US3112846A

US3112846A - Aerosol can package

Info

Publication number: US3112846A
Authority: US
Inventors: Hein Matthew Edward
Original assignee: American Can Co
Current assignee: Primerica Inc
Priority date: 1959-12-21
Filing date: 1959-12-21
Publication date: 1963-12-03
Anticipated expiration: 1980-12-03

Description

Dec. 3, 1963 M. E. HEIN AEROSOL CAN PACKAGEv Filed Deer 21, 1959 2 sheets-smet 2 hf Eff-l@ d@ /7 ZZ /l i7 INVENTOR. Z9 MATH/fw fon/4,90 Hf//v BYQM Q @A my @MM A T TOE/VE K5 United States Patent C) The present invention relates to a method of pressurizing an aerosol can and the package resulting therefrom. More particularly, it pertains to a method of introducing a pressure producing propellant into a can containing a product to be dispensed by the superatmospheric pressure generated within the can by the propellant and the resulting package.

in the packaging of products to be dispensed by means of pressure within the container, usually referred to as an aerosol can, one means of charging propellant into the can is through a sealable port or aperture located in one member of the can, usually the bottom end thereof. A soft, rubber plug, frictionally retained in this port, acts as the sealing means for the port. The plug performs its sealing function either by being inserted into the port after the propellant has been charged, or by closing oil.'

sealing channel through its body made by a hypodermic needle or the like through which the propellant was charged into the can. Each of these prior art practices to satisfy the high speed production requirements of modern manufacturing, necessitates specialized precision equipment which is both expensive and relatively cornplex in its operation.

lt is theretore an object of the present invention to provide a method whereby a propellant nay be charged into an aerosol-type can at a high rate of speed without the necessity for complex, high precision equipment.

Another object of the invention is to provide a method of the character described wherein highly precise alignment between the propellant charging unit and the inlet port in the container are made unnecessary.

Yet another object is to provide a method of the character described wherein inexpensive materials are utilized to produce the desired results.

A further object is to provide a package from which a product is to be dispensed by superatmospheric pressure within the container, which contains a buik-in safety valve to prevent explosion of the container due to accidental overheating.

Another object is to provide a package produced by he method of the instant invention.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

The above objects are achieved by providing a container having a tubular body member with a top closure member having a dispensing valve therein integral with one end of the body and a bottom closure member integral with the opposite end of the body; one of these members, preferably the bottom, being perforated to form a propellant charging port or aperture; a strip of flexible tape impermeable to the product and propellant to be packed in the container adhered to the inside surface of the perforated member adjacent the port, a portion of this tape extending over the port; bringing a propellant charging conduit into sealing engagement with the member having the port therein with the passage through the conduit in alignment with the port; forcing propellant from said conduit through the port and into said container by means of superatrnospheric pressure, whereby the portion of said tape extending over the port is pushed inwardly away from the port to permit passage of the Cit llt)

propellant therethrough; continuing introducing propellant in this manner until the pressure within the container reaches a predetermined superatmospheric pressure; discontinuing the propellant charging and removing said conduit from engagement with the member; subjecting the container to ambient atmospheric pressure whereby the inwardly extending portion of said tape is forced back against andheld over the port to provide a seal therefor.

Referring to the drawing:

FIGURE 1 is an elevational View, with parts broken away and parts in section, showing an aerosol package embodying the instant invention;

FlG. 2 is an enlarged fragmentary sectional view showing the end of an aerosol can embodying the subject invention;

FIG. 3 is a plan view of the end shown in FlG. 2;

FIG. 4 is an enlarged fragmentary sectional View of a modified form of the tape utilized in the subject invention;

FlGS. 5 and 7 are enlarged fragmentary plan views of a can end showing a modified form of the tape valve;

FlGS. 6 and 8 are sectional views talten substantially along lines 6 6 and 8 8 respectively;

FIG. 9 is an enlarged fragmentary view illustrating the method of charging the propellant into the container; and

FIG. 10 is an enlarged fragmentary sectional view of a modified form of the method of charging the propellant into the container.

