US3121517A - Valve construction for aerosol dispensers of high solids slurries - Google Patents

Description

Feb. 1964 D. c. GEARY ETAL 3,

VALVE CONSTRUCTION FOR AEROSOL DISPENSERS F HIGH SOLIDS SLURRIES Filed Aug. 4, 1960 l i u i i i u 3/ Z 2! I f ii W 2a 3 Ex .19 1 22 i T r hli fl [i i k I y H INVENTORS DANIEL C. GEARY ROBERT W.GAINE$ BVM A TTORNEV United States Patent 1 3,121,517 VALVE :CGNSTRUQTKQN FQR AEROSOL DIE- PENSERS Gi HEGH SGLIDS ESLURRHES Daniel C. Gear-y, Westwood, N.J., and Robert W. Gaines,

Dar-ion, Conn, assigncrs to Union Carbide Corporation, a corporation of New York Filed Aug. 4, H60, Ser. No. 424% 4 Claims. (Cl. 222-694) The present invention relates to a Valve for dispensing fluids and fluidized solids from pressurized aerosol container's and more particularly to a valve capable of dispensing high solids slurries containing as much as percent or more by weight of solid particles having diameters as large as 100 microns or more.

Pressurized aerosol containers are currently used to package and dispense a wide variety of fluids and fluidized solids materials. The valve included in these containers must be reliable, safe and, due to the disposable nature of such containers, should be easily manufactured and low in cost. in the most common type aerosol dispenser, the container is a hollow cylinder, tightly closed at one end, with the assembly comprising the valve mechanism arranged to form the other end of the container. For convenience, one end will hereafter be called the top or upper end and the other will be called the bottom or lower end of the container, although the container can be employed in any position. An annular shaped mounting cup, usually a metal stamping with an outer edge adapted to be tightly crimped over the top end opening of the pressure container, forms the valve support. A vertically positioned hollow cylindrical valve chamber with an open top and a closed bottom is crimped, swaged or otherwise affixed to the axial center of said mounting cup on the underside to support and guide the moving parts of the valve. Between the upper circular rim of said valve chamber and the underside of the mounting cup, an annular sealing gasket of rubber, flexible plastic material or the like having a centrally located circular opening therethrough is held in a fixed position but with the inner edge surrounding the circular opening free to be depressed in a downward direction. The moving parts of the valve comprise a vertically disposed cylindrical stem, reciprocally moveable in a centrally located opening in the mounting cup, having a longitudinal axial bore extending part way therethrough from its upper end, at least one lateral orifice connecting the axial bore with the stem exterior surface to form a valve stem inlet port, an increased diameter portion or shoulder located beneath said lateral orifice and an increased diameter portion bevelled downwardly and inwardly located above said lateral orifice; a coil spring disposed around said stem, lightly loaded in compression between the closed bottom of the hollow cylindrical valve chamber and the increased diameter portion :or shoulder on said stem to maintain the lateral orifice in a registering position within the sealing plane of the annular sealing gasket with the stem shoulder immediately beneath said gasket and the stem bevelled portion immediately above said gasket and, on the upper portion of the valve stem, a valve stem head, having passages to conduct material to be dispersed from the stem bore to the exterior of the dispensercontainer. One or more ports through the bottom of the cylindrical valve chamber provide passage means between the int'orior of the container and the interior of said valve chamber, and a hollow feeder or dip tube connected between the valve chamber bottom portion and a point near the bottom of the container assures full feeding of the contents to the dispensing valve assembly.

An aerosol dispenser of the type described above is operated by exerting downward pressure on the valve stem head, which causes the bevelled portion oi? the "ice valve stem to depress the inner rim of the sealing gasket downwardly and outwardly away from the lateral orifice in the stem, thereby uncovering the orifice and establishing a continuous iiow path from the container interior through the feeder tube, the ports through the bottom of the cylindrical valve chamber, the interior of the cylindrical valve chamber, the stem lateral orifice, the stem longitudinal bore and the passages of the valve stem head to the exterior of the container. The contents of the container are forced, by container internal pressure, along this flow path and dispensed through the valve stem head. When the valve stem head is released, the resilient action of the valve coil spring returns the valve stem to its closed position.

