Abstract:
A valve assembly can automatically dispense aerosol content from an aerosol container at predetermined intervals without the use of electric power. A diaphragm at least partially defines an accumulation chamber that receives aerosol content from the can during an accumulation phase. Once the internal pressure of the accumulation chamber reaches a predetermined threshold, the diaphragm moves axially, carrying with it a leg so as to unseal an outlet, and thereby initiate a spray burst. A pawl extends from the diaphragm, and engages a retention surface to resist movement of the diaphragm and prolong the accumulation phase. The diaphragm assumes its original position when the pressure within the accumulation chamber falls below a threshold pressure.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    Not applicable  
         STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH/DEVELOPMENT  
         [0002]    Not applicable  
         BACKGROUND OF THE INVENTION  
         [0003]    The present invention relates to aerosol dispensing devices, and in particular to valve assemblies that provide automatic dispensing of aerosol content at predetermined time intervals, without requiring the use of electrical power.  
           [0004]    Aerosol cans dispense a variety of ingredients. Typically, an active is mixed with a propellant which may be gaseous, liquid or a mixture of both (e.g. a propane/butane mix; carbon dioxide), and the mixture is stored under pressure in the aerosol can. The active mixture is then sprayed by pushing down/sideways on an activator button at the top of the can that controls a release valve. For purposes of this application, the term “chemical” is used to mean liquid, liquid/gas, and/or gas content of the container (regardless of whether in emulsion state, single phase, or multiple phase).  
           [0005]    The pressure on the button is typically supplied by finger pressure. However, for fragrances, deodorizers, insecticides, and certain other actives which are sprayed directly into the air, it is sometimes desirable to periodically refresh the concentration of active in the air. While this can be done manually, there are situations where this is inconvenient. For example, when an insect repellant is being sprayed to protect a room overnight (instead of using a burnable mosquito coil), the consumer will not want to wake up in the middle of the night just to manually spray more repellant.  
           [0006]    There a number of prior art systems for automatically distributing actives into the air at intermittent times. Most of these rely in some way on electrical power to activate or control the dispensing. Where electric power is required, the cost of the dispenser can be unnecessarily increased. Moreover, for some applications power requirements are so high that battery power is impractical. Where that is the case, the device can only be used where linkage to conventional power sources is possible.  
           [0007]    Other systems discharge active intermittently and automatically from an aerosol can, without using electrical power. For example, U.S. Pat. No. 4,077,542 relies on a biased diaphragm to control bursts of aerosol gas at periodic intervals. See also U.S. Pat. Nos. 3,477,613 and 3,658,209. However, biased diaphragm systems have suffered from reliability problems (e.g. clogging, leakage, uneven delivery). Moreover, they sometimes do not securely attach to the aerosol can.  
           [0008]    Moreover, the cost of some prior intermittent spray control systems makes it impractical to provide them as single use/throw away products. For some applications, consumers may prefer a completely disposable product.  
           [0009]    Thus, a need still exists for improved, inexpensive automated aerosol dispensers that do not require electrical power.  
         BRIEF SUMMARY OF THE INVENTION  
         [0010]    In one aspect the invention provides a valve assembly that is suitable to dispense a chemical from an aerosol container. It can automatically iterate between an accumulation phase where the chemical is received from the container, and a spray phase where the received chemical is automatically dispensed at intervals.  
           [0011]    The valve assembly has a housing mountable on an aerosol container, a movable diaphragm associated with the housing which is linked to a leg, the diaphragm being biased towards a first configuration. A pawl is also linked to the diaphragm, and there is an accumulation chamber inside the housing for providing variable pressure against the diaphragm. There is also a first passageway in the housing suitable for linking an interior portion of the aerosol container with the accumulation chamber, a second passageway in the housing suitable for linking the accumulation chamber with an outlet of the valve assembly, and a retention surface linked to the housing and facing the pawl.  
