Patent Publication Number: US-2020298266-A1

Title: Paint dispensing method and apparatus involving a vibrating membrance

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/819,886, filed Mar. 18, 2019, which is incorporated in its entirety herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This invention generally relates to methods and apparatuses for dispensing paint from pressurized or unpressurized paint containers. More specifically, aspects of the invention include a paint container storing liquid paint, optionally with or without a propellant in a quantity sufficient to expel a substantial portion (e.g., at least half) of the paint therein. The paint container storing the paint can be sealed by a pierceable membrane, and can lack a valve disposed within an interior space storing the paint. An external valve body includes a liquid droplet production apparatus and a piercing member. The piercing member of the valve body pierces the pierceable membrane as a result of the valve body being installed onto the paint container, establishing fluid communication between the interior space storing the paint and the liquid droplet production apparatus. Embodiments of the liquid droplet production apparatus can include an electronic spray device having a vibrating perforate membrane used to generate liquid droplets. Gravity urges the paint toward the perforate membrane while the assembly of the paint container and the valve body is inverted (i.e., the interior space storing the paint is arranged at an elevation vertically above an elevation of the perforate membrane). Actuation of the liquid droplet production apparatus in response to manual selection of a button, switch or other input device causes the production of the paint droplets that, when expelled via the liquid droplet production apparatus, are deposited onto a surface. 
     2. Description of Related Art 
     It is well known in the art to dispense paint from a pressurized can using a laterally displaced nozzle integrated into the top of the can. An example of such a known apparatus is aerosol paint can  200 , shown in  FIG. 2 , having laterally displaceable nozzle  202 . While such aerosol paint can products have enjoyed wide commercial success, a challenge presented by such aerosol paint cans is that of disposal. Because the can is pressurized, limitations may be placed on how and where the used paint cans can be disposed. It can be difficult for the user to depressurize the paint can once the desired quantity of paint has been sprayed. A second problem is once the user has finished spraying the paint some amount of the paint typically remains in the can. Both of these conditions lead to problems when the user needs to dispose of the paint can. The paint can may explode if one tries to burn or crush it. The applied heat or the crushing action will increase the paint can&#39;s internal pressure and thus an explosion risk is presented. Also, the paint remaining in a paint can may represent a hazardous chemical or fire hazard and thus another disposal problem. 
     BRIEF SUMMARY OF THE INVENTION 
     An apparatus and method for dispensing paint from containers that provides an economical, reliable, and easy method of depressurizing the containers is desired. Limiting the presence of a propellant within a paint container may also be desired to avoid at least some of the difficulties that may be encountered when disposing of depleted paint containers. 
     According to some embodiments of this invention, a fluid dispensing apparatus dispenses a paint fluid from an associated paint container. The associated paint container includes an internal space storing paint. The internal space is substantially devoid of a propellant that is suitable to expel a substantial portion of the paint from the internal space. A pierceable membrane encloses internal space. The fluid dispensing apparatus includes a valve body defining a bore that extends at least partially through the valve body, and an adaptor including a piercing member positioned to pierce the pierceable membrane and establish fluid communication between the internal space and the bore. The adaptor also includes a releasable fastener that cooperates with a portion of the paint container to releasably couple the valve body to the paint container. A liquid droplet production apparatus is in fluid communication with the bore, and controls a discharge of the paint from the paint container. The liquid droplet production apparatus includes a perforate membrane, and an actuator that is selectively operable to vibrate the perforate membrane and cause liquid droplets of the paint to be emitted from the perforate membrane and projected generally away from the paint container. 
     According to other embodiments, a liquid container includes a housing defining an internal space storing a liquid to be dispensed as droplets. The internal space is substantially devoid of a propellant suitable to expel a substantial portion of the liquid from the internal space. A pierceable membrane encloses the internal space storing the liquid. A fluid dispensing apparatus includes a valve body defining a bore that extends at least partially through the valve body. An adaptor includes a piercing member extending at least partially through the pierceable membrane, establishing fluid communication between the internal space and the bore. The adaptor also includes a releasable fastener cooperating with a portion of the liquid container to releasably couple the valve body to the liquid container. A liquid droplet production apparatus is in fluid communication with the bore to control a discharge of the liquid from the liquid container. The liquid droplet production apparatus includes a perforate membrane, and an actuator that is selectively operable to vibrate the perforate membrane, and cause liquid droplets to be emitted from the perforate membrane and projected generally away from the liquid container. 
