US2767023A - Spray nozzles - Google Patents

Description

SPRAY NOZZLES Frank Venus, Jr., Oxford, Conn., assignor to The Risdon Manufacturing Company, Naugatuck, Conn, a corporation of Connecticut Application March 27, 1956, Serial No. 574,263

8 Claims. (Cl. 299-114) This invention pertains to spray nozzles for liquid dispensing devices, and more particularly to nozzles adapted to give good atomization of liquids which ar substantially nonvolatile at ordinary ambient temperatures and which are propelled from such devices by means of pressure.

The atomization may be efiected by supplying under pressure to a nozzle the liquid to be dispensed, which may be done by means of a manually operated pump, or preferably by means of gas pressure generated Within a valved container in which such liquid is ordinarily held. in the latter case, the gas pressure is commonly produced by including in the container a low-boiling liquid which volatilizes at ordinary room temperature and acts as a propellant for the first liquid when the valve of the container is actuated.

While the nozzles of the invention find general applicability in dispensing any of various kinds of liquids, they are especially suited for use in dispenser devices of the last mentioned type wherein the liquid to be dispensed is essentially nonvolatile at ordinary ambient temperatures, is substantially immiscible in the propellent liquid and does not readily form an emulsion therewith. In such instances, there is present in the dispensing container a three-phase system consisting of two liquid phases and a gaseous phase. When a dispensing device of this char actor is used, the intake end of the conduit employed to deliver liquid to the nozzle is so positioned in the container that ordinarily only the non-volatile liquid is delivered to the nozzle. Unlike the so-called aerosol spray dispensing devices commonly used today for pa nts, insecticides and many other products in which the material to be dispensed forms a solution or emulsion with the propellant, i. e. in which there is a two-phase system in the container, the dispensing of a liquid in the form or a spray from a three-phase system as just described cannot rely on the volatilization of the propellent liquid as the container valve is actuated to assist in the dispersion of the liquid which it is the primary purpose to dispense. Good dispersion in the form of a fine mist of such liquid is accordingly dependent on the pressure applied to force the liquid from the container and mechanical means in the nozzle itself for breaking up the liquid into fine droplets. These two factors introduce troublesome problems to be considered in the production of dispensing devices which are economical to manufacture and yet really efiective in operation.

Good atomization or fine dispersion of fluids at very low pressures is highly desirable in many practical appli cations, for example in the case of cosmetics and medicaments where great projection of the spray particles is neither necessary nor desirable. The use of low fluid pressures moreover makes possible the employment of inexpensive containers, as elaborate precautions against the dangers or" explosion due to high internal fluid pressures are thus largely obviated. Owing to the fact that spray nozzles of the type here contemplated are designed for use more particularly with expendable containers tates Patent O 2,767,023 Fatented Oct. 16, 1956 which are simply thrown away when emptied, cost of construction is of utmost importance. Still it is essential of course that the nozzle means provide efiective atomization at the lowest possible pressure.

The nozzles of prior spray devices are generally characterized either by rather complicated constructions heretofore found necessary to get good results, or else they are subiect to poor atomizing operation at the low pressures desired to be employed. It is accordingly a principal object of the present invention to provide a nozzle of extreme mechanical simplicity which nevertheless af fords excellent atomization of a liquid at low pressures.

It is a further object of the invention to provide an atomizing nozzle consisting of a minimum number of parts of inexpensive construction which can be completely assembled by automatic machinery. In the spray nozzle here disclosed only two pieces are involved, and the assembly of these, aside from being adapted for accomplishment by automatic machines, does not rely upon separate securing means, such as adhesives, to retain them in assembled condition.

Nozzles embodying the inventive concept are illustrated in the accompanying drawings and are described hereinafter. In the drawings,

Fig. 1 is a partial view in vertical section of a spray nozzle and valve assembly secured to the mouth of a glass walled container adapted to hold a fluid under pressure and to dispense such fluid through the spray nozzle on actuation of the valve assembly;

Fig. 2 is a fragmentary view on an enlarged scale of the spray nozzle shown in Fig. 1;

Fig. 3 is a plan view taken along line 33 of Fig. 2; and

Fig. 4 is a front elevational view of the spray nozzle of Fig. l.

The dispensing valve and spray nozzle assembly indicated generally at 10 in Fig. 1 is secured in the mouth of a container 12 adapted to hold the liquid to be dispensed. As is conventional in dispensing devices of the type here illustrated, this liquid is stored in the container 12 under pressure of a propellent fluid, such as one of the Freons, which is volatile at ordinary room temperatures and pressures. The propellant is used to force the liquid to be dispensed up through an eductor tube 14 leading up from adjacent the bottom of the container to the valve and nozzle assembly 10 and out through the latter in response to manual actuation of the valve to open it and allow dispensing of the fluid to take place.

