Abstract:
A system for applying coatings and more specifically paint coatings is provided that combines fluid stored in separate reservoir containers prior to expelling the mixture for application. The reservoirs may be comprised of collapsible and disposable bags that eject its fluid upon activation of an actuator or expanding bladder. The fluid components are combined and blended together in a mixer that is positioned between the reservoirs and a nozzle.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of application Ser. No. 12/579,491 filed Oct. 15, 2009, now U.S. Pat. No. 8,501,282, which claims priority from Provisional Application No. 61/106,229 filed Oct. 17, 2008, the entirety of both of which is hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present invention pertains to systems for dispensing multi-component coatings, and in particular, paint coatings. The system incorporates multiple reservoirs that combine separate components of the paint coatings into a mixer and subsequently through a nozzle. 
     BACKGROUND OF THE INVENTION 
     Coatings are applied to the surfaces of many products for various reasons. Some coatings are used to lubricate moving parts or reduce glare on optical lenses. Other coatings protect against rust and corrosion while still others are applied purely for decoration. Paint is one example of a coating widely in use today. Typically, paint is applied to a substrate and includes components that cure or harden to form a thin layer of film. Advances over the past few decades have produced paint products that significantly extend the life of a painted article by reducing the effects of corrosion due to ambient conditions. 
     In many instances, paint consists of multiple components that must be combined prior to its application onto the substrate. In many cases, the components are reactive components (e.g. in solutions or dispersions), which are mixed together and react with each other in a crosslinking reaction to provide a curable coating composition. Up until the point of mixing, none of the individual components alone provides a curable coating composition. Typically, upon mixing, such multi-component coatings react and cure quickly. Thus, it is beneficial to mix the components together and apply the paint to a substrate soon after mixing. Paint may also consist of other ingredients, including but not limited to pigments, solvents catalysts, adhesion promoters, and UV light absorbers. Each of these ingredients can be used to impart various desired properties to the paint composition. 
     It is an important factor in using multi-component coatings that the components of the coating be mixed in precise quantities, i.e. at predefined ratios. As such, the process of mixing paint requires careful attention on the part of the operator. It may also be important to gauge how much paint is needed for a specific application. Mixing the right amount of paint can minimize material waste and cost. 
     BRIEF SUMMARY 
     The embodiments of the present invention pertain to a system for applying coatings and more specifically paint coatings. The system includes a spray gun having a nozzle that dispenses the paint in a spray pattern. Pressurized air is directed through the nozzle from a remote source, like for example an air compressor. A reservoir chamber is also included, which houses separate containers each filled with a different component of the paint. The components are fed through a series of orifices that combine the components at a particular mix ratio. Pressure from an inflatable bladder expels the components under pressure, of which the combined components are channeled into a mixing device that blends the components together just prior to being introduced into the nozzle. 
     In one aspect of the embodiments of the subject invention, the containers are plastic bags that collapse to expel the paint components into the mixer. 
     In another aspect of the embodiments of the subject invention, the mixing device is a static mixer having baffles that channel the paint components through a circuitous pathway. 
     Another aspect of the embodiments of the subject invention includes an orifice plate that covers the collapsible bags. 
     In even another aspect of the embodiments of the subject invention, the orifice plate may include individual apertures that allow the paint components to be combined in a particular mix ratio. 
     In still another aspect of the embodiments of the subject invention, the orifice plate is disposable. Additionally, the mixing device may also be disposable. 
     In even yet another aspect of the embodiments of the subject invention, the orifice plate may be exchanged with another orifice plate that mixes the paint components at a different mix ratio. 
     In another aspect of the embodiments of the subject invention, air drawn from an air compressor feeds the spray gun to dispense the paint and actuates the bladder to expel the components from the collapsible bags in the mixing device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an applicator for dispensing a coating according to the embodiments of the subject invention. 
         FIG. 2  is partial cutaway, perspective view of a reservoir chamber according to the embodiments of the subject invention. 
         FIG. 3  is an exploded view of the reservoir chamber of  FIG. 2  showing collapsible reservoirs according to the embodiments of the subject invention. 
         FIG. 4  is a partial cutaway, perspective view of the applicator shown in  FIG. 1  according to the embodiments of the subject invention. 
     
    
    
     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,  FIG. 1  shows an applicator  10  for applying a generally fluid substance, which may be a coating  12  for finishing the surface of a substrate. In one embodiment, the coating  12  consists of multiple reactive components that combine to form the finished product. For illustrative purposes, the embodiments of the subject invention will be described in the context of applying a specific type of coating  12 , namely paint formed from multiple reactive components  12 . However, it is to be construed that any multi-component fluid substance may be used with applicator  10  without departing from the intended scope of coverage of the embodiments of the subject invention. 
