Aerosol dispensing valve improvements

Abstract

An aerosol dispenser and aerosol dispensing valve for powders and other particulate materials, especially those which tend to agglomerate. The dispenser has a container with a top wall mounting the dispensing valve and a dip tube extending from the valve to the bottom of the container through which material within the container is caused to flow to the valve by the pressurizing medium in the container. The dispensing valve has a valve stem which is depressed to open the valve and a spring which biases the valve stem to closed position and is sealed within the valve housing against contact by the material in the container so as to avoid clogging of the spring by the material. The lower end of the valve stem extends into the dip tube and has an enlarged pointed head with teeth and cutting edges for breaking up any agglomerates of the material which are forced up through the dip tube or become lodged between the breakup head and a primary valve stem wiper seal on the lower end of the valve housing. This seal wipes the stem clean during each actuation of the valve to maintain the effectiveness of the seal. An annular clearance space may be provided about the lower end of the valve housing for receiving broken-up agglomerate masses.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to aerosol dispensers and more particularly to an aerosol dispenser and aerosol dispensing valve for powders and other materials containing particles such as granules, beads, flakes or the like, especially those which tend to agglomerate in the dispenser container.

2. Discussion of the Prior Art

Aerosol dispensers are utilized to dispense a wide variety of materials. Some of these materials, referred to herein as particulate materials, comprise or contain particles, such as granules, beads, flakes and the like. One example of such a particulate material is an anti-perspirant powder. This invention is concerned with aerosel dispensers for such particulate materials.

The prior art is replete with a vast assortment of aerosol dispensers and aerosol dispensing valves. Examples of such dispensers and valves are described in the following U.S. Pat. Nos.: 2,496,258; 2,552,857; 2,766,913; 2,801,029; 2,913,749; 2,925,937; 3,080,094; 3,134,505; 3,255,926; 3,338,479; 3,404,810; 3,404,811; 3,415,426; 3,422,992; 3,439,840; 3,455,489; 3,484,023; 3,498,506; 3,525,997; 3,603,483; 3,648,899; and 3,656,659.

An aerosol dispensing valve which is particularly designed for dispensing powders and anti-perspirants is described in the publication entitled AEROSOL AGE, May, 1972 issue, at pages 30, 31.

Dispensing powders and other particulate materials present certain problems to which this invention is addressed. One of these problems resides in the fact that a dispensing valve spring, if exposed to such materials, tends to become clogged by the materials with resultant improper closing or other malfunctioning of the valves. Moreover, many particulate materials tend to agglomerate in the container of the aerosol dispenser. The resulting agglomerates frequently block the dispensing passage of the valve or prevent proper closing of the valve.

SUMMARY OF THE INVENTION

The aerosol dispenser and aerosol dispensing valve of this invention are uniquely designed to obviate the above and other problems associated with aerosol dispensing of particulate materials. To this end, the dispenser has a container with a top wall mounting an aerosol dispensing valve and a dip tube extending centrally through the container from the valve to the bottom of the container. When the valve is opened, the material within the container is displaced from the annular region between the container wall and the dip tube into the lower end of the tube and then flows upwardly through the tube to the dispensing valve and finally through the dispensing passage of the valve to its dispensing orifice.

The dispensing valve has a tubular housing coaxially secured to the top wall of the dispenser container. Extending centrally through this valve housing is a valve stem having upper and lower ends extending above the container top wall and the lower end of the housing, respectively. An annular resilient wiper seal is secured to the lower end of the valve housing in surrounding wiping contact with the valve stem. A bearing member, such as a second annular resilient wiper seal, is secured to the upper end of the valve housing and guides the valve stem for longitudinal movement relative to the housing.

