US3415425A - Aerosol dispenser - Google Patents

Description

Dec. l0, 1968 F. J. KNIGHT ET AL AEROSOL DI SPENSER 5 Sheets-Sheet l Filed Nov. l5, 1966 INVENTORS ATTORNE Dec. 10, 1968 F. J. KNIGHT ET AL. 3,415,425

AEROSOL DISPENSER Filed Nov. l5. 1966 5 Sheets-Sheet 2 F. J. KNIGHT ET Al.

AEROSOL DISPENSER Dec. 10, 1968 Filed Nov. l5. 1966 5 Sheets-Sheet 5 NVENTORS FFAA/ 75 c/. /f/r FRAM/K 4C/r @52%. ATTO EY United States Patent O 3,415,425 AEROSOL DISPENSER Francis J. Knight, New Brunswick, and Frank J. Mack, New Shrewsbury, N .J., assignors to Johnson & Johnson, a corporation of New Jersey Filed Nov. 15, 1966, Ser. No. 594,561 3 Claims. (Cl. Z22-386.5)

ABSTRACT F THE DISCLOSURE This `application discloses an aerosol dispenser particularly useful for dispensing products in a closed system, i.e., medications through a hypodermic needle, that employs a flexible bag-like diaphragm for separating the container into two chambers, one containing the product and the other containing the propellant. The diaphragm is equipped at its closed end with a rigid disk-like member which by its configuration conforms to the top of the aerosol container and is adapted to accommodate the valve located at the top of the container in such a manner as to permit tactile discernment and inactuation of the valve mechanism upon exhaustion of the contents from the container.

Background of the invention This invention relates to aerosol dispensers and more particularly, is directed to improvements in aerosol dispensers of the so-called diaphragm type, i.e., aerosol dispensers using a llexible diaphragm for separating the dispenser into variable lower and upper chambers for containing a propellant and the material to be dispensed respectively.

Packaging of materials in aerosol dispensers has become very popular primarily `because of their convenience to the consumer and the ease with which such products can be dispensed. Generally such aerosol dispensers have been of two basic types. In the packaging of some products a propellant, such as a low boiling liquid or a gas under pressure, can be mixed with the product to be dispensed such that the containers do not require separate chambers for containing the products to be dispensed and the propellant. However, in many instances the product to be dispensed is not compatible with useful propellants or the particular application of the product to be dispensed dictates that the propellant cannot be dispensed therewith. In these latter instances, separate noncommunicating chambers are required for containing the product to be dispensed and the propellant used to dispense the product under pressure.

Two basic types of containers have been provided for aerosol dispensers employing noncommunicating chambers for containing the product to be dispensed and the propellant. There is the piston type aerosol dispenser which employs a circular piston closely tted transversely within the interior of a cylindrical container dividing the same into upper and lower chambers. To assure that there is no communication between the lower propellant chamber and the upper product containing chamber, the piston is often litted with a sealing ring about its circumferential surface. While such containers have met with some lamount of success, considerable improvement is yet to be desired. For example, during packaging, transportation and general handling, the cylindrical aerosol containers, which are generally made of metal, frequently become dented or deformed such that the close iitting piston binds within the container and is not free to move upwardly under the iniluence of the propellant to dispense the product from the upper chamber. Accordingly, it is seen that often times the aerosol Patented Dec. 10, 1968 dispensers of the piston type fail to dispense all of the product contained therein.

The second basic type of separate chamber aerosol dispenser employs a iiexible diaphragm member separating the container into an upper product chamber and a lower propellant chamber. As the product is gradually dispensed from the product chamber, the flexible diaphragm under the influence of the propellant contained within the lower chamber is forced into the void created by the depletion of material from the upper chamber. In general, the flexible diaphragm is formed such that when all the contents of the aerosol dispenser have been depleted, the lower chamber will conform to the total volume of the aerosol container. Such diaphragm containers have also met with a reasonable amount of success but one serious drawback remains. Because of the flexible nature of the diaphragm, there is a tendency for the contents of the upper chamber to become trapped in pockets between the diaphragm and the inner side walls of the container as the diaphragm distends to till voids created by the exhaustion of the upper chamber. Again, it is seen that such (aerosol dispensers often times fail todispense the total quantity of material contained in the dispensing chamber.