    
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWING 
       In the accompanying drawings, structures are illustrated that, together with the detailed description provided below, describe exemplary embodiments of the claimed invention. The invention may take physical form in certain parts and arrangement of parts, embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein: 
         FIG. 1  is a perspective view of a fluid dispensing apparatus on which a valve body and an adaptor of a fluid dispensing apparatus is installed in accordance with some embodiments of this invention. 
         FIG. 2  is a perspective top view showing a prior art paint can and nozzle. 
         FIG. 3  is a perspective view of a paint container in accordance with some embodiments of this invention. 
         FIG. 4A  is a perspective side view of an adaptor in accordance with some embodiments of this invention. 
         FIG. 4B  is a perspective bottom view of an adaptor in accordance with some embodiments of this invention. 
         FIG. 5  is a perspective view of a dispensing apparatus in accordance with some embodiments of this invention. 
         FIG. 6  shows a container in accordance with some embodiments of this invention with a pierceable membrane pierced. 
         FIG. 7  is a top perspective view of an alternate embodiment of a valve body of a fluid dispensing apparatus. 
         FIG. 8  shows a sectional view of a magnetic attachment of a perforate membrane to a bending mode actuator according to an embodiment of a liquid droplet production apparatus. 
         FIG. 9  is a schematic view of an actuator having a longitudinal configuration. 
         FIG. 10  is a schematic view of an actuator having a breathing mode configuration. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings wherein the showings are for purposes of illustrating embodiments of the invention only and not for purposes of limiting the same, and wherein like reference numerals are understood to refer to like components,  FIG. 1  shows a perspective view of a pressurized paint container  10  equipped with a fluid dispensing apparatus  50  according to some embodiments of this invention. While the pressurized paint container shown is a can, this invention will work with any type, size and shape of pressurized paint container. The paint dispensed by the fluid dispensing apparatus  50  may be a pressurized paint fluid that is a liquid, gas, vapor, or a mixture thereof. While the fluid dispensing apparatus  50  is designed to dispense paint, it may have application to other fluids as well, to dispense droplets of any liquid and/or gas as a mist. 
     The fluid dispensing apparatus  50  may, in some embodiments, include a nozzle  31 , a valve body  30 , and an adaptor  20 . The nozzle  31  may be similar to the nozzle  202  discussed above. For example, embodiments of such nozzles  31 ,  202  include laterally-displaceable nozzles that, when urged to be offset in a lateral direction relative to a longitudinal axis of the paint container  10 , open an interior passage, described below, through which the paint is to travel to be expelled from the fluid dispensing apparatus  50 . 
     With reference now to  FIGS. 3 and 6 , a container cap  11  is installed on the paint container  10  to contain the paint, or other liquid to be expelled, optionally in combination with a propellant. The container cap  11  may, in one embodiment, be fixedly joined to the top of the container  10  such as being crimped to a perimeter wall defining an aperture through which the paint and optional propellant are added to the container  10 . The container cap  11  may be, in one embodiment, positioned substantially concentrically with the container&#39;s longitudinal axis. The container cap  11  may have a well  13 , and a coupling surface  12  formed about a fluid passage bore  14  (visible in  FIG. 6 ) through which the paint is expelled from the container  10 . A membrane  15  forms an upper surface that closes and conceals the fluid passage bore  14  from view adjacent to the top of the coupling surface  12 . For example, the membrane  15  may be pierceable and located with respect to the fluid passage bore  14  in such a manner as to seal fluid passage bore  14  and prevent fluid from exiting container  10  until the membrane  15  is pierced.  FIG. 6  shows the membrane  15  in a pierced condition, which exposes fluid passage bore  14  to the ambient environment of the container  10 . 