           [0012]    When the diaphragm is in the first configuration the pawl abuts against the retention surface and the valve assembly can prevent spray of the chemical out of the valve assembly and permit chemical to flow from the aerosol container into the accumulation chamber via the first passageway. When the pressure of chemical inside the accumulation chamber exceeds a specified threshold the pawl can move off the retention surface and the diaphragm can move from the first configuration to a second configuration wherein spray is permitted to exit the valve assembly.  
           [0013]    In preferred forms a barrier is disposed in the first passageway to regulate the flow of chemical there through, a toe of the pawl can flare radially outwardly off of the retention surface as the diaphragm moves from the first configuration to the second configuration, the accumulation chamber further comprises a base having a surface facing the leg to define an inlet to the accumulation chamber, and the surface of the inlet is textured to regulate the flow of chemical into the accumulation chamber. If desired, a porous material can instead at least partially block the inlet to regulate the flow of chemical into the accumulation chamber.  
           [0014]    In another aspect the leg is axially displaced to open the second passageway as the diaphragm approaches the second configuration, the diaphragm will shift back to the first configuration from the second configuration when pressure of the chemical in the accumulation chamber falls below a threshold amount, and the accumulation chamber has a base that is sloped so as to direct liquid chemical that may collect in the accumulation chamber towards the first passageway.  
           [0015]    In other alternatives there may be a spring disposed in the housing operable to resist axial movement of the diaphragm from the first to the second configuration, and an actuator can be rotatable to cause chemical to be able to leave the container and enter the first passageway.  
           [0016]    In yet another aspect, methods are provided for using these valve assemblies with aerosol containers are also disclosed.  
           [0017]    The present invention achieves a secure mounting of a valve assembly on an aerosol can, yet provides an actuator that has two modes. In one mode the valve assembly is operationally disconnected from the actuator valve of the aerosol container (a mode suitable for shipment or long-term storage). Another mode operationally links the valve assembly to the aerosol container interior, and begins the cycle of periodic and automatic dispensing of chemical there from. Importantly, periodic operation is achieved without requiring the use of electrical power to motivate or control the valve.  
           [0018]    The valve assembly has few parts, and is inexpensive to manufacture and assemble. Further, it is relatively self-cleaning to help avoid clogs and/or inconsistent bursts. For example, the movement of the pawl and leg help reduce residue accumulation.  
           [0019]    The foregoing and other advantages of the invention will appear from the following description. In the description reference is made to the accompanying drawings which form a part thereof, and in which there is shown by way of illustration, and not limitation, preferred embodiments of the invention. Such embodiments do not necessarily represent the full scope of the invention, and reference must therefore be made to the claims herein for interpreting the scope of the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    [0020]FIG. 1 is a sectional view of an automatic dispensing valve of the present invention in an “off” configuration, mounted onto an aerosol can;  
         [0021]    [0021]FIG. 2 is a view similar to FIG. 1, but with the valve in an “on” position;  
         [0022]    [0022]FIG. 3 is an enlarged detail sectional view focusing on a portion of the FIG. 2 view;  
         [0023]    [0023]FIG. 4 is a further enlarged section view of the inlet of FIG. 3;  
         [0024]    [0024]FIG. 5 is a still further enlarged sectional view of the inlet of FIG. 3;  
         [0025]    [0025]FIG. 6 is a view similar to FIG. 3, but with the valve shown during the spray phase;  
         [0026]    [0026]FIG. 7 is a view similar to FIG. 4, but showing the valve during the spray phase;  
         [0027]    [0027]FIG. 8 is a view similar to FIG. 1, but of a second embodiment;  
         [0028]    [0028]FIG. 9 is a view similar to FIG. 1, but of a third embodiment;  
         [0029]    [0029]FIG. 10 is a view similar to FIG. 9, but showing the valve during an accumulation phase;  
         [0030]    [0030]FIG. 11 is an enlarged detail sectional view focusing on a portion of the FIG. 10 view;  
         [0031]    [0031]FIG. 12 is a further enlarged section view of the inlet of FIG. 11;  
         [0032]    [0032]FIG. 13 is a view similar to FIG. 11, but with the valve assembly in the spray phase;  
         [0033]    [0033]FIG. 14 is a view similar to FIG. 13, but of a fourth embodiment; and  
         [0034]    [0034]FIG. 15 is a view similar to FIG. 1, but of a fifth embodiment. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0035]    Referring initially to FIG. 1, an aerosol can  22  includes a cylindrical wall  21  that is closed at its upper margin by the usual dome  23 . The joint between the upper margin of the can wall  21  and the dome  23  is the can chime  31 . An upwardly open cup  27  is located at the center of the dome  23  and is joined to the dome by a rim  29 .  