A further limitation inherent in the so-called diaphragm aerosol dispensers heretofore available has been the inability to determine when the contents of the dispensing chamber have been completely exhausted when the aerosol dispenser is used in a closed system. Such a system, for example, is the injection of a medication from the aerosol container through a hypodermic needle into the cutaneous, subcutaneous, muscular, or vascular system of animals or humans. Without being Iable to observe visually the ejection of the contents of the aerosol container, subjects or patients are sometimes needlessly subjected to fruitless hypodermic punctures.

By the present invention, we have now provided improvements in aerosol dispensers of the so-called diaphragm type which overcome the above diiiiculties and objections inherent in both the diaphragm dispensers and piston dispensers heretofore available.

Summary of the invention vAccording to the present invention, there is provided an aerosol dispenser container having an upper product containing chamber and a lower propellant containing chamber separated from one another by a flexible diaphragm of bag-like conguration. The bag-like flexible diaphragm is secured circumferentially :at its open end to the inner side wall of the container at the base thereof. Communicating with the upper product containing chamber through the top of said container is a dispensing aperture with actuatable valve means positioned therein for selectively opening and closing the dispensing aperture. Secured to the flexible bag-like diaphragm at its inner closed end is a rigid disk-like member having a diameter less than the internal diameter of the aerosol container.

The disk-like member secured to the flexible bag-like diaphragm is disposed transversely in the aerosol container and is movable longitudinally upward therein as the product is dispensed from the product containing chamber. Further, the rigid disk-like member must have a diameter less than the internal diameter of the aerosol container by an amount equal to at least four times the thickness of the flexible diaphragm but by no more than an amount equal to 1/2 the internal diameter of the aerosol container.

These and other features lof the improved aerosol container of the present invention and the advantages obtained thereby, will Ibe even more apparent from the following description when read in conjunction with the accompanying drawings in which:

FIGURE 1 is a plan view of the improved aerosol container of the present inventionshown in its nondispensing, filled condition;

FIGURE 2 is a plan view, shown partly in elevation, of the top portion of the aerosol container in its nondispensing, empty condition;

FIGURE 3 is a cross sectional view of the container shown partly in elevation and taken approximately along line 3-3 of FIGURE 1;

FIGURE 4 is an elevational view of the rigid disk-like member employed in the aerosol container of the present invention;

FIGURE 5 is an enlarged plan View of the improved valve means of the present invention shown in its dispensing position;

FIGURE 6 is an elevational view, partly broken away for clarity, of the flexible diaphragm-rigid disk assembly as it is formed and used in the improved aerosol container ofthe present invention;

FIGURE 7 is an enlarged plan view of another type of aerosol valve assembly used in the improved aerosol dispenser of the present invention and shown in its nondispensing position; and

FIGURE 8 is a plan view of the valve assembly of FIGURE 7 showing the aerosol dispenser in its dispensing position.

Referring now to the drawings, first particularly to FIG URE 1, the invention in its preferred form contemplates acylindrical container 10 having anopen neck 12 surrounded by anexternal bead 14 and acap 16 fitted onto thecontainer neck 12. Thecap 16 includes aflange 18 which snaps over thebead 16 on the container i0 and is permanently secured to thecontainer 10 to provide a pressure tight seal.

Thecap 16 includes a raisedcentral portion 26 for mounting a hollowtubular valve member 22. The top of the raisedportion 20 has acircular dispensing aperture 24 positioned at the center thereof, and thevalve member 22 passes through theaperture 24 in slidable relation therewith. Anannular sealing gasket 26 is positioned internally at the top of the raisedportion 20 and has a central cylindrical opening of a diameter equal to or slightly less than the outer diameter of thetubular valve member 22 and is formed of a resilient material, such as valve rubber, which is flexible yet durable. Thegasket 26 is held in position against the internal top surface of the raisedportion 20 by a dependingcylindrical fitting 28 which is secured within the internal dimensions of the raisedportion 20 of thecap 16 by a force fit.

