CA1255266A - Expandable pressurized barrier container - Google Patents
Expandable pressurized barrier containerInfo
- Publication number
- CA1255266A CA1255266A CA000492323A CA492323A CA1255266A CA 1255266 A CA1255266 A CA 1255266A CA 000492323 A CA000492323 A CA 000492323A CA 492323 A CA492323 A CA 492323A CA 1255266 A CA1255266 A CA 1255266A
- Authority
- CA
- Canada
- Prior art keywords
- wall
- ring
- barrier
- product
- container
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000004888 barrier function Effects 0.000 title claims abstract description 133
- 239000000047 product Substances 0.000 claims abstract description 100
- 238000007789 sealing Methods 0.000 claims abstract description 25
- 239000000853 adhesive Substances 0.000 claims abstract description 9
- 230000001070 adhesive effect Effects 0.000 claims abstract description 9
- 239000000155 melt Substances 0.000 claims abstract description 5
- 239000003380 propellant Substances 0.000 claims description 52
- 239000000463 material Substances 0.000 claims description 19
- 239000002985 plastic film Substances 0.000 claims description 3
- 230000002730 additional effect Effects 0.000 claims 1
- 238000000034 method Methods 0.000 abstract description 9
- 230000008569 process Effects 0.000 abstract description 6
- 239000004033 plastic Substances 0.000 abstract description 5
- 229920003023 plastic Polymers 0.000 abstract description 5
- 230000002093 peripheral effect Effects 0.000 description 15
- 239000007789 gas Substances 0.000 description 8
- 229910052782 aluminium Inorganic materials 0.000 description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 238000013461 design Methods 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- -1 polyethylene Polymers 0.000 description 4
- 208000036366 Sensation of pressure Diseases 0.000 description 3
- 239000000443 aerosol Substances 0.000 description 3
- 230000003466 anti-cipated effect Effects 0.000 description 3
- 239000004698 Polyethylene Substances 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 239000003292 glue Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 229920001155 polypropylene Polymers 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- RZVAJINKPMORJF-UHFFFAOYSA-N Acetaminophen Chemical compound CC(=O)NC1=CC=C(O)C=C1 RZVAJINKPMORJF-UHFFFAOYSA-N 0.000 description 1
- 241000905957 Channa melasoma Species 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 101100459301 Mus musculus Myl4 gene Proteins 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 238000000071 blow moulding Methods 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 235000013351 cheese Nutrition 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000003138 coordinated effect Effects 0.000 description 1
- 230000000875 corresponding effect Effects 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000012943 hotmelt Substances 0.000 description 1
- 238000007373 indentation Methods 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000010309 melting process Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 101150049598 psiK gene Proteins 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000008093 supporting effect Effects 0.000 description 1
- 238000007666 vacuum forming Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D83/00—Containers or packages with special means for dispensing contents
- B65D83/14—Containers or packages with special means for dispensing contents for delivery of liquid or semi-liquid contents by internal gaseous pressure, i.e. aerosol containers comprising propellant for a product delivered by a propellant
- B65D83/60—Contents and propellant separated
- B65D83/62—Contents and propellant separated by membrane, bag, or the like
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B11/00—Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use
- B05B11/01—Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use characterised by the means producing the flow
- B05B11/02—Membranes or pistons acting on the contents inside the container, e.g. follower pistons
- B05B11/026—Membranes separating the content remaining in the container from the atmospheric air to compensate underpressure inside the container
- B05B11/027—Membranes separating the content remaining in the container from the atmospheric air to compensate underpressure inside the container inverted during outflow of content
Landscapes
- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Containers And Packaging Bodies Having A Special Means To Remove Contents (AREA)
Abstract
EXPANDABLE PRESSURIZED BARRIER CONTAINER
ABSTRACT OF THE DISCLOSURE
A pressurized thin walled expandable can from which a fluent pressurized product is dispensed is made from an expandable can wall and a barrier, which may be a fully evertable bag having uniform thickness and flexi-bility and shaped to fit within the can wall. The open end of the bag is mounted to the can wall by means which maintain a seal as the can wall expands and returns to its unexpanded condition. As product to be dispensed is introduced into the product chamber, the flexible bag is extended down into the lower end of the can. As the pro-duct is later expelled through a discharge opening, the flexible bag, which may be plastic, is fully everted into the upper end of the can to expel all the product. The can is thin walled, so that when pressurized, the can di-ameter expands by at least one-thousandth (1/1000) of its unexpanded value. In one embodiment, the bag is mount-ed by a ring inside the can. The ring includes a portion which expands to maintain the seal with the expanding can side wall. In another embodiment the ring is rigid, but of slightly larger diameter than the can. This ring stretches the can, so as to maintain the sealing contact with the can as the can expands. In other embodiments, the bag may be mounted by a stretchable adhesive and, if the bag is slightly elastic, it may be mounted by an ad-hesive or by a melt seal process such as heat sealing.
ABSTRACT OF THE DISCLOSURE
A pressurized thin walled expandable can from which a fluent pressurized product is dispensed is made from an expandable can wall and a barrier, which may be a fully evertable bag having uniform thickness and flexi-bility and shaped to fit within the can wall. The open end of the bag is mounted to the can wall by means which maintain a seal as the can wall expands and returns to its unexpanded condition. As product to be dispensed is introduced into the product chamber, the flexible bag is extended down into the lower end of the can. As the pro-duct is later expelled through a discharge opening, the flexible bag, which may be plastic, is fully everted into the upper end of the can to expel all the product. The can is thin walled, so that when pressurized, the can di-ameter expands by at least one-thousandth (1/1000) of its unexpanded value. In one embodiment, the bag is mount-ed by a ring inside the can. The ring includes a portion which expands to maintain the seal with the expanding can side wall. In another embodiment the ring is rigid, but of slightly larger diameter than the can. This ring stretches the can, so as to maintain the sealing contact with the can as the can expands. In other embodiments, the bag may be mounted by a stretchable adhesive and, if the bag is slightly elastic, it may be mounted by an ad-hesive or by a melt seal process such as heat sealing.
Description
EXPANDABLE PRESSURIZED BARRIER CONTAINER
BACKGROUND OF THE INVENTION
.. . . _ This invention relates to a pressurized can from which a fluent product is dispensed by actuating a prod-uct discharge valve, and particularly, a pressurized canhaving a barrier which separates the product from a pres-surlzed gaseous or liquefied propellant.
Pressurized cans are used for dispensing liquid, semiviscous and viscous products. A can from which a li-quid product is dispensed is often called an aerosol can.In some of these cans, in order to prevent cavitation, a barrier separates the product from the propellant. Three basic types of barriers in pressurized cans have typic-ally been used, a piston system, a sprayed on strippable film bag, or a bag system.
In the plston system, a ~ree piston, which is shiftable along the interior of the can, is the ~arrier.
See U.S. Patent 4,171,757. The piston system works for many products, but because the piston does not create an impenetrable barrier at the can wall, this system should not be used for products which may bypass the piston.
Furthermore, the piston system is also ineffective ~ith certain limited types of seamed cans, oddly shaped cans, cans that change in cross-section over the height of the can, and misshapen cans, since the barrier piston then has difficulty sealing to the wall of the can as the pis-ton moves.
In the strippable film system, a plastic compo-sition is sprayed onto the peripheral side wall and the bottom wall of the can. As the product is e~pelled from the can, the film is pushed up by the pressurized propel-lant beneath it, and the film gradually strips away from the sides and bottom of the can to push the product out.
~ecause the bag is being stripped away from the bottom upwardly, the bag cannot be "pinched-off" and a cut off in the flow of the product is avoided. To e~sure even stripping of the bag, the can should be relatively rigid.
The strippable film arrangement has a relatively expen-sive fabricating process.
The bag system may be made in a number of ways.
In one variant, a bag is inserted into the can and it is either brought out and around the lip of the can or it is sealed to the chime or top rim of the can. In either case, special folds or pleats formed in the bag or a col-lectlng tube in the bag are necessary to prevent the bag from collapsing and pinching or cutting off the flow of the product, especially as the bag collapses toward the top of the can under pressure while the product is being expelled~ The bag system of this variant tends to be expensive because the bags have to be made with either folds or pleats to avold the "pinching-off" problem.
further disadvantage of this bag system is that bags which are connected at their opening to the lip or chime _ 3 ~ S~ ~
of the cans tend to both collapse and tear off at ~he chime or at the seams. Although inserting a collecting tube into the bag may overcome some of these problems, the increased cost tend~ to make this approach impracti-cal.
In a modification of the just described bag sys-tem, the bag is simply secured at the top or the bottom of the can, without being a specially designed bag, but this system is not capable of fully expelling all of the contents of the can.
In another variant of the bag system, the bag is fixedly secured part way along the height of the can, be-tween the ends of the can. In typical examples of this system, the position of the bag along the height of the can is predetermined, before can assembly and filling, by the bag being secured between bottom and top halves of a two part container, by an attachment fixture in the can, or by slots or grooves in the can which fix the location of the bag. Such a bag may be capable of everting for expelling all of the contents of the can. But, this var-iant is not universally efficient i'or all pressures or all materials being expelled, for all types of propel-lants or all sizes of cans, and assembly of a can with such a bag system may be difficult or expensive.
Dif~erent propellants, e.g. a gaseous propellant or a liquid propellant, require that they occupy quite differen-t percentages of the total volume of a can, as discussed in more detall below. For any particular si~e can, where the posltLon of the bag along the can is pre-determined by the can design, it is necessary ~or a manu-~acturer to design and inventory difi1erent sets of cans for differently positioned bags in the cans. ~ can which is more universally usable would be preferred.
