US 3405846 A
Description (OCR text may contain errors)
G. H. KLUN AEROSOL VALVE Oct. 15, 1968 Filed June 24, 1966 INVENTOR. GODFREY H. KLUN ATTORNEY WV M r l u 1 ll J o 4 2 4 United States Patent T 3,405,846 AEROSOL VALVE Godfrey H. Klnn, Parma, Ohio, assignor to Union Carbide Corporation, a corporation of New York Filed June 24, 1966, Ser. No. 560,162 3 Claims. (Cl. ZZZ-402.20)
ABSTRACT OF THE DISCLOSURE A resilient diaphragm is provided for a pressurized metering aerosol valve which comprises a thin sleeve portion surrounding the valve stem of said aerosol valve to cover a valve stem opening therein and control flow of aerosol formulation from the metering chamber through the valve stem opening. The sleeve-like configuration of the diaphragm permits pressure within the metering chamber to compress the diaphragm about the valve stem at the opening thereby enhancing sealing and preventing leakage.
This invention relates to aerosol containers, and more particularly to novel and improved metering valves for aerosol containers.
Aerosol containers are known to be a very convenient means for dispensing fluids or solids suspended in a fluid stream. However, when finely divided solids either in a dry or in a slurry system are dispensed from such a container, presently available valves including those of the metering type tend to clog and inadvertantly limit or even cut off the fluidized stream of the dispensed material when such valves are in an open position. This clogging is invariably caused by caking and the tendency of the finely divided solids to agglomerate within the valve body and subsequently obstruct and hinder proper valve action. In addition, solid particles tend to accumulate on the valve seat, valve spring, etc., after each use of the aerosol container and eventually prevent the complete closure of the valve means. This, of course, results in leakage of the propellent from the aerosol container and vitiates its further utility. Also, solid particles accumulating in the valve increase the coeflicient of friction of the moving parts of the valve and hinder its operation.
It is the principal object of the present invention to avoid the aforementioned difiiculties and to provide an aerosol valve of the metering type particularly well suited for use with aerosol containers dispensing finely-divided solid materials.
It is another object of the invention to provide an aerosol valve of the metering type which does not clog or stick during use and to provide an aerosol valve in which the biasing means is externally mounted and not in contact with the dispensed materials.
These and other objects and advantages of the present invention will readily present themselves to the skilled artisan upon reference to the ensuing specification and the drawing in which FIGURE 1 is a sectional elevational view of the metering aerosol valve of the present invention, and FIGURE 2 is a sectional view taken along the line 22 of FIGURE 1 and showing the lands of the valve in greater detail.
The objects of the present invention are achieved by a metering aerosol valve assembly the principal feature of which is a valve body having a central metering chamber communicating with an eductor tube or dip tube extending into a suitable aerosol container. The valve body is conventionally sealed to the top closure and suitably supports therein a centrally disposed hollow valve stem by means of a steel support washer and a resilient diaphragm. The valve stem is biased upwardly so as to maintain upper slide valve means in a closed position by means of an external compression spring disposed about the 3,405,846 Patented Oct. 15, 1968 valve stem between the steel support member and a flanged portion of the valve stem. A spring housing positioned about the compression spring acts as a stop for the valve stem. At the base of the valve body is a comically-shaped valve seat which communicates with the eductor tube and with the closed end of the hollow valve stem. The upper slide valve means comprises a transverse inlet opening which communicates with the metering chamber to direct the metered charge to an axial outlet opening in the valve stem when said stem is depressed and biased downwardly to the open position.
Since the instant metering aerosol valve contemplates the use of a resilient diaphragm having a central bore through which the valve stem is slidably disposed, valve operations can be further enhanced by decreasing the coefiicient of friction of the moving parts within the valve assembly. An additional benefit can be gained if the valve stem, selected portions thereof, or the stationary bearing surfaces of the valve assembly are coated with a permanent resilient coating of a halohydrocarbon polymer. Typical illustrative halohydrocarbon polymers are homopolymers of tetrafluoroethylene, copolymers of tetrafluoroethylene and hexafiuoropropylene, and the like.
The coelficient of friction between the moving parts of the instant valve can be conveniently reduced by applying thereto a lubricant, which is relatively non-volatile under the normal service conditions of the aerosol valve and which is compatible with the materials of construction employed and with the components of the aerosol system. The lubricant can be applied also over the coated portions of the valve stem. Typical of such lubricants are hydrocarbon oils and greases, silicon oils and greases, and the like. Also, contemplated are the suspensions in the aforementioned oils and greases of solid lubricants such as graphite, molybdenum disulfide, boron nitride, powdered tetrafluoroethylene polymers, and the like.
