US3070265A - Bag lined pressure container - Google Patents

Description

Dec. 25, 1962 J. w. EVERETT BAG LINED PRESSURE CONTAINER 5 Sheets-Sheet 1 Filed June 13, 1960 INVENTOR Avg: '1,

Dec. 25, 1962 J. w. EVERETT 3,070,265

BAG LINED PRESSURE CONTAINER Filed June 13, 1960 3 Sheets-Sheet 2 Dec. 25, 1962 v.1. w. EVERETT BAG LINED PRESSURE CONTAINER 5 Sheets-Sheet 3 Filed June 13, 1960 INVENTOR by the E. I. du Pont de Nemours & Company.

3,670,265 BAG LHNED PRESSURE CONTAINER John W. Everett, 712 Keyser Bldgt, Baltimore 2, Md. Filed June 13, 1960, Ser. No. 35,801 2 Claims. (Cl. 222--386.5)

The present invention relates to an improved disposable pressure container and the method of making the same, and is a continuation in part of application Serial No. 785,086, dated January 5, 1959.

The invention has to do with the type of pressure con tainer in which the material carried by the container is maintained in a separate compartment from the medium used in creating pressure in the container for expelling the material. The container is especially designed for use with a pressure producing evaporating liquid such as Freon, a trade name for a product made and distributed by E. I. du Pont de Nemours & Company of Wilmington, Delaware, but does not exclude the use of other liquids of similar nature, and pressure mediums such as nitrogen gas, etc. The advantage of a liquid type pressure medium is that it can be compounded to evaporate at relatively low pressures and at the desired pressure for particular products which makes it ideal for pressure containers, and that the pressure may be kept constant. p

The present container is constructed with a rigid outer portion and a combination rigid and flexible bag carried within the outer rigid portion made preferably from an organic plastic substance and one whose walls are, for all practical purposes, impervious to the passage of the gas used in expelling the product. Such mate-rials are now available, one being in the form of a product known by the trade name Mylar, also made and distributed While Mylar has the advantage of being flexible and impervious to gas, it has practically no elasticity and therefore the use of such a bag made of this material must be so constructed and incorporated within the rigid outer container member as to be substantially in contact with the walls of the portion of the rigid outer container when in one of its positions in order to expel all the contents from the container with very little, or no stretching of the bag.

While Mylar is at present one of the best known materials for its imperviousness to gas, other materials also have a high degree of impe-rviousness, such as Pliofilm manufactured by the Goodyear Company of Akron, Ohio and certain laminated plastic materials. Therefor, it is not intended that only certain particular materials may, or can be used. Again the kind of product being carried in the container may have a great deal to do with the kind of material used in making the bag. If the product being carried is not for consumption, such as lubricating oil, the material from which the bag is made may not be required to be as impervious to gas as one carrying a food product such as a liquid, coffee, catsup, syrup, etc. Materials such as natural rubber, and more porous plastic materials may be used where small amounts of the expelling gas mixed with the material being dispensed do not matter too much.

There are various types of known pressure containers having the material carried in a bag. However, the present invention provides a container of this class having a controlled collapsing bag that will not island (that is, choke off a portion of the material in the bag) and at the same time afford a greater capacity for material carried by the container, than is possible at the present time with similar containers.

The primary object of the invention is to provide a container having a separate air-tight compartment for the material to be dispensed and a separate air-tight 3,070,265 Patented Dec. 25, 1962 ice compartment for the medium used as the expelling agent, in which the compartments are separated by a bag having a portion of its sidewall rigid and a portion of its sidewall flexible.

Another object of the invention is to provide an outer rigid hermetically sealed container including a combination rigid and flexible bag, the bag having an open end, and a portion of its side wall adjacent its open end fitted to the inside rigid outer side wall of the container and the flexible portion of its side wall and closed end movable relative to the rigid outer side wall of the container, the open end being secured to either the bottom, or top of the container, for dividing the same into two air-tight compartments whose sizes vary inversely to each other by moving the flexible portion of the bag longitudinally of the container.

A further object of the invention is to provide means for fixing the side wall area of the bag adjacent its open end in extended rigid position from one end of the container to a predetermined point outwardly from the end and along the rigid outer side wall of the container.