Valves of the above described type have been found to be generally unsuitable for dispensing aerosol powder formulations. It has been found that the powder agglomerates, clogs the valve orifices and blocks the sealing action of the valve sealing gasket. Powders which are abrasive also tend to Wear channels into the sealing portions of the valve with continued use, causing the propellant fluid to escape from the container when the valve stem is in the closed position. Due to the arrangement of the valve components, the valve stem lateral orifice is inaccessible for removing agglomerated particulate matter when in either the closed or open position. Valve malfunctions of the type described above become more pronounced and more frequent when such valves are used to dispense contents with more than 10 percent of solid particles and particularly where the particles have diameters greater than 10 microns.

The apparatus of the present invention obviates the foregoing difiiculties by providing a universal powder valve comprising a unique arrangement and disposition of valve components which, in operation, can dispense powder aerosols containing 25 percent or more of solid particles having diameters up to microns or more without clogging or leaking. The apparatus is also very effective for dispensing liquids, dispersions and the like.

The apparatus of the present invention also comprises a valve having a'stem lateral orifice in a position accessible for cleaning when said valve is in the closed position.

The invention also comprises novel details of construction and novel combinations of components, together with other features and results which will be more apparent from the following description. The drawings merely show and the description merely describe-s a preferred embodiment of the present invention which is given by way of illustration.

In the drawings:

FIGURE 1 is a partially sectional view of the upper portion of an aerosol container showing a universal powder valve, according to the present invention, in the valve-closed position and FIGURE 2 is a partially sectional view of the upper portion of an aerosol container showing the valve of FIGURE 1 in the valve-opened position.

in the embodiment of the drawings, a pressure container 11 is surmounted by a mounting cup 13, of metal, plastic or the like, have a centrally located circular opening therethro-ugh, tightly fitted to said pressure container by a rolled and crimped outer edge. A hollow cylindrical valve chamber 1-5, having an open top and. a closed bottom with ports 1-6 extending through said bottom, is pressfitted or 'swaged into a centrally disposed. circular, upwardly expanded portion of mounting cup 13. An annular valve seal 17 of rubber, plastic or the like, having a centrally located circular opening therethrough, is arhanged in the upwardly expanded portion of mounting cup 13 and is rigidly supported on its underside by a valve seal retainer 19 which is an annular shaped rigid component of metal or the like, having a centrally located circular opening therethrough. Valve seal 17 and valve seal retainer 19 are held in fixed position between the mounting cu-p underside and the upper rim of valve chamber in relative positions to bring approximately equal diameter, centrally located circular openings in mounting cup 13, the valve seal and the valve seal retainer into concentric registering positions.

The valve movable components comprise a vertically disposed cylindrical valve stem 21, reciprocally movable through the centrally located openings in mounting cup 13, valve seal 17 and valve seal retainer 19, having a longitudinal passage 25 extending from the valve stem upper end for somewhat more than one half the stem length, a lateral orifice 23 connecting valve stem passage 25 with the stem exterior surface to form a valve stem inlet port and a raised diameter portion or shoulder 22; a valve stem spring 24, disposed around the lower portion of said valve stem, lightly loaded in compression between the closed bottom of valve chamber 15 and the underside of stem shoulder 22 to maintain the upper surface of shoulder 22 in compressive contact with the underside of valve seal retainer 19; and, on the upper portion of valve stem 21, valve dispensing head 29, having connected passages 31 and 33 connecting, respectively, to valve stem passage 25 and to the exterior of the container-dispenser. A hollow feeder tube 35, is press fitted over the lower portion of valve chamber 15 and extends downwardly to a point near the bottom of container 11 to assure full feeding of the container contents to the dispensing valve assembly.

To operate the embodiment shown in the drawings, downward force is applied to valve dispensing head 2 causing valve stem 21 to move slideably through valve seal 17 and the openings in mounting cup 13 and valve seal retainer 19. Valve stem shoulder 22 compresses valve stem spring 27 against the bottom of valve chamber 15, thereby developing a valve closing force which acts upon removal of the downward force on the valve dispensing head. When valve stem 21 has been depressed to a position where valve stem lateral orifice 23 is beneath the sealing plane of valve seal 17, the valve is open and a continuous flow path is established from the container interior through the feeder tube, ports 16, the interior of valve chamber 15, stem lateral orifice 23, stem passage 25, and dispensing head passages 31 and 3-3. The contents of the container are forced, by container internal pressure, along this flow path and dispensed through dispensing head passage 33. When downward force is removed from dispensing head 29, energy stored in spring 27 returns the valve stem to the closed position.