         [0036]    A conventional valve  33  is located at the center of the valve cup  27 . The valve  33  has an upwardly extending valve stem  25 , through which the contents of the can may be expelled. Valve  33  is shown as a vertically actuable valve, which can be opened by moving the valve stem  25  directly downwardly. Instead, one could use a side-tilt valve where the valve is actuated by tipping the valve stem laterally and somewhat downwardly.  
         [0037]    A valve assembly  20 , configured for engagement with the vertically actuated type valve  33 , is mostly polypropylene, albeit other suitable materials can be used. The valve assembly  20  has a lower portion  26  including an inner wall  28  and peripheral skirt  30  that are joined at their axially outer ends. It should be appreciated that throughout this description, the terms “axially outer, axially downstream, axially inner, axially upstream” are used with reference to the longitudinal axis of the container. The term “radial” refers to a direction outward or inward from that axis.  
         [0038]    The inner wall  28  and skirt  30  engage the valve cup rim  29  and can chime  31 , respectively. In particular, inner wall  28  has a radially inwardly extending flange  35  that is configured to snap-fit over the rim  29 , while skirt  30  engages the inner surface of chime  31 . In operation, the dispenser  20  can be forced downwardly onto the chime  18  and rim  29 , thus fastening the dispenser  20  to the aerosol can  22 .  
         [0039]    Inner wall  28  is threaded on its radially inner surface to receive an assembly  32  that is rotatable therein. Assembly  32  includes an annular wall  38  that is threaded on its outer surface to engage the threads of inner wall  28 . The threads have a predetermined pitch such that, as the assembly  32  is rotated clockwise with respect to the assembly  26 , it is displaced axially along the direction of Arrow A with respect to aerosol can  22  to activate the valve  33  (FIG. 2) and begin an iterative dispensing cycle. The dispenser  20  may subsequently be disengaged from the can  22  by rotating assembly  32  counterclockwise, and is thus saved for future use.  
         [0040]    The dispensing cycle includes an accumulation phase and a spray phase. During the accumulation phase, aerosol content flows from can  22  and into the dispenser to generate pressure therein. Once the pressure within the dispenser reaches a predetermined threshold, the spray phase is initiated, whereby the aerosol content disposed within the dispenser exits via an outlet  64 . During the spray phase, additional aerosol content is permitted to flow from can  22  and out the outlet  64 . Accordingly and importantly, the spray that is projected by the dispenser may include a greater amount of chemical than that stored in the dispenser during the previous cycle. Once a sufficient amount of chemical is expelled from the dispenser  20  such that the internal pressure above the diaphragm subsides, the accumulation phase again initiated.  
         [0041]    Assembly  32  further includes an annular wall  40  disposed radially inwardly of wall  38  that defines therein an axially extending cylindrical first pathway portion  42  that is axially aligned with valve  33 . When assembly  26  is initially mounted onto aerosol can  22 , the axially inner edge of wall  40  is located adjacent and radially aligned with the valve stem  25 . However, it is not pressing down on stem  33 .  
         [0042]    Because the valve stem  33  is not yet activated in this position, the valve assembly  32  has not yet engaged the aerosol can  22 , and the assembly is in a storage/shipment position. However, as the valve assembly  32  is rotated to displace the dispenser  20  along the direction of arrow A, wall  40  depresses the valve stem  25 , thereby engaging the valve assembly with the aerosol can  22  and allowing the aerosol content to flow from the can into the upper valve assembly.  
