Abstract:
A bag-on-valve aerosol valve system in a container is provided. Propellant is pressure filled around the valve stem, outwardly over the stem gasket and down into the container space outside the bag. Product is filled through the valve stem into the bag. The valve stem has an exterior intermediate frusto-conical annular surface and the valve housing has an interior frusto-conical annular surface, with both surfaces engaging in annular sealing contact to block propellant access to the bag when the valve stem is deeply depressed to a first predetermined position for propellant pressure filling. A stem exterior surface indent interacts with radially-biased spring-loaded slides to lock the stem in a second less depressed predetermined position for product filling through the stem down into the bag.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a division of U.S. application Ser. No. 11/519,729 filed on Sep. 12, 2006, now U.S. Pat. No. 7,730,911, which is a division of U.S. application Ser. No. 10/616,665 filed Jul. 10, 2003, which issued on Oct. 24, 2006 as U.S. Pat. No. 7,124,788, the entire contents of all of which are incorporated herein by reference. Applicant claims the benefit of the prior U.S. applications. 
     This application is also related to U.S. application Ser. No. 11/519,728 filed on Sep. 12, 2006, which issued on Apr. 28, 2009 as U.S. Pat. No. 7,523,767. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the filling of propellant and product into aerosol containers. More specifically, the invention relates to the filling of such containers of the bag-on-valve barrier pack type wherein a bag within the container is intended to hold the product to be dispensed and the remainder of the container is intended to hold the propellant. 
     2. Description of Related Art 
     Aerosol containers of the barrier pack type include the well-known piston-in-can, and bag-in-can, embodiments. In one form of the latter, to which the present invention is directed, a flexible bag within the can may have its open end sealingly connected to the valve housing of the aerosol valve. Such embodiments are referred to as bag-on-valve systems. The product to be dispensed from the aerosol container commonly is filled into the flexible bag within the container and a liquified propellant or compressed gas is filled into the aerosol container outside of the bag between the bag outer wall and the inner wall of the can. When the aerosol valve is actuated, the propellant acts against the outer wall of the bag to force the product being dispensed out the aerosol valve to the environment outside the can. When the valve actuation ceases, of course, the product dispensing ceases. 
     Heretofore, the filling of the propellant into the container outside of the bag usually has been accomplished by filling propellant under the mounting cup or through the bottom of the container or by other complex schemes and structure. Such forms of propellant filling may require special and expensive filling equipment not owned by many commercial fillers who generally do own conventional pressure filling equipment to fill aerosol containers that do not include bag-on-valve systems. Such prior art forms of propellant filling can also be slow. In addition, prior art bag-on-valve systems do not generally permit product and propellant pressure filling to separately occur after the valve has been fixed to the container, such that the product and propellant cannot mix and the product filling cannot be shut off by imprecise stem positioning during product filling. 
     SUMMARY OF THE INVENTION 
     The present invention is intended to provide a simple and efficient means to pressure fill, in either order, propellant into the container outside of the bag and product (for example, a gel) into the bag in the container. Both operations are carried out by using mostly conventional pressure filling equipment after the bag has been sealingly mounted onto the housing or housing extension of the aerosol valve, or onto a fixture such as a wedge attached to the housing or housing extension. In this application, use of the term valve housing in connection with attachment of the bag shall also be taken to include attachment to such housing extension or fixture. 
     The propellant is filled from the filling head around the outside of the valve stem, between the valve stem and the mounting cup opening for the valve stem, over the top of the aerosol valve gasket, between the outside of the valve housing and the mounting cup, and down into the aerosol container outside of the bag mounted on the valve housing. The valve stem is depressed during this propellant filling operation so as to allow the aerosol valve gasket to bend to allow the propellant to flow above the gasket. At the same time, the filling head plugs the top dispensing opening of the valve stem so that the propellant only fills around the outside of the valve stem as described above. 
     The propellant filling operation as described above is generally well known for aerosol systems where there is no separate product bag already connected to the valve housing. The presence of such a connected product bag creates a serious impediment to such propellant filing in that the propellant passing around the stem also can pass between the bent valve gasket and the adjacent valve stem into the interior of the valve housing between the housing inner wall and the stem outer wall. This propellant would then have open access down into the product bag. This of course is highly disadvantageous in a bag-on-valve barrier pack wherein the product and propellant are to be maintained separate from one another. 
     A first aspect of the present invention allows the above-described propellant pressure filling to be used in a bag-on-valve system when the bag is already connected to the valve housing and the valve is fixed to the container. This is accomplished by providing an annular interior surface on the valve housing, for example a frusto-conical surface, and an annular exterior surface on the valve stem, for example a frusto-conical surface, the two said surfaces sealingly contacting each other only when the downward engagement pressure of the propellant filling head pushes the valve stem down the full distance to make such contact upon propellant filling. This downward pressure of the filling head will exceed the normal actuating pressure of the valve user in a downward or sideward direction on the stem to cause valve actuation and dispensing. Thus, the said respective frusto-conical surfaces of the stem and housing will not contact and seal against each other during normal valve actuation, since such contact and sealing during actuation would prevent product exiting the product bag into the valve housing and out the valve. The said respective frusto-conical surfaces of the stem and housing, upon sealing against each other during propellant filling, block propellant during filling entering into the product bag. Stem and housing surface profiles other than frusto-conical may be utilized as long as they effectively seal against each other to prevent propellant entering into the product bag. 
     In a second aspect of the present invention, the product bag in the can, sealingly connected to the valve housing, may be filled with product after (or before) the above-described propellant filling. The product filling is carried out through the dispensing conduit of the valve stem, with the valve stem being depressed a distance considerably less than during propellant filling but a sufficient amount to unseal the stem lateral orifices from the valve gasket. Product, for example a gel, flows down the center conduit of the valve stem, through the stem lateral orifices, into the valve housing interior, and down into the bag connected to the valve housing. The valve stem is held at a predetermined position of depression by a combination of a stem configuration and a novel insert adaptor configuration in the product filling head. More particularly, an annular indentation in the surface of the valve stem is utilized for engagement with spring loaded radial slides in the insert of the product filling head to maintain the position of the valve stem during filling. (Such stem indentations have been previously utilized, but for the unrelated purpose of securing actuator buttons). Without such a locking interengagement, the stem position can fluctuate under the pressure of product entering the valve stem. This fluctuation can either cause the stem to rise during product filling to partially or completely close the stem lateral orifices to prevent product filling, or may depress the stem so far as to seal the stem against the housing by the afore-described annular frusto-conical surfaces to prevent product filling down into the bag. 
     In a third aspect, the present invention discloses a novel method described above whereby propellant top pressure filling and product top pressure filling, in either order, are respectively carried out around the valve stem and through the valve stem into a bag-on-valve system wherein the product bag is already sealingly connected to the valve housing and the valve is already fixed to the container. The valve stem is in a first predetermined depressed position for propellant pressure filling and in a second predetermined depressed position for product pressure filling. 
     Other features and advantages of the present invention will be apparent from the following description, drawings and claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial axial cross-sectional view of a barrier pack, bag-on-valve, aerosol valve system of the present invention illustrating the aerosol valve in closed position; 
         FIG. 2  is a partial axial cross-sectional view of a bag-on valve aerosol valve system of the present invention corresponding to  FIG. 1 , and wherein propellant is being filled into the aerosol container outside the bag by a propellant filling head; 
         FIG. 3  is an axial cross-sectional view of an aerosol valve stem of the present invention; 
         FIG. 4  is a partial axial cross-sectional view of a product filling head of the present invention positioned above and not yet engaged with the bag-on-valve aerosol valve system of  FIG. 1 ; 
         FIG. 5  is a partial axial cross-sectional view corresponding to  FIG. 4  but with the product filling head engaged with the valve stem and filling product into the bag-on-valve aerosol valve system of  FIG. 1 ; 
         FIG. 6  is an enlarged axial cross-sectional view of slide member components of the product filling head of  FIG. 5 ; and 
         FIG. 7  is an enlarged plan view of the bottom of the slide member components of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1 , aerosol valve system  10  includes a conventional closed container or can  11  (only the top portion of which is shown) with a top circular opening  12  within which is mounted aerosol mounting cup  13 . Centrally disposed within mounting cup  13  is aerosol valve  14  comprised of valve stem  15  and valve housing  16 . Valve housing  16  at the extension  16   a  of its lower end has a flexible product bag  17  attached thereto in a sealingly connected manner. Flexible bag  17  may be comprised of polyethylene and/or other materials (including in laminated form) and is of well known structure. Bag  17  will contain the product to be dispensed from the aerosol container, and is a closed structure throughout except at the top of the bag where it is open only into the interior  18  of the valve housing. The bag  17  is welded all about its top opening to the outside of the lower extension  16   a  of the valve housing. The bag  17  alternatively may be welded to a wedge or other fixture at the end of lower extension  16   a . Bag  17 , only partially shown, extends down into the container to near the bottom of the container in known fashion. 
     Aerosol valve stem  15  includes a central dispensing channel  19  and lateral side orifices  20  which are sealed by gasket  21  when aerosol valve  14  is closed by annular gasket  21 , which has a central opening. Spring  22  in the interior  18  of the valve housing  16  biases the valve stem  15  to a closed position as shown in  FIG. 1  when the valve  14  is not actuated. 
     When propellant has been filled into aerosol container  11  into space  23  outside of bag  17 , and product has been filled into the interior  24  of bag  17 , the aerosol valve system is ready for use. When valve stem  15  is depressed (or moved laterally in the case of a tilt valve), gasket  21  unseals from stem lateral orifices  20 . The pressure of the propellant outside the bag  17  presses inward against flexible bag  17  to force the product in the bag up through the interior  18  of valve housing  16 , through lateral orifices  20  and up the stem dispensing channel  19  to the outside environment. As is known, an actuator (not shown, and of various forms) may be used to actuate valve stem  15  for dispensing. When stem  15  is no longer actuated, spring  22  forces valve stem  15  back to its position where gasket  21  again seals lateral orifices  20  to prevent further dispensing. 
     Now turning to the first aspect of the present invention, reference is made to  FIG. 2 . Propellant filling head  30  is shown in filling position and is a conventional well-known apparatus. Valve stem  15  has been depressed by the filling head and plug member  31  plugs the top of stem dispensing conduit  19  to prevent propellant passing down through the conduit upon filling. Plug member  31  is an annular member with a plurality of radially outward holes  32  for filling propellant therethrough as shown by the arrows of  FIG. 2 . Propellant is filled in known fashion down through filling head conduit  33 , through holes  32 , downward along the outside surface of stem  15 , through the circular opening  13   a  in the top of mounting cup  13  through which stem  15  passes, outwardly over the top of valve sealing gasket  21 , downwardly along the outside of valve housing  16 , and finally into container space  23  outside of bag  17 . This method of filling is well known, and shown for example in U.S. Pat. No. 4,015,752 (Meuresch) and U.S. Pat. No. 4,015,757 (Meuresch), both issued Apr. 5, 1997 and incorporated herein by reference. 
     It will be noted that the above-described propellant filling occurs while product bag  17  is already positioned within container  11  and welded to extension  16   a  of the valve housing. It is important in the barrier pack system of the present invention that the propellant during propellant filling not enter into bag  17 , which is solely for the containing of the product to be dispensed. This undesired entry would be possible with a standard valve stem  15  and valve housing  16 , in that, referring to  FIG. 2 , propellant to be filled over the top of gasket  21  also can force its way between gasket  21  and the side of valve stem  15  at the annular area of contact  21   a  with the stem  15  of the bent down gasket  21  shown in  FIG. 2 . In the standard aerosol valve, the valve stem  15  does not make a sealing contact with the inner surface of the valve housing  16  during propellant filling, and thus the propellant forcing its way between bent gasket  21  and the side of valve stem  15  will pass downward through the interior  18  of valve housing  16  and downward into bag  17 . This is avoided in the present invention by providing a frusto-conical surface  34  extending around an intermediate portion of the valve stem (also see  FIGS. 1 and 3 ), and frusto-conical surface  35  extending around the valve housing  16  (also see  FIG. 1 ). Surface  34  may for example be at an angle of twenty degrees to the vertical, and surface  35  may be at the same angle to the vertical. In the closed position of the aerosol valve (see  FIG. 1 ), the surfaces  34  and  35  are separated from one another. Likewise, when the aerosol valve is actuated in normal dispensing operation, valve stem  15  will not be depressed sufficiently to bring surfaces  34  and  35  into sealing contact by normal actuation pressure acting against the force of spring  22 . However, during propellant filling, the force of the propellant head against the valve stem  15  forces valve stem  15  to depress sufficiently such that frusto-conical surface  34  and  35  make annular plastic to plastic sealing contact with each other. Therefore no propellant being filled can pass down into the valve housing extension  16   a  into the bag  17  since surfaces  34  and  35  seal off the bag from propellant entry. A conventional propellant filling head  30  may thereby be used despite the presence of product bag  17  in the container  11 . Filling head  30  also includes spacer cylinder  36  and annular gasket  37 , as well known. 
     Turning to the second, product filling, aspect of the present invention, reference is made to  FIGS. 3 ,  4  and  5 . It should be understood that product filling may occur after, or before, the propellant filling operation of  FIG. 2 .  FIG. 4  illustrates product filling head  40  before it is positioned on the aerosol valve system, and  FIG. 5  illustrates product filling head  40  after it is in position for filling product into bag  17  in the can  11 . Filling head  40  includes outer annular wall  41 , inner annular product filling member  42  including product conduit  43 , spacer cylinder  44 , and product filing registration insert member  45 . Member  45  is comprised of U-shaped slide guides, and within the guides at for example positions one hundred and eighty degrees apart, radial slide members  47  and  48  (also see FIGS.  6 , 7 ) that are spring loaded by springs  49  and  50  to bias the slide members  47  and  48  radially inward and slightly into opening  46 . Springs  49  and  50  abut product filling member  42  on one end of each spring, the other end of each spring respectively fitting into openings  47   a  and  48   a  of slide members  47 ,  48 . When product filling head  40  is positioned onto the aerosol valve system, the top outer portion  15   a  of stem  15  fits into opening  46  and biases the slides  47 ,  48  radially outward against the springs  49  and  50 . Referring to  FIGS. 3 ,  4  and  5 , stem  15  also has annular indent  60  about the circumference of valve stem  15 . Therefore, as the top outer portion  15   a  of stem  15  passes upwardly through opening  46 , radial slides  47  and  48  snap into stem indent  60  under the force of the springs  49  and  50 . Curvilinear faces  51  and  52  (see FIGS.  6 , 7 ) of slide members  47  and  48  now encircle the stem  15 . At this position, as shown in  FIG. 5 , valve stem  15  is in a downwardly depressed position so that the lateral stem orifices  20  are no longer sealed by gasket  21 . The stem  15  is locked into its precise depressed position by slides  47  and  48  locked into stem indent  60 , which depressed position is sufficient to unseal stem orifices  20  but not so great as to sealingly engage stem and housing frusto-conical surfaces  34  and  35 . 
     To now carry out product filling into bag  17 , product is filled through conduit  43 , stem dispensing conduit  19 , stem lateral orifices  20 , interior space  18  of valve housing  16 , down through valve housing extension  16   a , and into bag  17 . When the product filling is completed, the product filing head  40  is removed. The precise positioning of the valve stem  15  permitted by radial slides  47 ,  48  and stem indent  60  not only prevents the stem  15  from being further depressed to seal surfaces  34 ,  35  and prevent product filling down into the bag, but also prevents the stem  15  from rising up due to filling back pressure to seal lateral orifices  20  and prevent product from entering the valve housing  16  during product filling. 
     In a third aspect of the present invention, it will be seen from the description above that a bag-on-valve system, with a bag already in the can and the valve fixed to the container, can therefore be top pressure filled with both propellant and product in either order. By controlling the degree of stem depression and stem sealing during the respective filing operations, and by providing first and second predetermined depressed stem positions during said operations, propellant only is filled to the can space outside the bag and product only is filled into the bag. A simple, fast and efficient filling system using conventional pressure filling equipment thereby results. 
     It will be appreciated by persons skilled in the act that variations and/or modifications may be made to the present invention without departing from the spirit and scope of the invention. The present embodiments are, therefore, to be considered as illustrative and not restrictive. Purely as an example, a dip tube may extend from the valve housing down into the product bag to prevent the bag “pocketing” during dispensing. It should also be understood that positional terms as used in the specification are used and intended in relation to the normal positioning shown in the drawings, and are not otherwise intended to be restrictive.