Thevalve member 22 is normally urged upwardly into contact with theannular gasket 26 to seal the unit by aspring 30 fitted under compression against the underside of anannular sealing flange 32 integral with thevalve member 22 and against the upper side of an inwardly directedridge 34 near the inner end of the dependentcylindrical fitting 28. Thevalve member 22 denes anaxial passage 36 which is closed at the inner end thereof and normally not in communication with the interior of thecylindrical container 10. Providing an internal opening into theaxial passage 36 of thetubular valve 22 is an inlet opening 38 passing through the side Wall of thevalve 22 above theannular Sealing flange 32. As shown in FIG- URE 1, when thevalve member 22 is normally urged upwardly with the sealingflange 32 pressed against theannular gasket 26, theinlet opening 38 is positioned well above theannular sealing gasket 26. In this position, thevalve member 22 seals the interior of thecylindrical container 10 from the atmosphere. To actuate thevalve member 22 and open the interior of theaerosol container 10 to the atmosphere, thetubular valve 22 is merely depressed against the pressure of thespring 30 until the inlet opening 38 moves below the sealinggasket 26. The contents within theaerosol container 10, if under pressure, will enter theaxial passage 36 in thevalve member 22 through the inner open end of the dependentcylindrical fitting 28 and thence through t-he inlet opening 38 as soon as the inlet opening 3S is depressed below the -annular sealing gasket 26.

The above merely describes, in essence, a standard aerosol valve mechanism but as is explained more fully hereafter, the valve mechanism is further provided in accordance with the present invention with means for indicating when the contents of the aerosol container are exhausted. Referring particularly to FIGURES l, 2 and 5, it is seen that thetubular valve 22 is provided on its inner closed end with a rigid rod-like extension 40 projecting axially and centrally within the bore of the dependingcylindrical tting 28. When thevalve member 22 is in its inoperative position, therigid extension 40 terminates approximately flush with the inner end of the dependingcylindrical fitting 28. Upon actuation of thevalve member 22 by depressing the same, therigid extension 40 projects below the inner end of the dependingcylindrical fitting 28 into the interior of the aerosol container 10 (FIGURE 5). The manner in which the rod-like projection 40 on thevalve member 22 operates to indicate exhaustion of the container contents will be explained more fully hereafter.

Thecylindrical container 10 includes a vertical,circular side wall 42 that terminates at its base in a circumferentialexternal bead 44. Extending inwardly from th base of the container 1f) is aflexible diaphragm 50 which is, in essence, a cylindrical bag-like structure formed at its open end with a circumferential,external flange 52 that ts over theexternal bead 44 at the base of thecontainer wall 42. Securing thediaphragm 50 within thecontainer 10 is abase plate 54 also provided with a circumferential,external flange 56 which is crimped over theexternal bead 44 of thecontainer Wall 42 with thediaphragm flange 52 pressed therebetween.

Referring now particularly to FIGURES l, 3, 4 and 6, there is shown the various components and configuration of theflexible diaphragm member 50 employed in theaerosol container 10 for dividing the same into a variable upperproduct containing chamber 58 and a variable lowerpropellant containing chamber 60. Thediaphragm 50 is made of flexible material which can be elastomeric, such as rubber, or can be made of a flexible inelastic material, such as polyethylene, polypropylene, and the like. While generally of bag-like structure, thediaphragm 50 is formed with the innerclosed end 62 thereof involuted to provide for the expansion of thediaphragm 50 upwardly as the contents are dispensed from the uppercontents containing chamber 58.

At the innerclosed end 62 of thediaphragm 50 is secured a rigid disk-like member. It can be made of metal or any plastic material that is relatively nondeformable. Being rigid, the disk imparts form stability to the area of the diaphragm defined as its innerclosed end 62. The outer circumference of therigid disk 64 is less than the inner circumference of theaerosol container 10 so that the disk is free to move longitudinally therein.

Because theclosed end 62 of thediaphragm 50 is involuted, it is seen that diaphragm S0 includes an ascendingouter side wall 66 and an innerdescending side wall 68. The outer and innerwalls 66 and 68 respectively, merge circumferentially along the inner surface of thecontainer wall 42 within the upperproduct containing chamber 58. As theclosed end 62 of thediaphragm 50 and also the rigid disklike member secured thereto are forced upwardly by the propellant contained in thelower chamber 60 when the product is being dispensed, theinner wall 68 converges into theouter side wall 66 such that the circular line of merger therebetween raised upwardly in the upper chamber at one half the rate that thedisk 64 rises. Thus, thedisk 64 must have a diameter less than the internal diameter of thecontainer 10 by an amount equal to at least four times the thickness of the flexible diaphragm to accommodate for theinner wall 68 moving upwardly relative to the fixedouter Wall 66.