For cosmetic materials it is highly desirable that glass containers be utilized, as unusual decorative effects can be most economically obtained to enhance the sales appeal of the item. In using such a container, however, unless special precautions are used to render the glass shatterproof, it is imperative for reasons of safety that very low pressures be employed in propelling the contents in order to avoid any liability of explosion due to defects in the container or accidental dropping of it. Then too, it is usually not necessary or desirable that the fluid contents be expelled from the container with great force or projected any great distance, but rather that a fine, uniform dispersion be obtained which may be directed upon a given area by placing the dispenser fairly close to the object upon which the spray is to be deposited. Accordingly if low pressures are to be used in propelling no volatile liquid contents, especially if they are substantially immiscible in the propellant, the mechanical means for effecting the dispersion into a fine mist becomes all the more significant as it is not possible to rely upon a high 7 tainer is simply one of many different types which can be ticular construction of this valve is disclosed in my pending application Serial No. 438,543, and reference to that disclosure is made for. fuller discussion of the various details of :its construction. For purposes of the present disclosure it is suficient to state that an annular groove 16 in the periphery of a hollow valve stem- 18 which is closed at its inner end is normally sealed by encirclement of the lower end of the stem 18 by a resilient elastic gasket 20'confined within a flanged valve cup 22 by' a metal cap portion 24. Communicating passages 26 are provided in the valve stem between groove 16 and the bore 28 of the stem. In normal condition, fluid under pressure delivered to the valve cup 22 through eductor tube 14 is prevented by gasket 20 from escaping from the container 12. When dispensing is desired, the valve stem 18 is pushed laterally at its upper endgwhereby it pivots about a point determined by abutment of a flange 27 on the valve stem against the underside of cap 24, and this causes the lower 1 end of the valve stem to be tilted, compressing the grommet 20 against the side of valve cup 22. This causes a portion of the annular groove 16 to be exposed at the side opposite from that at which the stem is pushed, and fluid in the valve cup 22 is accordingly allowed to enter into the groove 16 and bore 28 which, as seen in Fig. l,

. is open at its upper end.

An actuator head 30 is secured on the open, upper end is formed to provide a recess or socket 40 opening onto a' substantially fiat face 42 of the body 32. At the mouth 'or outer edge of this socket, the side walls 44 taper inwardly a short distance to provide a frusto-conical opening. At a point approximately midway of its depth, the side wall of the socket 40 is undercut to provide a lip 46 which overhangs a straight wall portion 48; The bottom of socket 40, as seen best in Fig- 3, is also formed to provide an annular groove 50 and'a' central depression 52, groove 50 being spaced inwardly a short distance from side wall .48 to leave an annular land 54 in the bottom of the socket. Groove 59 is spaced from central depression 52 to leave a second annular land 56 disposed between the. groove and-the central depression. Feed passage 38 extends throughthe bottom wall of the socket 40 into communication with passage 36 as previously described, passage 38 intersecting groove 54? and providing communication therewith. a

The bottom Wall of socket 40 likewise has formed in it a number of slots or grooves 58 which radiate outwardly from the central depression 52 to intersect groove 50 and provide communicating channels between the groove and the central depression. As seen more particularly in i Fig. 3, these grooves radiate tangentially from the periphcry of the central depression.

A cup 60 is disposed in the socket 40 of the spray nozzle body 32. In the illustration the cup is shown as being fabricated of relatively thin sheet metal. This'cup has a bottom wall 62 and an upstanding side wall 64, and is of' deformation, cup 60 can be snapped into position by insertion into the tapered mouth of'the socketby means of a punch, and once past the lip 46 it is firmly locked-in'seated a of valve stem 18. As here shown, thiscompri'ses a stiff but resilient body member'32 formed of a suitable plastic material and having incorporated integrally within it a position in the bottom of'the socket by engagement of .th lip on the rim 66 of the cup. 'Ihiscauses the cup to be continuously compressed against the upper surfaces of lands S4 and 56. When fluid enters feed passages 36 and 38 and progresses into the annular groove 50, it is thus prevented from leaking betweenthe'undersurface of the cup and the upper surface of lands 54 and 56, and is constrained to enter the radiating grooves 53 leading to cenorifice 68 which is pierced in the bottom of cup 69 substantially centrally of the depression 52.

Owing to the compressing effect of the overhanging lip 46 upon'cup 60, thus assuring a tight seal of its bottom surface on the upper surface of lands 54 and 56, no ad-' hesive or other securing means is necessary to hold the cup in place and prevent leakage of fluid intothe central de? pression 52, by-passing slots 58;

It has been found that by carefully proportioning the size of the discharge orifice 68 and feed passage 38 with respect to the cross-sectional area of grooves or slots 58, excellent atomization can be obtained at low fluid pressures; In speaking of low pressures, this term is used here to signify gauge pressures under 20 lbs. per square inch and as low as even 8 to 10 lbs. per square inch. Such low pressures are highly desirable, as explained hereinbefore, since they minimize the danger of'damage 'or injury resulting from explosion in case a glass container is employed in the dispenserdevice.