Extending centrally through the valve stem is a dispensing passage. The upper end of this passage opens to atmosphere through a dispensing orifice at the upper end of the valve stem. The lower end of the passage opens laterally through an inlet port in the stem wall. The valve stem is movable longitudinally between a lower open position wherein this inlet port is located below the wiper seal on the lower end of the valve housing and an upper closed position wherein the latter seal engages the stem below the port. Accordingly, when the valve stem is in open position, material may flow from the dispenser container into the stem passage through the inlet port and then upwardly through the passage to the dispensing orifice. When the valve stem is in closed position, the lower wiper seal blocks the inlet port.

According to one feature of the invention, the valve stem is biased to closed position by a spring contained in the valve housing, above its lower wiper seal. Accordingly, the spring is isolated from the material in the dispenser container and hence is immune to becoming clogged by the material.

According to another feature, the lower end of the valve stem has an enlarged agglomerate breakup head. This head has a pointed lower end and pointed teeth and edges which perform two agglomerate breakup functions. First, the head breaks up any agglomerates of the material being dispensed which are forced upwardly through the dip tube to the valve. Secondly, the head breaks up any agglomerates which lodge between the head and lower valve wiper seal and tend to block the inlet port and prevent proper closing of the valve. Preferably, an annular clearance space is provided about the lower end of the valve housing into which any broken agglomerate masses may be displaced by material entering the valve inlet port.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation of an aerosol dispenser according to the invention, with portions broken away for clarity;

FIG. 2 is an enlarged longitudinal section through the dispensing valve and showing the valve in closed position;

FIG. 3 is a section similar to FIG. 2 showing the valve open;

FIG. 4 is a section taken on line 4--4 in FIG. 2; and

FIG. 5 is a section taken on line 5--5 in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The aerosol dispenser 10 illustrated has a cylindrical container 12 with a cylindrical side wall 14, a dome-shaped top wall 16, and a dished bottom wall 18. Mounted centrally on the top wall 16 is an aerosol dispensing valve 20 of the invention. A dip tube 22 extends centrally through the container 12 from the valve 20 to the bottom of the container. In this case, the dip tube terminates a small distance above the bottom container wall 18 to provide a flow space 24 between the tube and latter wall. The bottom of the dip tube 22 must always be above the compacting mass of flake or powder.

When the valve 20 is open, the material within the container 12 is displaced, by the pressurizing medium in the container, from the annular region 26 between the container 14 and dip tube 22, through the flow space 24, into the lower end of the tube. The material then passes upwardly through the tube to the valve 20 and then through a dispensing passage in the valve to the dispensing orifice of the valve as described below.

The aerosol dispensing valve 20 has a tubular valve housing 28 which is concentrically supported at its upper end by the container top wall 16. To this end, the top wall has a central cup portion 30 surrounded by a circular bead or rim 32. Cup portion 30 has a bottom wall 34, the central portion of which is formed into a cap 36 which opens downwardly and receives the upper end of the valve housing 28. The cylindrical side wall of the cap is indented to form an internal annular shoulder 38 on the cap which engages under an external annular shoulder 40 on the valve housing to secure the latter to the cap.

Extending centrally through the valve housing 28 is a tubular valve stem 42. The upper end of this stem extends above the upper end of the housing and through an opening 44 in the upper wall 46 of the container top wall cap 36. The lower end of the valve stem extends below the lower end of the valve housing, through an opening 48 in a lower end wall 50 of the housing.

Bonded or otherwise secured to the lower end wall 50 of the valve housing 28 is an annular resilient wiper seal 52. Seal 52 surrounds and is disposed in wiping contact with the valve stem 42. At the upper end of the valve housing 28 is a bearing member 54 which cooperates with the opening 48 in the lower valve housing wall 50 to guide the valve stem for longitudinal movement relative to the valve housing. The outer edge of member 54 is firmly gripped between an annular knife edge 56 on the upper end of the valve housing and the top wall 46 of the container cap 36, and provides a seal between cap 36 and valve housing 28 to prevent leakage from the container interior.

