Valve for a pressurized product dispensing container

An axially actuated valve primarily for use in a pressurized container having a dip tube comprises a vertical moveable valve element having a stem, button on the base of the stem and sidewall openings at the lower part of the stem. A resilient annular sealing grommet has a recess in its base into which the button fits. When the valve is closed, the button engages the ceiling of the recess to block product from reaching the sidewall openings. The button is within the recess at all times between its closed and open states. The button has upper and lower disc portions. The lower disc portion optionally has a tubular tail to engage a dip tube. The upper disc portion has edge recesses that provide communication between the stem wall openings and a zone created when the valve element is depressed. The button has a vertical passageway through the lower disc portion and a horizontal passageway between the two disc portions extending out to the edge recesses in the upper disc portion. When the valve is open, a passage is provided to dispense product through the passageways within the button to communicate with the stem sidewall openings.

BACKGROUND OF THE INVENTION

This invention relates in general to valves for pressurized dispensing containers and more particularly to a valve whose design makes it particularly useful for containers in which a dip tube is employed. The dip tube provides a passageway between the pressurized product to be dispensed and the dispensing valve.

Applicant's U.S. Pat. No. 5,785,301 and No. 6,425,503 and No. 6,340,103 are representative of prior art valve designs for use in hand held pressurized containers.

Pressurized containers for dispensing product can be categorized into a first type that employs a barrier between the product and the pressurized gas and another type in which the pressurized gas and the product are mixed. The latter type typically employs a dip tube that extends from the dispensing valve to the bottom of the container in which the product and pressurized gas is mixed. This dip tube arrangement is normally employed where product being dispensed is a mist or a spray. However, a dip tube can also be used where the product being dispensed is a highly flowable product such as a shave gel.

The valve assemblies employed in these dip tube type of designs normally have five components. These five components are a mounting cup, a movable valve element that moves between an open and closed position, a first resilient sealing element to seal the valve to the dip tube, a second resilient sealing element to seal the valve stem openings when in the closed state and a spring to return the valve to its closed state once finger or hand pressure is removed from the actuator.

Maintaining the cost of these valve assemblies at a minimum its an important factor in keeping the cost of the end product reasonable and accessible to the public.

Part of the cost of these valve assemblies is in the number of components that constitute the valve assembly (five components in the typical known art) and part of the cost is in the difficulty or ease in assembling the various components that make up the valve assembly.

Accordingly, it is a major purpose of this invention to provide a valve assembly which is less expensive by reducing the number of components and reducing the cost to assemble.

It is another purpose of this invention to provide a dispensing valve that can be optimally adapted for use with a container in which a dip tube is used.

A further purpose of this invention is to provide a valve adapted to be used in a vertical fashion; that is, used by axial movement of the valve element.

BRIEF DESCRIPTION

The valve assembly disclosed has three components, a mounting cup, a movable valve element having a stem and a button and a sealing grommet having a recess into which the button of the stem fits. The button and grommet engage under pressure along the ceiling of the recess to seal the product in the closed or sealed state. The button has an upper segment with a smaller diameter and a lower segment with a greater diameter. The lower segment of the button has an interference fit relationship with the sidewall of the recess to prevent significant migration of product or propellant around the periphery of this lower portion of the button when the valve is in an open state.

The preferred button disclosed has a tail which engages a dip tube. The button has a passageway in the tail and through the main portion of the button. The upper segment of the button has recesses to provide communication for product being dispensed through the passageway within the button to the recesses and then into a zone above the button; which zone is created when the button is depressed in the open state of the valve. This zone above the button is in communication with the valve openings in the stem of the valve. This permits product, in the open state of the valve, to flow up through the valve stem and out the actuator at the upper end of the valve stem.

The passageway through the button extends up through the lower segment of the button and transversely within the button to the recesses in the button upper segment edge.

The grommet contains an upper boot portion for restoring the valve to its closed state when pressure is removed from the valve. The boot portion is an annular relatively thin upward extension of the main portion of the grommet. The boot terminates in an edge that engages a shoulder in the valve stem thereby providing upward pressure on the valve stem when the valve element is depressed against the upper edge of this boot.

It is important that the top of the boot have an inwardly directed annular flange that snugly engages an annular recess or groove in the valve stem. This assures that the boot does not escape the shoulder under the restoring pressure exerted when the boot is fully collapsed.

This arrangement of functions so that only three parts constitute the valve assembly requires that the button is specifically designed to have a horizontal component of the passageway through the button directed to the edges of the upper segment of the button and thus divert the product being dispensed into the zone created above the button when the valve stem is depressed during the open state of the valve.

The grommet has an annular bore that engages the valve stem. The lower part of the bore has an interference fit relation with the valve stem from the button to at least the top of the valve stem openings. This interference engagement enables user control over the rate at which product is dispensed. When the user partially depresses the valve element and thus exposes only a portion of the stem openings to the product, the rate at which product is dispensed is controlled.

In a preferred embodiment, the valve stem openings are elongate in the axial direction and have tapered edges. This design further enhances user control over the rate at which product is dispensed when the valve element is used in a vertical direction.