_ 4 _ ~ ~5~6 Conventional cans used in the bag system are relatively thick and rigid. In some cases, this is nec-essary to maintain the seal between the bag and the can wall~
It would be advantageous to provide a pressur-ized barrier container using a thin, expandable can wall, which would be substantially less expensive than a con-ventional thick, rigid can wall. In addition, it would be advantageous to provide such a container which could be used with an inexpensive barrier mounted in a simple manner to the can wall.
SUMMARY OF THE INVENTION
It is an object of the present invention to pro-vide a pressurized can with a barier system which may be used with a thin expandable can wall in which an inexpen-sive barrier is mounted in a simple manner.
Another object of the invention is to provide a barrier which dispenses the entire product contents of a pressurized can without trapping product in the can.
It is a ~urther object oi' the invention to pro-vide a barrier system which may be used with a great var-iety of cans, including cans which are oddly shaped.
Another object of the invention is to provide an effective barrier in an expandable can between the prod-uct to be dispensed and the pressurized dispensing pro-pellant.
It is still a ~urther object of the invention to provide a barrier system which can be firmly and immov-ably attached to the peripheral side wall o~ the can to avoid sealing problems.
Yet a further object of the invention is to pro-vide a barrier system using a flexible barrier which can be easily disposed at any selected location along the height o~ the can.
~5;5~i6 Another object o~ the invention is to assure that the flexible barrier positioned in the can will re-main sealed to the side wall of the can even as the pres-sure in the can causes its walls to e~pand.
A pressuri7able container according to the in-vention comprises an expandable can wall and a barrier~
The barrier is mounted to the can wall by means which ensure that a seal is maintained as the can wall expands due to pressure.
More specifically, the invention provides a bar-rier system for an expandable pressurized can from which a fluent product is dispensed under pressure through a discharge opening in the can. The can has a wall ~hich surrounds a can chamber and has the discharge opening at its upper end. The can side walls are thin enough that under pressures to which the contents of the can are pressurized, the side walls will flex and expand out-wardly slightly. The diameter of the wall across the can may increase by at leat one one-thousandth (l/lOOO) o~
its unexpanded value as the pressure goes from zero to 100 psi.
A flexible barrier, such as a bag in the shape of a cup, is mounted in the can to divide the can chamber into a product chamber above the barrier and a propellant chamber below the barrier. The barrier is impervious to the product being dispensed and to the propellant for dispensing it. The ~lexible barrier is sealed to the peripheral wall o~ the can by sealing means to guarantee that neither the propellant nor the product can leak past the seal, and the seal is maintained according to the inventlon even when the can pressure causes the can walls to flex and expand. The barrier is mounted in the can so that it everts as the product is dispensed from the can.
~2S~ 6 The sealing means may comp~ise a fairly rigid ring of plastic, or the like, which is disposed inside the open peripheral edge of the barrier. The ring has a peripheral exterior shaped and sized for snugly fitting against the inner surface of the side wall of the can.
The ring is inserted into the barrier, and the ring in-side the barrier presses against the side wall o-f the can. The ring is placed in the can at a height which will allow the barrier to be everted~
As the can walls are flexible and are expected to flex slightly when the can is pressurized, the ring must assure the continuing seal between the product and propellant chambers, respectively above and below the barrier. Appropriate means comprising at least one of either the can wall and the inserted ring are stressed and deformed before the can is pressurized such that upon pressurization of the can and slight expansion of its side wall, the seal is still rnaintained.
In one embodiment, the ring includes expansible zo wall engaging means at its periphery which are sized so that when the ring is installed in the can before the can wall has expanded, the expansible means on the ring are compressed and de~ormed by the contact with the wall o~
the can. For example/ a plurality of resilient annular ridges or flanges may be defined on the ring periphery.
The flanges normally have a fully extended diameter greater than the expanded diameter oi' the can wall. Upon pressurization of the can, with corresponding expansion of its flexible wall, the expansible means, i.e. the ~langes on the ring, expand or flex outwardly to maintain contact and seal with the wall. In an alternate embodi-ment, the periphery o~ the ring includes a receptacle, such as a groove, for receiving an expansible means, such as a separate, expansible and compressible O ring. The O-ring is of a diameter to be compressed when the sealing ~5~
-- 7 ~
ring is inserted in the can. The O-ring is expansible to maintain a seal with the side wall of the can when the can expands.
In a second embodimen-t of the sealing means, tbe ring is rigid and its periphery is rigid. However, the ring diameter is selected to be slightly greater than the diameter of the can when the can is unpressurized. As the ring is installed by pushing it into the can, it de-forms the side wall outwardly. Wherever the ring is lodged along the height of the can, the can will be slightly deformed outwardly at that location. The extent to which the ring diameter is greater than that of the can is only slight. Too great a difference in these di-ameters would permanently deform the can wall to a new shape, and upon pressurization, the seal between the can wall and the ring would be broken. However, slight de-formation of the can wall would not cause a permanent change in shape of the can wall, '~hen this can is pres-surized, its wall above and below the ring expands, while the slightly deformed section of the can wall at the ring does not correspondingly expand, and the can to ring seal is thereby maintained.
The sealing means may take other forms, provided that the seal is maintained as the can wall expands. In an additional embodiment, a stretchable adhesive is used which stretches as the can wall expands without cracking or otherwise breaking the seal. In another additional embodime~t, the barrier itself is sufficiently stretcha-ble that the sealin~ means may be a direct mounting of the barrier to the wall by adhesive or by a melting pro-cess such as heat sealing.
In one embodiment, the flexible barrier is formed from a sheet with a surface area which is greater than the transverse cross-section o~ the can. The sheet may form a bag in the shape of a cup. The flexible bar-rier is e~tendible into the can below the ring when thecan is filled with product, and is extendible above the ring through the pressure exerted by the propellant in the propellant chamber as product is being expelled from the product chamber~ The flexible barrier is everted above the ring and pushes the product out until substan-tially all of the product has been e~pelled.
The can is fitted with an upper cover which also supports a discharge valve through which the product is eventually expelled. The can is filled with product up to the underside of the cover. The upper cover may be in the shape of a dome, and the product discharge valve can be fitted at the apex of -the dome. A gaseous or liqui-fied propellant is introduced into the bottom of the can beneath the barrier to define the propellant chamber and this serves to pressurize the product within the can above the barrier.
~ s the product is expelled through the discharge opening, the barrier under pressure from below begins to evert into the upper region of the can to continually keep the product pressurized. The size or surface area of the barrier and the point along the height oE the can at which it is secured to the can are chosen such that when the barrier is ~ul]y everted, its top sur~ace is in contact with the peripheral side wall and with the upper cover of the can to ensure that substantially all o~ the product has been expelled ~rom the can.
Other ~eatures and advantages o~ the invention will be appar0nt trom the ~ollowing description of the preierred embodiments illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DR~WINGS
. .
Fig. 1 shows a cup shaped barrier assembled with a sealing ring prior to insertion into the can body.
~552~
g Fig. 2 shows the can body prior to the inser$ion of the barrier.
Fig. 3 is a cross-sectional, elevational view showing a pressurized fluent material containing and dis~
pensing can having in it a barrier according to a pre-ferred embodiment of the invention.
Fig. 4 shows the pressurized can after it has been filled with product and sealed ~ith a top cover and after a small quantity of product has been expelled from the can.
Fig. 5 shows the can and barrier after all the product has been expelled.
Fig. 6 shows a first sealing ring embodiment ~or the barrier for providing the seal between the product and propellant chambers of the pressurized can.
Fig. 7 shows a second embodiment of such a ring.
Fig. 8 shows a third embodiment of such a ring and can construction for such purpose.
Fig. 9 shows an alternate embodiment of pressur-~0 ized can in which the barrier is mounted directly to thecan wall, DETAILED DRSCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Fig~ 2, the pressurizable can ac-cording to the invention includes an outer can 10 com-prising a cylindrical body, defined by a cylindrical per-ipheral side wall 12, an open to~ 1~, and a closed bottom 16 shaped to allow the pr~ssurized can to stably rest on a ~lat surface. For strength, the can bottom 16 includes a peripheral rounded ridge 17 on whose crest the can sits, and a rounded depression 18. Other bottom shapes can be used to increase the strength of the can, and a number of such shapes are generally ~nown in the art.
The top o~ the depression has a pluggable hole 19 through it into the can. A gaseous or liquified propellant is conventionally supplied (Erom a source not shown) through the hole 19 after the top opening 1~ has been closed so that the can may be pressurized. Thereafter, a plug 21 is installed in the hole 19 to Glose it.
S The material of the can is typically metal.
However, other materials like strengthened paper or plas tic may be used, so long as it is strong enough to con-tain the pressure in a filled pressurized can. For safety, it is desirable often that the can be of metal.