Extending centrally through the valve stem 42 is a dispensing passage 58. The upper end of this passage communicates with a dispensing orifice 60 in a pushbutton like dispensing head 62 fixed on the upper end of the stem. The lower end of passage 58 opens laterally through an inlet port 64 in the wall of the stem. Valve stem 42 is movable between its upper closed position of FIG. 2 and its lower open position of FIG. 3. In closed position, the lower wiper seal 52 of the valve 20 engages the stem below and thereby blocks the inlet port 64. In open position, the port is located below the seal and opens to the interior of the container 12.

Valve stem 42 is biased to its upper closed position by a spring 66. According to a feature of the invention, this spring is isolated from the contents of the dispenser so as to prevent clogging of the spring by the material being dispensed and resultant improper or incomplete closing of the valve. To this end, the spring 66 is located within the valve housing 28, above its lower wiper seal 52. The spring surrounds the valve stem and seats at its ends against the lower valve housing wall 50 and a collar 68 secured to the stem within the housing so as to yieldably retain the stem in its closed position of FIG. 2.

The dip tube 22 has an internal diameter somewhat greater than an external diameter of the valve housing 28. The upper end of the tube is telescoped over the lower end of the housing and is secured to the housing by deforming the upper end of the tube over an external flange 70 on the housing. The lower end of the valve housing, below the flange 70, and the surrounding portion of the dip tube form an intervening annular clearance space 71 to be referred to again presently.

From the description to this point, it is apparent that the dispensing valve 20 is normally held closed by its spring 66. The valve is opened by pressing downward on the valve stem push button 62 to depress the valve stem 42 to its open position of FIG. 3. The pressurizing medium in the dispenser container 12 then displaces material from the annular container region 26, through the flow space 24, into the dip tube 22. The material passes up through the dip tube and then emerges from the dispenser through the valve stem inlet port 64, passage 58, and dispensing orifice 60.

As noted earlier, the aerosol dispenser 10 is primarily designed for dispensing powders and other particulate materials containing or comprising particles, such as granules, beads, flakes or the like. Many materials of this kind tend to agglomerate and the resulting agglomerates or masses tend to block the dispenser passages.

According to a further feature of the invention, blockage of the present dispenser by such agglomerates is prevented or at least greatly minimized by an agglomerate breakup head 72 on the lower end of the valve stem 42. This head has a generally star-shape in transverse cross-section and is formed with tapered radial teeth 74 circumferentially spaced about and projecting radially of the head. Teeth 74 taper outwardly to pointed tips 76 which are spaced a small distance from the dip tube 22 so as to provide a flow space about the head. Extending downwardly from the tooth tips 76 are cutting edges 78 on the teeth which converge to a lower pointed end 80. Extending upwardly from the tooth tips are converging cutting edges 82.

The lower cutting edges 78 and pointed end 80 of the breakup head 72 act to break up any agglomerated masses which are forced upwardly through the dip tube 22. The upper cutting edges 82 break up any agglomerated masses which become lodged between the lower wiper 52 of the valve 20 and the breakup head and tend to prevent or inhibit closing of the valve as well as blockage of the inlet port 64. The broken-up agglomerate masses are displaced into the annular clearance space 71 by the material exiting through the inlet port, thus, this exiting material tends to undergo swirling flow within the region between the wiper seal 52 and breakup head 72 and this swirling flow displaces the broken-up agglomerate masses into the clearance space 71 by centrifugal force.

The portion of the valve stem 42 between the inlet port 64 and the valve stem head 72 tapers smoothly to an increasing diameter, as shown, to provide a more effective sealing action when the valve is closed. Wiper seal 52 is deformed and compressed during valve closure by the tapered portion of the valve stem head, under the urging of spring 62, to provide a primary seal (FIG. 2). The wiper seal 52 wipes the valve stem clean each time the valve is opened and closed to further enhance the sealing action.

