US2774628A - Apparatus for dispensing under pressure - Google Patents

Description

Dec. 18, 1956 K. B. ENGSTRUM 2,774,628

APPARATUS FOR DISPENSING UNDER PRESSURE Filed May 10, 1954 ATTORNEY United States Patent 2,774,628 APPARATUS FOR DISPENSING UNDER PRESSURE Kathleen B. Engstrum, Arlington, Va. I Application May 10, 1954, Serial No. 428,553

Claims. (Cl. 299-95 10 that is, methyl chloride, dichloro-difluoro methane and the like, contained therein in a liquid and/or gaseous phase. 1

Heretofore aerosol containers, that is, pressure charged containers having a small quantity of material, which-is to be dispensed, have been used with some success. However, there are several problems in this method of material dispensing, which the prior art has failed to solve, namely, the problem of valve clogging due to flocculation of the material, particularly when relatively large quantities of such material are dispensed. Because of this lack of utility for dispensing quantities of materialifrom pressurized storage containers, the known dispensers of this type are not suitable for producing efiicient durable paint coatings or for extensive operations. I For example, if enough pigment material is stored in the container for providing reasonably thick coatings or for covering an extensive surface, the particles of the material flocculate and tend to clog the discharge or syphon tube and/ or the valve to such an extent that efiicient operation is impaired and often a complete shutdown results? Ac- .cordingly, means must be provided for cleaning the valve and discharge tube, prevent the tube and valve from clogging, or means must be provided to deflocculate or disperse these flocculates or clots ofmaterial formations in the syphon tube prior to discharge through the valve. .In other words, it is this known undesirable condition of the clogging of the syphon or dispenser tube and associated valve that limits the use and efiiciency of aerosol'containers or the like for satisfactorily surface coating automobiles, walls, floors and the like without brushes or the prior art spray guns. W e An object of the present invention is to eliminate valve clogging by preventing any flocculated material from'entering the discharge valve from-the syphon means of a pressurized dispensing container.

Another object is to provide a novel means in the discharge tube adapted to redisperse or defiocculate thematerial into a fine dispersed condition prior to discharge through the containers discharge valve.

' Another object is to provide a system of dispersing clots 'of material in a mixture being dispensed under pressure through a discharge valve comprising thev steps of pressure feeding a mixture with any undispersed clots of material through an arresting means, such as a perforated barrier or screen in a discharge tube and thereby arresting the clots against the barrier, and then dispersing the clots of material arrested by the barrier or screen by the jet action of the pressure dispensing medium. Still another object is to provide as an article of manufacture a novel syphon means with a redispersion chamber, which may be quickly attached during manufacture and assembly to any form of standard atomizingnozzle 2,774,628 Patented Dec. 18, 1956 ice usable with pressurized dispensing containers now on the market and generally known to the trade as aerosol bombs.

' With these and other objects in view, the present novel method and apparatus consists in the novel construction, arrangement, and combination of parts described in the following specification and illustrated in the accompanying drawings, wherein four forms of this invention are disclosed, as means to practice the same.

In the drawings wherein like reference characters refer to like parts on the figures:

Figure 1 is a longitudinal cross sectional view taken through a container adapted to house the present novel invention;

Fig. 2 is a longitudinal section of one embodiment of the invention and as shown in side elevation in Fig. 1;

Fig. 3 is a longitudinal section of another embodiment of the'invention; and

Fig. 4 is a longitudinal section of a third embodiment of the device formed of fewer parts, that is, with the redispersion chamber made in one integral unit.

Fig. 5 is a longitudinal section of a fourth embodiment of the device made spherical form.

- Referring in detail to the drawings and first with particular reference to the embodiment disclosed in Figures 1 and 2, numeral 10 indicates a hermetically sealed container containing a formation or layer A of solid material,

such as settled paint pigment, a formation or layer of highly volatile solvent such as a liquefied gas B, and a layer or formation of vaporized gas C. The liquefied gas maybe of any suitable kind. It may be a halogenated hydrocarbon, such as for example methyl chloride, dichloro-monofluoro methane (Freon 12) and the like.

Also, in the container 10, if desired, may be placed a pigment redispersing means 11, such as a metallic ball having a specific gravity greater than the paint pigment formation A. It is, of course, to be understood that the paint pigment may include a vehicle or carrier, such as linseed oil or the like for providing a proper paint mixture for combining with the volatile solvent of formations 'B and C in the container 10 in its respective liquid and to the end of a syphon or discharge unit D.