For economic reasons, that is to reduce the amount of materials re~uired in can fabrication, it is desirable to have thin walled cans. The can wall accord-ing to the invention is sufficientIy thin that it expands when the can chamber is pressurized. The dimension of the can w~ll across the can chamber, such as the diameter of a cylindrical can wall, will increase in length. For example, at the lower pressures described below, the can wall may be made by a drawn and ironed process from sheet steel or even sheet aluminum giving a wall thickness of .0045-.008 inch. It is even possible to use a steel can with a wall thickness of less than .0045 inch. In such a can which is sealed and under pressure, and where the temperature to which the can, its contents and the pro-pellant therein are exposed is in the range of 30-130F, the pressurization of the can could cause an increase in its diameter of between .002-.007 inch for temperatures of 30 130F, respectively. For a thin-walled can ac-cordlng to the invention, the diameter will increase by an increment whlch will be approximately one one-thous-andth (1/lO00) or more of its unexpanded value as it ispressuriz0d to a pressure of 100 psl. If the diameter is
BACKGROUND OF THE INVENTION
.. . . _ This invention relates to a pressurized can from which a fluent product is dispensed by actuating a prod-uct discharge valve, and particularly, a pressurized canhaving a barrier which separates the product from a pres-surlzed gaseous or liquefied propellant.
Pressurized cans are used for dispensing liquid, semiviscous and viscous products. A can from which a li-quid product is dispensed is often called an aerosol can.In some of these cans, in order to prevent cavitation, a barrier separates the product from the propellant. Three basic types of barriers in pressurized cans have typic-ally been used, a piston system, a sprayed on strippable film bag, or a bag system.
In the plston system, a ~ree piston, which is shiftable along the interior of the can, is the ~arrier.
See U.S. Patent 4,171,757. The piston system works for many products, but because the piston does not create an impenetrable barrier at the can wall, this system should not be used for products which may bypass the piston.
Furthermore, the piston system is also ineffective ~ith certain limited types of seamed cans, oddly shaped cans, cans that change in cross-section over the height of the can, and misshapen cans, since the barrier piston then has difficulty sealing to the wall of the can as the pis-ton moves.
In the strippable film system, a plastic compo-sition is sprayed onto the peripheral side wall and the bottom wall of the can. As the product is e~pelled from the can, the film is pushed up by the pressurized propel-lant beneath it, and the film gradually strips away from the sides and bottom of the can to push the product out.
~ecause the bag is being stripped away from the bottom upwardly, the bag cannot be "pinched-off" and a cut off in the flow of the product is avoided. To e~sure even stripping of the bag, the can should be relatively rigid.
The strippable film arrangement has a relatively expen-sive fabricating process.
The bag system may be made in a number of ways.
In one variant, a bag is inserted into the can and it is either brought out and around the lip of the can or it is sealed to the chime or top rim of the can. In either case, special folds or pleats formed in the bag or a col-lectlng tube in the bag are necessary to prevent the bag from collapsing and pinching or cutting off the flow of the product, especially as the bag collapses toward the top of the can under pressure while the product is being expelled~ The bag system of this variant tends to be expensive because the bags have to be made with either folds or pleats to avold the "pinching-off" problem.
further disadvantage of this bag system is that bags which are connected at their opening to the lip or chime _ 3 ~ S~ ~
of the cans tend to both collapse and tear off at ~he chime or at the seams. Although inserting a collecting tube into the bag may overcome some of these problems, the increased cost tend~ to make this approach impracti-cal.
In a modification of the just described bag sys-tem, the bag is simply secured at the top or the bottom of the can, without being a specially designed bag, but this system is not capable of fully expelling all of the contents of the can.
In another variant of the bag system, the bag is fixedly secured part way along the height of the can, be-tween the ends of the can. In typical examples of this system, the position of the bag along the height of the can is predetermined, before can assembly and filling, by the bag being secured between bottom and top halves of a two part container, by an attachment fixture in the can, or by slots or grooves in the can which fix the location of the bag. Such a bag may be capable of everting for expelling all of the contents of the can. But, this var-iant is not universally efficient i'or all pressures or all materials being expelled, for all types of propel-lants or all sizes of cans, and assembly of a can with such a bag system may be difficult or expensive.
Dif~erent propellants, e.g. a gaseous propellant or a liquid propellant, require that they occupy quite differen-t percentages of the total volume of a can, as discussed in more detall below. For any particular si~e can, where the posltLon of the bag along the can is pre-determined by the can design, it is necessary ~or a manu-~acturer to design and inventory difi1erent sets of cans for differently positioned bags in the cans. ~ can which is more universally usable would be preferred.
_ 4 _ ~ ~5~6 Conventional cans used in the bag system are relatively thick and rigid. In some cases, this is nec-essary to maintain the seal between the bag and the can wall~
It would be advantageous to provide a pressur-ized barrier container using a thin, expandable can wall, which would be substantially less expensive than a con-ventional thick, rigid can wall. In addition, it would be advantageous to provide such a container which could be used with an inexpensive barrier mounted in a simple manner to the can wall.
SUMMARY OF THE INVENTION
It is an object of the present invention to pro-vide a pressurized can with a barier system which may be used with a thin expandable can wall in which an inexpen-sive barrier is mounted in a simple manner.
Another object of the invention is to provide a barrier which dispenses the entire product contents of a pressurized can without trapping product in the can.
It is a ~urther object oi' the invention to pro-vide a barrier system which may be used with a great var-iety of cans, including cans which are oddly shaped.
Another object of the invention is to provide an effective barrier in an expandable can between the prod-uct to be dispensed and the pressurized dispensing pro-pellant.
It is still a ~urther object of the invention to provide a barrier system which can be firmly and immov-ably attached to the peripheral side wall o~ the can to avoid sealing problems.
Yet a further object of the invention is to pro-vide a barrier system using a flexible barrier which can be easily disposed at any selected location along the height o~ the can.
~5;5~i6 Another object o~ the invention is to assure that the flexible barrier positioned in the can will re-main sealed to the side wall of the can even as the pres-sure in the can causes its walls to e~pand.
A pressuri7able container according to the in-vention comprises an expandable can wall and a barrier~
The barrier is mounted to the can wall by means which ensure that a seal is maintained as the can wall expands due to pressure.
More specifically, the invention provides a bar-rier system for an expandable pressurized can from which a fluent product is dispensed under pressure through a discharge opening in the can. The can has a wall ~hich surrounds a can chamber and has the discharge opening at its upper end. The can side walls are thin enough that under pressures to which the contents of the can are pressurized, the side walls will flex and expand out-wardly slightly. The diameter of the wall across the can may increase by at leat one one-thousandth (l/lOOO) o~
its unexpanded value as the pressure goes from zero to 100 psi.
A flexible barrier, such as a bag in the shape of a cup, is mounted in the can to divide the can chamber into a product chamber above the barrier and a propellant chamber below the barrier. The barrier is impervious to the product being dispensed and to the propellant for dispensing it. The ~lexible barrier is sealed to the peripheral wall o~ the can by sealing means to guarantee that neither the propellant nor the product can leak past the seal, and the seal is maintained according to the inventlon even when the can pressure causes the can walls to flex and expand. The barrier is mounted in the can so that it everts as the product is dispensed from the can.
~2S~ 6 The sealing means may comp~ise a fairly rigid ring of plastic, or the like, which is disposed inside the open peripheral edge of the barrier. The ring has a peripheral exterior shaped and sized for snugly fitting against the inner surface of the side wall of the can.
The ring is inserted into the barrier, and the ring in-side the barrier presses against the side wall o-f the can. The ring is placed in the can at a height which will allow the barrier to be everted~
As the can walls are flexible and are expected to flex slightly when the can is pressurized, the ring must assure the continuing seal between the product and propellant chambers, respectively above and below the barrier. Appropriate means comprising at least one of either the can wall and the inserted ring are stressed and deformed before the can is pressurized such that upon pressurization of the can and slight expansion of its side wall, the seal is still rnaintained.
In one embodiment, the ring includes expansible zo wall engaging means at its periphery which are sized so that when the ring is installed in the can before the can wall has expanded, the expansible means on the ring are compressed and de~ormed by the contact with the wall o~
the can. For example/ a plurality of resilient annular ridges or flanges may be defined on the ring periphery.
The flanges normally have a fully extended diameter greater than the expanded diameter oi' the can wall. Upon pressurization of the can, with corresponding expansion of its flexible wall, the expansible means, i.e. the ~langes on the ring, expand or flex outwardly to maintain contact and seal with the wall. In an alternate embodi-ment, the periphery o~ the ring includes a receptacle, such as a groove, for receiving an expansible means, such as a separate, expansible and compressible O ring. The O-ring is of a diameter to be compressed when the sealing ~5~
-- 7 ~
ring is inserted in the can. The O-ring is expansible to maintain a seal with the side wall of the can when the can expands.
In a second embodimen-t of the sealing means, tbe ring is rigid and its periphery is rigid. However, the ring diameter is selected to be slightly greater than the diameter of the can when the can is unpressurized. As the ring is installed by pushing it into the can, it de-forms the side wall outwardly. Wherever the ring is lodged along the height of the can, the can will be slightly deformed outwardly at that location. The extent to which the ring diameter is greater than that of the can is only slight. Too great a difference in these di-ameters would permanently deform the can wall to a new shape, and upon pressurization, the seal between the can wall and the ring would be broken. However, slight de-formation of the can wall would not cause a permanent change in shape of the can wall, '~hen this can is pres-surized, its wall above and below the ring expands, while the slightly deformed section of the can wall at the ring does not correspondingly expand, and the can to ring seal is thereby maintained.
The sealing means may take other forms, provided that the seal is maintained as the can wall expands. In an additional embodiment, a stretchable adhesive is used which stretches as the can wall expands without cracking or otherwise breaking the seal. In another additional embodime~t, the barrier itself is sufficiently stretcha-ble that the sealin~ means may be a direct mounting of the barrier to the wall by adhesive or by a melting pro-cess such as heat sealing.
