US 3184118 A
Description (OCR text may contain errors)
INVENTOR M/LO E WEBSTER My D g May 18, 1965 M. E. WEBSTER AEROSOL SPRAY CONTAINER Filed June 14 United States Patent 3,184,118 AEROSOL SPRAY CQNTAINER Milo E. Webster, Rochester, N.Y., assignor to Bernz 0 Matic Corporation, Rochester, NFL, a corporation of New York Filed June 14, 1963, Ser. No. 287,909 4 Claims. (Cl. 222-189) This invention relates to an improved aerosol spray container.
Various fluids, such as, for example, pain-ts, insecticides, cleaners, deodorants, and the like are marketed in areosol spray containers which permit their dispensing and use as a fine aerosol spray.
The aerosol spray container generally comprises a pressurized container, as for example, a cylinder or can having therein the fluid to be dispensed and a propellant under pressure. A dip tube extends below the surface of the fluid and terminates at the bottom portion of the container and an aerosol spray valve, generally of the pushbutton type, is flow connected with the dip tube so that upon opening of the valve, as for example, by push-button operation, the pressure of the propellant forces the fluid from the container up through the dip tube and out through the aerosol valve in the form of a fine spray. The aerosol spray valve is provided with a terminal orifice which acts as the spray nozzle and is generally additionally provided with a primary orifice which is nor mally sealed but which becomes exposed, acting as the valve upon push-button operation. The orifices are in the form of constrictions having diameters which gen erally are larger than .020", as for example, between .020 and .040".
A major problem encountered in connection with the areosol containers is the tendency of the areosol valve to become plugged. This is particularly troublesome in connection with the dispensing of paint, and similar materials, but is also a problem in connection with the dispensing of other fluids. The plugging is generally caused by foerign particles or over-sized particles built up from the material being sprayed which sink to the bottom of the container and which are forced up the dip tube with the material being dispensed clogging one of the orifice constrictions in the aerosol spray valve. These particles which plug the orifice or orifice of the spray valve are firmly held in place by the pressure differential so that the plugging cannot be readily corrected and the container is rendered inoperative preventing further dispensing and use of the contents and resulting in severe customer dissatisfaction.
One object or this invention is a construction which reliably avoids the above-mentioned disadvantage in a simple and economical manner.
This and still further objects will become apparent from the following description read in conjunction with the drawing which shows a vertical cross-section of an embodiment of an aerosol container in accordance with the invention.
In accordance with the invention, I have discovered that the above-mentioned problem of plugging may be reliably prevented if the normally open end of the dip tube of the aerosol container is sealed and this end perforated with a multiple number of perforations of smaller size than the orifices of the aerosol spray valve. The perforations should preferably have a diameter of at least smaller than the diameter of the smallest other opening in the discharge path which is usually the primary or terminal orifice.
Referring to the embodiment shown in the drawing, 1 represents the pressurized container which in the embodiment shown is in the form of an aluminum cylinder,
ddhdfiih Patented May 18, 1965 though any known or conventional container, as for example, the conventional tin cans may be used. The opening at the upper end of the container is sealed by the conventional crimped sealing cap 2 which is provided with the aerosol spray valve having the plastic push-button spray head 3 provided with the terminal spray orifice 4, the intermediate expansion chamber 5, and the primary orifice 6. The primary orifice 6 consists of a lateral hole extending through the wall of the stem portion 7 in communication with the intermediate expansion chamber 5. The aerosol spray valve is also provided with the hollow metal housing 8 joined by crimping to the cup 2. The housing 8 contains the spring 9 and the spring plunger lit which is connected to the stem 7 of the spray button. The stem 7 extends through a central hole in the cap 2 provided with the gasket 11. The spring 9 normally forces the plunger 19 upward so that its upper edge contacts the gasket ii, and the primary orifice 5 is sealed by the gasket 11. When the spray button 3 is depressed, the spring 9 is compressed, and the primary orifice 6 exposed. Pressed into the lower end of the housing 3 is the dip tube 12 of the heat-scalable plastic material, as for example, polyethylene, polyvinylchloride or the like. The clip tube 12 extends to the bottom of the container 1 in the conventional manner, and as shown to the lowermost forward corner of the container. The normally open end of the dip tube is in accordance with the invention heat sealed at 13 and provided with a multiple number of small perforations 14 which are of smaller size than the orifices 6 and 4. Thus, for example, 3 to 12 small perforations of a size, for example between .010 and .015 in diameter may be provided.