Claims

The inventor claims:

1. A dispensing valve for an aerosol dispenser for dispensing a particulate material which tends to agglomerate comprising:

a tubular housing having normally upper and lower ends,

a tubular valve stem extending centrally through and beyond the ends of said housing and having a central passage opening through the upper end of said stem and laterally through a port in the lower end of said stem,

an annular resilient wiper seal at the lower end of said housing surrounding and disposed in wiping contact with said stem,

a bearing member at the upper end of said housing guiding said stem for axial movement relative to said housing and seal between a lower open position wherein said port is below said seal and an upper closed position wherein said seal engages said stem below said port,

a spring within said housing above said seal and engaging said stem and housing for urging said stem to closed position, and

an enlarged agglomerate breakup head on the lower end of said stem having a lower pointed end and pointed teeth with relatively sharp axially presented cutting edges.

2. A valve according to claim 1 wherein:

said cutting edges face toward said seal to cut through agglomerates situated between said seal and breakup head.

3. A valve according to claim 1 wherein:

said cutting edges face away from said seal to cut through agglomerates approaching said valve assembly.

4. A valve according to claim 1 wherein:

said teeth are spaced circumferentially about and project radially out from said head,

said teeth taper radially outward to pointed tips,

said teeth have upper convergent cutting edges extending from said tips toward said seal for cutting through agglomerates situated between said head and seal and lower convergent cutting edges extending from said tips away from said seal for cutting through agglomerates approaching said valve assembly.

5. A valve according to claim 4 wherein:

said stem tapers smoothly to an increasing diameter in the region between said port and head.

6. A valve according to claim 1 including:

a dip tube extending from the lower end of said valve housing in radially spaced surrounding relation to said head.

7. A valve according to claim 6 wherein:

the upper end of said dip tube surrounds the lower end of said housing in spaced relation thereto to form an annular clearance space between said tube and the lower housing end.

8. A dispensing valve for an aerosol dispenser for particulate material which tends to agglomerate, comprising:

a valve stem having normally upper and lower ends,

an annular resilient wiper seal surrounding and disposed in wiping contact with said stem, and

an enlarged agglomerate breakup head on the lower end of said stem having a lower pointed end and pointed teeth with relatively sharp axially presented cutting edges, said cutting edges facing toward said seal to cut through agglomerates situated between said seal and breakup head.

9. A dispensing valve for an aerosol dispenser for particulate material which tends to agglomerate, comprising:

a valve stem having normally upper and lower ends,

an annular resilient wiper seal surrounding and disposed in wiping contact with said stem, and

an enlarged agglomerate breakup head on the lower end of said stem having a lower pointed end and pointed teeth with relatively sharp axially presented cutting edges, said teeth being spaced circumferentially about and projecting radially out from said head,

said teeth tapering radially outward to pointed tips,

said teeth having upper convergent cutting edges extending from said tips toward said seal for cutting through agglomerates situated between said head and seal and having lower convergent cutting edges extending from said tips away from said seal for cutting through agglomerates approaching said valve assembly.

10. An aerosol dispenser for dispensing a particulate material which tends to agglomerate comprising:

a container having top and bottom walls,

a dispensing valve centrally mounted on said top wall,

a dip tube extending from said valve centrally through said container toward said bottom wall through which said material flows from said container to said valve assembly,

said valve assembly comprising a tubular housing secured to the upper end of said dip tube, a valve stem extending centrally through said housing and having an upper end extending above said container top wall and a lower end extending below the lower end of said valve housing into said dip tube, said stem having a central passage opening through the upper end of the stem and laterally through a port in the lower end of said stem, an annular resilient wiper seal at the lower end of said housing surrounding and disposed in wiping contact with said stem, a bearing member at the upper end of said housing guiding said stem for axial movement relative to said housing and seal between a lower open position wherein said port is below said seal and opens laterally to the interior passage through said dip tube and an upper closed position wherein said seal engages said stem below said port, a spring within said housing above said seal and engaging said stem and housing for urging said stem to closed position, an enlarged agglomerate breakup head on the lower end of said stem having a lower pointed end and pointed teeth with relatively sharp axially presented cutting edges.