Self-cleaning Valve For Aerosol Containers

Abstract

A valve is described wherein vaporous purging substance in the head space above the material to be dispensed in an aerosol container can be introduced into the valve in such quantity as to clean the valve and reduce the flow of the material to be dispensed therethrough. A method of cleaning a valve is also described.

Description

This application relates to a self-cleaning valve for aerosol containers. It also relates to a method for cleaning an aerosol valve used to dispense materials capable of clogging.

Due to the increasing demand of consumer public for common items in aerosol containers, the valves have to be developed to meet ever increasing demands of performance. Many prior art valves are subject to malfunctions due to the collection of solid materials in their fluid passages. Such solid materials are usually residues from the material that is dispensed in the valve and are present in various products including anti-perspirant sprays, starches, paint sprays and the like. When the residues are allowed to build up, clogging of the valve will occur resulting in malfunction or non-function.

There has been, therefore, a requirement for a compact, simple, and automatic self-cleaning aerosol valve. These functions desirably must be obtainable by a valve having a minimum of moving parts which will permit economic production.

SUMMARY OF INVENTION

The present invention pertains to a self-cleaning aerosol dispensing valve wherein a portion of the vapor or other purging substance in the head space above the material in the aerosol container is permitted to flow through the valve after the material is dispensed. Since the vapor is under pressure, the vapor stream will pick up and exhaust through the dispensing nozzle substantially all of the residual materials.

The foregoing function is accomplished by a novel valve of the invention wherein a valve housing is provided with a primary opening adapted to communicate with the material to be dispensed and a secondary opening communicating with a purging substance under pressure in the head space above the material. A valve means located within the housing is operable along a path of travel from an inoperative position to a dispensing position and movable relative to the secondary opening. A flexible gasket means is located adjacent the secondary opening which it is adapted to seal in response to action by closing means carried by the valve. The closing means is positioned with respect to said gasket such that the secondary opening will remain open for substantially the length of travel of the valve along its path of travel from inoperative to operative positions and vice versa. Because the secondary opening is allowed to remain open, there is a built-in time delay during which the vapor will be permitted to discharge through the valve thereby removing residual materials.

The secondary opening is preferably of a size such that the pressure in the aerosol container will substantially drop when the valve is open. Thus, only the purging substance will go through the valve inasmuch as the pressure in the container will not be sufficient to discharge the material to be dispensed. It can be seen, therefore, that the valve actually operates sequentially with a program of operation wherein purging substance is passed through the valve followed by closing of the secondary opening and dispensing, followed by opening of the secondary opening wherein purging substances again pass through the valve as the valve is moved from an inoperative to operative and back to inoperative positions.

This invention also provides a method for dispensing the material capable of clogging a valve. The method includes confining such a material with an active pressure producing ingredient in an aerosol container and providing a valve of the foregoing type for such container. The valve is then sequentially actuated and opened to the vapor in the head space above the material to be dispensed. Such opening is sufficient to rapidly reduce the pressure in the container whereby the pressure on the material to be dispensed will be insufficient for it to flow through the valve. Since only vapor flows through the valve, it will be cleaned of any residues left there by the dispensate. It is presently preferred to open the valve to vapor not only after dispensing, but prior to dispensing as well.

It was an object of the invention to provide a simple, economical self purging and cleaning valve adapted for dispensing a variety of aerosol products.

Another object of the invention is to provide such a valve in compact form.

Yet another object of the invention was to provide a self-cleaning valve wherein a minimum number of valve openings are utilized.

Yet another object of the invention was the provision of a self-cleaning valve wherein purging substance in the aerosol container itself is used for cleaning.

Another object of the invention is the provision of a method for cleaning a valve.

Further objects, details, and advantages of the invention will be apparent from the following description and accompanying drawings illustrating specific embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an aerosol container shown in combination with a valve means according to the invention;

FIG. 2 is an elevational view in cross section showing one embodiment of the valve according to the invention in an inoperative position;

FIG. 3 is a cross-sectional view taken on line 3--3 of FIG. 2;

FIG. 4 is a cross-sectional view taken on line 4--4 of FIG. 2;

FIG. 5 is a view similar to FIG. 2 but showing the valve in a fully operative position;

FIG. 6 is an elevational view in cross section showing an alternate embodiment according to the invention in inoperative position;

FIG. 7 is a sectional view taken on line 7--7 of FIG. 6;

FIG. 8 is a sectional view taken on line 8--8 of FIG. 6; and,

FIG. 9 is a view similar to FIG. 6 showing the valve therein in fully operative position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, there is shown in FIG. 1 an aerosol container 10 provided with a cup 11 which has a valve holding portion 11a. Positioned over the valve housing on the stem (not shown on FIG. 1) is an actuator button 13 provided with an outlet 14. For convenience, the button can have an indented upper surface 15 adapted to fit a user's finger. In normal operation when button 13 is depressed, material will be dispensed through opening 14. The container 10 is adapted to hold aerosol products such as antiperspirant sprays, starches, paint sprays or the like.