         [0043]    Assembly  32  further includes an annular wall  47  that extends axially downstream from wall  38 , and is displaced slightly radially outwardly with respect thereto. An outer annular sealing wall  44  extends axially upstream and radially outwardly from the axially outermost edge of wall  47 . The outer surface of axially inner portion of wall  44  engages the inner surface of a flange on skirt  30 , and is rotatable with respect thereto to provide a seal between the mounting assembly  26  and valve assembly  32 . Wall  44  is also easily engageable by a user to rotate the mounting assembly  26 , as described above.  
         [0044]    Wall  40  is integrally connected at its axially outermost end to a wall  50  that extends radially outwardly there from, and terminates in a substantially axially extending wall  83 . Wall  83  extends axially downstream, and connects to an axially extending wall  51  that is radially outwardly displaced from wall  83 . Wall  38  is integrally connected at its axially outermost end to a wall  52  that extends radially inwardly from wall  47 . Wall  52  further extends axially downstream at its radially inner edge to provide a seat for wall  51 . Wall  51  is integrally connected at its axially outer edge to a cover  49  that extends substantially radially outwardly to wall  47 . In particular, cover  49  has an axially inwardly extending notch disposed proximal its radially outer edge that engages the inner surface of wall  47  to secure the cover in place. Cover  49  is annular to define a centrally disposed opening that serves as outlet  64  for aerosol content, as will become more apparent from the description below.  
         [0045]    As best seen in FIGS.  3 - 7 , valve assembly  32  has an annular base which is defined by annular wall  50  that extends radially between walls  40  and  51 . Wall  50  includes a centrally disposed barrier  41  aligned with conduit  42 , having at least one aperture  37  extending there through and enables fluid (e.g. liquid/gas) to flow from the can  22  into dispenser  20 .  
         [0046]    A flexible, mono-stable diaphragm  58  is disposed within valve assembly  32 , and is movable between a first closed position (FIG. 3), and a second open position (FIG. 6) to activate the valve assembly at predetermined intervals, as will be described in more detail below. Diaphragm  58  is a radially extending bow-shaped wall whose concave surface faces wall  50 . The diaphragm is integrally connected at its radially outer edge to an axially extending wall  59  disposed radially inwardly of, and adjacent wall  51 . Wall  59  is integrally connected at its axially outer end to a cover  61 . Diaphragm  58  further includes a radially inner, axially extending annular leg structure  62  whose radially outer surface abuts the radially inner surface of cover  61 . Leg has, at its axially outer end, an outlet  64  of the dispenser  20  defined by a nozzle  60 . Leg  62  is further integrally connected to diaphragm  58  proximal its axially inner end, such that an annular reservoir  80  is defined by wall  50 , wall  51 , diaphragm  58 , and leg  62 . Reservoir  80  provides an accumulation chamber that receives chemical from can  22  during the accumulation phase.  
         [0047]    A flexible pawl  66  extends axially upstream from the radially inner edge of diaphragm  58 . Cover  61  includes an inner retention surface  68  that slopes in step fashion from leg  62  to cover  61 . In particular, retention surface  68  is stepped such that the axially upper surface of pawl  66  engages the step when the diaphragm  58  is relaxed. It should be appreciated that pawl could alternatively extend from any surface that is axially movable along with the diaphragm  58 .  
         [0048]    Leg  62  further includes at its axially inner end an annular fork/foot  39  extending upstream there from. The inner prong of fork  39  abuts barrier  41  to form a seal therewith during the accumulation part of the cycle, while the outer prong is recessed from the inner prong, and abuts the radially textured inner surface of wall  50 . Accordingly, a channel  71  (defined by aperture  37 , outer prong of fork  39 , and wall  50 ) extends from conduit  42  and allows chemical to flow into accumulation chamber  80  along the direction of Arrow B during an accumulation phase, as illustrated in FIGS. 4 and 5. Because the inner prong of fork  39  is sealed against the radially outer edge of barrier  41 , fluid is unable to flow out of accumulation chamber during the accumulation phase.  