     The coupling surface  12  may be of any size, shape and relative position that cooperates with a portion of the fluid dispensing apparatus  50  to couple the fluid dispensing apparatus  50  to the container  10 . According to the embodiment shown in  FIGS. 3 and 6 , the coupling surface  12  is cylindrical in shape, extending axially along a longitudinal axis of the container  10 . A threaded region  19 , as shown in  FIG. 3 , comprises external threading that cooperates with internal threading  57  ( FIG. 4B ) provided to a coupling element  21  of an adaptor  20 , described below. For the embodiment shown, the coupling surface  12  is cylindrical in shape and the threaded region  19  includes threading formed along the exterior surface of the coupling surface  12 , but the present disclosure is not so limited. Compatible regions of internal and external threading, or any other releasable fastener portions can be provided to the coupling surface  12  and adaptor  20  for removably coupling the fluid dispensing apparatus  50  to the container  10 . 
     Removably coupling the fluid dispensing apparatus  50  to the container  10  involves establishing a substantially fluid-tight connection between the fluid dispensing apparatus  50  and the container  10 , and allowing for the subsequent removal of the fluid dispensing apparatus  50  from the container  10  to be used with a different container  10 . In other words, the fluid dispensing apparatus  50  is installable on a first container  10  to control the release of the paint from the container  10 . When the container  10  is no longer in use, the fluid dispensing apparatus  50  can be unscrewed or otherwise removed from the container  10  to be installed on a second container  10 . 
     The adaptor  20 , embodiments of which are illustrated in  FIGS. 1, 4A, 4B and 6 , defines a interior passage that extends between a top region and an opposing bottom region. As shown in  FIG. 4B , the bottom region of the adaptor  20  includes a coupling element  21  that engages the coupling surface  12  of the container cap  11  to removably couple the fluid dispensing apparatus  50  to the container  10 . For example, in the specific embodiment illustrated in the drawings, the coupling element  21  can be formed on an inner surface of an arcuate, optionally cylindrical-shaped wall adjacent to the bottom of the adaptor  20 . The internal threading  57  forming a threaded region of the adaptor  20  is compatible with the threaded region  19  of the coupling surface  12  provided to the container cap  11 . 
     The adaptor  20  includes a fluid passage bore  26  that extends between the top region and the bottom region of the adaptor  20 . A piercing member  27  is arranged at least partially within the fluid passage bore  26 , as shown in  FIG. 4B , to pierce the membrane  15 . The membrane  15  is shown unpierced in  FIG. 3  and pierced in  FIG. 6 . The piercing member  27 , in some embodiments, may be located concentric with the longitudinal axis of fluid passage bore  26 . A distal end of the piercing member  27  includes a tip that can be sharp, or comes to a point to facilitate the puncturing of the membrane  15  during installation of the fluid dispensing apparatus  50  on the can  10 . The distal end of the piercing member  27  can optionally protrude beyond an end of the fluid passage bore  26 , or extend a suitable distance within the fluid passage bore  26  to extend at least partially through the membrane  15  when the fluid dispensing apparatus  50  is fully installed on the container  10 . Some embodiments of the piercing member  27  can be hollow, defining an interior passage through which paint expelled from the container  10  passes toward the nozzle  31  provided to the fluid dispensing apparatus  50 . 
     The adaptor  20  can also optionally include a seal  23 , such as a ring of an elastically compressible material for example, that interferes with fluid flow between the container  10  and the adaptor  20 , promoting fluid flow of the paint through the fluid passage bore  26 . The seal  23  may be formed of an elastomeric material, and is compressed between a portion of the container cap  11 , such as an upper region of the coupling surface  12  for example, and a portion of the adaptor  20 , such as a portion of the coupling element  21  for example. 