In one embodiment, the flexible barrier is formed from a sheet with a surface area which is greater than the transverse cross-section o~ the can. The sheet may form a bag in the shape of a cup. The flexible bar-rier is e~tendible into the can below the ring when thecan is filled with product, and is extendible above the ring through the pressure exerted by the propellant in the propellant chamber as product is being expelled from the product chamber~ The flexible barrier is everted above the ring and pushes the product out until substan-tially all of the product has been e~pelled.
The can is fitted with an upper cover which also supports a discharge valve through which the product is eventually expelled. The can is filled with product up to the underside of the cover. The upper cover may be in the shape of a dome, and the product discharge valve can be fitted at the apex of -the dome. A gaseous or liqui-fied propellant is introduced into the bottom of the can beneath the barrier to define the propellant chamber and this serves to pressurize the product within the can above the barrier.
~ s the product is expelled through the discharge opening, the barrier under pressure from below begins to evert into the upper region of the can to continually keep the product pressurized. The size or surface area of the barrier and the point along the height oE the can at which it is secured to the can are chosen such that when the barrier is ~ul]y everted, its top sur~ace is in contact with the peripheral side wall and with the upper cover of the can to ensure that substantially all o~ the product has been expelled ~rom the can.
Other ~eatures and advantages o~ the invention will be appar0nt trom the ~ollowing description of the preierred embodiments illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DR~WINGS
. .
Fig. 1 shows a cup shaped barrier assembled with a sealing ring prior to insertion into the can body.
~552~
g Fig. 2 shows the can body prior to the inser$ion of the barrier.
Fig. 3 is a cross-sectional, elevational view showing a pressurized fluent material containing and dis~
pensing can having in it a barrier according to a pre-ferred embodiment of the invention.
Fig. 4 shows the pressurized can after it has been filled with product and sealed ~ith a top cover and after a small quantity of product has been expelled from the can.
Fig. 5 shows the can and barrier after all the product has been expelled.
Fig. 6 shows a first sealing ring embodiment ~or the barrier for providing the seal between the product and propellant chambers of the pressurized can.
Fig. 7 shows a second embodiment of such a ring.
Fig. 8 shows a third embodiment of such a ring and can construction for such purpose.
Fig. 9 shows an alternate embodiment of pressur-~0 ized can in which the barrier is mounted directly to thecan wall, DETAILED DRSCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Fig~ 2, the pressurizable can ac-cording to the invention includes an outer can 10 com-prising a cylindrical body, defined by a cylindrical per-ipheral side wall 12, an open to~ 1~, and a closed bottom 16 shaped to allow the pr~ssurized can to stably rest on a ~lat surface. For strength, the can bottom 16 includes a peripheral rounded ridge 17 on whose crest the can sits, and a rounded depression 18. Other bottom shapes can be used to increase the strength of the can, and a number of such shapes are generally ~nown in the art.
The top o~ the depression has a pluggable hole 19 through it into the can. A gaseous or liquified propellant is conventionally supplied (Erom a source not shown) through the hole 19 after the top opening 1~ has been closed so that the can may be pressurized. Thereafter, a plug 21 is installed in the hole 19 to Glose it.
S The material of the can is typically metal.
However, other materials like strengthened paper or plas tic may be used, so long as it is strong enough to con-tain the pressure in a filled pressurized can. For safety, it is desirable often that the can be of metal.
For economic reasons, that is to reduce the amount of materials re~uired in can fabrication, it is desirable to have thin walled cans. The can wall accord-ing to the invention is sufficientIy thin that it expands when the can chamber is pressurized. The dimension of the can w~ll across the can chamber, such as the diameter of a cylindrical can wall, will increase in length. For example, at the lower pressures described below, the can wall may be made by a drawn and ironed process from sheet steel or even sheet aluminum giving a wall thickness of .0045-.008 inch. It is even possible to use a steel can with a wall thickness of less than .0045 inch. In such a can which is sealed and under pressure, and where the temperature to which the can, its contents and the pro-pellant therein are exposed is in the range of 30-130F, the pressurization of the can could cause an increase in its diameter of between .002-.007 inch for temperatures of 30 130F, respectively. For a thin-walled can ac-cordlng to the invention, the diameter will increase by an increment whlch will be approximately one one-thous-andth (1/lO00) or more of its unexpanded value as it ispressuriz0d to a pressure of 100 psl. If the diameter is
2.50 inches, -the increment will be approximately .0025 inch or more. This increment is approximate in that it is within the scope of the invention for the increment to ~5 5i~ D
be a few ten-thousandths of an inch less than this value, depending on the particular alloy of the can.
It has been found that even a gap of .OO1 inch between the side wall of the can and a ring suppor-ting a barrier in the can will permit leakage of propellant and/
or product past the ring and barrier, which is undesira-ble. Therefore, the container according to the invention includes means for mounting the edge of the flexible bar-rier to the can wall and for sealing the mounting for preventing the product and propellant from leaking past the edge of the barrier as the can wall expands and re-turns to its unexpanded condition~ This means may take any of several forms, as described below.
Because the propellant is not mixed ~ith nor ex-pelled with product from the can 10, the initial pressureand quantity of the propellant in the can need not be very high, and with some very fluent products and rela-tively larger discharge valve orificest -the can pressure can be quite low, e.g. 10-B0 psig for low viscosity prod-ucts, as compared with the conventional aerosol barriercan pressure of about 90-lOO psiK. This lower pressure helps to avoid stress on the seal and can-~a~ wall, per-mitting use of thinner walls and simpler bottoms, but higher presssure, up to 120 psig or more, could also be used with cans whose walls and bottoms are designed to withstand this stress.
There are a variety of dif ferent propellants which may be placed in the pressure chamber, including various compressed gases or liqui:Eied gases, Where the propellant is a compressed gas, typically in an aerosol container, the compressed gas pressure chamber occupies in the range oE 1/3-1/~ of the total volume of the entire can. On the other hand, where the propellant is in the Earm of a liquified gas, the pressure chamber occupies in the ran~e of 1/10-1/50 of the total volume of the can.
It is economically desirable to produce a st~ndard can design which can include a barrier that is adapted for either type of propellant, that is where the propellant chamber can be relatively smaller in volume or where it S must be larger. The invention permits this.
Also, there is a wide variety of fluent products which may be contained in and expelled from the can 10, including quite fluent li~uids of a viscosity of 10,000 cps or less and higher viscosity products like processed 10foods, e.g. cheese at a viscosity upwards of 300,000 cps or even higher, depending on the rheological properties of the product. Very low viscosity products, such as water and alcohol (1 cps or less) may also be contained and expelled.
15Referring to Figs. 1, 3-5, there is a barrier 20 in the can, which is shown in the shape of a cup. The barrier is a sheet of greater cross-section than the can, and the barrier sheet may be cut and folded so that the cup shape may be defined. Further, the sheet may have a pocket or generally tubular shape or it may be flat, al-though i-ts surface area and shape are preferably such that the sheet will extend to the closed cover of the can, as described below. The cup shaped barrier has a side wall 22 and a closed bottom. The barrier may simply be a flat sheet which is deformed in use. It may be a sheet with cut regions which enable the sheet to be shaped into a cup, and the cut regions of the sheet are attached to the can at their marginsl The cup is of a flexible material so that the cup may be filled and later everted as described below. The cup may also be made by vacuum forming or blow molding.
The material of the barrier 20 need merely be sufficiently ductile and flexible to evert as described below and be impervious to the product and to the propel-lant which contacts the barrier at its opposite sides.
The material is preferably not a highly stretchable material like rubber, although some stretching may be desired. For example, an ine~pensive plas-tic sheet or tube material of substantially uniform thickness and flexibility may be ~olded and heated to form a cup-shaped ~ bag. Suitable ~lastics could inclu~e polyethylene, poly-g~ propylene, Myl ~, Sara~,~an ~so ~o~th, The barrier maybe made of a paper, e.~. a waxed paper. It may be of any appropriate fabric. It could even be a metallic barrier, such as an alumi,num film, or metallized plastic, such as aluminum on Myla~o~r ~aran~rC~e~' J
The means for mounting and sealing the barrier 20 to side wall 12 of can 10 may take several ~orms. In general, the mounting and sealing means must maintain the seal despite the expansion of the can. If can wall 12 is smooth and continuous, a seal may be more easily main-tained, in most cases. The specific forms of the mount~
ing and sealing means described below include ring seals as well as adhesives and melt sealing.
F'igs. 1 and 3-5 show a general ring seal embodi-ment in which a barrier fastening ring 24 is inserted into the barrier 20 and is positioned in the region near the upper edge 26 of the cup shape. The barrier 20 with its ring 24 are inserted into the can 10 and are posi-tioned a distance clown from the open top 14 of the can.
The dimensions of the ring 24 and the barrier are selec-ted such that the ring 24 can snugly fit against the per-ipheral side wall 12 of the can 10, thereby securing the barrier cup 20 firmly in the can. In this manner, the can 10 is divided by the cup into the upper product cham-ber 30 and the bot-tom propellant chamber 32, The size and shape oi' the barrier are coordina-ted with the height of the can 10 and with the position oi the ring 24 along the height of the can intermediate the upper and lower ends so that when the barrier is sub-stantially fully extended, it will e~tend toward the bottom of the can and be substantially fully in contact with the peripheral side of the can when the can is loaded with the product and it will extend toward the top oi the can and be substantially fully in contact with the side of the can and with the cover over the can when all the product has been expelled. Although barrier 20 could be slightly larger than the upper region, it is prei'erable that the barrier substantially fill the upper region of the can when fully everted, barely leaving some unfilled space, so that it cannot be pinched off by islanding caused by the propellant and so that nearly all of the product may be expelled. This makes it unnecessary to use a tube or other device to prevent pinch-off. Any suitable type of valve may be used in the discharge open-ing.