Illustrative hydrocarbon base lubricants are mineral oil, petroleum jelly, polyglycols, and the like.
Illustrative silicon oils and greases are organic-siloxane fluid polymers with or without a thickening agent such as reactive silica, silica admixed with reactive boric oxide, soaps, and the like.
In FIGURES 1 and 2 of the drawing, there is shown a valve body or housing 10, and a resilient flanged diaphragm 12 which seals off the upper end of the housing 10 and together with the housing 10 defines a metering chamber 14. Suitable supporting means such as rigid washer 16 overlies the diaphragm 12 and serves to support suitable biasing means, such as compression spring 18, the latter of which is used to maintain the valve assembly in a closed position.
The valve stem 20 may be of plastic and is suitably tubular in form and closed at its lower hemisphericallyshaped end 21 (hereinafter described in greater detail). The stem 20 is mounted in the housing 10 and is provided with a longitudinal conduit 22 and an upper lateral valve stem opening 24. If desired, the lower portion of the valve stem 20 below the opening 24 may be solid. As best shown in FIGURE 2, a plurality of lands 15 guide and center the valve stem 20 within the valve housing 10. Three lands are suitable in the practice of the invention although four lands are illustrated and described herein. In the closed position of the metering valve of the invention, the upper lateral opening 24 is located adjacent to and covered by a depending sleeve portion 25 of the diaphragm 12. The central portion of the valve stem 20 extends through and is slidable in the central bore 26 of the diaphragm 12 and the valve stem is sufficiently long so as to project beyond the top of an aerosol container (not shown) so as to accept an actuator button 28.
Near the upper portion 30 of the valve stem 20 is a suitable protuberance or annular ridge 32 which functions 3 as a shoulder for the spring 18 and as a limit stop for the valve stem 20. If desired, the outside surface of the valve stem 20 may be coated with a halohydrocarbon polymer coating which provides a resilient mating surface with the diaphragm 12. The lower hemisphen'cally-shaped valve means 21 of the valve stem 20 is in proximity to a lower tapered valve stem seat 34 provided in the bottom portion of the valve housing 10. The valve means 21 serves to seal off the tapered opening 36 in valve housing 10 when the actuator button 28 is depressed and the metering valve of the invention is in the open position and expelling the metered charge residing in the metering chamber 14. The seat 34 is noted to have extending tip portion 45 which is urged into sealing engagement with said lower valve means 21 'by the internal gas pressure of said aerosol container. This same gas pressure is noted to aid in sealing said upper valve stem opening 24 with the depending sleeve portion 25 of said diaphragm 12 (see arrows in FIG- URE l).
The compression spring 18 is situated externally about the valve stem 20 between the rigid washer 16 and the annular ridge 32 so as to urge the bottom portion 21 of the valve stem 20 away from being in sealing engagement with the conical opening 36 of the valve stem seat 34. The valve assembly of the invention is held in place within an aerosol container by means of a conventional top cover or closure 37. The flange portion 39 and the crimp 41 of the closure 37 provide the means by which the valve assembly is held together and fixedly disposed and suspended within an aerosol container (not shown).
A conventional eductor tube 38 extends within a standard type aerosol container and is mounted to the lower portion of the valve housing 10 so as to communicate with the chamber 14 thereof. Care should be taken that the passageway of the eductor tube is not too close to the bottom portion 21 of the valve stem 20 so as to avoid compacting of loose powder against the passageway of the eductor tube 38 thereby plugging it. The proper spacing can be readily ascertained by one of ordinary skill in the art.
The actuator button 28 has a longitudinal passage 40 provided with a discharge orifice 42 the effective diameter of which is greater than that of the stem opening 24 to prevent clogging. The longitudinal pasage 40 communicates with the longitudinal conduit 22 of the valve stem 20 by means of the axial opening 43 at the upper end of the valve stem 20. When the actuator button 28 is depressed the valve stem 20 is moved longitudinally to compress against the spring 18 and from a normal sealing or closed position to an open or discharge position. The open or discharge position is reached when the longitudinal conduit 22 communicates with the chamber 14 of the valve housing 10 via the upper valve stem opening 24. Upon release of pressure on the actuator button 28 the spring 18 returns and closes off the upper valve stem opening 24 of the valve stem 20 and opens the lower valve means 21 thus allowing the metering chamber 14 to be filled for the next metered charge.
