Aerosol Valve

Abstract

An aerosol dispensing unit of the type wherein the propellant and the material to be dispensed are kept separate until aspiration. The unit has an outer container and an inner cartridge. A valve with a pushbutton is mounted on the inner cartridge. A double dip tube extends from the valve through the inner cartridge into the outer container. The first of the tubes connects to a first passageway through the valve into the pushbutton. A second passageway extends from the inner cartridge through the valve into the pushbutton. The second tube is part of an air return passageway which relieves the vacuum in the outer container.

Description

BACKGROUND OF THE INVENTION

The present invention relates to an improved aerosol dispensing unit of the type wherein the propellant and the material to be dispensed, usually a liquid, are kept in separate containers, and wherein such unit is constructed so that it is not subject to leakage, even when the unit is inverted and operated.

More specifically, the present invention relates to such an aerosol dispensing unit which provides for an integral air return passage located in the valve portion of the unit and which is opened during each actuation of the unit.

In the aerosol dispensing industry, it is often desirable to dispense a material, which for one reason or another, must be kept separate from its propellant until actual aspiration. Dispensing devices heretofore known for maintaining separation of the propellant and the material to be dispensed have been subject to leakage of the material to be dispensed.

One solution of the problem of leakage is proposed in U. S. Pat. No. 3,401,844. However, one disadvantage of the dispensing device shown in said patent is that an air return to the material to be dispensed for purposes of relieving vacuum created during dispensing is not provided for in the valve portion of the unit.

With this disadvantage in mind, it is the object of the present invention to provide an aerosol dispensing unit which includes a valve portion having an air return therein and which is opened during each actuation of the unit to relieve vacuum created in the container while the material is being dispensed.

A further object of the present invention is to provide an aerosol dispensing unit having an air return which is not subject to leakage when the unit is sprayed in the inverted position.

According to the present invention, the aerosol dispensing unit includes an outer product container containing the material to be dispensed and an inner cartridge containing the propellant. A valve portion is provided at the top of the inner cartridge. The valve portion provides passageways for the propellant, the material to be dispensed and the air return. A double dip tube extends from the valve portion through the inner cartridge into the outer container. One tube of the double dip tube connects to the passageway for the material to be dispensed, and the other tube of the double dip tube connects to the passageway for the air return. The passageways have obturating means therein which are actuated to open and close the passageways by the depression and release of a pushbutton of the dispensing unit.

The provision of an air return in the valve portion of the aerosol dispensing unit as shown in the present invention is desirable in that it enables relief of the vacuum in the unit during each dispensing operation. Furthermore, the invention according to one embodiment provides for the air return to extend to near the bottom of the dispensing unit. This eliminates liquid leakage if the unit is actuated in the inverted position, since the liquid is not in contact with the air return.

Other features of the invention will be made clear by the following description, taken together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an axial section view in schematic form of an aerosol dispensing unit according to the present invention;

FIG. 2 is an axial section view of the valve portion of the invention of FIG. 1 in the closed position;

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

FIG. 4 is an axial section view similar to FIG. 2 but with the valve in the open position;

FIG. 5 and FIG. 6 are axial section views in schematic form of a modified aerosol dispensing unit according to the present invention; and

FIG. 7 is an axial section view in schematic form of a further modified aerosol dispensing unit according to the present invention.

Referring to FIG. 1 of the drawings, an aerosol dispensing unit according to the present invention is shown, wherein an outer product container 1 contains the material to be dispensed and an inner cartridge 2 contains the propellant. A valve portion 3 is provided at the top of the inner cartridge 2 and is mounted in retaining cap 6. Retaining cap 6, outer container 1 and inner cartridge 2 interengage to form a sealed bead 7 in a known manner. As shown in FIG. 2 valve portion 3 has a body 8 with a bead 9 therearound. Retaining cap 6 has a raised central section 10 with an inwardly directed crimp 11 crimped under bead 9. A first gasket 12 is held in a sealing manner between central section 10 and the top of bead 9. Body member 8 is also retained on retaining cap 6 by crimp 11.