As a preferred or exemplary embodiment of the in stant invention, PEG. 1 illustrates an aerosol can generally designated lit, having a cylindrical sheet metal body ll formed from aluminum, steel, tin plate, or the like, an upper end closure l2 and a lower end closure i3, each integrally and rigidly connected to the body ll such as by a conventional double-seam ld. It should be understood that the upper closure l?. and body lll may be all one piece, as in a drawn or extruded container, in which case there would be no upper doubleseam M- connecting the upper end l2 to the body ll. Mounted in the upper end 12 is a dispensing valve l5. of any conventional construction.

The lower end 13 (PEG. 2) is concave or dome shaped, as is usual in pressure can construction, and has in the center thereof a hole or aperture i6. As will be more fully described hereinafter, the hole 16 provides a port for introducing the pressure producing propellant into the interior of the container'. IDisposed. over and sealing the hole le is a strip of tape or swingable means 18.

in the preferred embodiment shown in PEG. l, the can l@ contains in its upper portion a product l@ maintained under superatmospheric pressure by means of a pressure producing propellant 2u contained in the lower portion of the can tu. The product 119 and propellant 2t) are maintained separate by a piston 2l, which, upon actuation ci the valve l5, moves upwardly under the impetus of the pressure produced by the propellant 29 forcing all or a portion of the product i9 out of the can lil through the valve d5.

The tape or swingable means l@ may be composed of any suitable 4material that is exible, has cohesive strength, is impermeable to the propellant, and, if necessary, the product enclosed within the container. Examples of such suitable materials are synthetic resins such as vinylidene chloride polymer (Saran), polyethylene, terephthallate (Mylar), vinyl chloride polymers (KoroseaDand the like; thin gauge metals such as aluminum foil, and liquid or vapor impermeable fibrous materials such plastic coated paper. The synthetic resins are preferred for the tape 13 because of their impermeability, strength and exibility even when relatively thin. In the embodiment illustrated,

the tape is approximately 1 inch long by -1/2 inch wide and has a thickness of from 3 to l0 `mils and preferably about 5 mils.

The tape or swingable means 13 is adhesively secured to the en 13 with at least half its surface area in contact with the end 13. The remaining portion of the tape 1d, which extends over and covers the hole 16 may or may not be adhesively secured to the portion of the end 13 immediately surrounding the hole 16. As will be explained more fully hereinafter, the portion of the tape covering the hole and immediately surrounding area is held in place by the internal superatmospheric pressure generated by the propellant. However, to hold the tape more securely in place in the pressurized can, it is preferred that the portion of the tape 1S extending over the hole also be adhesively secured to the end 13.

FlG. 4 shows at 1S a modified form of tape or swingable means construction. To insure against blowing the entire strip of tape 13 oil the end 13 during the propelllant charging operation, the tape 1S' is made thicker at the portion extending over the hole 16. This may be accomplished either by initially forming the tape 1 thicker in that portion that is to extend over the hole; or, as shown in FiG. 4, an additional piece of tape 292 may be adhesively secured to that portion of the tape 1S extending over the hole. For some reason, not readily understood, tape having the increased thickness at one end is more readily iiexible or hingeable immediately adjacent hole 16 so that the thickened portion will raise during the propellant charging operation without the remaining portion of the tape becoming loosened and disengaged from the end 13.