For use with liquified gas propellants, the ini-tial volume of the upper product chamber 30 may be much larger than that of the bottom propellant chamber 32, on ~0 the order of 15 or 20 to one, thereby utilizing the majority of the space within the can body for the prod-uct. For use with compressed gas propellants, the ini~
tial volume of the product chamber 30 to the initial vol-ume of the propellant chamber 32 would typically be on the order of 2 or 3 to 1. To accommodate these different chambers of different volume in a can of a standard size, and to enable the two chambers 30, 32 to have a correct volume relationship, lt is desirable to be able to posi-tion the ring 24 and the barrier at appropriate selected positions along the height o~ the can wall.
As the invention is intended to assure complete expulsion of product in the chamber 30, the barrier size and shape are selected so that the barrier will press against the inside of the can cover on eversion to expel product, and the barrier will not be folded or wrinkled there but will instead be i'ully extended.
The two chambers 30, 32 are sealed off at the peripheral side wall of the can by the outward ~orce ex-ertsd by the ring 2~ on the wall 12. As the pressures in the product and propellant chambers are identical when the discharge Yalve 38 is closed and are nearly identical when that valve is open, the holding ring is not likely to move along the wall of the can.
After the product has been loaded in the product chamber 30 of the can 10 and the propellant has been loaded in the propellant chamber 32 of the can 10, the can is pressurized. The internal pressure in the can causes the side wall of the can to bulge slightly in di-ameter. For example, if the can 10 is of aluminurD with a 2.5 inch diameter and with a wall that is 0.005 inch thick, when the can is pressurized to 60 psi at normal room temperature of 70C, its diameter will increase ap-proximately 0.004 inch. If this expansion is not compen-sated for, a radial clearance will be created between the interior of the can wall and the exterior of the ring 24.
The radial clearance will provide a leakage path between the product and propellant chambers allowing gas and/or product to bypass the barrier cup 20, resultlng in a pressure reduction in the can, leakage of propellant out of the valve of the can and inability to properly expel all of the product from the product chamber.
A number of ring seal embodiments described herein compensate for the bulging enlargement of the di-ameter of the can.
The first alternative is to provide the ring 24 with a preloaded, radially expansible, elastic seal against the can wall, so that even when the can expands as it is pressurized, the ring expands with the can and maintains the seal. As shown in Fig. 6, the ring 24 is provided on its periphery 42 with a vertically spaced array of annularly uninterrupted, resilient flanges 44, ~25~
each with a diameter greater than the anticipated inside diameter of the can when it has been e~panded under pres-sure. The flanges 44 are thin and flexible enough that as the ring 2~ is installed in the can, the flanges 44 are deflected radially inwardly, that is, they are some-what flattened against the periphery 42 of the ring. As the can wall expands upon pressuriza~ion, the resilient, somewhat flattened flanges resiliently deflect slightly outwardly to maintain their biased contact against the internal wall of the can for pressing the barrier against the can wall and maintaining the seal.
In the second embodiment of Fig. 7, in contrast, the ring 46 is of a different design. It is a solid, annular body with an exterior peripheral channel 48 which opens radially outwardly. The channel receives and holds in it an elastic, resilient, compressible sealing element 50, illus-trated as an O-ring. The diameter of the seal-ing element ring 5~ is slightly greater than the internal diameter of the can, even when the can has stretched un-der pressure. When the ring 46 with the captive O-ring 50 in the channel 48 is installed in the can, the O-ring 50 is compressed through its engagement against the can wall. As the can wa]l expands under pressure, the resil--ient ring 50 tends to restore itself to its undeflected condition and is biased outwardly against the barrier and the can wall for maintaining the seal there.
The third embodiment shown in Fig. ~ uses a dif-ferent approach to accomplish the same result. The above described thin, metal can wall is slightly deformable 3n under pressure. If the~ can wall is only slightly de-formed, at less than the degree of deformation which will permanently deflect the can wall from its normal profile, the normal resilience of the metal can material will tend to restore the wall to its original undeflected shapeO
(This is what occurs as th~ can is pressurized to a nor-~25~
mal extent and is gradually depressurized through use.) As shown in Fi~. 8, the annular ring 5~ inside the can 10 has an outer periphery 56 with a diameter that is only slightly greater than the diameter of the can wall even when that wall is pressurized. As a result, when the ring 54 is installed in the can, it does not unduly stretch and deform the can wall. The can wall therefore does not assume a new, deformed shape. Instead, the can wall yields slightly as the ring is moved along the can wall until it is finally lodged in a selected position.
The resilient, but not permanently de~ormed can wall maintains a tight seal with the ring and prevents leakage past the ring between the can chambers.
The ring 54 is si~ed so that it stretches the can wall larger than the diameter to which the can would expand at maximum loaded pressure and maximum anticipated temperature, but less than the yield point of the can material. For example, if an aluminum can with a 2.50 inch inner diameter and with 0.005 inch thick wall is pressurized to 60 psi at 70F, it expands approximately 0.004 inches in diameter, to an inner diameter of 2.50~
inches. This will create a hoop stress of approximately 15,000 psi. The ring 54 has its periphery sized to ex-pand the can wall by at least about two to four one-thousand-ths (2/1000-~/1000) from lts unexpanded diameter, and may expand it to 2.509 inch diameter, for example.
This expansion, referred to as interference, results in a seal which is maintined as the can expands under pres-sure. This wiL1 also create a hoop stress in the area of the ring of approximately 33,750 psi, which is still well below the yield point of the aluminum can material and of the ring, Even if the internal pressure in the can is raised to 100 psi at 70F, this will only expand the can tQ approxirnately 2,507 inch, with a hoop stress of 25,000 psi. Under all expected circumstances to which the can - 18 - ~ ~5~2~6~
may be exposed, the can will, therefore, not expand so that its inner diameter is greater than the outer diame~
ter of the periphery 56 of the ring. Good sealing con-tact will thereby be maintained and bypass of the ring between the two chambers is avoided.
The above techniques of maintaining a seal rely upon the elasticity of at least one of the can and ring ~or maintaining the seal, with the first mentioned tech-niques of Figs. 6 and 7 using the resilience of the ring to maintain the seal and the latter technique of Fig. 8 using the resilience of the can to maintain the seal.
A completely assembled pressurized can with a ring seal according to the invention is shown in Fig. 3.
The upper cover 34 closes off the top opening 1~ of the can. The cover 34 is shown dome shaped and has an apex 36 with a hole 37 through it in which a hole sealing, product discharge valve 38 is affixed. The cover is crimped to the chime 39 at the top of the can.
The can is filled with a fluent product through the hole 37 before the discharge valve 38 is emplaced.
This moves the barrier 20 down to the bottom of the can and defines and completely fills the barrier 20 and the product chamber 30. The can is i'illed with product to the underside of the cover 34, i.e. until it is com-pletely filled. Then the dlscharge valve 38 is emplaced,which closes the hole 37. The discharge valve may be a known tilt operated valve (or any other valve suitable for the purpose), and it seals the product chamber when it is closed. Next, the propellant chamber 32 is filled with a ~aseous, or liquifled propellant through the hole 19. When the desired pressure level or quantity is at-tained, the gaseous pressure supply or liquified propel-lant is removed and the hole 19 is plugged by a plug 21.
The can is now ready for operation.
~5~
-- 19 ~
The can in Fig. 4 is shown at a stags after a portion of the product has been expelled from the can through the valve 38. The barrier 20 is shown partially everted due to the propellant as the barrier assumes a shape defined by the remaining product.
Because the barrier is mounted to the peripheral side ~all 12 at a height which is near the middle of the can 10 with its cover on, the barrier moves from extend-ing downward into the can, is deflected up past the ring 24 and finally everts and extends upward into the cover 34, as substantially all the product is finally expelled, as shown in Fig. 5. This eversion prevents the barrier from pinching-off or islanding which would prevent expul-sion of the product due to some product being captured in a pinched-off region of the barrier.
The barrier cup is so shaped and the ring 2~ is so positioned that when the barrier 20 is fully everted as shown in Fig. 5, it substantially fills the space bounded by the cover 34 and the side wall 12 of the can located above the fastening ring 24. When the product chamber 30 is filled before product is expelled, the bar-rier fills a portion of the space bounded by the con-tainer bottom 16 and the side wall of the can. This as-sures that almost the entire volume which is bounded by the walls and bottom of the can 10, besides that volume needed for propellant, may be filled with the product and that all of the product is usefully expelled from the can when the barrler has been fully everted.
The sealing effectiveness can be increased through the lntroduction of sealing compounds between the fastening rin~ and the barrier and/or between the barrier and the can wall.
As the pressure differential across the barrier is usually ~uite small, it may alternatively be suffi-~
cient to secure the barrier cup 20 directly to the can wall without a ring 24. Other means ~or mounting and sealing the barrier may be used for directly mounting the barrier to the can wall at a seal 84 as shown ~n Fig. g.
Seal 64 may be obtained with a ring of adhesive applied directly between the entire upper edge of the barrier and the can wall or by a melt process in which the upper edge of the barrier is melted and sealed to the can wall.