Valve shown in FIGS. 2 through 5 is of the self-cleaning aerosol type according to this invention. As shown, valve housing 12 is positioned in cup 11 and firmly held therein by means of inwardly formed crimps 16 which are disposed below outwardly extending shoulder portions 17 of valve housing 12.

Above housing 12 in cup 11 are sleeve gasket 18 and a stem gasket 19. The sleeve gasket tightly surrounds actuator 13. The stem gasket 19 provides the seal for the valve means 20 which has an upwardly extending pointed annular peripheral rim 21. As best shown in FIG. 2, the valve when in an inoperative position has the upper peripheral rim 21 substantially embedded in the material of stem gasket 19. This provides an effective tight seal to maintain the valve in inoperative position, and to close primary opening 22.

The valve is maintained in a normally closed position by spring means 23 which forces peripheral rim 21 against stem gasket 19.

Positioned annularly around the lower portion 24 of valve means 20 is a flexible gasket 25. Means are associated with valve means 20 for forcing said flexible gasket 25 against annular peripheral upstanding edge 26. Said associated means is formed as shoulder 27. Positioned below flexible gasket 25 is a secondary opening 28 which is adapted to communicate with vapor in the head space above the material to be dispensed in aerosol container 10. Extending downward from valve housing 12 is a dip tube 29 which communicates with the material in said aerosol container. Ring gasket 30 maintains flexible gasket 25 in position and provides a seat for spring means 23.

In operation, material is dispensed from the valve by pressing push button 13 downwardly. This in turn moves valve means 20 downward and breaks the seal between peripheral rim 21 and stem gasket 19, permitting communication between material in the interior of housing 12 and dispensing conduit 31. Thus, material is permitted to flow up dip tube 29 through the longitudinal fluid directing conduit 32 within valve means 20 after it passes lower orifice 33, thence through dispensing conduit 31 and finally out nozzle outlet 14.

As valve means 20 moves along its path of travel from an inoperative to a dispensing position, primary opening 22 is first put into communication with the material to be dispensed. Then, as the valve means 20 is continued to be depressed by force on push button 13, shoulder 27 comes into contact with the upper portion of flexible gasket 25. As the flexible gasket is moved downward, it comes into contact with peripheral upstanding edge 26 and forms a seal around the circumference thereof. This seal closes off communication through opening 28. Thus, when the push button 13 is fully depressed, communication between vapor in the head space above the material to be dispensed in the aerosol container and the interior of valve housing 12 is shut off, whereby only the material to be dispensed passes through the valve.

When pressure is released upon push button 13, valve means 20 is forced by spring 23 along a path of travel from a material dispensing position to an inoperative position whereby peripheral rim 21 is again seated against stem gasket 19 and primary opening 22 is closed. As shoulder 27 moves upward, flexible gasket 25 resumes its normal position (as shown in FIG. 2) and the seal between the underside of gasket 25 and peripheral upstanding edge 26 is broken permitting communication of the vapor in the head space with the interior of valve housing 12. Thus, vaporous purging substance will be permitted to enter the valve housing 12 for the purpose of cleaning impurities and residues therefrom.

It will be noted that opening 28 is positioned in a lower portion of valve housing 12 whereby vapors will clean substantially all of the movable parts of the valve. Moreover, it will be noted that the arrangement of valve means 20 with stem gasket 19 provides an efficient and reliable poppet-type valve.

In the preferred embodiment of the valve, secondary opening 28 is sufficiently large so that when it is open, the pressure in the head space above the material to be dispensed will be reduced to an extent that there will be insufficient pressure in the container to force the material to be dispensed through dip tube 29. Accordingly, the valve of the invention can be used as a sequential valve wherein material is dispensed and then effectively shut off when purging substance is permitted to flow through the valve. The valve shown in FIGS. 1 through 5 has been found particularly useful and therefore preferable for dispensing starch compositions; however, its utility is not so limited.

There is shown in FIG. 6 an alternate embodiment of the valve according to the invention which is particularly useful for certain products. This valve includes a valve means 50 having a stem 51 and a dispensing conduit 52 therein. As shown, valve means 50 is formed as a slide valve. Push button 53 is positioned on stem 51 and provided with outlet 54. Spring means 55 is positioned to maintain valve means 50 in an inoperative position closing primary opening 56 which leads to dispensing conduit 52 sealed by gasket 57. Positioned on the lower part of valve means 50 is shoulder 58 which comes into contact with flexible gasket 59 which in turn is forced against annular peripheral upstanding edge 60 when the valve is in a fully actuated position. In such position, secondary opening 61 is sealed off and thereby vapor in the head space above the material to be dispensed in the container is isolated from the interior of valve housing 62. A tertiary opening 63 can be provided to introduce vapor into the material to be dispensed as it passes up dip tube 64 and through lower orifice 65.

