Abstract:
A method and apparatus for substantially simultaneously mixing two fluids to form a mixture for application to a substrate.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a non-provisional application claiming benefit of U.S. Provisional Application Ser. No. 60/874,785 filed Dec. 13, 2006, and entitled “Inject-A-Color” Custom Coloring Of Caulk In Off-The-Shelf Cartridge Or Tube, incorporated herein by reference in its entirety. 
    
    
     FIELD 
     This invention relates to the field of multi-chambered fluid mixing devices and methods for using such devices. 
     BACKGROUND 
     Various fluid mixing devices and methods for using such devices have been developed for mixing two or more fluids. One such device, described in U.S. Pat. No. 6,910,799, incorporated herein by reference in its entirety, involves mixing a viscous caulking compound with colorant using a mixer shaft that is reciprocated for mixing. Another related U.S. Pat. No. 7,070,318, incorporated herein by reference in its entirety, also involves mixing a viscous caulking compound with colorant using a rotatable mixer shaft that is rotated and reciprocated for mixing. However, these techniques require at least the reciprocation of a mixing shaft having a blade to accomplish the mixing. 
     Many other types of applications require the mixing of two or more fluids to accomplish the formation of a desired mixture such as the mixing of two fluids to form epoxy (e.g., as described in U.S. Pat. No. 5,333,737, incorporated herein by reference in its entirety), the mixing of two fluids to form rubber cement (e.g., as described in U.S. Pat. No. 4,007,233, incorporated herein by reference in its entirety), and the mixing of two or more fluids to form a polymeric sealant (e.g., as described in U.S. Pat. No. 5,426,148, incorporated herein by reference in its entirety). U.S. Pat. No. 6,520,335, incorporated herein by reference in its entirety, more broadly describes a method and a container for mixing multi-component polymer coatings and adhesives using two or more sealed pouches in a mixing container. 
     None of these references briefly discussed above describe a simple apparatus or method for mixing two or more fluids in an apparatus that requires no reciprocating or rotating mixing action and whereby the mixture may be accurately dispensed substantially while mixing is taking place. 
     What is needed, therefore, is a simple mixing apparatus that requires no back and forth reciprocating motion and no rotating motion to accomplish the mixing of two or more fluids. What is also needed is a simple mixing apparatus that is capable of accurately dispensing a mixture substantially while two or more fluids are being mixed in the apparatus to form the mixture. 
     SUMMARY 
     The above and other needs are met by a mixing apparatus, preferably handheld, configured for mixing two or more fluid substances substantially simultaneously without the need for reciprocal mixing motion, axial mixing motion, or moving parts within the mixing chamber. Some of the preferred embodiments are described further below. 
     A preferred embodiment includes an apparatus for mixing two or more fluid substances. The apparatus includes an elongate primary chamber configured for containing a first substance, the primary chamber including a primary chamber dispensing end and a primary chamber non-dispensing end; an elongate secondary chamber substantially aligned longitudinally with and attached to the primary chamber, the secondary chamber configured for containing a second substance, the secondary chamber including a secondary chamber dispensing end and a secondary chamber non-dispensing end wherein the secondary non-dispensing end is proximate the primary chamber dispensing end; a movable back plug configured for longitudinal movement along the primary chamber, wherein such longitudinal movement toward the primary chamber dispensing end causes at least a portion of the first substance to exit through the primary chamber dispensing end and at least a portion of the second substance to exit through the primary chamber dispensing end; and a removable dispensing tip attached to the primary chamber dispensing end, the removable dispensing tip including a mixing chamber that, when the back plug is moved toward the primary chamber dispensing end, causes substantial mixing of the first substance with the second substance. 
     The first chamber is preferably shaped substantially similarly to a caulk tube so that a caulking gun or other similar device may be used along with certain embodiments of the invention. In a preferred embodiment, the first substance preferably includes caulk and the second substance preferably includes colorant as defined herein. 