The container 1 contains the liquid 15 to be dispensed, as for example, the paint, and is additionally charged with a propellent as for example liquefied propane, the propane vapor filling and pressurizing the upper space at 16. A conventional agitator ball or balls, as for examrle the glass agitator ball 17 is also provided in the container to aid the mixing of the paint by shaking prior to use.
in operation, the container is shaken and the agitator ball 17 aids in mixing the paint which generally consists of pigments, vehicle solids such as resin, and solvent. The terminal orifice 4- is then pointed at the surface to be coated and the spray head 3 depressed. The downward movement of the spray head 3 exposes the primary orifice 6 and causes downward movement of the plunger 10' and compression of the spring a.
The pressure of the propellent vapor forces the paint through the perforations 14 up through the dip tube 12 past the plunger 3, which is provided with suitable clearance or openings for this purpose, through the primary ritice 6 into the expansion chamber 5 and out through the terminal orifice 4 in the form of a fine spray which is used to coat the surface.
Normally, if a foreign particle were present in the paint, as for example a flake of aluminum in connection with aluminum containers or a piece of oxidized steel in connection with steel containers, or an agglomeration of pigment particles, or over-sized pigment particles or the like, the same, after sinking to the bottom of the container would be forced through the dip tube 12 clogging either the primary orifice 6 and/or the terminal orifice 4 rendering the container inoperative. The diiferential pressure would lock such particle in place over or in the orifice in question so that the situation could not be readily remedied except for example by exchanging the spray head.
With the construction in accordance with the invention, however, such a particle would merely become wedged against a perforation 14 and would not interfere with are of a large size than the perforations'14. Even if all the perforations 14 would become covered by such foreign particles, this would not present a serious problem as further agitation and the action of the agitator ball would dislodge such particles so that the container could be rendered again operative.
Upon release of the spray head 3, the action of the spring 9 in the conventional manner forces the spray head 3 upwardly so that the orifice 6 is masked by the gasket 11 shutting off the spray.
The improvement in accordance with the invention is, of course, applicable in connection with any of the known or conventional aerosol spray containers provided with any of the known or conventional aerosol spray valves and charged with any of the conventional aerosol materials, and conventional propellents, as for example fiuorinated hydrocarbon, such as the various freons used for this purpose.
While the invention has been described in detail with reference to specific embodiments shown, various changes and modifications which fall Within the spirit of the invention and scope of the appended claims will become .apparent to the skilled artisan. The invention, therefore,
is only intended to be limited by the appended claims or their equivalents wherein I have endeavored to claim all inherent novelty.
1. In an aerosol spray container comprising a pressurized container having therein a fluid to be dispensed and a propellant under pressure, a dip tube extending below the surface of said fluid and terminating at the bottom portion of the container and an aerosol spray valve having at least one orifice constriction flow connected with the dip tube, the improvement which comprises the end of said dip tube being sealed and the wall of said dip tube being provided with a plurality of perforations, said perforations being disposed in proximity to the sealed end of said dip tube, with each perforation having a flow area which is smaller than that of the smallest orifice inthe spray valve.
2. Improvement according to claim 1 wherein the total flow area of the perforations is greater than the flow area of the smallest orifice in the spray valve.
3. Improvement according to claim 1 wherein the perforations have a size between about 0.010 and 0.015 inch diameter.
4. The improvement according to claim 1 wherein each perforation has a diameter whichis at least 20% smaller than the diameter of the smallest orifice in the spray valve.
References Cited by the Examiner V UNITED STATES PATENTS 1,486,041 3/24 Schmidt 239-337 X 1,995,098 3/35 Healy 222464 X 2,258,524 10/41 Vigurs 222-189 X 2,605,018 7/52 Croce et a1. 222-107 2,774,628 12/56 Engstrum 222189 2,808,926 10/57 Drake et al. 222107 X 2,995,278 8/61 Clapp.
r 3,087,707 4/63 Moonan 222394 X RAPHAEL M. LUPO, Primary Examiner.