Two modifications of the propellant charging port or aperture, over the simple hole `16, are shown in FIGS. 5 to 8. fFlGS. 5 and 6 shows a substantially hemispherical or bowl-like depression situated in the center of the bottom end member 13 and extending outside the can 10. Extending in a circular pattern in the curved sides of the depression 2S are four evenly spaced perforations or slots 25 providing the ports or apertures through which the propellant may be introduced into the can 1t). The tape 18 is adhered to the inside of the can end 13 in the same manner as for the port 15 and extends over or bridges the depression 25 when the can is unpressurized as shown in the `full lines of FIG. 6. During the introduction of the propellant, the portion of the tape 1S extending over the depression 25 is readily lifted,

ecause there is no contact or adherence between the tape andthe inside surface of the depression. However, when the can has been presurrized, the internal pressure presses the portion of the tape 18 extending over the depression 25 down into the depression sealing off the slots 2.6 as shown in dotted lines in FiG. 6. 'lt is to be understood that the length of tape overlying the depression 25 and adjacent portion of the can end 13 (to the right as viewed in FiGS. 5 and 6) must be sucient to conform to the entire inside surface of the depression after the can is pressurized. The advantages of this modied construction are that it reduces the tendency of the tape to expand through the port forming a bubble on the outside of the can, thereby permitting the use of thinner, more flexible tape, and the position and size of the slots protect the tape from. accidental perforation.

The modilication illustrated in FIGS. 7 and 8 comprises a bowl-like depression 27, somewhat similar to the depression 25, centrally located in the can end 13. The center of the depression 27 is raised to form a projection ZS extending towards the interior of the can 1Q but not above the level of the adjacent portion of the can end 13. The uppermost, central portion of the projection 23 is removed to form a propellant charging port or hole 29. As with the previously described constructions of the propellant charging port, a ilexible tape 13 is adhered to the can end 13 adjacent the depression Z7 and, before pressurizing, extends over or bridges the depression as shown in full lines in FG. 8. presstnizing, a portion of the tape in contact with tne end 13 readily lifts, permitting the entrance of the propellant into the can. After pressurizing, the greater internal pressure forces the tape 1S into contact with the port 29, sealing it against escape of the propellant. This is shown in dotted lines in PEG. 8. in addition to the advantages disclosed for the modiiicatic-n shown in FiGS. 5 and 6, the instant modification has the advantage of having the tape cover the raw metal edges surrounding the port, thereby protecting these edges from corrosion.

`it is to be understood that the can parts illustrated in FlGS. 5 to 8 are grossly exaggerated for clarity. For the conventional, home-size pressure can, e.g. tooth paste, shaving cream, insecticide, the major dimension of the depressions ZS and 27, ie. across the top of the depression, is between /lc, and J/s inch with the ports 25 and 29 of proportionate size.

However, it is considered apparent to those skilled in the art that the depressions and ports may have a variety of sizes depending upon the size of the can.

Referring to the method of charging the propellant 2d into the container, Fifi. 9 shows a conduit 3?, with the passage therethrough in alignment with the hole 16. Surrounding the conduit 30 is a resilient washer or gasket 31 which is pressed tightly and held against the end 13 by a metal collar or back-up ring 32, rigidly secured to conduit 36; The gasket 31 seals the connection between the conduit 39 and the end 13, thereby insuring the passage of the propellant 20 from the conduit 30 through the hole 16 and into the interior of the container 16, without the occurrence of leakage. During charging, the propellant 2t?, which may he liquid or gaseous, is forced into the can 1? at a pressure higher than the pressure within the can, thereby forcing the portion of the tape 18 extending over the hole 16 away from the hole 16, permitting the propellant to enter the can. in effeet, the tape 18 hinges along a line immediately adjacent the hole 15, with a portion of the tape 18 spaced from the hole 16 remaining securely adhered to the end 13. The tape 18 may have a groove or score line (not shown) across its width adjacent the hole to facilitate this hinging action.

This propellant charging operation is continued until the can 10 contains a predetermined amount of the propellant 29, i.e. an amount suiiicient to produce, during use of the can, an internal superatmospheric pressure, usually between i-l00 p.s.i.g. Upon reaching this predetermined amount, the conduit and its associated parts, i.e. rgasket 31 and ring 32, are removed from contact with the can end 13, whereby the pressure differential, i.e. greater inside the can than outside, forces the inwardly extending portion of the tape 18 back against the inside surface of the can end 13 and over the hole 16, thereby sealing the hole against escape of propellant therethrough. To insure covering and sealing of the hole 16 after withdrawal of the conduit Sil, the angle between the adhered portion and the inwardly extending portion of the tape 13 must be less than 90 F.