         [0049]    As best illustrated in FIG. 5, the radially inner surface of wall  50  is textured to provide a timing seal that permits a slow leak to allow chemical to flow into accumulation chamber  80  from conduit  42 . The textured surface thus provides flow regulation. As pressure increases due to a temperature rise in a room in which the can is stored, the forks  39  will tend to deflect outward and thus more tightly against the textured surface. This reduces the cross-sectional area of passages through the textured surface, thereby reducing flow to compensate for the increased room temperature.  
         [0050]    The textured surface can be molded as part of the adjoining wall using the same material (e.g. polypropylene, polyethylene, etc.). Alternatively, the surface could be adhered to the wall, or the wall could even be smooth which would enable a greater flow rate into accumulation chamber  80 . The textured surface could also be of an elastomeric material such as Kraton that is co-molded, or two-shot molded onto the wall.  
         [0051]    In operation, a consumer rotates the valve assembly  32  relative to mounting assembly  26 , preferably by rotating wall  44 . This causes the valve assembly  32  to become displaced axially inwardly, and biases wall  40  against valve stem  25 , thereby causing the aerosol contents to flow out of can  22 , and beginning the accumulation phase. The aerosol contents flow through conduit  42  and into opening  37 , through channel  71 , and into accumulation chamber. The rate at which the aerosol contents are able to flow through channel  82  can be regulated by the density and configuration of texture on wall  50 , as well as the number of apertures extending through barrier  41 .  
         [0052]    During the accumulation phase, the constant supply of aerosol content flowing from intake channel  82  into the accumulation chamber  80  causes pressure to build therein, and such pressure acts against the underside of diaphragm  58 . Once the accumulation chamber  80  is sufficiently charged with aerosol content, such that the pressure reaches a predetermined threshold, the mono-stable diaphragm  58  becomes deformed from the normal closed position illustrated in FIG. 3 to the open position illustrated in FIG. 6. This initiates a spray phase as inner prong of fork  39  no longer abuts against barrier  41 .  
         [0053]    The deformation of diaphragm  58  is resisted by the flexibility of the diaphragm along with the engagement of the pawl  66  with retention surface  68 . The internal pressure continues to accumulate within the accumulation chamber  80  until it exceeds the maximum pressure threshold, at which point a toe of the pawl  66  flares radially outwardly off of the surface  68  as the diaphragm approaches the second configuration. This allows the diaphragm  58  to open by flexing axially outwardly from the hinge between formed between its radially outer edge and wall  59 .  
         [0054]    Leg  62  travels along with the radially inner edge of diaphragm  58  such that, when the diaphragm is open, leg  62  and fork  39  are moved downstream of barrier  41  to create an outlet channel  84  extending through leg  62 , between accumulation chamber  80  and the outlet end  64  of the dispenser  20 . Accordingly, during the spray phase, the stored aerosol content flows from accumulation chamber  80 , along outtake channel  84  along the direction of arrow C (FIG. 7), and exits the outlet end  64  of dispenser  20  as a “puff” into the ambient environment.  
         [0055]    Axial movement of leg  62  removes the outer prong of fork from wall  50 , thereby enabling an even greater flow rate out of the accumulation chamber  80  during the spray phase than the flow rate into the accumulation chamber during the accumulation phase. Furthermore, because the seal between inner prong of fork  39  and barrier  41  is removed during the start of the spray phase, aerosol content is able to flow from can  22  along the direction of Arrow D, and directly out the outlet end  64 , such that the output spray comprises more chemical than that stored in accumulation chamber  80  during the previous accumulation phase. The amount of chemical escaping from can  22  during the spray phase may be regulated by the duration of the spray phase as well as the size and number of opening(s)  37 . The duration of spray phase may be controlled by many factors, such as the size of accumulation chamber  80 , flexibility of diaphragm  58 , flexibility of pawl  66 , and slope of retention surface  68 .  