     With reference to  FIG. 1 , the applicator  10  may comprise a spray gun  11  using pressurized medium to propel the paint  12 . The spray gun  11  includes a frame  15  that supports a handle  16  for manipulating the spray gun  11  and a nozzle  17  for dispensing the paint  12  in a particular spray pattern. The nozzle  17  may be connected to one or more paint component reservoirs  20  designed to hold the various components mentioned above. To dispense the paint  12 , pressurized medium may be channeled from a remote source through a hose or other conduit into the spray gun  11 . In the preferred embodiment, pressurized air is used to propel the paint  12  as supplied from, for example, an air compressor, not shown in the Figures. However, any form of pressurized medium may be chosen as is appropriate for use with the embodiments of the present invention. The applicator  10  may further include a switch  18 , which in one embodiment, may be a trigger  18 , for activating the spray gun  11 . The trigger  18  engages to dispense the paint  12  by controlling the flow of pressurized air channeled through the spray gun  11 . In this manner, activating the trigger  18  releases the flow the pressurized air that atomizes the paint components and propels the paint  12  from the nozzle  17 . Persons of ordinary skill in the art will appreciate the use of flow control valves, pressure regulators and other similar equipment with compressed air systems. 
     With reference to  FIG. 2 , a reservoir chamber  23  is provided that supports one or more reservoirs  20 , which contain the various paint components. The reservoir chamber  23  is constructed from one or more walls  25  that comprise a support structure or housing. The walls  25  may be generally rigid and may define an interior region designed to contain the reservoirs  20 . In one embodiment, the reservoir chamber  23  also houses an actuator  40  constructed to expel or dispense the paint components from their respective reservoirs  20 . A cap  28  is also incorporated having a first function to enclose the interior region of the reservoir chamber  23 . Additionally, the cap  28  may function to support a conduit  31  and static mixer  50  that blends the components together prior to introducing the mixture into the pressurized stream of air, as will be discussed further in a subsequent paragraph. 
     Referencing  FIGS. 2 through 3 , the components of paint  12  may be stored in individual reservoirs  20 . One reservoir  20  may be provided for each separate component of the paint mixture. In an exemplary manner, three reservoirs  20  are provided and may respectively contain film forming binder, crosslinking agent and catalyst. Alternatively, the reservoirs  20  may each contain, for example, separate pigmented toners that combine in specific proportions to produce a desired color. However, it is to be understood that any number of reservoirs  20  may contain any combination of substances as is suitable for use in making the paint  12  or coating  12 . It will be appreciated that certain products combine individual components in specific ratios and while the reservoirs  20  depicted in the Figures may appear similar in size, same or differently sized volume reservoirs  20  may be utilized as required by a specific mix ratio. In fact, any quantity and/or volume of reservoirs  20  may be incorporated as is appropriate for use with the embodiments of the present invention. In another embodiment, a single reservoir with multiple sections may be used. Each section may be individually referred to herein as a reservoir. 
     With continued reference to  FIG. 3 , the reservoirs  20  may be fluidly communicated to a mixing device  49 . The mixing device  49  may function to mix the components of the paint  12  together. In particular, the mixing device  49  may sufficiently blend the components to produce a substantially homogeneous mixture. The mixing device  49  may be comprised of a static mixer  50  received within conduit  31 . In one embodiment, the static mixer  50  may incorporate a series of baffles that define a circuitous pathway for thoroughly mixing the paint components. Still, any means for mixing the paint components together may be incorporated, including but not limited to rotating impellers. In this manner, the components of the paint  12  enter a first end of conduit  31 , pass through the static mixer  50 , and egress through a distal end of conduit  31  where the mixture is introduced into the pressurized stream of air as described above. 
     The applicator  10  may further include an orifice plate  34  for metering particular quantities of the paint components into the conduit  31  and mixing device  49 . The orifice plate  34  may be generally planar and may cover the reservoirs  20  filled with the respective components of paint  12 . In one embodiment, the orifice plate  34  may be concave and may have a monolithic structure. However, any configuration of orifice plate  34  may be chosen as is appropriate for use with the embodiments of the present invention. Additionally, channels  36 , which may be holes or apertures  36  fashioned in the orifice plate  34 , may be incorporated for directing fluid from the reservoirs  20  into the conduit  31 . It is noted here that the orifice plate  34 , apart from metering fluids into the mixing device  49 , prevents fluid in one reservoir from mixing with fluids from another reservoir. Stating it another way, when assembled, the orifice plate  34  may function to cap the individual reservoirs  20  preventing the intermixing of paint components. Additionally, the orifice plate  34  may incorporate check valves, not shown, that prevent paint  12  once mixed together from flowing back into the reservoirs  20 . The check valves may be disposed within or proximate to the apertures  36 . However, the check valves may be positioned at any location that prevents the back flow of fluid into the reservoirs  20 . In one embodiment, the orifice plate may be equipped with a peripheral extension. Such a peripheral extension may be positioned within the reservoir chamber and/or reservoir(s), or around the outer periphery of the reservoir chamber and/or reservoir(s). The peripheral extension may also be placed within or around the reservoir chamber but not within or around the reservoir(s). In an alternative embodiment, the orifice plate may be positioned on top of, but not within or around, the reservoir chamber and/or reservoir(s). 