This syphon or discharge unit D includes an intermediate enlargement, such as a chamber 15, and tube sections hereafter referred to in detail. The chamber 15 comprises two truncated conically-shaped hollow sections 16 and 17, respectively, secured together to form a bellshaped body and rolled over to form a joint 18, see Fig. 2. This joint 18 includes the peripheral edge 19 of a screen or foraminous barrier 20 across the chamber 15 in the line of material dischange either at right angles to the axis of the syphon line or at acute angles thereto. The chamber 15 on each side of the screen or barrier 20 is formed with sockets or nipples 21 and 22, respectively. The volume of the chamber 15 below the screen or forminous barrier must be greater than the volume of the tube section 24, to permit expansion of the gaseous propellant therein. The internal bore of each socket or nipple is frictionally coupled around the external bore of the respective ends of each of the individual sections 23 and 24 of the syphon tube D, so that tube section 23 connects the chamber 15 to the valve nipple 13 and tube section 24 extends arcuately downward into the soft settling of the paint formation A. The section 24, preferably is offset from the center of the container bottom, that is, it extends toward the bottom side of the container 10 in the axial direction of the valve nozzle discharge port 25. This provides for greater etficiency during use, as when coating a surface the container is usually tilted in the direction of the discharge port 25 and with the tube in this position it will remain immersed in the mixture to be dispensed. 7

Before describing the operation and functioninglof the invention illustrated in Figures 1 and 2, a -brief description of the second and third embodiments of Figures .3 and 4 will be given asthe novel redispersionchambersmf these embodiments each operate andfunction-inthe same manner.

In Figure 3 the syphonunit isidentical-tothefirst.unit, except as to formation .and'sh'ape and comprises-an inverted bell-shaped or cup-lilce-body :30 :formed with a flange .31 and a coupling .socket-or'nipp'le 32rzfor receiving Land frictionally embracing :the exterior :circumference of the end of a tube section 33 as in thezfirst embodiment. A dome or-capfillhaving a flange portion 35 maybe turned .over and :folded under :the flange 31 by the body 30 to form 1a ;-joint.36 tor'the .=joint.may be formed in any suitable manner as-by welding-;or.-.otherwise. Prior to'-'forming-the joint-*36, ascreen or.foraminous barrier 37 is seated over 'thezflange filzand across the wide open part of the body .30 .and thus :when the flange portionSS is turned overrand foldedzunder flange 31, the screen or forarninous .barrierzis sealed-inoperative position. The volume of" the .body -30;in this 1 form also must begreater thanthe volume of .the tubesectioni33 :to permit expansion of the-formulation of thepigment solvents and the gases therein.

.The dome orcap 34 includes a .coupling:socket:or nipple 38 forfrictionally-coupling around the exterior endof the syphon tube section-39.

The chamber .40 of the third embodiment, illustrated in .Fig. 4, is formed witha single wall 41 having aligned coupling sockets or nipples 42 and 43 for receivingxthe endsof discharge tube sections 44 and 45, respectively, and as in the other embodiments, the volume of the chamber 40 below-the screen or forarninous barrier must be greater than the volume of the tube section 45 "to permit expansionolf' the formulation of thepigment s01- vents and gases by the gaseous propellant therein. .Also, the screen-or-foraminous barrier 46 is seated in .an .an-

.nular bead 47 and fused thereto for the purposes, which will be apparent hereinafter under the heading Method of operation of the device.

-Methad of operation of the device When the present invention is to beused the container is usually [agitated by-shaking,-to thereby cause-the pigment redispersing means 11 to disperse the paint pigment-formation A.i.n.the bottom of the container. This step of the operation is conventional and essential to ;all devices of this type now on the market and after thoroughly shaking thecontainer the valve unit 12.is actuated andthe dispersed pigmentrformationA combined with "the highly volatile solvent will be'discharged'under .pressure "in an atomized spray over a surface to be treated.

This much of the operation is usually satisfactory, particularlyifthe redispersing means 11 has-succeeded in thoroughly dispersing or .deflocculating theipaint pigment formation. However, .asoften as necessary, theuser may temporarily stop to rest or to recondition a part of the sur-facebeing treated, which-cessation of operation will oftenileave some of the paint mixture with pigment in the syphon tube sectionbelow the screen orforaminous barrier, such as disclosed in Figures 2, 3 and 4. 'When this happens, the pigment mixture left in the lower tube section will 'flocculate or clot and clog the syphon tube and cannot be redispersed by the usual redispersing means 11. Accordingly, the present invention was developed to provide for a -very fine 'redispersion or deflocculation Of-clotsof fiocculated pigment collected :below thescreen or: barrier in the syphon tube:.below the; same. For-example, when the valve unit 12 .is again actuated aftera temporary shutdown, the highly volatile solvent and pressure propellant by jet action blasts the clots and redisperses the pigment in the syphon tube and in the redispersion chamber 15, for example, said chamber being of a volume below the screen or barrier greater than the volume of the lower tube section to permit expansion of the formulation of the pigment solvents and gases by the :gaseous propellant -t'herein for approaching .a maximum or:barrier which co-acts with the highly volatile solvent and high .pressure 'forces .of the self propellant mediums to thoroughly deflocculate or redisperse the pigment clots knownto heretofore .eollectin the syphon tubeand valve mechanisms.