         [0056]    During the spray phase, the pressure within the accumulation chamber immediately abates as the stored aerosol content exits the dispenser  20 . Once the pressure falls below a predetermined threshold, the diaphragm snaps back to its normal position, re-establishing the seal inner prong of fork  39  and barrier  41 , and re-engaging the outer prong with textured surface of wall  50 . As the diaphragm  58  closes, pawl  66  rides along, and re-engages, retention surface  68  to again initiate the accumulation phase. Aerosol content flowing through opening  37  is thus directed through intake channel  71  and into accumulation chamber, as described above. The dispensing cycle is thus automatic and continuously periodic until the can contents are exhausted.  
         [0057]    Referring now to FIG. 8, a dispenser is mounted onto an aerosol can  122  in accordance with an alternate embodiment of the invention. FIG. 8 is illustrated having reference numerals corresponding to like elements of the previous embodiment incremented by 100 for the sake of convenience. Dispenser  120  is configured to be mounted onto an aerosol can  122  that terminates at its radial end with a valve cup rim  129  rather than a chime as illustrated in FIGS. 1 and 2.  
         [0058]    Accordingly, the mounting assembly includes a threaded wall  128  including radially inwardly extending flange  135  that engages valve cup rim to securely mount the dispenser  120  onto the can  122 . Threaded wall  128  receives correspondingly threaded wall  138  such that a user rotates wall  147  to displace valve assembly  132  in the axial direction and actuate the dispenser  120 , as described above.  
         [0059]    Furthermore, wall  146  of dispenser  120  is integrally connected to wall  151 . Radially outer end of diaphragm  158  is seated between walls  159  and  183 . Additionally, cover  161  extends radially inwardly from wall  159 , and terminates short of leg  162 . As a result, cover  161  is permitted to flex outwardly slightly as the pawl  166  is biased axially outwardly under forces from diaphragm  158 . The pawl  166  thus becomes more easily disengaged from retention surface  168 , thereby reducing the duration of each accumulation phase.  
         [0060]    When pressurizing the accumulation chamber  180 , some gaseous materials may liquefy and could accumulate at the bottom of the accumulation chamber. This would result in them not being fully expelled during a single spray phase. The pooling of aerosol content could increasingly reduce the effective volume of accumulation chamber  180 .  
         [0061]    To address this problem, dispenser  120  includes an anti-pooling feature which prevents the accumulation of liquid within the accumulation chamber  180 . In particular, base  150  of the accumulation chamber  180  slopes radially inwardly, such that unmixed liquid is forced towards channel  184  and in the path of aerosol content as it flows from the accumulation chamber  180  out the dispenser  120  during the spray phase. As a result, the liquid that has pooled during a single accumulation phase becomes mixed with the leaving propellant to produce a fine mist that is emitted out the dispenser  120  during the spray phase.  
         [0062]    Referring next to FIG. 9, a third embodiment of the invention is illustrated having reference numerals corresponding to like elements of the previous embodiment incremented by 200. Mounting assembly  226  includes a lever  281  that may rotated by a user to displace the valve assembly  232  axially in the direction of Arrow E, as illustrated in FIG. 10 and described above. Additionally, lever  281  could include a perforated tab (not shown) between itself and wall  228  that is broken before the dispenser can be actuated, thereby providing means for indicating whether the dispenser has been tampered with. An annular hub  279  extends axially upstream from the radially inner edge of wall  252 , and abuts the radially outer surface of wall  246 .  
         [0063]    Wall  259  extends axially upstream from the radially outer edge of cover  261 , and abuts the radially inner edge of cover  249 . Wall  251  is integrally connected wall  250 , and extends axially outwardly there from between a void formed between wall  259  and wall  263 , which extends axially downstream from the radially outer edge of diaphragm  258 . A flange extends radially outwardly at the axially outer end of wall  263 , and fits between the axially outer edge of wall  251 , and the axially inner edge of cover  261  to secure the diaphragm  258  in place.  
