational view similar to Figure 5, -rotated 90 about the longitudinal axis, also showing the filled configuration of the container in phantom lines for comparison.
Figure 7, appearing on the same sheet as Figure 4, is an elevational view of an alternative embodiment of the container of this invention.
Referring to Figures 1 through 3, container 10 : :
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is shown positioned in a blow mold half 12. As shown in Figure 3, mating mold half 14 is provided to enclose a pari-son which may then be blow molded to form container 10, using retractable blowing tube 16 (shown in the retracted position). Neck mold halves 18, 20, which may be separate, are also shown. All of the mold halves are mounted on pis-tons for advancement and retraction as desired to receive the hot parison, to close around it, and to expel the com-pleted, blow-molded container 10 in accordance with conven-tional technology.
Container 10 defines a generally flat, relatively rigid base 22 from which protrudes a hanger member 24. Hanger member 24 may be connected to base 22 by a thinned web portion 26 so that hanger member 24 can be easily folded into flat, parallel relation with base 22 when it is desired to stand the container up. Hanger member 24 may be integral with con-tainer 10, or may be separately added after manufacture.
At the other end of the container is defined a relatively rigid neck portion 28, through which the contents of the container may be inserted and withdrawn, and a rela-tively rigid shoulder portion 30.
Tubular Wall 31, which is relatively flexible when compared with the relatively rigid base 22 and shoulder por-tion 30, extends between the peripheries of shoulder portion 30 and base 22 to form a sealed, flexible container.
The container of this invention is advantageou~ly made from materlals having a plastic flexural modulus of at ~;

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least 60,000 according to the test of ASTM-D790 (secant modulus of elasticity), and preferably no more than about 250,000, for example medium and high density polyethylene, polypropylene, or copolymers thereof.
In accordance with this invention, opposed pairs of gusset portions are provided in tubular wall 31 adjacent both base 22 and shoulder 30. Gussets 32, adjacent base 22, are defined during the blow molding operation by appropriate channels and elevations defined in mold halves 12, 14. In-cluded in each gusset 32 is a recessed, folded line 34 positioned adjacent to and in generally longitudinal relation to the adjacent truncated edge 36 of the generally oval base.
Each gusset portion 32 also defines in the wall 31 a pair of lines of folding weakness 38 which join together in angular relationship to define an outwardly pointing apex 40, which also points away from base 22. The lines of weakness 38 extend toward respective ends of their associated recessed, folded line 34 to define a generally triangular arrangement.
Recessed line 34 may be formed by a projection 4~
in each mold half 12, 14 (Figure 1). Portion 36 of base 22, as well as lines of weakness 38, may be defined by mold halves 12, 14, using grooves defined in the mold halves, as particularly shown with respect to edge portion 36 in Figure .
1. These groove portions may preferably define, in cross section, arcs in the mold halves having a circumferential : . ... -: -, . : .. - ,: . , .

10'79Z31 length which is from forty to sixty percent greater than the direct width of such grooves. The result of this is that, as the plastic material of the container expands into the grooves in the mold, a thinning effect takes place so that S the minimum wall thickness within the lines of folding weakness is preferably from about forty to seventy percent of the thickness of the container wall adjacent the lines of folding weakness. Accordingly, the folding characteris-tic of the container is focused, and the lines of folding weakness provide improved ease of folding when subjected to a low suction pressure, as may be encountered when the con-tents of the container are expelled through a parenteral solution administration set.
The gussets 43 adjacent shoulder 30 also define a recessed, folded line 42 which is in generally longitudinal relation with the adjacent edge 44 of shoulder 30.
Lines of folding weakness 46 are defi~d in each gusset 43, and join together in angular relatior.ship to de-fine an outwardly pointing apex 48, which also points away from shoulder 30. The lines of weakness 46 extend toward re-spective ends of their associated, recessed folded line 42 to also define a generally triangular arrangement.
Recessed, folded line 42 may be formed by a projection 50 in mold halves 12, 14, as shown in Figure 1, while trun-cated edge 44 of generally oval shoulder 30 may be formed by a groove in the mold halves as shown, with the result that _g_ , 1~'79231 the shoulder tips 44 are thinned in the manner of oval base edges 36 and form a line of flexing weakness. Lines of weak-ness 46 may also be formed by grooves in the mold halves, and thus thin as they expand into the grooves, forming the lines of flexing weakness.
If desired, longitudinal line of folding weakness 52 may also be formed in container 10, if desired, by a longi-tudinally positioned groove in the mold, into which the parison can expand and accordingly thin, as previously described for other lines of folding weakness.
As shown in Figure 3, gussets 32 define a roughly ~- triangular shape with a pair of curved legs 38, the eleva-tion 53 of the triangular gusset 32 being less than the ele-vation 55 of gusset 43, for example from three fourths to one ~ 15 half the length of elevation 55. Similarly, the length of J line 34 may be less, for example, from three fourths to one , half the corresponding length of line 42. Alternatively how-ever, it is also contemplated that the various gussets may be of equal size, or that gussets 32 may even be larger than gus-~sets 42. The relative sizes and dimensions of base 22 and shoulder 30 may also be varied as desired.
Referring to Figure 4, it is shown how the con-tainer of this invetnion can preferentially collapse at its upper end in its position of use, which end is base 22.
Container 10 is shown to be hanging from its hanger 24, with a conventional closure 54 having been attached by heat or solvent sealing, or any other desired technique, to the neck portion 28. A conventional parenteral solution set 56 has penetrated one of the ports of closure 54, which may provide :