Particular attention is directed to the location of the stem lateral orifice in the drawings. When the valve is in the closed position, as shown in FIGURE 1, the stem lateral orifice is outside the valve chamber and container, in a position accessible for visual inspection and cleaning. In addition, by means of this arrangement, an unbroken peripheral surface of valve stem 21 is presented to the sealing face of valve seal 17, with the valve in either the closed or open position.

Valve seal 17, held firmly in place by valve seal retainer 19, effects a wiping action against the valve stem as it is moved reciprocally bewteen the closed and open positions. The seal thus acts, during the valve closing movement, to wipe the stern surface clear of any agglomerated mate-rial which may collect around lateral orifice 23- while the valve is in the open position. The valve seal retainer 19, in addition to holding the valve seal firmly to effect the stem wiping action, holds the seal in contact with the underside of mounting cup 13, preventing excessive deflection of the seal center portion and excluding the possibility of agglomerated or comrninuted material from collecting between the valve seal and mounting cup and deflecting the seal sufficiently to cause leakage of the aerosol propellant.

In the preferred embodiment of the present invention, the valve stem length and travel distance and the position of the valve stem lateral orifice are selected to obtain passage of the lateral orifice to the container exterior before the stem has moved more than one-quarter to one-third of the total distance of travel between the open and closed positions, This arrangement minimizes the possibility of inadvertent loss of contents from the valve sticking in the open or partly open position due to agglomerated powder build-up between the valve stem shoulder and the valve seal retainer or valve seal.

A further improvement over known valves is comprised in the downwardly extended lower or container-interior end of the vertically disposed valve stem which, during the valve opening movement, passes concentrically through valve stem spring 27 to break up agglomerated material on and around the spring coils, thereby maintaining a clear flow path through valve chamber 15.

Those skilled in the art will recognize that certain modifications may be made to the above-described embodiment of the present invention without departing from the basic concept. For example, the wiping action and sealing function of the valve seal could be accomplished by substituting an O-ring gasket of rubber or the like, retained in a recess integral with the mounting cup.

It will also be apparent to those skilled in the art that the embodiment shown in the drawings can be operated with the container in any position and that for continued use in an inverted position improved operation will result if the feeder tube 35 is omitted.

While, in the foregoing description, certain specific details and operative steps have been set forth, together with certain suggested modifications, it will be obvious that considerable variation may be made in these without departing from the spirit of the present invention.

The foregoing description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom.

What is claimed is:

1. A valve for dispensing fluidized material containing as much as 15 percent or more by weight of solid particles having diameters as large as microns or more from a pressurized aerosol container comprising, in combination, a valve mounting cup forming a wall portion of said container and having an opening therethrough, an elongate valve stem extending through said mounting cup opening with an end interior and an end exterior of said container, reciprocally moveable between a first position and a second position, having a longitudinal internal passage extending from the stem exterior end for less than the stem length, a transverse passage connecting said longitudinal internal passage to the stem exterior located in said stem to be exterior of the pressurized container when the stem has travelled one-quarter to onethird from said second position towards said first position and interior of the pressurized container when the stem is in said second position, and means on said stem to re tain said stem partially within the container; a valve chamber having an open end and a closed end with ports extending therethrough attached to the interior side of said mounting cup to support and guide said stem; resilient means compressively loaded to exert force between said closed end of said valve chamber and the stem retaining means and means to effect sealing between the pressurized interior and exterior of said container against the periphery of said stem and to effect wiping action on the peripheral surface of said stem during reciprocal stem movement, wherewith which combination said fluidized material is substantially completely dispensed from said aerosol container, the agglomeration of said solid particles, with the sticking of said stem periphery in said sealing means, and with the consequent loss of pressure, being prevented by the above-recited location of said transverse passage and the above-recited extent of travel of said valve stem.