Still another object of the invention is to provide that the bag be only flexible from the inner end of the rigid portion to its closed end and the remainder of the bag being rigid to its open end forming a definite fold line for the flexible portion of the bag just beyond and adj'acent the inner edge of the rigid portion of the bag side wall, and locating the fold line at a predetermined point along the outer rigid side wall of the container for caus ing the flexible portion of the side wall of the bag including the flexible end of the bag to be moved longitudinally of the container and to fit into the upper end of the container when extended toward the top thereof.

A still further object of the invention is to provide means by which certain areas of the flexible portion of the wall of the bag may be made more rigid than other areas of the flexible portion aiding in con-trolling its collapsing.

While several of the objects of the invention have been mentioned, other objects together with its use-s and advantages will become more apparent as the nature of the invention is more fully disclosed, which consists of its novel construction and arrangement shown in the preferred embodiment in the accompanying drawings and described in the following specifications, and specifically defined in the appended claims.

In the drawings:

FIGURE 1 is a sectional view of one form of the container having a combination rigid and flexible bag carried therein and secured to the bottom of the container for .dividing the container in two air-tight compartments.

FIGURE 2 is an enlarged fragmentary sectional view taken on line 2-2 of FIGURE 1 showing the relative relationship between the bag and the outer container wall.

FIGURE 3 is a sectional view similar to FIGURE 2 showing the bag and the outer container wall and illustrating the flexible side wall of the bag folded inwardly and extending along the inner surface of the rigid portion of the bag and folded along a definite fold line adjacent the inner edge of the rigid portion.

FIGURE 4 is a sectional view illustrating the relative relationship between the bag and to outer container wall of another form of the bag.

FIGURE 5 is a sectional view similar to FIGURE 4 illustrating the manner in which the flexible wall portion of the form of bag shown in FIGURE 4 is folded inwardly with respect to the stiffened portion of the bag.

FIGURE 6 is a sectional view similar to FIGURE 1 showing a form of container having a combination rigid and flexible bag secured in the top of the container for dividing the container into two air-tight compartments.

FIGURE 7 is an enlarged fragmentary sectional view taken on line 77 of FIGURE 6, showing the relative relationship between the side wall of the bag and the outer container wall. 7

FIGURE 8 is a sectional view similar to FIGURE 7 showing the bag and the outer container wall and illustrating the flexible portion of the side wall of the bag fitted into and extending upwardly and along the inner surface of the rigid portion of the bag and folded along a definite fold line adjacent the inner edge of the rigid portion.

FIGURE 9 is an enlarged fragmentary sectional view showing the detailed construction of a form of seam used in sealing the bag and either the bottom or top cover to the outer rigid body portion of the container.

FIGURE 10 is an elevational view of one form of bag and the one that is illustrated generally with the container shown in FIGURE 1.

FIGURE 11 is an enlarged fragmentary sectional view of thebag taken on line 11-31 of FIGURE 10 illustrating a difference in thickness of the side wall of the bag to provide rigidity by increasing the thickness in the side wall of the bag and flexibiiity by reducing the thickness of the side wall of the bag.

FIGURE 12 is an elevational View of another form of the bag illustrating a manner in which rigidity may be added to a portion of the bag by coating the area to be made rigid.

FIGURE 13 is an enlarged fragmentary sectional view of the bag taken on line 13-4.? of FIGURE 12 illustrating how the added material may appear on the bag surface in the area where rigidity is desired.

In describing the invention, like numerals are used to designate like and similar parts throughout the several views.

Referring generally to the drawings, the container comprises a rigid outer body 1, a rigid cover member 2, a rigid bottom 3 preferably of metal and a bag B, preferably of an organic plastic material. The outer container body 1 is preferably of cylindrical shape and the top is preferably of convex shape, and the bottom 3 is preferably of concave shape. However, the detailed shapes of the top and bottom member may be changed without altering the function of the container so far as this invention is concerned. It will be noted in FIGURES 1 and 6 that the bottom 3 is provided with anopening which will be more particularly referred to later on in the specifications. The top cover 2 is also provided with a top opening 7 and is adapted to receive a closure 8.

The closure is provided with a valve mechanism 9. Ex-

tending outwardly from the housing is a spout 1t) having an aperture therethrough and connected with the opening in the closure for dispensing the product from the container when the housing is depressed.

