Abstract:
A fill valve for selective interconnection with a container is provided. The fill valve includes a head shaft and shoulder separated by grooves that are selectively positioned in an aperture of the container to selectively provide a flow path into the container.

Description:
FIELD OF THE INVENTION 
     Embodiments of the present invention are related generally to valves that are operably interconnected to the ends of aerosol containers and which allow pressurized fluid to be selectively added to the interior thereof. 
     BACKGROUND OF THE INVENTION 
     Prior art aerosol containers generally include a collapsible bag or pouch disposed therein. The bag or pouch is filled with a fluent material that is dispensed by the container upon actuation of a dispensing valve. A propellant chamber is formed between the bag and the container sidewall. A container end closure is interconnected to the bottom of the side wall and comprises a domed portion with an opening that receives a fill valve. Initially, the bag or pouch is placed in the container and the dispensing valve is attached to a top portion of the container. A propellant is subsequently injected into the container via the fill valve to pressurize the items stored within the bag. For example, a 7 oz. container may contain about 10-12 grams of propellant, such as butane, that is used to pressurize the bag. To inject the propellant, the fill valve is unseated somewhat from the container end closure to provide a space to allow propellant to flow into the chamber and to pressurize the item stored in the bag. The fill valves of the prior art generally include a stem that fits through the aperture in the container end closure, an inner sealing element formed on one side of the stem, and a “bow tie” section formed on the other end of the stem. In addition, opposed longitudinally extending grooves extend from the bow tie section along the side of the stem. During filling, a nozzle presses against the bow tie section of the valve and pushes the valve a sufficient distance inwardly to expose the grooves so that the propellant can flow into the chamber. Additionally, the pressure of the propellant causes the fill valve to flex upward to create a larger opening for the pressurized gas to enter the container. When the nozzle is withdrawn, the pressure in the chamber forces the inner sealing element of the fill valve against the inner surface of the container bottom to seal the container. An example of this type of aerosol container is generally shown in U.S. Pat. No. 5,915,595, which is incorporated by reference in its entirety herein. 
     A second type of aerosol container utilizes a piston disposed in the container wherein the product to be dispensed is located on an outlet valve side of the piston. The other side of the piston defines a propellant chamber that receives the propellant. The propellant is introduced to the container through a similar fill valve that is fitted into the container end closure in the manner described above. 
     There are a number of problems associated with aerosol containers that utilize fill valves of the prior art. One significant problem is associated with improper sealing of the fill valve subsequent to filling, which allows propellant to leak from the container. Improper sealing generally refers to a less than ideal engagement between the sealing portion of the fill valve and the aperture of the aerosol container. Propellant leakage associated with improper sealing dramatically reduces product dispensing efficiency, and if a substantial amount of propellant leaks from the container, a “dead” container will result. A “dead” container is one which does not dispense product when the outlet valve is actuated. It will be appreciated by one skilled in the art that the time between a container filling and use may be significant. This period is a function of container packaging, shipping, warehousing and storage. Any loss of propellant, however small, will affect the usefulness of the container. It has been estimated that even a small leak can result in a loss of as much as one gram of propellant per year. 
     Another related problem occurs during the manufacturing of the fill valve. Generally, fill valves of the prior art are compression molded which has been found to result in poor sealing associated with poor cross linking of the molded material. Cross linking is the formation of chemical links between molecular chains and polymers. Poor cross linking results in poor compression that adversely affects the seal. The result is that even if the fill valve properly seals after filling, propellant may still escape from the container over time due to this poor compression set. In addition, a cryogenic process that is used to remove flash created during compression molding is associated with poor sealing. “Flash”, as used herein, refers to ancillary bits of rubber or other material formed on the finished part during the molding process. During compression molding, flash is created and is later removed by freezing of the product and chipping off the brittle flash. The cryogenic freezing process used to remove the flash may form cracks in the fill valve that potentially become leak paths. 
     Another problem with fill valves of the prior art is related to indicia identifying the particular mold and mold cavity from which the fill valve was formed. The indicia assists in identifying defective valves. Currently, this indicia is comprised of raised alpha/numeric characters on a surface of the fill valve. The raised characters often influence the movement of the fill valve along conveyor belts associated with the manufacturing process. This haphazard movement of fill valves may result in tipping or sticking to the conveyor belt and require additional manpower to ensure that the fill valves arrive to the assembly station and are properly oriented for insertion into the container end closure. 
     SUMMARY OF THE INVENTION 
     Embodiments of the present invention are generally related to an aerosol dispensing container incorporating a bag holding a product to be dispensed in a propellant chamber formed between the bag and a container sidewall. More specifically, an improved fill valve by which a propellant is introduced into the container and retained therein until generally all of the product in the container is dispensed is provided. The term “fill valve”, as used herein shall generally refer to a grommet, umbrella valve, or seal often found interconnected to the end closure of aerosol containers of the art. Alternatively, the container may employ a piston wherein the product to be dispensed is located on one side of the piston and the propellant chamber is located on one side of the piston. Again, the improved fill valve allows a propellant to be introduced into the chamber and retained therein until generally all of the product is dispensed. 
     It is one aspect of the present invention to provide a fill valve for incorporation into an aerosol container that provides enhanced sealing capability. The fill valve of one embodiment is fabricated using a flashless injection molding process rather than the compression molding process previously employed. As part of this process, both the mold cavity and molding material are heated to an elevated temperatures which significantly improves the cross linking that occurs during the molding process. Further, the fill valve includes a recessed portion that improves flexing of the valve after the propellant is injected which creates a more responsive seal. Furthermore, information about the fill valve is now engraved on the surface of the valve so as to facilitate conveying of the valve during the container manufacturing process. 
     It is another aspect of the present invention to provide fill valve that possesses a more consistent dimensional and operational characteristics and that is thus less prone to leaking. More specifically, due to the injection molding process described above, each valve produced during manufacture includes substantially the same dimensions, thereby allowing for predictability of the fill valve. 
     It is another aspect of the present invention to provide a fill valve of a unique shape and dimension. For example, one embodiment of the fill valve includes a centralized shaft having a head for insertion into the container interconnected on one end and a sealing shoulder connected on another end. An upper groove separates the head from the shaft and a lower groove separates the shaft from the shoulder. Integrated into the head and the shaft is at least one passage. In some embodiments of the present invention, two fluid channels are formed laterally in the shaft wherein the two filled channels meet within the fill valve. When the upper groove is engaged within the aperture of the container end closure, the propellant is capable of flowing into the container by way of the flow channels. When the lower groove is engaged within the aperture, the channels completely positioned are within the container and thus flow of propellant into and out of the container is prevented. Prior art fill valves related to the present invention of this type are described in U.S. Pat. No. 6,945,284 to Hurd et al. and U.S. Pat. No. 7,225,839 to MacKenzie et al., both of which are incorporated by reference in their entirety herein. Both Hurd and MacKenzie each include a channel to allow propellant to enter a container. The seal provided by the fill valves of these of common prior art fill valves is about 0.00304 sq. in. Embodiments of the present invention employ a unique geometry that facilitates filling of the aerosol container while employing a seal with a surface area of about 00446 sq. inches. 
     The fill valve of one embodiment includes two fluid channels that are situated at an angle relative to the shaft. The two channels join at an apex located within the fill valve. The angularly-situated channels provide a greater space between the fill valve and the container when the fill valve is situated within the aperture, which facilitates filling of the container. Furthermore, the fill valve employs a portion with an enlarged diameter that acts as a seal. The fill valve includes a bore that allows the seal to flex and conform to the container, thereby improving the sealing capabilities of the fill valve. 
     The improved fill valve has a number of advantages over previous valves of the prior art. For example, the fill valve has a more consistent dimension and operational characteristics. Further, the improved fill valve provides a more capable seal and a valve less prone to formation of cracks. This significantly reduces the possibility of propellant leakage from a container, even those with prolonged shelf lives. This in turn, reduces warranty returns and associated costs of replacing a non-functioning or dead container. Additionally, because the improved sealing capability, the reduction in leakage reduces pollution. It may also be possible to reduce the amount of propellant injected into a container during filling because with less leakage, more propellant will remain in the container, thus additional filling to compensate for leaking will not necessarily be required. 
     The Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the present invention. The present invention is set forth in various levels of detail in the Summary of the Invention as well as in the attached drawings and the Detailed Description of the Invention and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of elements, components, etc. in this Summary of the Invention. Additional aspects of the present invention will become more readily apparent from the Detail Description, particularly when taken together with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description of the invention given above and the detailed description of the drawings given below, serve to explain the principles of these inventions. 
         FIG. 1  is a cross-sectional view of a common aerosol container; 
         FIG. 2  is a perspective view of a fill valve of one embodiment of the present invention; 
         FIG. 3  is a side elevation view of  FIG. 2 ; 
         FIG. 4  is a front elevation view of  FIG. 2 ; 
         FIG. 4A  is a view similar to  FIG. 4 , wherein dimensions of one embodiment of the invention are provided; 
         FIG. 5  is a side elevation view of  FIG. 2 ; 
         FIG. 5A  is a view of  FIG. 5  wherein dimensions of one embodiment are provided; 
         FIG. 6  is a top plan view of the fill valve shown in  FIG. 2 ; 
         FIG. 7  is a bottom plan view of the fill valve shown in  FIG. 2 ; 
         FIG. 8  is a cross-sectional view of a container end with the fill valve engaged thereto for filling of the container; and 
         FIG. 9  is a cross-sectional view of the container end showing the fill valve inserted into the container to prevent leakage of propellant therefrom. 
     
    
    
     To assist in the understanding of the present invention the following list of components and associated numbering found in the drawings is provided herein: 
     It should be understood that the drawings are not necessarily to scale. In certain instances, details which are not necessary for an understanding of the invention or which render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.
         # Components     2  Container     6  Container body     10  End closure     14  Valve assembly     18  Product bag     22  Product     26  Aperture     30  Fill valve     34  Propellant chamber     38  Shaft     42  Head     46  Shoulder     50  Upper groove     54  Lower groove     58  Fluid passage     62  Bore     66  Cylindrical portion     70  Conical portion     74  Center axis     78  Center plane     82  Planar surface     86  First point     90  Second point     94  First plane     98  Third point     102  Second plane       

     DETAILED DESCRIPTION 
     Referring now to  FIGS. 1-9 , an aerosol container  2  that includes a cylindrically shaped body  6 , a container end closure  10  and a dispensing valve assembly  14  is shown. A product bag  18  is disposed in the container  2  for dispensing a product  22 . In order to pressurize the product  22 , the container  2  is filled with a pressurized propellant material. The container end closure  10  includes an aperture  26  with a fill valve  30  positioned therein to allow for selective opening and closing of the container  2 . A propellant chamber  34  is thus formed in the container and propellant, such as butane, is injected into the container through the fill valve  30  to pressurize the propellant chamber  34  and thus the product bag  18 . The fill valve  30  of one embodiment of the present invention is comprised of a shaft  38  that is interconnected on one end to a head  42  and on another end to a shoulder  46 . An upper groove  50  is located between the head  42  and the shaft  38  and a lower groove  54  is located between the shaft  38  and the shoulder  46 . The upper groove  50  and lower groove  54  are adapted to selectively engage the aperture  26  of the container end closure  10 . 
     Referring now to  FIGS. 2-7 , the fill valve  30  of one embodiment of the present invention is shown. The fill valve  30  also includes a passage  58  that allows propellant to enter into the container  2  when the upper groove  50  is situated within the aperture  26  of the end closure  10 . When filling is complete, the fill valve  30  is transitioned upwardly into the container  2  such that the lower groove  54  is situated within the aperture  26 , thus positioning the passages  58  within the container  2 . 
     More specifically, with reference to  FIGS. 5 and 6 , the fill valve  30  of one embodiment of the present invention is comprised of a shaft  38 . The shaft  38  includes a generally cylindrical portion  70  with a first diameter and a generally conical portion  70 , wherein a longitudinal center axis  74  is positioned through the cylindrical portion  70  and the conical portion  74  that defines a center plane  78 . The head  42  is interconnected to the conical portion  70  of the shaft  38  with the upper groove  50  positioned therebetween. The head is also defined by a generally planar surface  82  that is generally perpendicular to the center plane  78 . The shoulder  46  is interconnected to the cylindrical portion  66  of the shaft  38  with the lower groove  54  therebetween. 
     The fill valve  30  also includes a fluid passage  58  formed within the head  42  and the shaft  38  that is defined by a first point  86  and a second point  90 . The first point  86  is generally located on the longitudinal center axis  74  and positioned a predetermined distance from the planar surface  82  of the head  42 . The second point  90  is positioned within the cylindrical portion  66  of the shaft  38  and a predetermined distance from an exterior surface of the cylindrical portion  66 . Thus the passage  58  is bounded by a first plane  94  that is defined by the first point  86  and the second point  90  that is angled with respect to the planar surface  82  of the head  42 . 
     Further, the fill valve  30  includes another fluid passage  58  formed within the head  42  and the shaft  38  that is defined by the first point  86  and a third point  98 . Similar to the second point  90 , the third point  98  is positioned within the cylindrical portion  66  of the shaft  38  and a predetermined distance from the exterior surface of the cylindrical portion  66 . Thus the passage  58  is bounded by a second plane  102  that is defined by the first point  86  and the third point  98  that is angled with respect to the first plane  94 . 
     The fill valve  30  must also include a bore  62  partially through its thickness that decreases the wall thickness of the shaft  38 . The decrease in thickness associated with the bore  62  allows the fill valve  30  to expand radially when pressure is removed therefrom. This radial expansion presses against the sides of the aperture  26  to enhance the sealing characteristics of the fill valve  30 . 
     Referring now to  FIGS. 8 and 9 , operation of the fill valve of one embodiment of the present invention is shown. Initially, the upper groove  50  of the fill valve  30  is engaged within the aperture  26 , thereby providing a path for fluid flow through the passage  58 . Once sufficient pressurized fluid is added to the container, the fill valve  30  is transitioned to a second position wherein the lower groove  54  is placed in contact with the walls engaged within the aperture  26 . As shown in  FIG. 9 , the passages  58  are located inside the container  2  and thus fluid flow is blocked by the shoulder  46 . The bore  62  of the fill valve  30  allows for selective radial compression of the fill valve  30  to aid transition from the first position of use to the second position of use. 
     Referring now to  FIG. 9 , specifically, when the radial compression is released, the resilient nature of the fill valve  30  will spring outwardly to further contact portions of the end closure  10  to facilitate sealing of the container  2 . 
     While various embodiments of the present invention have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present invention, as set forth in the following claims.