2. A valve in accordance with claim 1 in combination with means to connect said valve chamber with the lowest practical ievel of said aerosol container.

3. A valve in accordance with claim 1 in which said means to effect sealing and wiping comprises, in combination, a valve seal having an opening therethrough located in registering relationship with the opening in said mounting cup and a valve seal retainer arranged conti uously to said valve seal and having an opening therethrough located in registering relationship with the respective openings in said mounting cup and said valve seal.

4. A valve in accordance with claim 1 in which said resilient means comprises a coil spring and said valve &

stem end interior of said container extends concentrically substantially through said coil spring When the stem is in said second position.

References Cited in the tile of this patent UNITED STATES PATENTS 2,721,010 Meshberg Oct. 18, 1955 2,812,884 Ward Nov. 12, 1957 2,837,249 Meshbe rg June 3, 1958 2,858,053 \Valdhen Oct. 23, 1958 2,886,217 Thiel May 12, 1959 2,932,432 Beard Apr. 12, 1960 2,953,284 Prussin 'et a1 Sept. 20, 1960

Claims (1)

1. A VALVE FOR DISPENSING FLUIDIZED MATERIAL CONTAINING AS MUCH AS 15 PERCENT OR MORE BY WEIGHT OF SOLID PARTICLES HAVING DIAMETERS AS LARGE AS 100 MICRONS OR MORE FROM A PRESSURIZED AEROSOL CONTAINER COMPRISING, IN COMBINATION, A VALVE MOUNTING CUP FORMING A WALL PORTION OF SAID CONTAINER AND HAVING AN OPENING THERETHROUGH, AN ELONGATE VALVE STEM EXTENDING THROUGH SAID MOUNTING CUP OPENING WITH AN END INTERIOR AND AN END EXTERIOR OF SAID CONTAINER, RECIPROCALLY MOVEABLE BETWEEN A FIRST POSITION AND A SECOND POSITION, HAVING A LONGITUDINAL INTERNAL PASSAGE EXTENDING FROM THE STEM EXTERIOR END FOR LESS THAN THE STEM LENGTH, A TRANSVERSE PASSAGE CONNECTING SAID LONGITUDINAL INTERNAL PASSAGE TO THE STEM EXTERIOR LOCATED IN SAID STEM TO BE EXTERIOR OF THE PRESSURIZED CONTAINER WHEN THE STEM HAS TRAVELLED ONE-QUARTER TO ONETHIRD FROM SAID SECOND POSITION TOWARDS SAID FIRST POSITION AND INTERIOR OF THE PRESSURIZED CONTAINER WHEN THE STEM IS IN SAID SECOND POSITION, AND MEANS ON SAID STEM TO RETAIN SAID STEM PARTIALLY WITHIN THE CONTAINER; A VALVE CHAMBER HAVING AN OPEN END AND A CLOSED END WITH PORTS EXTENDING THERETHROUGH ATTACHED TO THE INTERIOR SIDE OF SAID MOUNTING CUP TO SUPPORT AND GUIDE SAID STEM; RESILIENT MEANS COMPRESSIVELY LOADED TO EXERT FORCE BETWEEN SAID CLOSED END OF SAID VALVE CHAMBER AND THE STEM RETAINING MEANS AND MEANS TO EFFECT SEALING BETWEEN THE PRESSURIZED INTERIOR AND EXTERIOR OF SAID CONTAINER AGAINST THE PERIPHERY OF SAID STEM AND TO EFFECT WIPING ACTION ON THE PERIPHERAL SURFACE OF SAID STEM DURING RECIPROCAL STEM MOVEMENT, WHEREWITH WHICH COMBINATION SAID FLUIDIZED MATERIAL IS SUBSTANTIALLY COMPLETELY DISPENSED FROM SAID AEROSOL CONTAINER, THE AGGLOMERATION OF SAID SOLID PARTICLES, WITH THE STICKING OF SAID STEM PERIPHERY IN SAID SEALING MEANS, AND WITH THE CONSEQUENT LOSS OF PRESSURE, BEING PREVENTED BY THE ABOVE-RECITED LOCATION OF SAID TRANSVERSE PASSAGE AND THE ABOVE-RECITED EXTENT OF TRAVEL OF SAID VALVE STEM.

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