     In a related embodiment, the apparatus includes an elongate primary chamber including a tube, the tube containing a first substance, the primary chamber including a primary chamber dispensing end and a primary chamber non-dispensing end; an elongate secondary chamber substantially aligned with and attached to the primary chamber, the secondary chamber including a non-rigid bladder configured for containing a second substance, the secondary chamber including a secondary chamber dispensing end and a secondary chamber non-dispensing end; a back plug configured for longitudinal movement along the primary chamber, wherein such longitudinal movement toward the primary chamber dispensing end displaces at least a portion of the first substance out of the primary chamber and at least a portion of a second substance out of the primary chamber; an engagement member attached to the primary chamber at a location along the dispensing end of the primary chamber; a dispensing tip removably attachable to the engagement member, the dispensing tip including a mixing chamber that, substantially when the back plug is moved toward the primary chamber dispensing end, causes substantial mixing of the first substance from the primary chamber with a second substance from the secondary chamber; a fill port located along the outer surface of the primary chamber, the fill port configured for fluid communication through the fill port to the secondary chamber such that the secondary chamber may be filled with a second substance by insertion of a second substance through the fill port; and a barrier structure configured for substantially obstructing fluid communication between the fill port and the secondary chamber. 
     In another aspect, the embodiments of the invention provide methods for mixing two or more fluid substances. A preferred embodiment of such a method includes the step of providing a mixing apparatus including an elongate primary fluid storage zone having been pre-filled with a first substance; an elongate secondary fluid storage zone longitudinally aligned with the primary fluid storage zone for storing a second substance; a mixing zone; and a separation barrier obstructing the first substance and the second substance from entering the mixing zone. The method further includes the steps of inserting a second substance into the secondary fluid storage zone; breaching the separation barrier; and forcing the first substance and the second substance, substantially simultaneously, to the mixing zone. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages of the invention are apparent by reference to the detailed description in conjunction with the figures, wherein elements are not to scale so as to more clearly show the details, wherein like reference numbers indicate like elements throughout the several views, and wherein: 
         FIG. 1  depicts a cross-sectional view of a multi-chambered mixing apparatus including a fill port located proximate a primary chamber non-dispensing end; 
         FIG. 2  depicts a lower portion of the multi-chambered mixing apparatus shown in  FIG. 1  and further showing a dispensing tip attached to the mixing apparatus; 
         FIG. 3  depicts a top view of the helical mixer segment taken along line C-C in  FIG. 2 ; 
         FIG. 4  depicts a cross-sectional view taken along line A-A in  FIG. 1  showing the configuration of the apparatus at line A-A including a primary chamber, a secondary chamber, and a back plug; 
         FIG. 5  is a cross-sectional view taken along line B-B in  FIG. 1  showing the configuration of the apparatus at line A-A including a primary chamber, a secondary chamber, and a back plug; 
         FIG. 6  depicts a cross-sectional view of an alternate embodiment of the mixing apparatus in which the fill port is located along a primary chamber dispensing end; 
         FIG. 7  depicts a cross-sectional view of the upper portion of the embodiment of the mixing apparatus shown in  FIG. 1  showing the back plug moved slightly toward the dispensing end of the mixing apparatus; 
         FIG. 8  depicts a cross-sectional view of an alternate embodiment the dispensing tip shown in  FIG. 2 ; 
         FIG. 9  depicts a cross-sectional view taken along line D-D in  FIG. 8 ; 
         FIG. 10  depicts a snap-in grommet including a removeable barrier structure attached thereto located along a fill port along the primary chamber surface; 
         FIG. 11  depicts a self-sealing stopper for a fill port wherein a needle type syringe may be employed to insert a second substance into the secondary chamber; 
         FIG. 12  depicts a cross-sectional view of the primary chamber dispensing end in which the fill port is located along the same aperture in which fluid is to be dispensed from the mixing apparatus including a specialized syringe for inserting a second substance into the secondary chamber; 
         FIG. 13  depicts a cross-sectional view of the primary chamber dispensing end in which the fill port is located along the same aperture in which fluid is to be dispensed from the mixing apparatus including a barrier structure; 
         FIG. 14  depicts a side view of bladder configured for holding a second substance; 
         FIG. 15  depicts a cross-sectional view taken along line E-E in  FIG. 14 ; 
         FIG. 16  depicts a cross-sectional view of the top portion of a mixing apparatus in which the mixing apparatus has no fill port (i.e., a pre-filled embodiment in which the primary chamber and the secondary chamber were both at least partially pre-filled with a first substance and a second substance, respectively), the fill port is not located along the primary chamber non-dispensing end, or the upper portion of the secondary chamber that protruded above the primary chamber non-dispensing end (e.g.,  FIG. 1  and  FIG. 7 ) has been removed (e.g., by cutting). 