Also, as :many changes could .be made in the above construction, combinations and arran'gemenbofthe-parts without departing from the scope :thereof, it is to-beexpressly understood that all matter contained in'the above description or shown in the accompanying drawingshall be interpreted as illustrative vand :not in a limiting sense.

-What is claimed is: 1. For use with an .atomizing nozzle formed to-discharge fluent mixtures under pressure from a container loaded with a liquefied gaseousmedium, a syphon means inside of the container comprising a-tube and a chamber, aforaminous barrier across said chamber, said chamber having tube connected'socket openings on eachside of said 'barrier, and a section'of said tubing-being-inconnection with one ofsaid sockets and to said atomizing nozzle, said chamber below said barrierhaving an internal volume greater than the internal volume of said tubing below said barrier.

'2. For use with'an'atomizing nozzleformed to dischargefluent mixtures under'pressure from a container loadedwith a liquefiedgaseous medium, a syphon means inside of the container comprising a chamber, aforaminous barrier-across said chamber, said chamber having openings on each side'of said barrier, and discharge tubing'coupled in said openings and to said 'atomizing nozzle, said barrier serving'to separate anyfloeculated materialifrom deflocculated materialin said fluent mixture dischargingthrough said syphon means, thereby preventing clogging of said atomizing nozzle, said chamber below,said barrier having an internal volume greater than theinternal volume of sai'dtubing belowxsaid bar- -rier,whereby'anyflocculated'material in said chamber 'below'said barrier is deflocculated by pressure into a fine dispersedstate for efficient atomization by saidnozzle.

'3. A syphon discharge unit for coupling to valves of pressurized .spray'containers comprising a syphon tube, abell-shaped chamber interposed in said tube, and an arresting screen across said chamber, said chamber below said screenhaving an internal volumegreater than with v'an internal annular support, and said screen is secured thereto across the chamber.

6. A syphon discharge unit comprising a syphon tube, a hollow sphere interposed in said tube, and a screen centrally disposed therein, said chamber below said screen having an internal volume greater than the internal volume of said tube below said screen.

7. A syphon discharge unit for hermetically sealed containers comprising a syphon tube with an enlarged intermediate hollow chamber completely housed within an operatively associated container, and a foraminous barrier dividing said chamber into sections, the volume of said section below the barrier being greater than the volume of the tube below the barrier, to thereby permit expansion of the formulation of pigments, solvents and gases by the gaseous propellant in said container.

8. A pressurized dispensing container having therein a soft settling of substance, at super-imposed formation of liquefied gas above the substance and a superimposed vapor phase formation, a valve at the top of the container, a tube connected to the valve inside the container extending from the valve to a position adjacent the bottom of the container into said settling of substance, said valve normally hermetically sealing said container, means for dispersing the settled substance in the bottom of the container around the end of the tube there in, a redispersion chamber connected intermediate the tube through which the container contents passes when the valve is open, said barrier means mounted in said chamber, said chamber being of greater volume below said barrier than the volume of the tube connected to the chamber below said barrier.

9. A pressurized dispensing container having therein a soft settling of substance, a superimposed formation of liquefied gas above the substance and a superimposed vapor phase formation, a valve at the top of the container, a tube connected to the valve inside the container extending from the valve to a position adjacent the bottom of the container into said settling of substance, said valve normally hermetically sealing said container, means for dispersing the settled substance in the bottom of the container around the end of the tube therein, a redispersion chamber connected intermediate the tube through which the container contents passes when the valve is open, and a perforated barrier across said chamber and the internal bore of the tube adapted to retain flocculated material therein for re-dispersion, said internal bore of said tube below said barrier being of relatively smaller volume than the volume of said chamber below the barrier.

10. In a pressurized container with a valve, said container having a soft settling of material, a superimposed formation of liquefied gas above the pigment and a superimposed vapor phase formation, a tube extending from the valve at the top of the container to an offset position adjacent the bottom of the container into the said settling of material, means comprising a freely movable agitating member in said container adapted to disperse and intermix the pigment with the said liquefied gas to produce a dischargeable volatile mixture, said tube being formed with an intermediate redispersion chamber through which the container contents passes, and a perforated barrier across said chamber in the tube and the internal bore of the tube below said valve adapted to retain flocculated material therein for redispersion when said valve is open, said internal bore of said tube below said barrier being of relatively smaller volume than the volume of said chamber below the barrier.

References Cited in the file of this patent UNITED STATES PATENTS 189,771 Morgan Apr. 17, 1877 1,899,222 Werder Feb. 28, 1933 2,090,334 Paasche Aug. 17, 1937 2,565,954 Dey Aug. 28, 1951 2,580,132 Seymour Dec. 25, 1951

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