This arrangement still must compensate for the anticipa-ted e~pansion of the can wall under pressure and its re-turn to the unexpanded condition.
If an adhesive is used to form seal 64, the ad-hesive substance and the upper edge ~2 of the barrer must -together be sufficiently expansible and contractable to compensate for change in can diameter. Any suitable ad-hesive which provides a sufficient bonding force to main-tain the seal may be used, including rubber cement, glue and hot melt glue. The barrier may be a stretchable material such as polypropylene.
If a melt process is used to form seal 6~, upper edge 62 of the barrier must alone be sufficiently expans-ible and contractable to compensate for can diameter change. The melt process may employ thermal, sonic, or radio frequency heating. The barrier may be polyethylene or polypropylene or any other suitable material. Again, it is nece9sary to obtain a suf~icient bonding force to maintain the seal. The barrier and the adhesives must be capable of stretching as needed without tearing and with-out tearing away from the periphery of the can.
The invention simplifies production oi the can and its product-propellant barrier and eliminates concern about close manu~acturin~ tolerances i~or the barrier and i'or its attachment to the can. For example, in previous barrier pack cans, which employ a piston barrier system, or in the bag barrier system with folded or pleated bag ~25~
side walls to enable the bag to collapse without pinch-off, the consistent predictable shape of the can lO was critical to the operation of the barrier system. With a piston system, an indentation in the container above the piston would prevent the piston from traveling ~]p the peripheral side ~all o~ the can. With the present bar-rier system, however, the container can be of almost any size or shape. It is not even necessary that the periph-eral side walls of the container be generally parallel to each other as with other known systems. Consequently, cans could be used with either esthetically pleasing shapes or other shapes which are designed in accordance with human iactor engineering principles.
Although the present invention has been de-scribed in connection with preferred embodiments thereof, many variations and modifications will now become appar-ent to those skilled in the art, It is preferred, there-iore, that the present invention be limited not by the speciiic disclosure herein, but only by the appended claims.
be a few ten-thousandths of an inch less than this value, depending on the particular alloy of the can.
It has been found that even a gap of .OO1 inch between the side wall of the can and a ring suppor-ting a barrier in the can will permit leakage of propellant and/
or product past the ring and barrier, which is undesira-ble. Therefore, the container according to the invention includes means for mounting the edge of the flexible bar-rier to the can wall and for sealing the mounting for preventing the product and propellant from leaking past the edge of the barrier as the can wall expands and re-turns to its unexpanded condition~ This means may take any of several forms, as described below.
Because the propellant is not mixed ~ith nor ex-pelled with product from the can 10, the initial pressureand quantity of the propellant in the can need not be very high, and with some very fluent products and rela-tively larger discharge valve orificest -the can pressure can be quite low, e.g. 10-B0 psig for low viscosity prod-ucts, as compared with the conventional aerosol barriercan pressure of about 90-lOO psiK. This lower pressure helps to avoid stress on the seal and can-~a~ wall, per-mitting use of thinner walls and simpler bottoms, but higher presssure, up to 120 psig or more, could also be used with cans whose walls and bottoms are designed to withstand this stress.
There are a variety of dif ferent propellants which may be placed in the pressure chamber, including various compressed gases or liqui:Eied gases, Where the propellant is a compressed gas, typically in an aerosol container, the compressed gas pressure chamber occupies in the range oE 1/3-1/~ of the total volume of the entire can. On the other hand, where the propellant is in the Earm of a liquified gas, the pressure chamber occupies in the ran~e of 1/10-1/50 of the total volume of the can.
It is economically desirable to produce a st~ndard can design which can include a barrier that is adapted for either type of propellant, that is where the propellant chamber can be relatively smaller in volume or where it S must be larger. The invention permits this.
Also, there is a wide variety of fluent products which may be contained in and expelled from the can 10, including quite fluent li~uids of a viscosity of 10,000 cps or less and higher viscosity products like processed 10foods, e.g. cheese at a viscosity upwards of 300,000 cps or even higher, depending on the rheological properties of the product. Very low viscosity products, such as water and alcohol (1 cps or less) may also be contained and expelled.
15Referring to Figs. 1, 3-5, there is a barrier 20 in the can, which is shown in the shape of a cup. The barrier is a sheet of greater cross-section than the can, and the barrier sheet may be cut and folded so that the cup shape may be defined. Further, the sheet may have a pocket or generally tubular shape or it may be flat, al-though i-ts surface area and shape are preferably such that the sheet will extend to the closed cover of the can, as described below. The cup shaped barrier has a side wall 22 and a closed bottom. The barrier may simply be a flat sheet which is deformed in use. It may be a sheet with cut regions which enable the sheet to be shaped into a cup, and the cut regions of the sheet are attached to the can at their marginsl The cup is of a flexible material so that the cup may be filled and later everted as described below. The cup may also be made by vacuum forming or blow molding.
The material of the barrier 20 need merely be sufficiently ductile and flexible to evert as described below and be impervious to the product and to the propel-lant which contacts the barrier at its opposite sides.
The material is preferably not a highly stretchable material like rubber, although some stretching may be desired. For example, an ine~pensive plas-tic sheet or tube material of substantially uniform thickness and flexibility may be ~olded and heated to form a cup-shaped ~ bag. Suitable ~lastics could inclu~e polyethylene, poly-g~ propylene, Myl ~, Sara~,~an ~so ~o~th, The barrier maybe made of a paper, e.~. a waxed paper. It may be of any appropriate fabric. It could even be a metallic barrier, such as an alumi,num film, or metallized plastic, such as aluminum on Myla~o~r ~aran~rC~e~' J
The means for mounting and sealing the barrier 20 to side wall 12 of can 10 may take several ~orms. In general, the mounting and sealing means must maintain the seal despite the expansion of the can. If can wall 12 is smooth and continuous, a seal may be more easily main-tained, in most cases. The specific forms of the mount~
ing and sealing means described below include ring seals as well as adhesives and melt sealing.
F'igs. 1 and 3-5 show a general ring seal embodi-ment in which a barrier fastening ring 24 is inserted into the barrier 20 and is positioned in the region near the upper edge 26 of the cup shape. The barrier 20 with its ring 24 are inserted into the can 10 and are posi-tioned a distance clown from the open top 14 of the can.
The dimensions of the ring 24 and the barrier are selec-ted such that the ring 24 can snugly fit against the per-ipheral side wall 12 of the can 10, thereby securing the barrier cup 20 firmly in the can. In this manner, the can 10 is divided by the cup into the upper product cham-ber 30 and the bot-tom propellant chamber 32, The size and shape oi' the barrier are coordina-ted with the height of the can 10 and with the position oi the ring 24 along the height of the can intermediate the upper and lower ends so that when the barrier is sub-stantially fully extended, it will e~tend toward the bottom of the can and be substantially fully in contact with the peripheral side of the can when the can is loaded with the product and it will extend toward the top oi the can and be substantially fully in contact with the side of the can and with the cover over the can when all the product has been expelled. Although barrier 20 could be slightly larger than the upper region, it is prei'erable that the barrier substantially fill the upper region of the can when fully everted, barely leaving some unfilled space, so that it cannot be pinched off by islanding caused by the propellant and so that nearly all of the product may be expelled. This makes it unnecessary to use a tube or other device to prevent pinch-off. Any suitable type of valve may be used in the discharge open-ing.
For use with liquified gas propellants, the ini-tial volume of the upper product chamber 30 may be much larger than that of the bottom propellant chamber 32, on ~0 the order of 15 or 20 to one, thereby utilizing the majority of the space within the can body for the prod-uct. For use with compressed gas propellants, the ini~
tial volume of the product chamber 30 to the initial vol-ume of the propellant chamber 32 would typically be on the order of 2 or 3 to 1. To accommodate these different chambers of different volume in a can of a standard size, and to enable the two chambers 30, 32 to have a correct volume relationship, lt is desirable to be able to posi-tion the ring 24 and the barrier at appropriate selected positions along the height o~ the can wall.
As the invention is intended to assure complete expulsion of product in the chamber 30, the barrier size and shape are selected so that the barrier will press against the inside of the can cover on eversion to expel product, and the barrier will not be folded or wrinkled there but will instead be i'ully extended.
The two chambers 30, 32 are sealed off at the peripheral side wall of the can by the outward ~orce ex-ertsd by the ring 2~ on the wall 12. As the pressures in the product and propellant chambers are identical when the discharge Yalve 38 is closed and are nearly identical when that valve is open, the holding ring is not likely to move along the wall of the can.
After the product has been loaded in the product chamber 30 of the can 10 and the propellant has been loaded in the propellant chamber 32 of the can 10, the can is pressurized. The internal pressure in the can causes the side wall of the can to bulge slightly in di-ameter. For example, if the can 10 is of aluminurD with a 2.5 inch diameter and with a wall that is 0.005 inch thick, when the can is pressurized to 60 psi at normal room temperature of 70C, its diameter will increase ap-proximately 0.004 inch. If this expansion is not compen-sated for, a radial clearance will be created between the interior of the can wall and the exterior of the ring 24.
The radial clearance will provide a leakage path between the product and propellant chambers allowing gas and/or product to bypass the barrier cup 20, resultlng in a pressure reduction in the can, leakage of propellant out of the valve of the can and inability to properly expel all of the product from the product chamber.
A number of ring seal embodiments described herein compensate for the bulging enlargement of the di-ameter of the can.