By way of illustration, critical dimensions for a particularly suitable commercial spray nozzle for use at propellent pressures of around 12 to 18 p, s. i. g., are as follows: Using an orifice diameter of 0.016 for orifice 63 in cup 60, four radial slots 58 each 0.008" Wide by 0.008" deep, in combination witha feed passage 38 which has a diameter of 0.025, gives excellent results. In the i foregoing example, the annular groove 50 is 0.019 deep .by 0.008 wide. 7

' Other dimensions proportional to these are useful, and 'it appears that the ratios indicated below are substantially critical in achieving optimum results at the-low pressures mentioned. These ratios areas follows:

Total cross-sectional area 7 of tangential slots 58 Area of terminal orifice 68 =a'pprox' Total GI'OSSrSGObiOHQl area.

of tangential slots 58 Minimum cross-sectional area of feed passage 38 In fabricating the spray nozzle, a material which has been found excellent in practice for the body 32 is polyethylene (e. g. Polythene) which is easily molded, has good rigidity and dimensional stability, yet possesses sufficient resiliency to allow thenozzle cup 60 to be forced into place without permanent deformation of the body. As an example, in the nozzle specifically described above, a metal cup of 0.175 outside diameter can be snapped into a socket 40 of the same inside diameter in which the lip 46 overhangs the wall 48 by 0.004 to 0.005". .Making =approx. 0.52 to 0.78

the inside diameter of the socket to below the lip 46 the same as the outside diameter of the cup 6% ensures a good tight seal atthe sides of'the socket. The same isobtained at the bottom of the socket by making. the height of the 7 cup wall slightly greater than the distance from the under- The the various passages which arise when an excess of cement is used. Also of course, the arrangement greatly simplifies the assemblyiug operations and permits them to be done by completely automatic machinery.

What is claimed is:

1. The combination in a spray nozzle of a stifi but resilient plastic body member having a socket formed in one face thereof, the side wall of said socket being undercut below said body face to provide an overhang, an annular groove and a central depression formed in the bottom of said socket, said groove being spaced from said central depression to form an annular land in the bottom of the socket, slots radiating from said central depression across said land to intersect said groove and a feed passage formed through said head and communicating with said groove to supply fluid thereto from a supply under pressure, a cup snapped into position within said socket beneath said overhang, the bottom of said cup being continuously compressed against the land in the bottom of said socket by elastic deformation of said plastic head resulting from engagement of the underside of said overhang with the rim of said cup, said cup being pierced in its bottom wall to provide an orifice opening into said central depression.

2. The combination as defined in claim 1, wherein the side wall of said socket tapers inwardly substantially from said body face to the point of undercutting.

3. The combination as defined in claim 1, wherein said slots radiate tangentially from the periphery of said central depression to said groove, and said orifice in said cup overlies the center of said depression.

4. The combination as defined in claim 3, wherein the ratio of the combined cross-sectional area of said tangential slots to the area of said cup orifice is approximately 1.28. I

5. The combination as defined in claim 4, wherein the ratio of the combined cross-sectional area of said tangential slots to the minimum cross-sectional area of said feed passage is approximately 0.52 to 0.78.

6. The combination as defined in claim 3, wherein the ratio of the combined cross-sectional area of said taugential slots to the minimum cross-sectional area of said feed passage is approximately 0.52 to 0.78.

7. The combination in a spray nozzle for low pressure atomization which comprises a spray head of resilient plastic, said head being formed to provide a cylindrical socket opening on one of its faces, the side wall of said socket having an overhanging lip adjacent the outer edge of the socket, an annular groove formed in the bottom wall of the socket, said groove being spaced inwardly from the side wall slightly to provide a peripheral shoulder in the bottom of the socket, a feed passage formed in said head to deliver fluid to be atomized from a supply under pressure through said head to said annular groove, a cylindrical depression located concentrically of said socket in the bottom wall thereof and spaced peripherally from said groove to form an annular land surrounding said depression, grooves radiating from said depression and extending across said land to intersect said annular groove, a cylindrical cup disposed in said socket, said cup being of a size to snugly engage the side and bottom walls thereof, being slightly greater in height than the distance from the bottom wall of the socket to the underside of said overhanging lip whereby the bottom of said cup is continuously pressed into contact with the bottom wall of the socket by the elastic deformation of the head resulting from engagement of said overhanging lip with the rim of said cup, said cup having an orifice in its bottom wall opening into said cylindrical depression.

8. The combination in a spray nozzle as defined in claim 7, wherein said grooves extending across said annular land radiate tangentially from said cylindrical depression.

References Cited in the file of this patent UNITED STATES PATENTS 1,289,962 Thompson Dec. 31, 1918 1,837,339 Schlick Dec. 22, 1931 1,919,027 Klotzman July 18, 1933 2,362,080 Martin Nov. 7, 1944 2,605,142 Gold et al. July 29, 1952 2,702,957 Cooprider et al Mar. 1, 1955

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