     As just mentioned, the channels  36 , or apertures  36 , meter fluid from the multiple reservoirs  20  into the conduit  31  and subsequently into mixing device  49 . Accordingly, one aperture  36  may be included for each reservoir  20 . It will readily seen that the size of apertures  36  will determine the amount of fluid allowed to flow therethrough thus fixing the ratio at which the paint components are combined. In one embodiment, each of the apertures  36  provided may be similar in size. That is to say that each aperture  36  dispenses or directs fluid at substantially the same rate. In another embodiment, the apertures  36  may facilitate flow at different rates as accomplished by providing one aperture  36  having a larger or smaller diameter than another or by providing multiple similarly sized apertures  36  that connect to a single reservoir  20 . Still, any manner of metering fluid from the reservoirs  20  into the mixing device  49 , in any proportions, may be chosen without departing from the intended scope of coverage of the embodiments of the subject invention. It is noteworthy to mention here that the orifice plate  34 , conduit  31  and mixing device  49  may be disposable elements of the applicator  10 . This makes it easy for an operator to clean and maintain the spray gun  11  for subsequent use. Additionally, changing the mix ratio of the paint  12  may be easily accomplished simply by exchanging one orifice plate  34  with that of another having a different pattern or size of apertures  36 . 
     Continuing to reference  FIG. 3  and now also  FIG. 4 , the reservoirs  20  may be collapsible, which allows its contents to be dispensed by compressing the reservoirs  20  under force. In one particular embodiment, the reservoirs  20  may be produced as bags  21  constructed from a generally pliable material, such as for example a polymeric material or a foil material. In this manner, the bags  21  may expand up to a maximum volume for holding a fluid substance and may be compressed to expel the fluid during operation of the applicator  10 . It follows from that described above, that the bag size, i.e. volume, may vary from one bag  21  to the next in a manner consistent with metering the paint components at a predetermined ratio. It is expressly noted here that the bags  21  may be disposable making it convenient to set up the applicator  10  for any particular mix ratio as well as making it convenient to clean and maintain the applicator  10 . 
     To expel the fluid, an actuator  40  is provided that engages to apply pressure to the collapsible reservoirs  20 . The actuator  40  may be comprised of a bladder  42  that expands when filled with a pressurized medium. In one embodiment, the bladder  42  may be accordion shaped having wall sections that fold one upon another, although other bladder configurations may be implemented as is appropriate for use with the embodiments of the present invention. Moreover, any type of expanding actuator  40 , mechanical or otherwise, may be chosen to expel fluid from the reservoirs  20 . In this manner, action from engaging the actuator  40  compresses the reservoirs  20  thereby pressurizing the fluid components therein for expulsion through the apertures  36 . It will be recognized that the pressure of the paint components entering the conduit  31  may be sufficient to project the fluid through the static mixer  50  thoroughly blending the paint  12  upon contact with the baffles. Thus a substantially homogeneous mixture is provided just prior to introducing the paint  12  into the nozzle  17 . 
     The actuator  40 , and in particular the accordion shaped bladder  42 , may be actuated by pressurized air supplied from a remote source, which may be an air compressor. The actuator  40  may have a dedicated air line connected directly to the air compressor. However, in one embodiment, air flow for activating the actuator  40  may be diverted from the air stream connected to the spray gun  11 . It is to be understood that in either instance, the actuator  40  is activated when the trigger  18  is depressed. It follows that as the trigger  18  is released, the flow of air to the actuator  40 , as well as the spray gun  11 , stops or is closed off. 
     With reference now to all of the Figures, operation of the applicator  10  will now be discussed. An operator may respectively fill individual reservoirs  20 , i.e. collapsible bags, with components of a paint  12  or coating  12  that is to be dispensed by the applicator  10 . The operator may select bags that hold a particular quantity of fluid as determined by the mix ratio of the paint  12  or coating  12 . Additionally, the operator may select an orifice plate  34  having a particular number and size of apertures  36  that correspond to the number of bags and to the mix ratio. Subsequently, the bags may be filled and placed into the reservoir chamber  23  for installation into the spray gun  11 . Alternatively, pre-filled bags may be provided, which eliminates one step in the setup process. Hoses or other conduit may then be connected that route pressurized medium, which may be pressurized air, to the spray gun  11  and to the actuator  40 . Activation of the trigger  18  will then release the flow of pressurized medium through the spray gun  11  discharging fluid from the bags into the mixing device  49  and subsequently into the nozzle  17 . 
     The invention has been described herein with reference to the disclosed embodiments. Obviously, modifications and alterations will occur to others upon a reading and understanding of this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalence thereof.