Terminology

As used herein, the term “upper” and formatives thereof should be understood to refer to a location closer to the dispensing actuator; that is, the element which is usually actuated with the finger of the user. The terms “lower” and “down” and formatives thereof should be understood to refer to a location closer to the interior of the container on which the valve assembly is mounted. Most containers are stored on their base. The input end of the valve is lower in the container and the output end is at the upper end. Many products are dispensed upside down or laterally. It should be understood herein that the terms “upper” and “lower” are used to indicate relative position or direction in connection with the above convention; and are not used with respect to the container when dispensing product.

The term “valve” is sometimes used in a more inclusive sense and other times in a less inclusive sense. As used herein, the term “valve assembly” will normally be used to refer to the three element combination of the mounting cup, a movable valve element and a sealing grommet. The term “valve” will usually be used to refer to the combination of the movable valve element and the sealing grommet. And, to provide an appropriate distinction, the term “valve element” will be used to refer to the element around which the grommet is mounted and which is depressed in a downward direction relative to the grommet to provide an open state and when released move up relative to the grommet to provide a closed state.

The grommet has as its main function to seal the valve stem openings by sealing contact between the upper surface of the button and the ceiling of the recess in the grommet. Thus, it is referred to herein as a sealing grommet. The upper portion of the grommet is referred to as a boot. The boot portion engages a shoulder on the valve stem. The boot is resilient and compresses when the valve is opened. The boot serves to provide a restoring force on the valve element to close the valve when finger pressure on the actuator is released.

There is a “full engagement” relationship between the flange54at the top of the boot50and the recess56in the valve stem22. In the embodiment disclosed, a 20 mil thick resilient material flange engages a 20 mil thick non-resilient recess. This engagement is referred to herein as a “full engagement” or as “two elements being fully engaged”. This engagement will normally be tighter than that which is called a slip fit relationship and thus is also referred to as a “snug” relation. Nominally the two dimensions being engaged are equal. There may be some slight variation depending upon the requirements of assembly and the materials used. The purpose is to provide as snug a fit as possible in order to avoid having the boot50slip out of engagement and move over the shoulder48when the valve is fully depressed.

The open state of the valve is normally used to refer to both fully open and partially open valve conditions.

A mil is a thousandth of an inch (0.001 inches).

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The FIGS. represent a single embodiment. The valve assembly10is shown mounted on a container12that does not have a barrier between the product14to be dispensed and the gas16which provides the pressure. A spray actuator18is shown mounted on the top of the valve assembly10. The valve assembly10is composed of three elements; namely, a mounting cup20, a vertically movable tubular valve element22and a grommet24which surrounds the center section of the valve element22. The grommet24has a recess25in its base (seeFIG. 7). The valve element22has a button26at its lower end (seeFIG. 4). The button26fits into the recess25. There is an interference fit relation between the lower segment38of the button26and the sidewall27of the recess25. The recess25is deep enough so that the button26stays within the recess25even when depressed into the fully open state. A tail28of the button engages a dip tube31which extends down from the valve element22to the bottom of the container12.

The valve element22has a stem32with a center passageway34. The button26is at the base of the stem32. The tail piece26which holds the dip tube31extends below the button26. Sidewall openings36near the base of the stem26are sealed by the grommet24when the valve is in its closed state. In that closed state, the valve element22is in its uppermost position. The valve stem sidewall openings36are in communication with the product being dispensed when the valve is in an open state. When the valve element22is depressed, the openings36are exposed to a zone46around the top of the button26which zone46in turn is in communication with the product to be dispensed through passageways in the dip tube31, the tailpiece28and the button26.

A dip tube31is typically used in a design where the product and propellant are mixed together under pressure within the container12. When propellant is a liquid, usually hydrocarbon, the pressure tends to remain the same because the liquid hydrocarbon evaporates. However, if the propellant is a gas such as nitrogen under pressure, then there will be a loss of pressure as product is dispensed. In addition, there is a design in which a foreshortened dip tube (not shown) is used that extends into a bag containing product. In that case, the propellant under pressure is outside of the bag and the bag is a barrier between propellant and product.

In all cases, one of the advantages of the design shown is that it provides the user with an ability to control the rate at which product is dispensed. This user dispensing control function can be used in the appropriate situation to compensate for the lower pressure that occurs as product is dispensed. The dispensing control function can also be employed to permit the user to control the rate at which product is sprayed and therefore affect the spray pattern. This latter situation is most likely in a context where the propellant is a liquid mixed in with the product.

The portion29of the grommet24that engages the lower portion of the stem32, does so with an interference fit relationship. For example, in a typical mist applicator embodiment, a stem wall outer diameter of 152 mils may be engaged by a grommet which in its relaxed state has an inner diameter of 142 mils.