The first alternative is to provide the ring 24 with a preloaded, radially expansible, elastic seal against the can wall, so that even when the can expands as it is pressurized, the ring expands with the can and maintains the seal. As shown in Fig. 6, the ring 24 is provided on its periphery 42 with a vertically spaced array of annularly uninterrupted, resilient flanges 44, ~25~
each with a diameter greater than the anticipated inside diameter of the can when it has been e~panded under pres-sure. The flanges 44 are thin and flexible enough that as the ring 2~ is installed in the can, the flanges 44 are deflected radially inwardly, that is, they are some-what flattened against the periphery 42 of the ring. As the can wall expands upon pressuriza~ion, the resilient, somewhat flattened flanges resiliently deflect slightly outwardly to maintain their biased contact against the internal wall of the can for pressing the barrier against the can wall and maintaining the seal.
In the second embodiment of Fig. 7, in contrast, the ring 46 is of a different design. It is a solid, annular body with an exterior peripheral channel 48 which opens radially outwardly. The channel receives and holds in it an elastic, resilient, compressible sealing element 50, illus-trated as an O-ring. The diameter of the seal-ing element ring 5~ is slightly greater than the internal diameter of the can, even when the can has stretched un-der pressure. When the ring 46 with the captive O-ring 50 in the channel 48 is installed in the can, the O-ring 50 is compressed through its engagement against the can wall. As the can wa]l expands under pressure, the resil--ient ring 50 tends to restore itself to its undeflected condition and is biased outwardly against the barrier and the can wall for maintaining the seal there.
The third embodiment shown in Fig. ~ uses a dif-ferent approach to accomplish the same result. The above described thin, metal can wall is slightly deformable 3n under pressure. If the~ can wall is only slightly de-formed, at less than the degree of deformation which will permanently deflect the can wall from its normal profile, the normal resilience of the metal can material will tend to restore the wall to its original undeflected shapeO
(This is what occurs as th~ can is pressurized to a nor-~25~
mal extent and is gradually depressurized through use.) As shown in Fi~. 8, the annular ring 5~ inside the can 10 has an outer periphery 56 with a diameter that is only slightly greater than the diameter of the can wall even when that wall is pressurized. As a result, when the ring 54 is installed in the can, it does not unduly stretch and deform the can wall. The can wall therefore does not assume a new, deformed shape. Instead, the can wall yields slightly as the ring is moved along the can wall until it is finally lodged in a selected position.
The resilient, but not permanently de~ormed can wall maintains a tight seal with the ring and prevents leakage past the ring between the can chambers.
The ring 54 is si~ed so that it stretches the can wall larger than the diameter to which the can would expand at maximum loaded pressure and maximum anticipated temperature, but less than the yield point of the can material. For example, if an aluminum can with a 2.50 inch inner diameter and with 0.005 inch thick wall is pressurized to 60 psi at 70F, it expands approximately 0.004 inches in diameter, to an inner diameter of 2.50~
inches. This will create a hoop stress of approximately 15,000 psi. The ring 54 has its periphery sized to ex-pand the can wall by at least about two to four one-thousand-ths (2/1000-~/1000) from lts unexpanded diameter, and may expand it to 2.509 inch diameter, for example.
This expansion, referred to as interference, results in a seal which is maintined as the can expands under pres-sure. This wiL1 also create a hoop stress in the area of the ring of approximately 33,750 psi, which is still well below the yield point of the aluminum can material and of the ring, Even if the internal pressure in the can is raised to 100 psi at 70F, this will only expand the can tQ approxirnately 2,507 inch, with a hoop stress of 25,000 psi. Under all expected circumstances to which the can - 18 - ~ ~5~2~6~
may be exposed, the can will, therefore, not expand so that its inner diameter is greater than the outer diame~
ter of the periphery 56 of the ring. Good sealing con-tact will thereby be maintained and bypass of the ring between the two chambers is avoided.
The above techniques of maintaining a seal rely upon the elasticity of at least one of the can and ring ~or maintaining the seal, with the first mentioned tech-niques of Figs. 6 and 7 using the resilience of the ring to maintain the seal and the latter technique of Fig. 8 using the resilience of the can to maintain the seal.
A completely assembled pressurized can with a ring seal according to the invention is shown in Fig. 3.
The upper cover 34 closes off the top opening 1~ of the can. The cover 34 is shown dome shaped and has an apex 36 with a hole 37 through it in which a hole sealing, product discharge valve 38 is affixed. The cover is crimped to the chime 39 at the top of the can.
The can is filled with a fluent product through the hole 37 before the discharge valve 38 is emplaced.
This moves the barrier 20 down to the bottom of the can and defines and completely fills the barrier 20 and the product chamber 30. The can is i'illed with product to the underside of the cover 34, i.e. until it is com-pletely filled. Then the dlscharge valve 38 is emplaced,which closes the hole 37. The discharge valve may be a known tilt operated valve (or any other valve suitable for the purpose), and it seals the product chamber when it is closed. Next, the propellant chamber 32 is filled with a ~aseous, or liquifled propellant through the hole 19. When the desired pressure level or quantity is at-tained, the gaseous pressure supply or liquified propel-lant is removed and the hole 19 is plugged by a plug 21.
The can is now ready for operation.
~5~
-- 19 ~
The can in Fig. 4 is shown at a stags after a portion of the product has been expelled from the can through the valve 38. The barrier 20 is shown partially everted due to the propellant as the barrier assumes a shape defined by the remaining product.
Because the barrier is mounted to the peripheral side ~all 12 at a height which is near the middle of the can 10 with its cover on, the barrier moves from extend-ing downward into the can, is deflected up past the ring 24 and finally everts and extends upward into the cover 34, as substantially all the product is finally expelled, as shown in Fig. 5. This eversion prevents the barrier from pinching-off or islanding which would prevent expul-sion of the product due to some product being captured in a pinched-off region of the barrier.
The barrier cup is so shaped and the ring 2~ is so positioned that when the barrier 20 is fully everted as shown in Fig. 5, it substantially fills the space bounded by the cover 34 and the side wall 12 of the can located above the fastening ring 24. When the product chamber 30 is filled before product is expelled, the bar-rier fills a portion of the space bounded by the con-tainer bottom 16 and the side wall of the can. This as-sures that almost the entire volume which is bounded by the walls and bottom of the can 10, besides that volume needed for propellant, may be filled with the product and that all of the product is usefully expelled from the can when the barrler has been fully everted.
The sealing effectiveness can be increased through the lntroduction of sealing compounds between the fastening rin~ and the barrier and/or between the barrier and the can wall.
As the pressure differential across the barrier is usually ~uite small, it may alternatively be suffi-~
cient to secure the barrier cup 20 directly to the can wall without a ring 24. Other means ~or mounting and sealing the barrier may be used for directly mounting the barrier to the can wall at a seal 84 as shown ~n Fig. g.
Seal 64 may be obtained with a ring of adhesive applied directly between the entire upper edge of the barrier and the can wall or by a melt process in which the upper edge of the barrier is melted and sealed to the can wall.
This arrangement still must compensate for the anticipa-ted e~pansion of the can wall under pressure and its re-turn to the unexpanded condition.
If an adhesive is used to form seal 64, the ad-hesive substance and the upper edge ~2 of the barrer must -together be sufficiently expansible and contractable to compensate for change in can diameter. Any suitable ad-hesive which provides a sufficient bonding force to main-tain the seal may be used, including rubber cement, glue and hot melt glue. The barrier may be a stretchable material such as polypropylene.
If a melt process is used to form seal 6~, upper edge 62 of the barrier must alone be sufficiently expans-ible and contractable to compensate for can diameter change. The melt process may employ thermal, sonic, or radio frequency heating. The barrier may be polyethylene or polypropylene or any other suitable material. Again, it is nece9sary to obtain a suf~icient bonding force to maintain the seal. The barrier and the adhesives must be capable of stretching as needed without tearing and with-out tearing away from the periphery of the can.
The invention simplifies production oi the can and its product-propellant barrier and eliminates concern about close manu~acturin~ tolerances i~or the barrier and i'or its attachment to the can. For example, in previous barrier pack cans, which employ a piston barrier system, or in the bag barrier system with folded or pleated bag ~25~
side walls to enable the bag to collapse without pinch-off, the consistent predictable shape of the can lO was critical to the operation of the barrier system. With a piston system, an indentation in the container above the piston would prevent the piston from traveling ~]p the peripheral side ~all o~ the can. With the present bar-rier system, however, the container can be of almost any size or shape. It is not even necessary that the periph-eral side walls of the container be generally parallel to each other as with other known systems. Consequently, cans could be used with either esthetically pleasing shapes or other shapes which are designed in accordance with human iactor engineering principles.
Although the present invention has been de-scribed in connection with preferred embodiments thereof, many variations and modifications will now become appar-ent to those skilled in the art, It is preferred, there-iore, that the present invention be limited not by the speciiic disclosure herein, but only by the appended claims.