Body 8 has an inner recess in which valve stem 13 is positioned. The recess has a first bore 14, a second smaller diameter bore 15 and a third even smaller diameter bore 16. A first retaining ring 17 fits within the first bore is supported on the ledge 18 between the first and second bores. A second retaining ring 19 fits within the first bore and has a lower projection 20 which is supported by the upper surface of the first retaining ring 17. A second gasket 21 is held in a sealing manner between a ridge 22 on the upper surface of the first retaining ring 17 and an inwardly extending ring 23 of second retaining ring 19. A third gasket 24 fits within the second bore 15 and is held in a sealing manner between the lower surface of first retaining ring 17 and a ridge 25 formed on the ledge between second bore 15 and third bore 16. Upward movement of retaining rings 17 and 19 is prevented by the lower surface of inward projection 26 of body 8. A coil spring 27 is positioned between the upper surface of ring 23 and the lower surface of an outwardly projecting portion 28 of valve stem 13 and urges valve stem 13 in an upward direction as viewed in FIG. 2. The action of spring 27 causes first gasket 12 to be compressed between the upper surface of position 28 and the bottom surface of central section 10, thereby forming an airtight seal when the dispensing unit is in the closed position shown in FIG. 2.

Valve stem 13 at its upper portion is fitted with pushbutton 29, as at surfaces 30 and 31. Pushbutton 29 has a downwardly depending outer tube 32 which surrounds surface 33 of valve stem 13. Surface 33 has a plurality of outwardly projecting parallel splines 34 spaced therearound. The splines 34 form a plurality of passages 35 therebetween, as shown in FIG. 3. The inner surface of outer tube 32 slidingly fits over the outer surfaces of splines 34. Passages 35 terminate at their lower ends in openings 35a formed between the lower edge of outer tube 32 of pushbutton 29 and the upper surface of portion 28 of valve stem 13. Inner tube 36 of pushbutton 29 fits tightly around surface 30 of valve stem 13. Inner tube 36 contacts with the downwardly and outwardly sloping ledge between surfaces 30 and 33 of valve stem 13, thereby limiting the sizes of space 42 and openings 35a.

Valve stem 13 has a central conduit 37 connecting at its upper end with conduit 38 of pushbutton 29 and terminating at its lower end at radial openings 39 through stem 13. Third gasket 24 is positioned to seal openings 39 when dispensing unit is in the position shown in FIG. 2. Radially outwardly from central conduit 37, valve stem 13 has a series of passageways 40 separated by a plurality of webs 41 (see FIG. 3). Passageways 40 at their upper ends connect through space 42 with passage 43 in pushbutton 29. At their lower ends passageways 40 terminate at radial openings 44 through stem 13. Second gasket 21 is positioned to seal openings 44 when the dispensing unit is in the position shown in FIG. 2.

Outer dip tube 4 is sealingly attached to reduced diameter portion 45 of body 8 and extends through the bottom of inner cartridge 2, to which the outer dip tube 4 is sealed at 46. Inner dip tube 5 is sealingly attached radially inwardly of outer dip tube 4 to reduced diameter portion 47 of body 8 and extends to adjacent the bottom of outer container 1. Inner dip tube 5 has a bulb 5a therein. After the first spraying of the dispensing unit tube 5 remains filled with the material to be dispensed. Bulb 5a is of a size sufficient to hold enough of the material to be dispensed so that the unit may be sprayed in the inverted position. (see FIG. 6). The interior of inner dip valve 5 is in communication with a vertical passage 48 in body 8. The upper end of passage 48 opens into first bore 14 from ledge 18. First retaining ring 17 is provided on its bottom surface with a plurality of radial grooves 49 and circular grooves 50 and 51, which communicate with the interior of inner dip tube 5 through passage 48. The space between the inner and outer dip tubes is connected by vertical passageway 52 in body 8 to space 53 between body 8 and valve stem 13. Communication is provided from the inner cartridge 2 to the interior of bore 16 through lateral bore 54 in body 8.

The operation of the invention will now be explained with reference to FIG. 4. When pushbutton 29 is depressed valve stem 13 is lowered in opposition to the force of spring 27. When this occurs, gasket 24 is flexed downwardly and radial openings 39 are opened. This allows propellant to escape from inner cartridge 2 through lateral bore 54, bore 16, radial openings 39 and central conduit 37 into conduit 38 and a nozzle 56 of pushbutton 29.

At the same time, as gasket 24 is flexed downwardly, seal 57 formed between the bottom surface of first retaining ring 17 and the upper surface of gasket 24 is opened. Simultaneously, as valve stem 13 is lowered, gasket 21 is flexed downwardly, thereby opening radial openings 44. The material to be dispensed is thus aspirated from the outer container 1 through inner dip tube 5, passage 48, grooves 49, 50 and 51, opened seal 57, openings 44 and passageways 40 into space 42, passage 43 and nozzle 56 of pushbutton 29.