In certain cases where oxygen is detrimental to the product 19 or the can 1t), it is desirable if not necessary to remove the air from the can prior to the propellant charging operation. FIG. 10 shows a modified form of propellant charging operation wherein deaeration or vacuumizing of the can may also be accomplished. in this modified method, a portion of a conduit 33 is inserted through the hole 16, physically pushing and holding the portion of the tape 1S covering the hole 16 away from the end 13. With the tape 13 so positioned, the resilient gasket 31 and ring 32 provides a seal between the conduit 33 and the end 13, in the same manner as described and the method illustrated in FIG. 9.

One side 34, controlled by a valve 35, of a T connection Iis attached to a suitable source of Vacuum (not shown) and communicates with the conduit 33. The

aliases other side 36, controlled by a valve 37, of the T connection is attached to a source of the propellant and also communicates with the conduit 33. With the conduit in the position shown in FIG. 10, the valve 37 is closed `and the valve 35 open, whereby the air is drawn from the can 10. Thereafter the valve 35 is closed and the valve 37 is opened to cause the propellant 20 to be` forced into the can i0 until a predetermined amount is present in the can i0; and thereafter the conduit 33 and its associated parts are withdrawn from contact with the can, causing the greater internal pressure in the can to force the tape 118 back over the hole 16 into contact with the end 13, thereby sealing the hole 16. Any suitable means such as handle 38 can be used to facilitate movement of the conduit 33 and associated parts.

The instant method and package construction is applicalble to and may be used with any aerosol can regardless of whether the product and propellant are intimately mixed, such as in insecticide sprays and aerated foams, or are maintained separate, such as in a toothpaste dispensing can. Where the product and propellant are in intimate contact, the hole 16 and tape valve 1S therefor may be in any portion oi the can, Le. the body or either end. However, where the product and propellant are to be maintained separate, such as by means of the movable barrier or piston 2i, as in the preferred embodiment of the instant invention, it is preferred that the hole 1.6 and tape valve 18 be situated in the bottom end of the container.

The tape valve utilized in the instant invention provides an advantage additional to those set forth hereinabove. If, due to inadvertence, the iilled and pressurized can should be subjected to relatively high temperatures, tending to increase the internal pressure of lthe can to an excessive and unsafe level, the portion of the tape covering the hole will rupture, thereby releasing this excessive pressure before the metal portions of the can are subjected to any severe stress.

lt is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction, and arrangement of the parts and that changes may be made in the steps of the method described and their order of accomplishment ywithout departing from the spirit and scope of the invention or sacricing all of its material advantages, the form hereinbefore described bein-g merely a preferred embodiment thereof.

I claim:

1. An aerosol package, comprising: a Huid-tight container having a tubular body member and substantially rigid upper and lower end members integral therewith; an amount of fluid product to be dispensed and fluid pressure producing propellant within said container to produce a container internal pressure 'm the order of magnitude of 100 p.s.i.g.; a dispensing valve mounted in said upper end member for dispensing said duid product; one of said end members containing a port for introducing said propellant into said container; swingable means within said container normally overyring and sealing said port under the intiuence of said container internal pressure, but being operative to swing substantially completely away from said port to unseal said port and allow introduction of propellant into said container when the container' external pressure exceeds the container internal pressure; said swingable means including a strip of flexible tape having a lthickness in the order of magnitude of 0.005 Pinch; said exible tape being formed of material which is diierent from the material of the ported end member |and which is impermeable to said propellant and said product, said swingab-le means also including an adhesive layer which attaches one end of said flexible tape to said end member adjacent the port while leaving the other end of said flexible tape free to swing away from said port when the pressure outside said container exceeds the pressure inside it.

2. The package set forth in claim 1 wherein said product and propellant are mutually insoluble.

3. The package set forth fin claim 1 where-in said product exists in one portion of said container and said propellant exists in a separate portion of said container.