The controlling of the collapsing of the bag may be done in a number of ways, one being to increase the thickness of the area of the side wall of the bag where rigidity is desired. Another is to coat or laminate the area where rigidity is desired by a more rigid composition, still another is to treat the areas where rigidity is desired by treating the material from which the original bag is made with a chemical compound, such as, a hardening agent now used in paints, etc. These coatings may be sprayed on the bag, dipped, etc. The wall of the bag may be subjected to different temperatures to bring about rigidity to certain areas of the bag and flexibility to certain other areas.

Referring first in particular to FIGS. 1, 2 and 3, the bag B is formed with a closed end and open end and the open end is made to fit snugly within the lower portion of the container body 1, the outer surface of the bag is adapted to conform to the inner wall of the rigid body portion 1 and the rigid container cover 2, as shown in dotted lines in FIG. 1.

The bag is constructed with a stilf, or rigid side Wall portion 12 adjacent its open end and the remainder of the bag side wall 13 including its closed end 13 being extremely flexible in comparison to the stiff portion, in fact, the flexible portion of the bag is of such flexibility that it is very easily movable longitudinally of the container with a very slight difference in pressure on either side thereof. The rigidity of the portion 12 of the bag is contained in the bag itself and is achieved by having an additional thickness in the material in this portion of the bag. The additional thickness ends abruptly in a circle inwardly from the end of the body portion about the container wall, as shown at 15 in FIG. 1, providing a definite fold line immediately beyond the inner edge of the rigid portion for the flexible end of the bag when the flexible portion is in a downward position. When the flexible closed end portion of the bag is in its extended downward position, it is positioned above the rigid bottom of the container, as shown in FIGURES 1 and 6. This allows space for using an injection needle through the elastic member 31 for introducing the liquid pressure solution. The inner edge of this rigid portion predetermines a line about the bag and about which the flexible portion of the bag is foldable within and through the rigid portion 12 of the bag. The additional thickness in the portion 12 of the bag is preferably done in the molding or forming of the bag itself and from the original stock from which the bag is made. However, the extra thickness may be accomplished by building up the side wall of the original material with the same, or an appropriate material which will be referred to more particularly later on. For better control of the movement of the bag, the flexible portion of the bag is made slightly more rigid adjacent its center as shown at 13' than it is at its sides adjacent the inner edge of the rigid portion in order to cause the flexible outer edges of the flexible portion of the bag to move, at least initially, upwardly and close to the wall of the container body 1, in order that the bag will have a tendency to roll up along the inner surface of the container body wall. This slight rigidity to the central portion of the closed end of the flexible portion of the bag is accomplished by slightly increasing the thickness of the bag and having it gradually thin out as it extends outwardly toward the side Wall of the bag, but may also be accomplished in other ways, such as coating this portion of the bag with some appropriate material and by methods previously referred to, to give rigidity to this portion of the bag.

At the open end of the bag there is a narrow area including the flange 18 which is of less rigidity than the adjacent rigid wall portion 12 of the bag and is adapted to be rolled into a seam S as shown in FIG. 9 between a similar flange 19 formed on the ends of the body portion 1 and a flange 29 formed on the top 2 or bottom 3, as the case may be, to form a double seam which is well known in the art.

In FIGS. 10 and 11 the bag is shown having the thicker portion of the bag extending on the inner surface of the bag as shown at 12. In FIGS. 12 and 13 the thicker portion of the bag extends outwardly on the outer surface of the bag as shown at 12". In FIGS. 10 and ll the thicker portion is usually molded in the bag at the time the bag is originally made and is generally molded from the material from which the complete bag is made. Where the thicker wall appears on the outer side of the bag as shown in FIGS. 12 and 13 the added thicknessis most likely done by spraying, laminating, dipping, etc.

In FIGS. 4 and 5 there is illustrated a modified form of bag 17 having a part 17 treated wfth a stiffening agent, adapted to give the rigid portion of the wall stiffness by combining, to a great extent with the original material, adding stiffness without adding materially to the thickness of the wall.

In FIGS. 6 to 8 inclusive there is shown a bag similar to that shown in FIGS. 1 to 3 having its open end secured in the seam S between the top end of the body portion 1 and the cover member 2. This bag which is designated as B is formed in substantially the same manner as bag B, including a stiff, or rigid portion 23 adjacent its open end and a flexible portion 24 including its closed end 24. Where these two portions meet there is defined a very definite fold line 26 on which the flexible portion of the bag folds inwardly and upwardly through the rigid portion having its closed end coming to rest adjacent the inner surface of the top cover member 2. The position of the inner edge of the rigid portion of the bag determines the location of the fold line of the bag.