Furthermore, when pushbutton 29 is depressed, outer tube 32 flexes gasket 12 downwardly, thereby opening a seal 58 formed between gasket 12 and the upper surface of portion 28. This allows air to flow through a channel 59 in pushbutton 29, passages 35 opened seal 58, space 53, passageway 52 and outer dip tube 4 into the outer container 1. Outer container 1 is thereby vented to relieve the vacuum created therein by the outward flow of the material to be dispensed.

Gaskets 12, 21 and 24 therefore operate as obturating means to open and close seal 58, openings 44, and seal 57 and openings 39, respectively, in response to the depression and release of pushbutton 29. By means of this novel arrangement, the outer container 1 is vented during each actuation of the dispensing unit, thereby assuring steady flow of the material to be dispensed.

By the provision of the cartridge and container, of separate passageways through valve portion 3, and of separate passageways in pushbutton 29, the propellant and the material to be dispensed do not come into contact until actual aspiration at nozzle 56 of pushbutton 29.

In a second embodiment of the present invention, as shown in FIG. 5, the outer dip tube 4 may be extended to approximately the bottom of outer container 1. Preferably, the outer tube is extended to within one-half inch to 1 inch from the end of inner dip tube 5. It is not desirable that both tubes be of the same length, since if this were so, air from the outer dip tube would be expelled with the material to be dispensed through the inner dip tube.

The advantage of this embodiment of applicant's invention may clearly be seen with reference to FIG. 6. When it is desired to spray the dispensing unit in the inverted position, the placement of the outer dip tube near the bottom of the outer container eliminates the danger of leakage of the material to be dispensed through the outer dip tube. This danger is precluded since the material to be dispensed does not come in contact with the end of the outer dip tube. The propellant in FIG. 6 is adsorbed on a silica powder or other means to insure continuous release of gaseous propellant only.

In another embodiment of the invention, as shown in FIG. 7, a flexible bag 59 may be sealingly attached to the end of inner dip tube 5. The use of bag 59 is desirable when the material to be dispensed would corrode outer container 1 or the cartridge. The bag 59 is therefore constructed of a material which will not be corroded by the material to be dispensed. In the embodiment of FIG. 7, air supplied through outer tube 4 tends to compress bag 59, thereby venting the unit. The use of bag 59 also enables the unit to be actuated in the inverted position without the danger of leakage through the air return passage.

Although several embodiments of the invention have been described in detail such description is intended to be illustrative only, and not restrictive, since many details of the construction of the invention may be altered or modified without departing from the spirit or scope of the invention.

Claims

What we claim is:

1. An aerosol dispensing unit comprising an outer container containing the material to be dispensed; an inner cartridge containing the propellant and sealingly seated in said outer container; a valve portion having a pushbutton attached thereto, said valve portion comprising a body having a recess and a valve stem positioned in said recess; means for sealingly attaching said valve portion to said inner cartridge; a first dip tube sealingly attached to said valve portion and extending through and sealed to said inner cartridge; a second dip tube sealingly attached to said valve portion, said second dip tube extending adjacent to the bottom of said outer container; a first flow passage from said inner cartridge through said valve portion to said pushbutton; a second flow passage from said second dip tube through said valve portion to said pushbutton, said second flow passage being sealingly separate from said first flow passage; an air return passage through said pushbutton, said valve portion and said first dip tube into said outer container, said air return passage being sealingly separate from said first and second flow passages; and obturating means in said valve portion for sealing each of said passages, said obturating means being operable to open said passages upon the depression of said pushbutton.

2. An aerosol dispensing unit as claimed in claim 1 wherein said second dip tube is located concentrically with said first dip tube.

3. An aerosol dispensing unit as claimed in claim 2 wherein said flow passages comprise passageways through both said body and said valve stem, and said obturating means sealing said flow passages comprise flexible gaskets positioned between said body and said valve stem.

4. An aerosol dispensing unit as claimed in claim 3 wherein said obturating means sealing said air return passage comprises a flexible gasket positioned between said pushbutton and said valve stem.

5. An aerosol dispensing unit as claimed in claim 1 wherein said first dip tube extends to near the bottom of said outer container.

6. An aerosol dispensing unit as claimed in claim 5 wherein the end of said first dip tube extends to within one-half inch to 1 inch of the end of said second dip tube.

7. An aerosol dispensing unit as claimed in claim 1 wherein said outer container has a flexible bag therein containing the material to be dispensed, said flexible bag being sealingly attached to said second dip tube.