4. -T he package set forth in Iclaim l wherein the portion of said ltape covering said port is thicker than the lportion adjacent the port.

5. The package set forth in claim l wherein said port is in said lower end member.

6. r1"-he pacleage set forth in claim 1 wherein a portion of said lower end member including said port is domed outwardly.

7. The package set forth in claim 6 wherein said port in said outwardly domed end member contains a plurality of holes for introducing said propellant into said container.

8. 'Ilhe package set forth in claim 6 wherein the central portion of said `dome is turned inwardly and pierced to provide a hole for introducing said propellant into said container and said tape is larger than said dome and having a por-tion thereof extending into said dome and covering and sealing said hole.

References Cited in the file of this patent UNITED STATES PATENTS 1,051,738 Kavanagh Jan. 28, :1913 2,307,768 Deibel v Jan. 12, 1943 2,400,955 Samei May 28, 1946 2,488,946 Turpin Nov. 22, 1949 2,582,982 Gammeter Ilan. 22, 1952 2,651,139 Gregg Sept. 8, 1953 2,693,418 Smith Nov. 2, 1954 2,761,833 Ward Sept. 4, 1956 2,809,774 Kaye et al. Oct. 15, 1957 2,956,570 Stanford Oct. 18, 1960 2,961,131 Bradbury Nov. 22, 1960 3,022,923 l-loman Feb. 27, 1962 FOREIGN PATENTS 370,535 Great Britain Apr. 14, 1932

Claims

1. AN AEROSOL PACKAGE, COMPRISING: A FLUID-TIGHT CONTAINER HAVING A TUBULAR BODY MEMBER AND SUBSTANTIALLY RIGID UPPER AND LOWER END MEMBERS INTEGRAL THEREWITH; AN AMOUNT OF FLUID PRODUCT TO BE DISPENSED AND FLUID PRESSURE PRODUCING PROPELLANT WITHIN SAID CONTAINER TO PRODUCE A CONTAINER INTERNAL PRESSURE IN THE ORDER OF MAGNITUDE OF 100 P.S.I.G.; A DISPENSING VALVE MOUNTED IN SAID UPPER END MEMBER FOR DISPENSING SAID FLUID PRODUCT; ONE OF SAID END MEMBERS CONTAINING A PORT FOR INTRODUCING SAID PROPELLANT INTO SAID CONTAINER; SWINGABLE MEANS WITHIN SAID CONTAINER NORMALLY OVERYING AND SEALING SAID PORT UNDER THE INFLUENCE OF SAID CONTAINER INTERNAL PRESSURE, BUT BEING OPERATIVE TO SWING SUBSTANTIALLY COMPLETELY AWAY FROM SAID PORT TO UNSEAL SAID PORT AND ALLOW INTRODUCTION OF PROPELLANT INTO SAID CONTAINER WHEN THE CONTAINER EXTERNAL PRESSURE EXCEEDS THE CONTAINER INTERNAL PRESSURE; SAID SWINGABLE MEANS INCLUDING A STRIP OF FLEXIBLE TAPE HAVING A THICKNESS IN THE ORDER OF MAGNITUDE OF 0.005 INCH; SAID FLEXIBLE TAPE BEING FORMED OF MATERIAL WHICH IS DIFFERENT FROM THE MATERIAL OF THE PORTED END MEMBER AND WHICH IS IMPERMEABLE TO SAID PROPELLANT AND SAID PRODUCT, SAID SWINGABLE MEANS ALSO INCLUDING AN ADHESIVE LAYER WHICH ATTACHES ONE END OF SAID FLEXIBLE TAPE TO SAID END MEMBER ADJACENT THE PORT WHILE LEAVING THE OTHER END OF SAID FLEXIBLE TAPE FREE TO SWING AWAY FROM SAID PORT WHEN THE PRESSURE OUTSIDE SAID CONTAINER EXCEEDS THE PRESSURE INSIDE IT.