It is also found that therigid disk 64 can be substantially smaller in diameter relative to the internal diameter of the container which further enhances the ease with which it can be moved longitudinally upwardly under the influence of the propellant. By being substantially smaller, greater clearance is provided between the periphery of thedisk 64 and thewall 42 of thecontainer 10. With the greater clearance therebetween, thedisk 64 remains free to move longitudinally under the inliuence of the propellant even if thecontainer 10 becomes dented or otherwise deformed during its manufacture, shipment or storage. Such clearance can be provided because thediaphragm 50 to which therigid disk 64 is secured prevents leakage of propellant from the lower chamber y60 into theupper chamber 58.

The maximum amount of clearance that can be provided, however, in accordance with the invention, is that which exists when the diameter of thedisk 64 is equal to 1/2 the internal diameter of thecontainer 10. If the diameter of thedisk 64 is less than 1/2 the internal diameter of thecontainer 10, there is a tendency for the disk to tilt from its transverse, horizontal position during its longitudinal travel upwardly under the inuence of the propellaut. In soI doing, theouter wall 66 of thediaphragm 50 would tend to separate from the internal surface of thecontainer wall 42 particularly along the portion of thecontainer wall 42 existent in theupper chamber 58 as the inner wall -68 of thediaphragm 50 converges to form theouter wall 66 as thedisk 64 moves upwardly. If thediaphragm 50 is thus prevented from conforming to the internal surface ofthecontainer wall 42, some of the prod- -uct contained in theupper chamber 58 becomes trapped in the pockets thus formed and will not be dispensed from the aerosol container. Further, if thedisk 64 is too small and accordingly, tilts out of its horizontal position, it will fail to mate with the internal surface presented at the top of thecontainer 10 again causing a considerable amount of product to become trapped and nondispensable therefrom.

The rigid disk-like member 64 is provided with a cenltral recessedportion 70 which accommodates the dependingcylindrical fitting 28 that extends downwardly into theproduct containing chamber 58 from the top 16 of thecontainer 10 when the rigid disk member `64 has been moved to the top of the container upon all the contents thereof having been dispensed under the inuence of the propellant in thelower chamber 60. Also, since the internal surface at the top of the container as shown has a domed configuration, the rigid disk-like member 64 is of similar domed configuration with the above mentionedrecess 70 centrally disposed. In essence, it is seen that the top surface of the rigid disk-like member `64 is shaped generally to conform to the shape of the internal surface of the aerosol container at the top thereof, so that thediaphragm 50, while being rigid and inexible in the area of its inner closed end, will still be capable of fitting substantially into the volume defined by the top of the container when the contents are exhausted or nearly exhausted therefrom. This then, assures, first that little of the contents within the aerosol container will fail to be dispensed therefrom.

Further, the recessedportion 70` of the rigid disk-like member 64 is formed to engage and close off the inner end of the dependentcylindrical fitting 28` when the diaphragm reaches its uppermost extension (FIGURE 2). As described earlier, the rod-like projection 40 on thevalve member 22 terminates approximately flush with the innermost end of the dependentcylindrical fitting 28 when the valve member is in its nondispensing or closed position. If the contents of the upperproduct containing chamber 58 are exhausted, the rigid disk-like member 64 forming the closed inner end of theflexible diaphragm 50 will be held securely against the inner end of the depending Vcylindrical fitting 2.8 by the pressure exerted by the propellant in the lower propellant containing cham- 6 ber |60. With the rigid disk-like member 64 so disposed, depression of thevalve member 22 is resisted by therodlike projection 40 on thevalve member 22 resting against thedisk 64, and accordingly, the operator will be able to determine tactilely that the aerosol container is empty even if its contents are being dispensed in a closed system.

Referring now particularly to FIGURES 7 and 8, a modified valve mechanism can be employed in accordance with the present invention and is particularly useful when the aerosol container is used to dispense medications that are to be injected by a hypodermic into the tissues of animals or humans. The modified valve is, in essence, a metering valve which provides for predetermined quantities of medicated product to be dispensed upon lany single actuation of the valve mechanism. While the metering valve, per se, is generally well recognized in the art, the valve assembly employed in accordance with the present invention is modified so as to provide means for determining when the contents of the aerosol container have been exhausted when the aerosol container having a metering valve is used in such a closed system.