         FIG. 17  depicts a cross-sectional view of an embodiment of a mixing device described herein including no fill ports (i.e., a pre-filled embodiment). 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  depicts a preferred embodiment of a mixing apparatus  10  for mixing two or more fluids as described herein. The term “fluid” is broadly defined to include, but not be limited to, liquids, colloids, suspensions, slurries, plastic solids, and combinations thereof. The apparatus  10  resembles caulk tube and preferably has substantially the same dimensions as a caulk tube so that a caulking gun may be used along with the mixing apparatus  10 . The apparatus  10  further includes a primary chamber  12  capable of holding a first substance such as first substance  11  and a secondary chamber  14  capable of holding a second substance such as second substance  13 . The primary chamber further includes a primary chamber dispensing end  16 , a primary chamber non-dispensing end  17 , and, in certain embodiments, a first aperture  18  located along the primary chamber dispensing end  16 . The secondary chamber further includes a secondary chamber dispensing end  20  and a secondary chamber non-dispensing end  22 . The apparatus also includes a back plug  24  and an engagement member  26 . A fill port  28  is located along the secondary chamber non-dispensing end  22  and a barrier structure  30  is associated with the fill port  28 . 
       FIG. 2  shows a cross sectional view near the primary chamber dispensing end  16  in which a dispensing tip  32  has been attached to the engagement member  26 . Although the dispensing tip  32  is attached to the engagement member  26  via threads  34  located along the outer surface of the engagement member  26 , other attachment techniques known to persons having ordinary skill in the art may be used in related embodiments of the invention. A fluid channel  36  is located along engagement member  26  for the passage of fluid from the apparatus  10  to the dispensing tip  32 . In the embodiment shown in  FIG. 2 , the dispensing tip  32  further includes a mesh mixing section  38 , a substantially helical mixing section  40 , and an air pocket reducing section  42 . A top view (cut along line “C” in  FIG. 2 ) of the helical mixing section  40  is shown in  FIG. 3 . In related embodiments, the dispensing tip  32  may include only a mesh mixing section or, alternatively, only a helical mixing section. Additionally, an air pocket reducing section may be absent from other related embodiments of the invention. The mesh mixing section  38  preferably includes mesh material similar to or substantially like steel wool. The mesh material may be made of metal, plastic, rubber, other polymeric materials known to persons having ordinary skill in the art, or a combination thereof. In a related embodiment, a dispensing tip  41  may include a plurality of baffles  43  as shown in  FIG. 8  and  FIG. 9 . The baffles  43  may vary in shape and could be, for example, curved, helical, flat, any similar shape known to persons having ordinary skill in the art, or a combination thereof.  FIG. 9  is a top view cut a line “D” in  FIG. 8 . 
     In the embodiment shown in  FIG. 1  and  FIG. 2 , the primary chamber preferably includes an elongate rigid tube  44  made from polymeric material and/or metal having a thickness similar to the thickness of a standard tube of caulk. The secondary chamber preferably includes an elongate non-rigid bladder  46  made from materials such as polyethylene (most preferably ranging from about 1 mil to about 8 mil), polypropylene (most preferably ranging from about 1 mil to about 8 mil), or other similar material known to persons having ordinary skill in the art. The bladder  44  is preferably attached to the interior surface of the tube  44  using one or more adhesives such that the secondary chamber non-dispensing end  22  substantially covers the first aperture  18 , substantially preventing any fluid from exiting from the primary chamber  12  through the first aperture  18 . In a preferred embodiment shown in  FIG. 14  and  FIG. 15 , the bladder  44  is preferably includes a first bladder layer  48  and a second bladder layer  50 .  FIG. 15  is a top view cut from line “D” in  FIG. 14 . The first bladder layer  48  is attached to at least the inner longitudinal surface of the primary chamber  12 , preferably by one or more adhesives. The second bladder layer  50  is attached to the first bladder layer  48  along edge area  52 A and  52 B, thereby forming a void  54  between the first bladder layer  48  and the second bladder layer  50 . In this embodiment, if the secondary chamber is filled with fluid, the fluid resides within the void  54  and is kept substantially separated from (i.e., out of fluid communication with) any content in the primary chamber  12 . 