     As shown in  FIG. 4A , a coupling element  22  can be located adjacent to the top of the adaptor  20 . In the illustrated embodiment of  FIG. 4A , the coupling element  22  is formed as external threading  59  formed along an outward-facing cylindrical shaped portion of the adaptor  20 , for example. The coupling element  22  engages with a compatible region of the valve body  30 , as will be discussed further below. A seal  24  may be used to seal the connection between the top of the adaptor  20  and the bottom of the valve body  30 . For the embodiment shown, the seal  24  is an O-ring received around the cylindrically shaped portion of the adaptor  20  that has the coupling element  22 . The seal  24  can be formed of an elastomeric material, for example. The adaptor  20  can optionally include a shoulder  25  extending outwardly, as shown. The top of the shoulder  25  may have a surface  51  that acts as a stop that contacts a surface of the valve body  30  when the adaptor  20  and valve body  30  are attached together. 
     With reference to  FIGS. 1 and 5 , the valve body  30  may have a valve cap  35  on its top to receive the nozzle  31 , for example. In one embodiment, shown, the valve cap  35  is similar in design to the top of the can  200 , just below the nozzle  202 , shown in  FIG. 2 . The valve body  30  may be substantially cylindrical in shape and may have a height  61 . The height  61  may range between 1.0 to 4.0 inches. Valve body  30  may have a fluid passage bore  34 , shown in hidden lines in  FIG. 1 , that extends from a bottom to a top of the valve body  30 , defining a fluid flow path through the valve body  30  through which paint passes from the container  10  to the ambient environment where the substrate being painted is located. In one embodiment, the bore  34  may be centered along the valve body&#39;s longitudinal axis. A coupling element  33  may be located on a bottom surface, as shown. In one specific embodiment, shown, coupling element  33  may be formed on an inner cylindrical shaped portion of valve body  30  and may have a threaded section  37 . The coupling element  33  may be used to engage with coupling element  22  of the adaptor  20 . In one specific embodiment, threaded section  37  engages threaded section  59  to attach the valve body  30  to the adaptor  20 . The valve body  30  may be formed of any material chosen with the sound judgment of a person of skill in the art. 
     As shown in  FIG. 5 , the nozzle  31  including a fluid passage bore  39  is joined to the valve cap  35 . Nozzle  31  may dispense paint out of the valve body  30  to the ambient when the nozzle  31  is operated, such as by laterally displacing the nozzle  31  relative to the valve body  30  by manually-generated forces, for example. Nozzle  31  can optionally be configured with a biased position such that when no force is applied, nozzle  31  returns to a position that prevents fluid communication between the interior space of the container  10  and the central bore  34 . 
       FIG. 7  shows another embodiment of the valve body  30  provided with a liquid droplet production apparatus  190 . The liquid droplet production apparatus  190  can be used to dispense paint from containers  10  that lack a propellant. Instead of being forced through the nozzle  31  by a propellant, the paint is pooled on a surface of a perforate membrane  44 , which is rapidly vibrated to cause droplets of paint to be expelled through apertures  47  formed in the membrane. According to such embodiments, the paint is caused to flow toward, and pool on the surface of the membrane  44  by the force of gravity when the container  10  equipped with the valve body  30  of  FIG. 7  is inverted, meaning at least a portion of the container  10  is at an elevation that is vertically above the elevation of the valve body  30 . 
     The present embodiment of the valve body  30  is compatible with an adaptor  20  to be releasably coupled to a container cap  11  of a container  10  as described above. Instead of a nozzle  31  that is to be laterally displaced relative to a longitudinal axis to open an internal passageway forming a fluid flow path through the fluid dispensing apparatus  50 , however, the valve body  30  of  FIG. 7  includes the liquid droplet production apparatus  190  to regulate the discharge of paint from the container  10 . 
     The liquid droplet production apparatus  190  uses ultrasonic vibration to generate liquid droplets of paint. Generally, the liquid droplet production apparatus  190  includes a membrane  44  defining a plurality of apertures  47 . Liquid paint  204  is pooled on an interior surface  206  ( FIG. 8 ) of the membrane  44  by the force of gravity. An actuator  201  vibrates the membrane  44 , so that the vibration causes liquid droplets of paint to be ejected from the apertures  47  at the other, exterior surface  208  of the membrane  44 , and deposited onto a substrate being painted. 