Claims (20)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A pressurizable container for containing a fluent product under pressure and for dispensing the pro-duct through a discharge opening, said container comprising:
a can wall surrounding and defining a can cham-ber and having an upper end with the discharge opening defined therein and an opposite lower end; the can wall being resilient and expanding slightly when the can cham-ber is pressurized and returning to an unexpanded condi-tion as the pressure in the can chamber is reduced to zero; the can wall having a dimension across the can chamber which increases by at least approximately one one-thousandth (1/1000) of its value in the unexpanded condition as the pressure in the can chamber goes from the unexpanded condition to a pressure of 100 psi;
a flexible barrier having an edge mounted to the can wall in the can chamber, the barrier dividing the can chamber into a product chamber comprising a part of the can chamber between the barrier and the upper end of the can wall for containing a fluent product to be stored and dispensed and a propellant chamber comprising a part of the can chamber between the barrier and the upper end of the can wall for containing a propellant adapted to pro-vide pressure upon the barrier to urge the barrier into the product chamber for expelling the product through the discharge opening; the barrier comprising material that is impervious both to the product and propellant; and means for mounting the edge of the flexible bar-rier to the can wall in a manner that seals the barrier to the can wall for preventing the product and propellant from leaking past the edge of the barrier as the can wall expands and returns to the unexpanded condition;
the flexible barrier being extendible toward the lower end when the product chamber is initially filled with fluent product and being gradually extensible toward the upper end through pressure generated by propellant in the propellant chamber to expel the fluent product out of the can chamber through the discharge opening.
a can wall surrounding and defining a can cham-ber and having an upper end with the discharge opening defined therein and an opposite lower end; the can wall being resilient and expanding slightly when the can cham-ber is pressurized and returning to an unexpanded condi-tion as the pressure in the can chamber is reduced to zero; the can wall having a dimension across the can chamber which increases by at least approximately one one-thousandth (1/1000) of its value in the unexpanded condition as the pressure in the can chamber goes from the unexpanded condition to a pressure of 100 psi;
a flexible barrier having an edge mounted to the can wall in the can chamber, the barrier dividing the can chamber into a product chamber comprising a part of the can chamber between the barrier and the upper end of the can wall for containing a fluent product to be stored and dispensed and a propellant chamber comprising a part of the can chamber between the barrier and the upper end of the can wall for containing a propellant adapted to pro-vide pressure upon the barrier to urge the barrier into the product chamber for expelling the product through the discharge opening; the barrier comprising material that is impervious both to the product and propellant; and means for mounting the edge of the flexible bar-rier to the can wall in a manner that seals the barrier to the can wall for preventing the product and propellant from leaking past the edge of the barrier as the can wall expands and returns to the unexpanded condition;
the flexible barrier being extendible toward the lower end when the product chamber is initially filled with fluent product and being gradually extensible toward the upper end through pressure generated by propellant in the propellant chamber to expel the fluent product out of the can chamber through the discharge opening.
2. The container of claim 1 in which the bar-rier has a surface area greater than the cross-section of the can wall.
3. The container of claim 1 in which the bar-rier has a size and shape and is mounted to the can wall so that the barrier substantially fills the upper end of the can wall and meets the top cover when fully expanded toward the upper end for expelling substantially all of the product from the product chamber.
4. The container of claim 3 in which the bar-rier is a cup-shaped bag which everts as it extends to-ward the upper end.
5. The container of claim 4 in which the cup-shaped bag has an upper opening at the edge mounted to the can wall and has a closed bottom away from the upper opening; the cup-shaped bag being deformable between an initial condition in which the bottom of the cup extends down below the edge mounted to the can wall and a final condition in which the cup-shaped bag is everted with the bottom extending up above the edge mounted to the can wall and toward the upper end.
6. The container of claim 5, further comprising an upper cover fitted over the upper end of the can wall and having the discharge opening defined therein, the upper cover being for retaining the fluent product in the product chamber, the container further comprising a dis-charge valve in the discharge opening for allowing the fluent product to be discharged therethrough.
7. The container of claim 4 in which the cup-shaped bag is of substantially uniform thickness and flexibility.
8. The container of claim 4 in which the bag comprises a material selected from the group of plastic sheet material, metallized plastic sheet material, and metallic film.
9. The container of claim 3 in which the can wall further comprises a top cover portion at its upper end, the top cover portion and the upper end of the can wall defining an upper end surface, the barrier having a size and shape and being mounted to the can wall so that it is at most slightly larger than the upper end surface for preventing pinching off of some of the product when the barrier is fully extended toward the upper end.
10. The container of claim 1 in which the can wall has a smooth continuous inner surface.
11. The container of claim 1 in which the mounting means comprises an adhesive, at least one of the adhesive and the barrier being expansible and contract-able for maintaining a seal.
12. The container of claim 1 in which the mount-ing means comprises a melt seal of a part of the barrier to the can wall, the barrier being sufficiently expansi-ble and contractable to maintain a seal.
13. The container of claim 1 in which the can wall is cylindrical and the mounting means comprises a ring mounted inside the edge of the barrier and holding the barrier in a sealed manner against the can wall, at least one of the ring and the can wall being sufficiently resilient to deform resiliently upon mounting the ring in the can wall to create a seal and also to resiliently press the ring against the can wall to continue to main-tain the seal as the can wall expands.
14. The container of claim 13 in which the ring is capable of cooperating with the can wall for being disposed at any of various locations along the height of the can wall.
15. The container of claim 13 in which the ring has a periphery facing toward the can wall; the ring hav-ing expansible-contractable means at the periphery there-of for engagement with the can wall, and the ring being of a size with respect to the diameter of the can that the expansible-contractable means are deflected and con-tracted upon mounting of the ring and the barrier in the can chamber while the can chamber is unpressurized and the expansible-contractable means being adapted for ex-panding to maintain the seal between the periphery of the ring and the can wall upon the can chamber being pressur-ized and the diameter of the can wall increasing slightly.
16. The container of claim 15 wherein the expan-sible-contractable means comprises an angular, deflect-able flange on the periphery of the ring.
17. The container of claim 16 wherein there are a plurality of the flanges on the periphery of the ring arranged above each other along the height of the ring.
18. The container of claim 15 wherein the expan-sible-contractable means comprise a compressible, resili-ent element supported at the periphery of the ring for expanding into continuous sealing engagement with the can wall.
19. The container of claim 18 wherein the ring includes an annular groove at the periphery thereof and the compressible, resilient element comprises an addi-tional ring around the first-mentioned ring and supported in the groove in the first-mentioned ring.
20. The container of claim 13 wherein the ring has a diameter which is slightly greater than the diame-ter of the wall when the ring is in the can wall and the can chamber is not pressurized, for slightly deflecting the can wall without permanently deforming it; the diame-ter of the ring with respect to the diameter of the can wall being selected such that when the can chamber is pressurized and tile can wall thereby increases in diame-ter, the ring diameter still remains greater than the diameter of the can wall, for thereby maintaining the seal between the ring and the can wall.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US658,274 | 1984-10-05 | ||
| US06/658,274 US4562942A (en) | 1984-07-03 | 1984-10-05 | Rolling diaphragm barrier for pressurized container |
| US771,491 | 1985-09-05 | ||
| US06/771,491 US4641765A (en) | 1984-10-05 | 1985-09-05 | Expandable pressurized barrier container |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1255266A true CA1255266A (en) | 1989-06-06 |
Family
ID=27097597
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000492323A Expired CA1255266A (en) | 1984-10-05 | 1985-10-04 | Expandable pressurized barrier container |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0177047B1 (en) |
| JP (1) | JPS61178873A (en) |
| AU (1) | AU582189B2 (en) |
| CA (1) | CA1255266A (en) |
| DE (1) | DE3582213D1 (en) |
| IL (1) | IL76599A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61178873A (en) * | 1984-10-05 | 1986-08-11 | ジヨ−ジ ビ−．ダイアモンド | Pressure vessel |
| US4842165A (en) * | 1987-08-28 | 1989-06-27 | The Procter & Gamble Company | Resilient squeeze bottle package for dispensing viscous products without belching |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USRE24918E (en) * | 1949-10-07 | 1961-01-03 | Dispensing package and method | |
| NL288808A (en) * | 1962-02-19 | |||
| JPS4912981A (en) * | 1972-05-10 | 1974-02-04 | ||
| US3931834A (en) * | 1974-06-26 | 1976-01-13 | The Goodyear Tire & Rubber Company | Expansion tank diaphragm assembly |
| DE2500996A1 (en) * | 1975-01-11 | 1976-07-15 | Ode | Discharging liquid from spraying containers - flexible cartridge filled with compressed aiir and inserted in container |
| US4089443A (en) * | 1976-12-06 | 1978-05-16 | Zrinyi Nicolaus H | Aerosol, spray-dispensing apparatus |
| US4562942A (en) * | 1984-07-03 | 1986-01-07 | Diamond George B | Rolling diaphragm barrier for pressurized container |
| JPS61178873A (en) * | 1984-10-05 | 1986-08-11 | ジヨ−ジ ビ−．ダイアモンド | Pressure vessel |
-
1985
- 1985-10-02 JP JP60221098A patent/JPS61178873A/en active Pending
- 1985-10-03 AU AU48267/85A patent/AU582189B2/en not_active Ceased
- 1985-10-04 EP EP85112585A patent/EP0177047B1/en not_active Expired - Lifetime
- 1985-10-04 CA CA000492323A patent/CA1255266A/en not_active Expired
- 1985-10-04 DE DE8585112585T patent/DE3582213D1/en not_active Expired - Lifetime
- 1985-10-06 IL IL76599A patent/IL76599A/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61178873A (en) | 1986-08-11 |
| AU4826785A (en) | 1986-04-10 |
| IL76599A (en) | 1989-06-30 |
| EP0177047A2 (en) | 1986-04-09 |
| AU582189B2 (en) | 1989-03-16 |
| DE3582213D1 (en) | 1991-04-25 |
| IL76599A0 (en) | 1986-02-28 |
| EP0177047B1 (en) | 1991-03-20 |
| EP0177047A3 (en) | 1987-10-07 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |