Patent Publication Number: US-7582242-B2

Title: Method of forming an aerosol valve actuator

Description:
This application is a division of U.S. application Ser. No. 10/738,855 filed Dec. 17, 2003, which issued as U.S. Pat. No. 7,104,424 on Sep. 12, 2006. Applicant claims the benefit of the prior U.S. application. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to aerosol valve actuators, and more particularly to such actuators of the enclosure type for use with products that expand and foam when first exposed to air. 
     BACKGROUND OF THE INVENTION 
     Aerosol valve actuators of the enclosure type generally have the enclosure base mounted onto the product container and/or onto the mounting cup of the aerosol valve on the container. Finger actuatable means on the actuator are operationally associated with the aerosol valve stem for actuating the aerosol valve and dispensing the product. The finger actuatable means may be for example a hinged finger pad integrally molded as one piece with the remainder of the actuator and extending into an opening in the upper portion of the actuator; or, may be a separate cap member on a base member, wherein the top of the cap member may be manually pushed by a finger downwardly with respect to the base to actuate the aerosol valve. 
     Certain products dispensed through an aerosol valve foam and expand when exposed to air, for example shaving creams and shaving gels. When actuation of the aerosol actuator dispensing these products first ceases, product remains in the product conduit inside the actuator between the aerosol valve stem and the actuator outlet. These products continue to foam and expand in the product conduit so that a small amount of foamed product exits the actuator outlet after actuation ceases. This is not only an aesthetic issue, but is also unsanitary, messy, and generally requires wiping away the foamed product outside the outlet before the next dispensing of product. 
     Various attempts have been made to solve the above-described “after-foaming” or “post-foaming” problem inherent in the dispensing of such products. These attempts have included providing means to block the aerosol outlet after actuation or providing space inside the actuator to absorb the foaming expansion of the product after actuation ceases. Such means have not been fully satisfactory, can be overly complex and can result in the accumulation of post-foaming product within the actuator body. Among the above attempted solutions have been the use of an actuator cap with a product dispensing opening that aligns with a product dispensing opening in the actuator base on actuation, and misaligns with the product dispensing opening in the base when actuation ceases. 
     SUMMARY OF THE INVENTION 
     The present invention is intended to provide an aerosol valve actuator that avoids the post-foaming problem, which is strongly constructed, easily manufactured and assembled, and which functions reliably and efficiently. In particular, no unsightly, unsanitary and messy product occurs outside the actuator outlet after actuation ceases, and no post-foaming product accumulates within the actuator in a manner that is not removed on the next actuation. 
     The aerosol valve actuator of the present invention includes an enclosure, an aerosol valve stem engaging portion, a product dispensing opening, and a flexible and expandable product conduit extending between said valve stem engaging portion and said product dispensing opening. The product conduit is molded at least in part of a first expandable and flexible plastic material which is softer than a second plastic material from which the remainder of the actuator is molded. The remainder of the actuator is first molded, followed by molding the first plastic material to form at least a part of the product conduit. The second, harder, plastic material may be polypropylene, and the first plastic material may be a thermoplastic elastomer such as Santoprene. In operation, after the actuator has been actuated to dispense a foaming product and actuation ceases, the post-foaming product expands within rather than outside the product conduit since the conduit itself expands to absorb the product expansion. Thereafter, when the next actuation occurs, the post-foaming product in the product conduit merely exits the actuator outlet as it is forced out by the product in the container being dispensed. 
     The actuator of the present invention may comprise a two-piece actuator having a cap and a base. The base includes a side wall with a product dispensing opening, a centrally located tube that is engageable at its bottom with the aerosol valve stem, and the at least in part flexible and expandable product conduit extending between the bottom of the tube and the base side wall product dispensing opening. The cap has a top wall for finger engagement, and a side wall with a product dispensing opening therein. The cap in its non-actuated position is in its up position, with its product dispensing opening misaligned with the product dispensing opening in the base, and with the side wall of the cap blocking the product dispensing opening in the base. When the cap is manually pressed, it slides downwardly on the base to a position where the product dispensing openings in the cap and base are aligned for product dispensing. After product dispensing, the cap returns to its upper position where it blocks the base product dispensing opening. The post foaming of the product in the product conduit cannot exit the actuator, and the foaming expansion in the conduit is taken up by expansion of the product conduit itself. 
     The base of the actuator includes a side wall with a plurality of inwardly flexible members. The cap has a plurality of internal ramps. When the cap slides downward on the base, the cap ramps flex the base side wall flexible members inwardly. After actuation ceases, the base flexible members act against the ramps to bias the cap to slide upwardly on the base to its non-actuating position. 
     The base is comprised of an upper portion and a lower portion connected together by one or more flexible tab members that allow the upper portion to be depressed in relation to the lower portion to actuate the aerosol valve. The valve stem engaging central tube is located in the upper portion of the base. When the cap is manually depressed to slide downwardly on the upper portion of the base, it reaches the position where the cap and base product dispensing openings are aligned. When the cap is further depressed, it forces the upper portion of the base to telescope within the lower portion of the base, at which point the central tube of the upper portion actuates the valve stem to initiate product dispensing. After product dispensing ceases, the aerosol valve spring pushes the upper portion of the base upwardly to its non-actuating position. 
     The assembly of the base and cap is facilitated by a number of features. The base has a top surface with a plurality of openings within which a plurality of protrusions extending downwardly from the underside of the cap wall extend and lock into (via enlargements on the end of the protuberances). Said base and cap respectively also have interfitting side wall slots and protrusions to properly align and stabilize the cap and base with respect to each other upon assembly. 
     The product conduit in the base may comprise a tubular portion of the softer expandable plastic that extends between the base side wall product dispensing opening and the top of the base centrally located tube, and a wall portion of the softer plastic extending down said centrally located tube to form with the inner tube wall a further conduit portion. 
     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 perspective view of an assembled aerosol valve actuator of the present invention; 
         FIG. 2  is an axial cross-sectional view of the assembled actuator of  FIG. 1  before it has been actuated; 
         FIG. 3  is an axial cross-sectional view corresponding to  FIG. 2  and showing the assembled actuator in its initial actuation phase of opening the dispensing orifices; 
         FIG. 4  is an axial cross-sectional view corresponding to  FIG. 2  and showing the assembled actuator in its product dispensing phase; 
         FIG. 5  is an axial cross-sectional view corresponding to  FIG. 2  and showing the assembled actuator in its post-dispensing, shut-off phase; 
         FIG. 6  is a perspective view of the base of the aerosol valve actuator of the present invention; 
         FIG. 7  is a bottom plan view of the base of the actuator of  FIG. 6 ; 
         FIG. 8  is a top plan view of the base of the actuator of  FIG. 6 ; 
         FIG. 9  is an enlarged axial cross-sectional view of the base of the actuator of  FIG. 6 ; 
         FIG. 10  is a bottom plan view of the cap of the aerosol valve actuator of the present invention; and 
         FIG. 11  is an axial cross-sectional view of the cap of the aerosol valve actuator of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENT 
     Referring to  FIG. 1 , aerosol valve actuator  10  is shown assembled from molded plastic base  11  and cap  12 . Cap  12  has a product dispensing opening  13  in its side wall, and a top surface  14  for finger actuation of the actuator by pressing downward. 
       FIGS. 2-5  are axial cross-sectional views of the assembled actuator of  FIG. 1  in various operational positions of the cap  12  in relation to the base  11 . Base  11  is shown mounted on the mounting cup  15  of an aerosol container  16  by base flange  17  that snaps under edge  18  of the mounting cup (see  FIG. 2 ). Mounting cup  15  supports an aerosol valve with aerosol valve stem  19  in known fashion. 
     Base  11  is shown by itself in perspective in  FIG. 6  and in axial cross-section in  FIG. 9 . Referring to  FIG. 9 , base  11  has side wall  20  with a product dispensing opening  21  therein. Base  11  includes a centrally located tube  22  with bottom region  23  for engagement with the aerosol valve stem  19  (see  FIG. 2 ). Extending between bottom region  23  and product dispensing opening  21  is product conduit  24 . Product conduit  24  is at least in part flexible and expandable, and as shown is comprised of a softer thermoplastic elastomer (TPE) such as Santopreme. The remainder of base  11  is comprised of a harder plastic such as polypropylene. The horizontal portion of conduit  24  leading to opening  21  is a tubular TPE member  25  extending through opening  21 , and the essentially vertical portion of conduit  24  is formed of a TPE curvilinear member  26  that meets and together with the inner side wall of centrally located tube  22  defines vertical portion  24 . Base  11  is initially injection molded of the harder plastic in a two-component molding machine, followed by the softer expandable plastic of conduit  24  being overmolded onto base  11 . Base  11  also is comprised of upper portion  27  and lower portion  28  which are connected together by a plurality of thin flexible tab hinges  29  (see FIGS.  1 , 6 ). 
     Now referring back to  FIGS. 2-5 ,  FIG. 2  illustrates base  11  and cap  12  in the assembled, non-actuated condition. Cap  12  is in its upper position, and cap product dispensing opening  13  is above and unaligned with base product dispensing opening  21 . The inner surface  30  of cap wall  31  abuts against and seals the open protruding end  32  (see  FIG. 9 ) of product conduit tubular TPE member  25  in base  11 . 
     When the top surface  14  of cap  12  is initially pressed downwardly by the user&#39;s finger, cap  12  slides down base  11  to the position shown in  FIG. 3  where the respective product dispensing openings  13  and  21  of the cap and base are aligned with one another preparatory to product dispensing from container  16 . Tab hinges  29  remain in the same position as shown in  FIG. 2 . Aerosol valve stem  19  has not yet been actuated. 
     Further depression of the user&#39;s finger on top surface  14  of cap  12  will result in cap  12  continuing to slide downwardly on base  11 . Aerosol valve stem  19  is now actuated as base upper portion  27  is telescoped into the central opening in base lower portion  28  through the action of cap  12  onto base  11 , tab hinges  29  are snapped to the position shown in  FIG. 4 , and the respective cap and base product dispensing opening  13 , 21  remain aligned for product dispensing. As can be seen in  FIG. 4 , the product in container  16  now flows upward and outward through product conduit  24 , and out aligned product dispensing openings  13 , 21 . 
     When the user&#39;s finger is released from the top surface  14  of cap  12  to cease product dispensing, the condition and relationships shown in  FIG. 5  now occur. The conventional aerosol spring (not shown) raises valve stem  19  back upwardly so that base upper portion  27  is raised back upwardly in relation to base lower portion  28 , and tab hinges assume again the position shown in  FIG. 2 . Further, cap  12  now rises upwardly in relation to base  11  under an action described in detail hereafter. Cap and base product dispensing opening  13 , 21  again become misaligned, and the product conduit tube  25  again becomes sealed at its outer open end  32  by the inner surface of the cap wall. 
       FIG. 5  illustrates a primary feature of the present invention, in that after dispensing of a foaming product when the aerosol valve is shut off, product conduit  24  is sealed and the post-foaming action of the product is take up by the expansion of product conduit  24  by virtue of its flexible, expandable nature due to the soft TPE material defining the conduit. No post foaming of the product occurs outside of cap opening  13 , and unsightly, unsanitary and messy product outside and adjacent the actuator dispensing opening is eliminated. When the next dispensing operation occurs, the foamed product in expanded conduit  24  is forced out of the outlet openings  13 , 21  by new product from container  16 . 
     Cap  12  slides upwardly on base  11  after product dispensing has ceased by a combination of features. More specifically, referring to  FIGS. 6-11 , the side wall of base upper portion  27  has a plurality of inwardly flexible members  35 , and cap  12  has a plurality of corresponding ramps  36 . When cap  12  is slid downwardly on base  11  under normal pressure, ramps  36  are positioned in cap  12  so as to flex said flexible members  35  inwardly toward the central axis of base upper portion  27  (see  FIGS. 2-4 ). After product dispensing when cap  12  is no longer being pressed downwardly by the user, flexible members  35  seek to flex back outwardly and in so doing act against corresponding ramps  36  to cause the sliding return of cap  12  back up to its  FIG. 5  non-actuated position. 
     To facilitate the assembly and operation of base  11  and cap  12 , the underside of the cap top surface  14  has a plurality of protrusions  40  with enlarged knobs  41  on the ends thereof ( FIGS. 10 and 11 ). In turn, base upper portion  27  has in its top wall a corresponding plurality of holes  42  (FIGS.  6 , 7 , 8 ) through which knobs  41  are forced and protrusions  40  extend. Protrusions  40  slide through holes  42  as cap  12  slides up and down on upper base portion  27 , and knobs  41  keep these parts from separating. Upper base portion  27  also has a plurality of sidewall slots  43  within which fit and slide cap inner wall protuberances  44  (see  FIG. 10 ) to align and stabilize cap  12  in one position with respect to base  11  upon assembly. 
     The features of the present invention described above together define a unique aerosol valve actuator which eliminates the post-foaming problem, is strongly constructed, is easily manufactured and assembled, and functions reliably and aesthetically in a sanitary manner for the consumer. 
     It will be appreciated by persons skilled in the art that variations and/or modifications may be made to the present invention without departing from the spirit and scope of the invention. The present embodiment is, therefore, to be considered as illustrative and not restrictive. 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.