Referring again to FIGS. 1 to 3 and to the assembly of the container, the rigid body 1, including the top cover 2 are preferably assembled first. The bag is inserted into the bottom of the container body it which is adapted to fit closely to the inner side wall of the body 1 as shown in FIG. 1. The bottom 3 is applied and the flange 18 of the bag is rolled into a' hermetically sealed seam S between the lower end of the body 1 and the bottom 3. The flexible portion of the bag is then reversed as shown in full line at 13 and 13, the bag folding about the fold line just inwardly from the inner edge of the rigid portion 12. After the rigid outer portion, top and bottom of the container and the bag have been assembled, the closed flexible end of the bag, if not already there, is placed downwardly toward the bottom of the container to receive the contents it -is adapted to carry. This may be done in a number of ways, one being by air pressure being applied through the opening 7 in the container cover 2, another being to pull a vacuum on the bottom of the container through the opening 5, or by forcing theclosed flexible end of the bag down toward the bottom of the container by filling'the container through the opening 7 in the cover. At this point the cap 8 is not in-place in the opening in the top cover 2. Likewise, the opening 5 in the bottom of the container is left open until after the product is placed into the container. After the container is filled, the closure 8 for the opening 7 in the top is sealed in place. Through the opening 5 and in the area A in the bottom of the container there is introduced the proper amount of Freon or other suitable propellent for creating pressure below the end of the bag.

For closing the opening 5 in the bottom of the container there is provided a closure 30 adapted to be crimped in the opening. The closure is provided with a small opening 30 which is closed by a soft plug 31 which is compounded to melt at a predetermined temperature, such as, woodsmetal. This would allow for sterilization of the product and testing of the container, but in case the container was subjected to excessive heat, such as, an incinerator, the plug would melt out and prevent any excessive build up of pressure within the container that would cause the container to explode.

The propellent may be introduced in various ways after the material has been introduced into the container and the opening 7 closed as mentioned before, one way to introduce the propellent into the bottom of the container, is to insert the liquid through the opening 5 be neath the closed end of the bag, and insert and seal the cap 30 in the opening 5. Another method would be to provide the opening 5 with a closure having a soft flexible plug similar to that used in football bladders. rafts, etc. (not shown) and injecting the propellent fluid through the soft plug by means of a plunger. After the propellent has built up suflicient pressure against the outer surface of the flexible portion of the bag, the container is ready for use. The material may be dispensed by pressing inwardly on the housing, the valve in the closure 8 will be opened and the material will be dispensed through the spout 10. As the material is dispensed from the container the flexible portion of the bag will begin to "shown in FIGS. 6 to 8 is very similar to that already --described for the container shown in FIGS. 1 to 4. The

move upwardly toward the top of the container. The flexible side wall of the bag will move up the inside surface of the side wall of the container body 1 and the closed end of the bag will move toward the top cover 2, dispensing all of the material.

When all the material has been expelled from the container the bag B will be extended at full length as shown in dotted lines at 13 in FIG. 1 contacting the inside surfaces of both the body member 1 and the top cover member 2.

It is readily seen by this construction and operation that all the material has been dispensed without being in contact with the propelling agent.

The bag is adaptable to most containers, regardless of size where at least one end of the container is seamed to the outer rigid wall portion and the diameter of the sealed on end is substantially the same as the diameter of part of the outer rigid wall portion of the container, such as, the aluminum drawn containers now in general use which has either a bottom or top seamed to the body portion.

For certain types of materials to be dispensed, bags may be made from a material containing a small amount of stretch in the flexible portion of the bag together with the increased rigidity adjacent the center of the flexible portion as shown at 13' in FIG. 1 to allow the flexible end of the bag to move first upwardly from the fold line'and progressively upwardly from the fold line adjacentthe side wall of the outer rigid body 1 toward the top of the container and then outwardly in contact with the rigid outer'body and move progressively upwardly in contact with the outer body member including the top of the container as the last remaining contents of the container are dispensed.

The construction, use and operation of the bag B as main difference being that the open end of the bag B' is' seamed in'the seam S'- between the top of the outer rigid container body and the cover 2, as illustrated in FIG. 9. In this modification the bag B extends downwardly into the container and is filled in this position and, slowly reverses itself when fluid pressure is supplied to the outer surface of the closed end of the bag as previously described for the bag shown in FIGS. l to 4 for dispensing the material. The flexible portion 24 of the bag will gradually move back through the rigid portion 23 of the bag and into the top cover 2 as shown in dotted lines in FIG. 6 at 24', as the contents of the container are expelled.

In this. type of container the difference in pressure on each surface of the bag itself is very small, that is, if there is thirty pounds of pressure created by the propellent on the outer surface of the flexible closed end of the bag, the pressure on the material side of the bag is pracically the same, particularly when the flexible portion of the bag is extremely pliable. The bag acts as a rather extended free floating diaphragm between the expelling fluid and the material being dispensed. Therefore, there is very little tendency for the expelling fluid to go through the bag into the material chamber if the material from which the bag is constructed is reasonably impervious to gas. By using a material in the making of the bag that is substantially impervious to fluids, there will be little intermingling of the propellent and the material being dispensed. This is very desirable for certain products mentioned hereinbefore.

In constructing the container, the inner edge of the rigid portion of the bag and the fold line are positioned downwardly from the top of the container at a distance substantially equal to the length of the movable portion of the bag.

This arrangement in a container provides, when using an evaporating liquid gas an even and constant pressure on the flexible portion of the bag in which the product is contained, which gives the same pressure on the last remaining amount of the contents as it does at the beginning. Also when an evaporating liquid is used as the propellent medium it may be calculated as to the necessary amount to be transformed into gas of a predetermined pressure to fill the containerwhen the bag is fully extended in the upper end of the container.

Of course it is not intended that the invention be limited to the exact details of construction herein shown and described as these maybe varied within the scope of the appended claims.

Having illustrated and described the invention, what is claimed as new and useful and desired to be covered by Letters Patent is:

1. An internal pressure container for dispensing materials comprising in combination, an outer rigid body portion of greater vertical height than its diameter, an outer rigid bottom upon which the container may be independently supported hermetically'fixed on one end of the body portion and an outer rigid top cover hermetically enclosing the opposite end of the body portion including an opening for receiving a closure and a-valve mechanism fixed within the opening'through which-the material is introduced and dispensedya reversible bag having a side wall, a closed end and an open end,'-a

,portion of the side .wallof the 'bag adjacent its open end being of greater thickness than the remaining portion of the bag for holding said portion in extended position,

said thick portionlbeing slidably receivable into and fitted to the inside surface of the rigid body portion having its closed end formed to substantially fit adjacent the inner s fa e i the p t th container wh n f lly extended in anupwa d positi t b g ha g t p n end hermetically sealed about one end of the body portion, the thicker portion of the bag being of-such thickness as to increase its rigidity sufficiently to preventits collapsing under "the weight of the material and the internal pressure of the containenthe thicker portion of the side wall extending to-"substantially one :half the height of the container, the closed end of the bag and the "portion of the side wall beyond the inner edge of the thicker extended portion being flexible and foldable into and about the inner end of the thicker extended portion of the bag, the inner end of the thicker extended portion of the bag providing a fulcrum about which the flexible portion of the bag is folded into the inner end of the extended thicker portion, whereby the flexible wall and closed end portion of the bag is movable longitudinally of the container from the top thereof to a point adjacent the bottom of the container for receiving the material to be dispensed, the length of the flexible portion of the bag being substantially the same length as the distance from the inner edge of the thicker portion of the side wall of the bag to the top of the container, said container being provided with a space between the bottom of the container and the closed end of the bag when the closed end of the bag is in a downward position within the container for receiving an expandable fluid for exerting pressure on thesurface of the bag presented towards the bottom of the container for forcing the flexible portion of the bag and the material upwardly toward the top of the container for dispensing the material through the said dispensing valve mechanisrn.

2. An internal pressure container as claimedin claim 1 he e n h cen e Qt t vfle b P n o t e b ;is slightly thicker than the remaining flexible portion of the bag, thereby enabling the remaining side wall of the flexible portion of the bag to first yield under the pressure of the expandable fluid.

References Cited in the file of this patent UNITED STATES PATENTS

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