Operationally, the valve of FIG. 6 functions in a manner similar to that shown in FIGS. 1 through 5 with the exception that some vapor is permitted to flow through tertiary opening 63 when the valve is in a dispensing position. As in the case of the valve shown in FIGS. 1 through 5, secondary opening is preferably sufficiently large to reduce the pressure on the material to be dispensed sufficiently to shut off flow through the dip tube when it is open. Tertiary opening 63 is preferably smaller so that pressure will be maintained on the material to be dispensed by the active propellent therein. This valve has been found particularly advantageous in dispensing antiperspirant materials.

According to the method of invention, valves of the types described above can be advantageously used by confining a material to be dispensed with an active pressure producing ingredient in an aerosol container, thus pressurizing said material. Then, with the valves shown in normal dispensing position, the valve can be actuated fully to dispense a material. When pressure is removed from push button 13 or 53, (FIGS. 2 and 6 respectively) the valve is open to the vapor in the head space above the material. The opening is sufficient to rapidly reduce the pressure in the container whereby flow of the material to be dispensed will cease and the vapor will clean the valve of any residues or clogging substance which might have been deposited therein from the dispensing step.

The foregoing method can be advantageously used with materials which cause clogging such as spray starch or antiperspirant suspensions, as well as other materials having clogging characteristics of the foregoing, wherein a relatively small percentage of propellants, e.g., 6 per cent is utilized.

The following examples demonstrate the usefulness of valves of the foregoing type as well as the method.

EXAMPLE 1

An aerosol spray starch formula was used in an aerosol container with a valve similar to that shown in FIGS. 1 through 5. The formulation was as follows:

Percent by Weight __________________________________________________________________________ Sodium borate, powdered 0.2100 Derivatized amylopectin fluidity 2.8400 starch Silicone antifoam emulsion (30%) 0.0053 Sodium benzoate, technical 1.0500 Morpholine 0.1100 Nonyl phenoxy poly (ethyleneoxy) 0.5300 ethanol Water, make up to 100% --

This formulation was placed in an aerosol can using 6 per cent isobutane propellent. Lower orifice 33 had a diameter of about 0.04 inches. Secondary opening 28 had a diameter of about 0.035 inches.

The valve functioned well and was found to be kept free of clogging materials.

EXAMPLE II

An antiperspirant suspension was used in an aerosol container having a valve similar to that shown in FIG. 6. The antiperspirant suspension had the following formula:

Percent by Weight __________________________________________________________________________ Aluminum chlorhydroxyde complex 4.00 impalpable Ultrafine pyrogenic silica 0.20 Hexachlorophene 0.10 Perfume 0.10 Isopropyl myristate 6.00 Trichloro monofluoro methane 62.72 (Freon 11) Dichloro-difluoro methane 26.88 (Freon 12)

Lower body orifice 65 had an inside diameter of about 0.04 inches. Secondary opening 28 had an inside diameter of about 0.035 inches. Tertiary opening 63 had an inside diameter of about 0.022 inches. The valve was found to function well throughout the dispension of the antiperspirant suspension and did not clog or malfunction.

The foregoing specific examples show typical product applications of the method and valves according to the invention. It should be noted that the valve of FIG. 6 is particularly suitable for use with antiperspirants inasmuch as tertiary opening 63 permits vapor to dilute the antiperspirant composition and thereby reduce the "shock" that otherwise might occur if the undiluted antiperspirant were permitted to come into contact with the skin.

The valves of the present invention can be used with powdered, as well as liquid, materials.

Other product uses are, of course, capable with the valves according to the invention.

Claims

We claim:

1. A self-cleaning aerosol dispensing valve comprising:

a valve housing;

a primary opening within said housing adapted to communicate with the material to be dispensed;

a secondary opening in said housing adapted to communicate with a purging substance in the head space above the material to be dispensed;

a valve means located within said housing, said valve means movable relative to said secondary opening and being operable along a path of travel from an inoperative position to a dispensing position;

a flexible gasket means located adjacent said secondary opening, said gasket being adapted to seal said secondary opening, said gasket being normally out of contact with said opening;

means associated with said valve means for moving said gasket into sealing contact over said secondary opening, said means being positioned with respect to said valve means so that said secondary opening will remain open while the valve is moved along its path of travel from an inoperative to an operative position for a time sufficient to enable said purging substance to flow through said valve for cleaning same, said secondary opening being in the lower portion of said valve housing whereby vapor will clean all of the movable parts therein.

2. A self-cleaning aerosol dispensing valve according to claim 1 further comprising a tertiary opening adapted to communicate with the purging substance in the head space above the material to be dispensed, said tertiary opening being positioned such that said purging substance passing therethrough is mixed, said material to be dispensed in said valve housing.