     Gravity urges the paint toward the perforate membrane while the assembly of the paint container and the valve body  30  is inverted (e.g., a portion of the paint container is at a vertical elevation that is vertically above an elevation of a portion of the valve body  30 ). At least one, and optionally a plurality of apertures  47  are formed in the perforate membrane  44 . The plurality of apertures  47  can optionally be arranged in a regular array as shown in  FIG. 7 . Operation of the liquid droplet production apparatus  190  can be initiated in response to manual selection of a button  46 , switch or other input device to cause production of the paint droplets that, when expelled via the liquid droplet production apparatus  190 , are deposited onto a surface. 
     An example of the actuator  201  is shown in  FIG. 8 . This device combines a bending mode actuator with the separable perforate membrane  44 . The actuator  201  can include a piezoelectric layer  41  bonded to a substrate  42  which can be made of a metal such as steel. An on-board power source such as a battery (not shown) is selectively connected to the actuator  201 , to supply the electric energy required to energize the piezoelectric layer  41  in response to selection of the button  46 . 
     Examples of the substrate  42  material include a hard magnet, in which case separate magnetic elements may not be required. Magnets provide an attractive force to hold a perforate membrane  44  in place. The perforate membrane  44  can be a ferromagnetic material, so that an attractive force is provided. In a preferred embodiment, this material is a magnetic stainless steel, as high attachment forces are provided by materials with high saturation inductions. This bending mode actuator can be configured in an axi-symmetric geometry, wherein the line  45  shows the axis of symmetry, or in linear format, where the line  45  is the center-line of an actuator  201  that extends out of the page. 
     Another example of the actuator  201 , shown in  FIG. 9 , is a linear actuator  201  that includes an active component  210  capable of being energized to generate the cyclical forces that vibrate the membrane  44  at a frequency suitable to cause liquid drops of paint to be emitted from the external surface of the membrane  44 . The active component  210  generates forces in directions, indicated by double arrow  207 , general perpendicular to the major plane of the membrane  44 . Examples of the active component  210  of the actuator  201  include, but are not limited to piezoelectric, electrostrictive or magnetostrictive (i.e. a material that changes shape in response to an applied electric or magnetic field, henceforth referred to as the active component) devices. 
     The active component  210  of the actuator  201  is supported by a metallic or other support material referred to as a “passive component  212 ,” which is also coupled to the membrane  44 . The membrane  44  can be permanently attached to the passive component  212  through a bond produced by an adhesive, laser welding, brazing, soldering, or and the like. This attachment mechanism must transmit a time varying force across the interface, where the force is primarily normal to the bonding surface. 
     In addition to supporting the active component  210  and the membrane  44 , the passive component  212  deforms in response to the forces exerted on it by the active component  210 . Deformation of the passive component  212  amplifies the vibratory forces produced by the active component  210 , causing the membrane  44  to repeatedly flex in directions (indicated by arrows  214 ) parallel to the directions  207  of the forces generated by the active component  210 , thereby causing the liquid droplets of paint to pass through the apertures  47 . The membrane  44  may entirely vibrate in phase, have one wavelength of motion across its radius (i.e. the central region may be out of phase with the periphery, as shown in  FIG. 9 ), or more than one wavelength of motion. 
     Another example of the actuator  201  includes a breathing mode configuration, shown in  FIG. 10 . Similar to the longitudinal configuration discussed above, the breathing mode configuration of the actuator  201  includes the active component  210  and the passive component  212 . However, energizing the active component  210  causes cyclical vibrations in a direction, indicated by arrows  216 , that is substantially parallel to a major plane of the membrane  44 . According to the present embodiment, the in-plane directions  216  of motion generates vibrations of the membrane  44  in directions  214  substantially normal to the in-plane directions  216  of vibration generated by the active component  210 . 
     Although specific embodiments of the actuator  201  are described herein for the sake of clarity, the present disclosure is not limited to only those configurations. Any actuator  201  that is suitable to generate rapid flexing of the membrane  44  is within he scope of the claimed subject matter unless expressly stated otherwise. 
     In use, the coupling element  21  of the adaptor  20  provided to the valve body  30  of  FIG. 7  is screwed or otherwise installed on the coupling surface  12  of the container cap  11  enclosing a container  10  of paint or other liquid to be dispensed. The paint or other liquid can optionally be stored in the container  10  without a chemical propellant such as a hydrocarbon or hydrofluorocarbon, for example, that expands in response to a change in pressure to force the paint through the nozzle  31 . 
     The adaptor  20  can be coupled to the valve body  30  in a fixed relative angular orientation. For example, a portion of the adaptor can be embedded in an underside of the valve body  30 . As the valve body  30  is pivotally adjusted about a central axis of rotation, the threading  57  of the connector element  21  cooperates with the threaded region  19  of the connector surface  12  of the container cap to urge the valve body  30  and adaptor toward the container  10 . 
     The piercing member  27  of the valve body  30  pierces the pierceable membrane  15  as a result of the valve body  30  being installed a suitable extent onto, and urged toward the container  10 . Once the membrane  15  is pierced, fluid communication is established through the hollow piercing member  27  between the interior space of the container  10  storing the paint and the liquid droplet production apparatus  190  of the valve body  30 . The seal  23  is compressed between a portion of the adaptor  20  and a portion of the container cap  11  to interfere with an escape of the paint between the adaptor  20  and the container cap  11 . 
     When the container  10  equipped with the valve body  30  including the liquid droplet production apparatus  190  is inverted, paint stored in the container  10  is caused to flow through the piercing member  27  under the force of gravity, and pool on the interior surface  206  of the membrane  44 . Pressing the button  46  or other activation of the input device provided to the valve body  30  connects the actuator  201  to an onboard power source, such as a battery for example, provided to the valve body  30 , energizing the actuator  201 . The actuator  201  causes vibration of the membrane  44  on which the paint has pooled, causing the membrane  44  to vibrate at a frequency to expel a stream of paint droplets at a suitable flow rate suitable for the specific painting or other coating operation. Releasing the button  46  or other input device terminates vibration of the membrane  44 , ceasing the deposition of paint droplets on the substrate. 
     If the container  10  remains inverted, liquid paint continues to pool on the interior surface  206  of the membrane  44 , which is stationary relative to the valve body  30  while the actuator  201  is de-energized. In the absence of the vibrational forces generated by the actuator  201 , the apertures  47  are closed, interfering with the flow of paint through the membrane  44 . Returning the container  10  to an upright orientation allows at least a portion of the paint that pools on the interior surface  206  of the membrane  44  to flow through the interior passage defined by the piercing member  27  under the force of gravity, back to the interior space of the container  10 . 
     After emission of the liquid paint in the container  10  is complete, the valve body  30  can be pivotally adjusted relative to the container  10  to cause the cooperating threading of the adaptor  20  and the coupling element  12  to urge the valve body  30  away from the container  10 . Once the threading of the adaptor  20  has been fully disengaged from the threading of the coupling element  12 , the valve body  30  can be separated from the container  10 , and installed on a second container  10  to regulate the discharge of paint from the second container. Thus, the fluid dispensing apparatus  50  is reusable, limiting waste and allowing the container  10  to be thoroughly emptied in preparation for disposal or recycling. 
     The foregoing description of examples and embodiments have been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the forms described. Numerous modifications are possible in light of the above teachings. Some of those modifications have been discussed, and others will be understood by those skilled in the art. The examples and embodiments were chosen and described in order to best illustrate principles of various examples as are suited to particular uses contemplated. The scope is, of course, not limited to the examples and embodiments set forth herein, but can be employed in any number of applications and equivalent devices by those of ordinary skill in the art. It will be apparent to those skilled in the art that the above methods and apparatuses may incorporate changes and modifications without departing from the general scope of this invention. It is intended to include all such modifications and alterations.