The metering valve assembly is essentially the same as the valve assembly depicted in FIGURES 1, 2 and 5 but includes in addition areservoir chamber 72 which meters a predetermined quantity of medication upon actuation of the valve assembly.

Thus it is seen, the valve assembly, as in the previously described embodiment, consists of acap 116 that includes a raisedcentral portion 120 with acircular dispensing aperture 124 in the center thereof, through which passes thetubular valve member 122 in slidable relation therewith. Anannular sealing gasket 126 formed of a resilient material which is flexible yet durable is secured internally at the top of the central raisedportion 120 by a dependingcylindrical fitting 128 which is force fitted within the central raisedportion 120.

Thevalve member 122 is provided with anannular sealing flange 132 which is normally urged upwardly into sealing engagement with lthe annular sealinggasket 126 by aspring member 130 compression fitted between the under surface of the sealingflange 132 and the upper surface of an inwardly directedridge 134 near the inner end of the dependentcylindrical fitting 128. Above theannular sealing ange 132 is aninlet opening 138 in the side Wall of thetubular member 122. Theinlet opening 138 in the side wall of thetubular valve member 122, when the latter is normally urged upward into sealing engagement with the sealingflange 132 pressed ,against theannular sealing gasket 126, is positioned well above theannular sealing gasket 126.

The dependentcylindrical fitting 128 is also provided with anopening 139 in the side wall thereof. Fitted about the internal end of the dependent cylindrical fitting is acollar 141 which is adapted to slide longitudinally in close fitting engagement -with the internal end of the dependentcylindrical fitting 128. Tightly fitted on theslidable collar 141 is a funnel-shapeddiaphragm member 143 of flexible material, the top circumferential edge of which iS provided with a circumferentialexternal flange 145 which is force fitted between the circumferentialexternal bead 114 at the top of the cylindrical aerosol container and the circumferentialexternal flange 118 of thecap member 116 which is crimped over theexternal bead 114 in the container wall.

Thetubular valve member 122 of the metering valve assembly, as in the previously described unmetered valve assembly, is provided with a rigid rod-like extension on its inner closed end which projects axially and centrally Within the bore of the dependingcylindrical fitting 128. The length of the rod-like extension is such that when thevalve member 122 is in its inoperative position, therigid extension 140 terminates approximately ush with the inner end of the depending cylindrical tting 1128. In the metering valve assembly, the rodi-like projection 140 on thetubular valve member 122 has fitted thereon a cup-shapedannular seal 147 of flexible material such as, valve rubber, which, when thevalve member 122 is normally urged upwardly in an inoperative position, is out of sealing engagement with the inner end of the depending cylindrical fitting 12S. The annular cup-shapedseal 147 is prevented from moving axially with respect to the rod-like extension 140 on thevalve member 122 by fitting into a circumferentialrectangular groove 149 located on the rod-like extension 140.

The interior of the funnel-shaped,flexible diaphragm 143 around the valve assembly defines areservoir chamber 72. When thetubular valve member 122 is in its nonoperative position, it is seen that the pressures existent Within thereservoir chamber 72 and the upperproduct containing chamber 58 are equal by virtue of the opening through the inner end of the dependentcylindrical fitting 128 and the opening provided in the side wall thereof. When the tubular valve member is depressed to dispense the product from the aerosol container (FIG- URE 8), the cup-shapedseal 147 closes off the opening at the inner end of the dependentcylindrical fitting 128, and the inlet opening 138 in the side wall of thetubular valve member 122 becomes positioned below theannular sealing gasket 126. In this position, under the pressure exerted by the propellant contained within the lower propellant containing chamber of the aerosol container, thefunnelshaped diaphragm 143 is forced inwardly toward the outer side walls of the dependentcylindrical fitting 128. To accommodate for the inward iiexing of thediaphragm 143, thecollar 141, to which the inner end of thediaphragm 143 is secured, is free to slide longitudinally upwardly on the inner end of the dependentcylindrical fitting 128. In this manner, the volume within thereservoir chamber 72 is decreased thus forcing the product contained within thereservoir chamber 72 to flow through theopening 139 to the interior of the dependentcylindrical fitting 128, then through the inlet opening 138 in the side wall of thetubular valve member 122, and thence outwardly to the at- Inosphere until all of the product contained within thereservoir chamber 72 has been dispensed. Since thetubular valve member 122 in its operative position places the cup-like seal 147 in :a position to `close off the opening at the inner end of the dependentcylindrical fitting 128, no additional product can enter thereservoir chamber 72 as long as the tubular Valve member 1122 is maintained in its open position. vUpon release of thetubular valve member 122, the inlet opening 138 in the side wall thereof moves above theannular sealing gasket 126 while at the same time the cup-shapedannular seal 147 moves out of sealing engagement with the inner end of the dependentcylindrical fitting 128, once again permitting the pressures in thereservoir chamber 72 and in theproduct containing chamber 58 to equalize, returning theflexible diaphragm 143 to its normal unfiexed state.