         [0064]    Furthermore, as better illustrated in FIGS. 11 and 12, the flow of aerosol content from the can  222  to the chamber  280  may be controlled using a flow regulator, such as a porous gasket  285 . In particular, gasket  285  extends axially substantially the length of outer prong, and is disposed between the radially outer surface of outer prong of fork  239  proximal its axially inner end, and the radially inner surface of wall  250 . Because gasket  285  is disposed in channel  271 , any aerosol content flowing from can  222  into the chamber  280  along the direction indicated by Arrows F must pass through it, and thereby be slowed. Gasket  285  is preferably made of an open-celled foam or any other similarly permeable material. The installation of gasket  285  thus limits the flow rate of aerosol content from the can  222  to correspondingly prolong the accumulation cycle and decrease the frequency of sprays during operation.  
         [0065]    Referring to FIG. 13, once the pressure within accumulation chamber  280  exceeds the maximum threshold during the accumulation cycle, the spray phase is initiated whereby pawl  266  becomes disengaged from retention surface  268 , and diaphragm  258  flexes axially outwardly. Fork  239  becomes displaced axially outwardly from gasket, thereby allowing the stored aerosol content to flow from the accumulation chamber  280  along channel  284  in the direction of Arrows G, and out the outlet  264  as a spray. As described above, chemical content of can  222  also flows through orifice  237  in the direction of Arrow H, and along channel  284  to the outlet  264  during the spray cycle.  
         [0066]    Referring next to FIG. 14, a fourth embodiment of the invention is illustrated having reference numerals corresponding to like elements of the previous embodiment incremented by 300. Dispenser  320  now includes a spring  387  that extends between the axially inner surface of cover  361  and axially outer surface of fork  339 . Spring  387  biases diaphragm  358  towards its normal position and thus resists the transition to the spray phase. As a result, a greater amount of internal pressure generates within accumulation chamber  380  before the spray phase is initiated. This lengthens the duration of accumulation phases, and shortens the duration of spray phases.  
         [0067]    Referring next to FIG. 15, a fifth embodiment of the invention is illustrated having reference numerals corresponding to like elements of the previous embodiment incremented by 400. Dispenser  420  incorporates features similar to those described above with reference to FIGS. 8 and 9.  
         [0068]    For instance, dispenser  420  is configured to be mounted onto an aerosol can  422  that terminates at its radial end with a valve cup rim  429  rather than a chime. Accordingly, the mounting assembly includes a threaded wall  428  including radially inwardly extending flange  435  that engages valve cup rim to securely mount the dispenser  420  onto the can  422 . Threaded wall  428  receives correspondingly threaded wall  438  such that a user rotates wall  447  to displace valve assembly  432  in the axial direction and actuate the dispenser  420 , as described above.  
         [0069]    Additionally, wall  459  extends axially upstream from the radially outer edge of cover  461 , and abuts the radially inner edge of cover  449 . Wall  451  is integrally connected wall  450 , and extends axially outwardly there from between a void formed between wall  459  and wall  463 , which extends axially downstream from the radially outer edge of diaphragm  458 . A flange extends radially outwardly at the axially outer end of wall  463 , and fits between the axially outer edge of wall  451  and the axially inner edge of cover  461  to secure the diaphragm  458  in place. Dispenser  420  further includes flow regulator  485 , as described above.  
         [0070]    The above description has been that of preferred embodiments of the present invention. It will occur to those that practice the art, however, that many modifications may be made without departing from the spirit and scope of the invention. In order to advise the public of the various embodiments that may fall within the scope of the invention, the following claims are made  
       INDUSTRIAL APPLICABILITY  
       [0071]    The present invention provides automated dispenser assemblies for dispensing aerosol can contents without requiring the use of electric power.