     The fill port  28  allows for the bladder  46  to be filled with a fluid such as the second substance  15 . In a preferred embodiment, the upper end  48  of the secondary chamber  14  is preferably semi-rigid, thereby making it easier to insert fluid into the secondary chamber  14  to a location  54  along the bladder  46  beyond where the back plug  24  is in direct contact with the bladder  46 . In a related embodiment, the back plug  24  includes a groove  50  oriented in substantial alignment with and substantially conforming to the bladder  46 , thereby making it easier to insert fluid into the secondary chamber  14  to about location  48 . 
     Because the tube  44  and the back plug  24  are substantially rigid and the bladder  46  is substantially non-rigid, the back plug edge  56  squeezes the bladder  46  in the area where the back plug edge  56  is in contact with the bladder  46 . This effect is demonstrated by comparing  FIG. 4 , a top view cut along line “A” in  FIG. 1  where the bladder  46  is being squeezed by the back plug  24 , and  FIG. 5 , a top view cut along line “B” in  FIG. 1  where the portion of the bladder  46  that is shown is not in direct contact with the back plug  24 .  FIG. 7  also gives a cross sectional perspective of the influence of the back plug  24  on the bladder  46 . 
     Barrier structure  30  as shown with the embodiment displayed in  FIG. 1  and  FIG. 7  is a removable plastic cap that allows the secondary chamber non-dispensing end  22  to be substantially sealed and resealed. In certain embodiments, barrier structure  30  may include a grommet to reinforce the fill port  28 . Also, in various embodiments, the cap may be attached by different attachment structures such as by snapping, screwing, or other fastening techniques known to person having ordinary skill in the art. In related embodiments, the barrier structure  30  may include self-sealing stopper, preferably made of an elastomeric material. Such a stopper could be used, for example, as an insertion and removal point for a hollow needle used with a syringe to fill or refill the secondary chamber with a fluid.  FIG. 10  shows a snap in type grommet  58  which has been inserted through an aperture  60  made through a primary chamber wall  62  and a secondary chamber wall  64 . The grommet includes a canal  66  that operates as a fill port for inserting fluid into the secondary chamber  14 .  FIG. 10  also shows, for example, a cap  68  for substantially resealing the grommet  58 .  FIG. 11  shows a similar embodiment including a snap in type grommet  70  having substantially no continuous canal, the grommet  70  being made of a self-sealing material allows for a hollow needle  72  to be inserted through the grommet and into the secondary chamber  14 . Thus, a syringe may be used to insert a specifically calculated volume of fluid into the secondary chamber  14 . Substantially when the needle  72  is removed, the grommet  70  substantially reseals itself. 
       FIG. 6  shows an alternative embodiment in which a fill port  74  is located at a different location than the location shown on the embodiment in  FIG. 1 . Fill port  74  is located along the primary chamber dispensing end  16  and the fill port  74  is preferably in fluid communication with the secondary chamber  14 , and secondary chamber  14  is kept substantially sealed by barrier structure  71 . In a related embodiment, bladder  46  must be breached via channel  73  to put fill port  74  in fluid communication with the secondary chamber  14 .  FIG. 16  shows what the primary chamber non-dispensing end  17 , the secondary chamber non-dispensing end  22 , and the back plug  24  would look like in this particular embodiment. In related embodiments, a fill port may be located substantially anywhere along the outside surface of the primary chamber  12  as long as the location allows for such a fill port to be in fluid communication with the secondary chamber  14  but not in fluid communication with the primary chamber  12 . No matter where a fill port is located along the primary chamber  12 , a barrier structure similar to barrier structure  30  is preferably associated with such fill port to reseal the fill port after fluid has been inserted into the secondary chamber  14 . 
     In yet another embodiment shown in  FIG. 12  and  FIG. 13 , the first aperture  18  and/or fluid canal  36  operate act as a fill port  76 . In a preferred embodiment, a special syringe  78 , made to substantially sealingly attach (e.g., as by threads  80 ) to the engagement member  26  may be used to insert fluid into the secondary chamber through fill port  76 . In the embodiment shown in  FIG. 12 , the secondary chamber  14  includes an aperture  82  such that fluid may enter the secondary chamber  14 . The aperture  82  may be made, for example, by puncturing, using a sharp instrument (e.g., a nail) through the fluid channel  36  and, in some embodiments, through the primary chamber dispensing end  16  if no aperture  18  is originally present.  FIG. 13  shows an example of a barrier structure  84  (e.g., a threaded cap) that may be fastened to the engagement member  26  to prevent inserted fluid from escaping from the secondary chamber  14  out of the first aperture  18  and the fluid channel  36 . 