The location of the upper valve stem opening 24 is critical in that is must be such that when the valve stem 20 is moved longitudinally to adischarge position, the upper opening 24 is moved away from its sealingrelationship with'the diaphragm 12 and into communication with the metering chamber 14. At the same time, the lower bottom valve 21 of the valve stem 20 seals off the metering chamber 14 whereby enabling only a predetermined metered quantity of aerosol formulation within the cavity 14 to be expelled from the aerosol container. The tapered opening 36 is noted to be completely sealed before the opening 24 enters the chamber 14. Similarly, when the actuator button 28 is released, the opening 24 must leave the chamber 14 before the same is opened to the eductor tube 38 and the internal pressure of the aerosol container which, of course, automatically fills the metering chamber 14 every time the valve assembly is in the normally closed or sealing position.
, i l In the metering valve of the invention, the chamber 14 is filled by the pressurized aerosol formulation with the material to be dispensed when the valve stem 20 is not depressed and the lower valve 21 is in an open position while the upper valve stem opening 24 is in the normally closed or sealing position. When the valve stem 20 is subsequently moved to the discharge position, the material contained in the chamber 14 is dispensed through the discharge orifice 42 by means of opening 24, longitudinal conduit 22 and opening 43. Of course, the dosage to be dispensed is controlled by the capacity or volume of the chamber 14. It should be noted that the compression spring 18 is externally mounted and does not come into contact with the material to be dispensed so that consequently it cannot be clogged and will essentially be jam-proof. Tests have shown that when the bias means is positioned where it will be in direct contact with the material to be dispensed, repeated use of such a valve will cause the bias means to become clogged and hence inefiective. It should also be noted that the gas pressure in the container and in the metered cavity aids in respectively holding the extending tip portion 45 of said lower tapered valve seal 34 in sealing engagement with the lower valve means 21 of the valve stem 20, and in holding the depending sleeve portion 25 of said diaphragm 12. in sealing engagement with said upper valve stem opening 24.
The foregoing discussion is intended to be illustrative. Other modifications of structure and rearrangement of the parts can be resorted to without a departure from the spirit and scope of the present invention.
What is claimed is:
1. In a metering aerosol valve for a pressurized aerosol container including a housing defining a metering chamber containing a pressurized predetermined quantity of aerosol formulation to be dispensed, lower valve means defined by said housing through which aerosol formulation may flow from said container to said metering chamber, a valve stem extending into said housing and defining internally thereof a passageway for dispensing aerosol formulation from said metering chamber, valve stem opening means defined by said valve stem between said passageway and said metering chamber, spring means mounted exterio rly of said valve stem biasing said stem to a closed-valve position and defiectable to permit displacement of said stem to an open-valve position, closure means surrounding said valve stem blocking flow through said valve stem opening means when said stem is in said closed-valve position and permitting exposure of said valve stem opening means to the aerosol formulation in said metering chamber when said stern is in said openvalve position, and means on said valve stem blocking flow through said lower valve means when said stem is in said open-valve position, the improvement in combination therewith wherein said closure means comprises a resilient diaphragm having a relatively thin sleeve portion snugly extending over a portion of the exterior of said valve stem which is exposed to pressure within said metering chamber, said sleeve portion being compressed by said pressure about said valve stem thereby enhancing the sealing engagement of said diaphragm over said valve stem opening means. i
2. In a metering aerosol valve according to claim 1 the improvement in combination therewith wherein said lower valve means comprise a conically shaped opening defined by a conically shaped lip portion extending from said housing, with the end of said valve stem moving into said opening when in the open-valve position, said end of said stern being shaped to block aerosol formulation flow through said valve means, said valve stem end being completely disengaged and out of contact with said conically shaped lip portion when in the closed-valve position thereby penmitting com-pletely free flow of aerosol formulation therethrough.
3. A metering aerosol valve according 'to claim 2 wherein said conically shaped lip portion is configured to be compressed against said valve stem when in the open-valve positon by pressure within said aerosol container thereby enhancing the sealing engagement therebetween.
References Cited UNITED STATES PATENTS 2,822,960 2/1958 Lengel 222402.24
6 3,128,924 4/ 1964 Gorman 222402.2 3,178,078 4/ 1965 Wittke 222402.2
FOREIGN PATENTS 1,264,367 5/1961 France.
ROBERT B. REEVES, Primary Examiner.
F. R. HANDREN, Assistant Examiner.