This interference fit relationship extends from the button26up through at least the top of the stem wall openings36. When the user pushes down part of the way on the valve22, only a portion of the openings36are exposed to product. This assures an ability for the consumer to control the rate at which product is dispensed and, in particular, to compensate for the fact that the pressure is greater when product is first dispensed and lesser when most of the product has been dispensed. The interference fit, at the stem zone where the openings36are located, assures that this partial opening will be effective. The interference fit prevents the product under pressure from forcing the grommet away from the portion of the openings36covered by the grommet.

The corner33of the grommet24is orthogonal in relation to the horizontal sealing surface35of the grommet. This assures that the grommet surface38will be flush against the entire lower portion of the valve stem32.

There are two stem wall sidewall openings36. Each opening36is elongated in an axial direction and has tapered edges so that the width of the opening goes from a minimum at the lower point of the opening to a maximum near the top of the opening. An upper segment of the opening36is not tapered in one preferred embodiment. The dimensions of a typical opening in one embodiment are shown inFIG. 6. This variable width opening is of additional value to provide the user easy control over the rate at which product is dispensed.

The design of the button26is particularly important to provide the three piece valve assembly. The button26has an upper disc segment37and a lower disc segment38. The lower disc segment38has an interference fit relation with the sidewall27of the grommet recess25to prevent product from migrating around the button26. Recesses40are provided at the edges of the upper disc segment37. The passageway within the button26has a first vertical portion42and a second horizontal portion44. The horizontal portion44extends along the base of the upper disc segment37to the edge recesses40to complete communication from below the button, through the button to the recesses40. When the valve opens and the button26moves down away from the ceiling of the grommet recess25, an annular zone46is created which allows communication between the outlet of the horizontal passage44and the valve stem openings36.

The horizontal passage44is preferably rectangular in order to provide a large enough passageway to avoid serving to constrict the valve openings36.FIG. 4illustrates an inner end view of one half of the horizontal passageway44. In general, all product passageway cross sectional areas should be at least equal to the cross section area of the valve openings36.FIG. 4illustrates an inner end view of one half of the horizontal passageway44.

Thus in the dip tube embodiment, opening the valve by pressing down on the actuator18creates a path for product from the product chamber, through the dip tube31and tail piece28, through the vertical passage42in the button, through the horizontal passages44in the button, to the edge recesses40, into the annular zone46and then through the valve stem openings36, up the valve stem passageway34to be dispensed at the actuator18.

This resilient sealing grommet24has an upper boot portion50. The upper surface52of the boot50engages a shoulder48on the valve stem32to provide an upward force to assure that the valve element22returns to a closed state when pressure is removed from the actuator18attached to the valve. An inwardly extending annular flange54at the top of the boot50engages an annular recess56in the valve stem32. This is a snug engagement so as to assure that the grommet24will remain properly positioned relative to the valve element22during the opening of the valve. This snug engagement54,56together with the increased diameter of the shoulder48, assures that when the valve element22is depressed, the boot50will not move up on the valve stem32and thus assures that the boot50will be appropriately compressed so that the force required for returning the valve12,24to its closed position will be available.

The boot50has a concave inner surface58which assures that the boot50will buckle out when vertical pressure is applied when the valve element22is moved downward and thus avoid having the boot significantly resist opening of the valve. A vertical slit (not shown) in the boot50might be useful to ease actuation. That will depend on grommet material and boot size. The outer surface of the boot wall is radially recessed from the top outer edge of the boot so that the boot wall will resist opening only enough to assure that the boot wall on compression will provide the force needed to close the valve when operator pressure is removed.

An annular bump60on the bore of the grommet24can be of value to prevent product from leaking up between the valve stem and grommet when the valve is in its fully or partially open state.

The stem bore34extends below the openings36to reduce the amount of plastic used in molding and to facilitate cooling after molding.

Dimensions

In one example of the embodiment disclosed, a product useful for dispensing a mist or spray has the following dimensions. The FIGS. are not proportional to the following dimensions in order to provide a clearer presentation of the important features.

Button26: 150 mils thick; 100 mils for the upper disc segment37and 50 mils for the lower disc segment38. Upper disc37is 250 mils in diameter and lower disc38is 253 mils in diameter.

Button horizontal passageway44within the upper disk37is 50 mils by 60 mils and vertical passageway42within the lower disc38is 70 mils in diameter.

Grommet24inner diameter at the lower portion: 142 mils in relaxed state; engaging the 152 mil valve stem32.

Center passageway34at location of the valve openings in valve stem30: 70 mils (this passageway is slightly tapered in order to permit removal from the mold) and thus does not have a completely uniform diameter).

Valve Stem Openings28: Dimensions are shown inFIG. 6. Total opening about 3850 square mils.

While the foregoing description and drawings represent a presently preferred embodiment of the invention, it should be understood that those skilled in the art will be able to make changes and modifications to those embodiments without departing from the teachings of the invention and the scope of the claims.

For example, the preferred embodiment disclosed is for use with a dip tube. However this three piece valve assembly design could be used to dispense product without the tail32and without the dip tube31.

The recesses40and passages42and44through the button26are designed as disclosed as they are easiest to implement and mold. However it is possible to design alternate passageway geometry.