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~9~31 a sterile seal to the container until punctured for draining of the liquid inside of the container.
As the liquid is drained, the walls of the con-tainer fold inwardly about lines of weakness 58 extending about the edges of base 22 between gussets 32, which may also be made by appropriate grooves in molds 12, 14 for thinning of lines 58. Simultaneously therewith, the walls of the container which define gussets 32 fold outwardly (see the full lines of Figure 6), with this action being per-mitted by the interaction of lines 38, 34 and 36, so that the container folds simultaneously inwardly and outwardly about base 22. As the container collapses, it is possible for the collapse to proceed progressively down the length of the container, so that the amount of liquid expended can be determined with quick examination.
As the container completes its emptying, lines of weakness 60, which may also be formed by appropriate grooves in mold halves 12, 14, permit both walls of the container to collapse inwardly about the inner surface of shoulder 30 as shown, for example, in Figure 5, to reduce the residual volume of the container. Simultaneously, gussets 43 fold outwardly, to facilitate the collapse with a reduced number of fold lines, as shown in the full lines of Figure 6.
As the container collapses, it shortens in length, as the walls adjacent the ends collapse inwardly and outwardly.

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1~79Z31 Accordingly, a container is provided which is capable of collapsing to a residual volume of about five percent or less of the original volume with only a gentl~
suction pressure exerted, for example, by the suction head of a column of parenteral solution in a set extending from the container to the patient. This remarkable advantage can be obtained even though the container is made out of a rela-tively stiff material, for example, polypropylene or copoly-mers of polyethylene and polypropylene, having an overall wall thickness at the collapsible tubular wall 31 of, pre-ferably, about 0.01 to 0.018 inch, and having a wall thickness at shoulder 30 and base 22 of preferably about 0.02 to 0.03 inch. The lines of weakness may preferably be approximately forty to seventy percent thinner than the adjacent walls, for example 0.0~5 to 0.007 inch at the thinnest. The thick-ness of the wall may be thinner adjacent the base 22 than adjacent the shoulder 30 to facilitate preferential collapse at the base area.
Referring to Figure 7, a modified container in ac-cordance with this invention is shown which is identical with the previous embodiment in all characteristics except as otherwise described herein.
The container 62 comprises, as before, a neck por-tion 63, a relatively stiff shoulder portion 64, and relatively stiff base 66, which may be slightly concave in shape, in part to accomodate the folded hanger member 68, which can fold flat into the concave recess of base 68 along thinned line of weakness 70.

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,: ' '' ' ' : ' :, , A chief distinction of container 62 from the prior embodiment of container 10 is that the tubular wall 72 ex-- tending from the shoulder to the base is generally uniform in cross-sectional circumference, and not of the increasing circumference from shoulder to base, as in the previous em-bodiment.
Gussets 74, 76 are provided, in which the altitude of generally triangular gussets 74 may once again be different from the altitude of the generally triangular gussets 76.
The initial collapse of the container generally takes place in the region of gussets 74 and base 66, followed by ' the progressive collapse from the base end toward the shoul-der end, and the ultimate outward folding of gussets 76 and inward folding of line of weakness 78, to provide a collapsed container of a configuration essentially similar to the pre-vious embodiment.
It is also contemplated that, as before, the rela-tive dimensions of base 66 and shoulder portion 64 may be varied. For example, the width of shoulder portion 64, i.e.
the minor axis of its generally oval shape, may be greater than the width of base 66. The respective lengths of shoul-der portion 64 and base 66 may be identical or different, as desired.
The above has been offered for illustrative purposes only and is not for the purpose of limiting the invention of this application, which is as defined in the claims below.

Claims (10)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In a flexible, collapsible container defining a relatively rigid shoulder and neck portion at one end, a relatively rigid base at the other end, and a flexible, tubular wall between said shoulder and base, the improvement comprising, in combination, said container defining, in its original, unstressed condition, first and second pairs of oppositely-disposed gussets defined in said flexible wall and positioned respectively adjacent said shoulder and said base, the first pair of gussets each defining in said wall a recessed, fold line positioned adjacent to and generally parallel with the adjacent edge of said shoulder, the second pair of gussets each defining a recessed, fold line positioned adjacent to and generally parallel with the adjacent edge of said base, each gusset portion also defining in said walls a pair of lines of folding weakness which join together in angular relationship to define an apex, said lines of weakness extending toward respective ends of their associated recessed, fold line to define a generally triangular arrangement, whereby, upon collapse of said container, said gussets fold outwardly respectively from the shoulder and base.

2. The container of Claim 1 in which said shoulder and base are generally oval in shape, said gussets being positioned adjacent the ends of the major axes of said shoulder and base.

3. The container of Claim 2 in which the circumference of said tubular wall increases in the direction of said base.

4. The container of Claim 2 in which the first gussets are different size than said second gussets.

5. The container of Claim 2 in which the elevation of said first gussets in the direction of the longitudinal axis of said container is greater than said elevation of the second gussets.

6. The container of Claim 2 in which the thickness of said flexible wall adjacent said first gussets is greater than the thickness of said flexible wall adjacent said second gussets.

7. The container of Claim 2 in which said base is generally concave in shape; a hanger portion being attached to said base and defining foldable means whereby the hanger portion can be extended for hanging or be folded to lie flat in a recess formed by the concave base, to facilitate the ease of standing of said container on the base.

8. The container of Claim 2 in which the circumference of said tubular wall is generally constant between said shoulder and neck portion and said base.

9. The container of Claim 2 in which said container is free of additional, longitudinally-oriented lines of folding weakness adjacent the shoulder and base portions.

10. The container of Claim 2 in which said gusset portion does not extend the entire maximum width of said container.