As with the earlier described lembodiment of the valve assembly, it is seen that the rigid rod-like extension 140 provides a means for tactilely determining when the contents within the aerosol container of the present invention are exhausted. The rigid disk-like member 64 secured on theinner end 62 of theflexible diaphragm 50 that separate the product `containing :chamber S8 and thepropellant containing chamber 60, and which is shaped generally to conform to the interior configuration at the top of the container, is urged into fitting engagement with the inner end of the dependentcylindrical fitting 128 when the product within the upperproduct containing chamber 58 has been exhausted. With the rigid disk-like member 64 in this position, depression of thetubular valve member 122 is opposed by way of the rigid rod-like extension 140 resting against the uppercentral surface 70 of the rigid disk-like member 64 (FIGURE 2). As mentioned earlier, this means for tactilely determining when the contents` of the 8 aerosol container of the present invention have been depleted is particularly useful and `advantageous when the aerosol container is used in a closed system such as when medications are injected by way of a hypodermic needle fitted to thetubular valve member 122.

While we have described our invention in detail as it is incorporated in preferred embodiments, it is to be understood that many changes, alterations, and modifications can be made therein without departing from the spirit and scope of the invention as defined in the following :appended claims.

We claim:

1. In tan aerosol dispenser container having an upper product containing chamber and a lower propellant containing tohamber separated from one another by a fiexible diaphragm of bag-like configuration, said diaphragm being secured circumferentially at its open end to the inner side Wall of said container at the base thereof, a dispensing aperture communicating with the upper product containing chamber through the top of said container and actuatable Valve means in said dispensing aperture extending into said product containing chamber for the selective opening and closing of said dispensing aperture, the improvement comprising:

(a) A rigid disk-like member secured to said flexible bag-like diaphragm at the inner closed end thereof and :having a diameter less than the internal diameter of said container by an amount equal to at least four times the thickness of said iiexible diaphragm but by no more than an amount equal to 1/2 the internal diameter of said container,

(1) said rigid disk-like member being disposed transversely in said container and movable longitudinally upwardly therein as said product is dispensed from said product containing chamber, and

(2) said rigid disk-like member having a centrally disposed recessed portion for accommodating that portion of said valve means extending into said product containing chamber when substantially all of said product has been dispensed therefrom.

`2. The improved aerosol dispenser container as defined in claim 1 wherein the improvement comprises, in addition, a product reservoir chamber interposed between said dispensing aperture and said product containing chamber for limiting the amount of product dispensed from said container upon any single actuation of said valve means.

3. The improved aerosol dispenser ias defined in claim 1 wherein said valve means includes la rigid extension that projects into said product containing chamber upon actuation thereof and which rigid extension is prevented from Iprojecting into said product containing chamber by said rigid disk-like member when the product is exhausted from said product containing `chamber thereby also preventing yactuation of said valve means to open said dispensing aperture.

References Cited UNITED STATES PATENTS 2,735,589 2/1956 Milster et al. 222-3865 3,019,947 2/1962 Gorman 222-4022 3,109,463 11/1963 Clemens Z22- 386.5 X 3,189,231 `6/1965 Kibbel et al. Z22-386.5 X 3,319,420 5/ 1967 Mercier 222-386.5 X

ROBERT B. REEVES, Primary Examiner.

HADD S. LANE, Assistant Examiner.

U.S. Cl. X.R.

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