     In yet another embodiment substantially similar to the embodiment shown in  FIG. 1 , a mixing apparatus  86  includes a primary chamber  88  pre-filled with a first substance  90 , a secondary chamber  92  pre-filled with a second substance  94 , a back plug  24 , and an engagement member  26 . The primary chamber  88  includes a dispensing end  96 . The apparatus may be breached (e.g., punctured) using a nail (e.g., nail  95 ) or the like to form an aperture  98  through the primary chamber dispensing end  96  and further breaching the secondary chamber such that the first substance  90  and the second substance  94  may exit through aperture  98 . In a related embodiment, the secondary chamber substantially covers a pre-formed aperture  98  at the primary chamber dispensing end  96 , obstructing fluid flow from the primary chamber  88 . In this embodiment, the secondary chamber  92  may be breached via the aperture  98  by using a breaching tool capable of fitting through the aperture  98 . 
     Although the apparatus  10  shown in  FIG. 1  is shown to contain a first substance  13  and a second substance  15 , persons having ordinary skill in the art appreciate that other embodiments of the apparatus  10  may initially be substantially void of any substances for mixing. In a preferred embodiment, the first substance ( 13 ,  90 ) comprises caulk and the second substance ( 15 ,  94 ) comprises colorant. The term “caulk” is broadly defined to include various types of caulking fluids. Substantially white caulk (when applied) or substantially clear caulk (when applied) is preferred. The term “colorant” is broadly defined to include paint (including latex paint and oil-based paint), pigment, dye, and mixtures thereof. 
     In a related embodiment, the first substance ( 13 ,  90 ) comprises low molecular weight polymer (e.g., polyester) and the second substance ( 15 ,  94 ) comprises a curing agent (e.g., amine-acetoacetate), whereby the first substance and the second substance may be mixed to form a sealant. 
     In a related embodiment, the first substance ( 13 ,  90 ) comprises prepolymer (e.g., diepoxy) and the second substance ( 15 ,  94 ) comprises a curing agent (e.g., diamine), whereby the first substance and the second substance may be mixed to form an epoxy material. 
     In yet another embodiment, the first substance ( 13 ,  90 ) comprises a nitrile rubber (e.g., a copolymer of acrylonitrile (ACN) and butadiene) and the second substance ( 15 ,  94 ) comprises a phenolic resin, whereby the first substance and the second substance may be mixed to form a cement material. 
     Although various embodiments of the invention have been described above, other embodiments of the invention include methods, including methods for using the apparatus described above. 
     A preferred method includes the steps of (1) providing an apparatus including a primary zone and a secondary zone, the primary zone being at least partially filled with a first substance; (2) inserting a second substance into the secondary zone; (3) breaching the secondary chamber such that the first substance and the second substance may exit to a mixing zone; (4) attaching a mixing zone (e.g., dispensing tip  32 ) to the primary chamber; and (5) forcing at least a portion of the first substance and at least a portion of the second substance into a mixing zone so that the first substance and the second substance are substantially mixed in the mixing zone prior to exiting the mixing zone. The “inserting” step may be accomplished at a number of fill port locations on the particular apparatus used, as demonstrated by the various apparatus embodiments discussed above. The inserting may be accomplished by a graduated syringe with a needle; by a specialized syringe for attaching to, for example, engagement member  26 ; or any other device known to persons having ordinary skill in the art that is capable of forcing fluid into a chamber. The “breaching” step as described above may be accomplished, for example, by puncturing the lower and upper layer of the secondary chamber as shown in  FIG. 1 . In an alternative situation in which the secondary chamber is at least partially pre-filled with a second substance, the “breaching” step may include removing a barrier structure such as barrier structure  84  shown in  FIG. 13 . The “forcing” step preferably includes moving a back plug (e.g., back plug  24 ) toward a dispensing end of the primary chamber. This “forcing” step is preferably accomplished using a caulking gun or similar apparatus. 
     The foregoing description of preferred embodiments for this invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments are chosen and described in an effort to provide the best illustrations of the principles of the invention and its practical application, and to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.