PATENT ABSTRACT
A caulk product is provided. The product comprises an amount of caulk that is formulated so as to be white in color prior to curing and clear after curing. A cylindrical cartridge contains the amount of caulk, wherein the cartridges comprises a dispensing tip, a substantially cylindrical body, a removable and replaceable endcap, and a breakable seal located between the tip and the body. A transparent area is disposed within a wall of the cartridge so as to allow the color of the caulk to be viewed, wherein the area defined by the cartridge body is adapted to accommodate the insertion of colorant and a mixing tool without overflow. A related method for coloring caulk is also provided.

PATENT DESCRIPTION
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation of U.S. application Ser. No. 10/382,648, filed Mar. 7, 2003. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates generally to methods and apparatus for mixing and dispensing caulking compounds and more particularly to tinting caulking compound that has been dispensed into prepackaged containers to match a selected color of paint.  
         [0004]     2. Related Art  
         [0005]     Caulking compounds are used to join, for example, wood or synthetic trim to painted surfaces; laminates at their seams or to walls; sinks to counters; flooring to painted, laminated or wood surfaces; and so on. Caulking compounds are generally used to caulk joints where a waterproof seal is needed in the joint and which can be subsequently painted if necessary. Most caulking compounds are generally white or off-white tending toward a gray color which is the natural color of most caulking compounds, although some limited quantities of black or special order quantities of colors are available. The colored compounds, i.e. those other than white, cannot generally be commercially obtained except in very large quantities upon special order from the manufacturer. The reasons for this is that there is not a great deal of a demand for large quantities of particular colors of colored caulking compounds and it is therefore impractical for a caulking compound manufacturer to produce large quantities of tinted caulking compounds having various colors and shades.  
         [0006]     Therefore, such tinted caulking compounds are generally not available for small users such as home owners and smaller commercial construction companies whose volume of use is not sufficient to warrant special orders of a particular tinted color of caulking compound. There is a desire, however, on the part of the purchasing public to have caulking compounds of various colors.  
         [0007]     In the use of certain materials such as caulking or other sealing materials which are sold in plastic dispensing tubes such as LIFETIME® Adhesive Sealant, it is often desirable to color the material to match, e.g., the wall color being applied to a room. For example, in the use of conventional white caulking material, as soon as the material sets up sufficiently, usually about two hours or longer, the material can be painted the same color as the room. Where the paint is of a light shade in particular, it may be difficult to cover the material completely without multiple paint coats. Also, it is often necessary to do some additional caulking after the final coat of paint is applied. In that event, the white caulking is painted over as the final step. The advantage of having color matched caulk is that a great saving of time is possible. The user does not have to apply the paint itself with precision at joining edges or, alternatively, does not have to paint over white caulk previously applied. The user may first paint next to, but not exactly on, the joint and then afterwards fill in the unpainted surface with caulk.  
         [0008]     Consequently, some paint dealers have undertaken to mix colorant into the caulking material by hand for certain customers, but considerable time and effort is involved and often results in inferior mixing and considerable clean up time. The problem is that, unlike paint, caulk is very viscous. Therefore, there are problems in mixing the tinting agent with the caulk and in dispensing the caulk into the tubes which are used in caulk guns, since it cannot readily be poured. There is presently no economical means available of supplying this needed product since manufacturers of the caulking compounds cannot maintain sufficient variety of inventory or small quantities of caulking compound to suit the consumer needs.  
         [0009]     Thus, there is a need for an apparatus and method which allows the contractor or the home hobbyist to purchase tubes of caulk and add colorant to the caulk to duplicate the color of their paint, tile, laminate, or the like. There is also a need for a quick, effective, convenient and cleaner method and apparatus for substantially automatically performing the mixing operation.  
       BRIEF SUMMARY OF THE INVENTION  
       [0010]     A method for tinting caulk is provided. In an exemplary embodiment of the invention, the method comprises: providing an amount of caulk, wherein the caulk is white in color prior to curing and clear after curing; providing a cylindrical cartridge to contain the caulk, wherein the cartridge comprises a substantially cylindrical body, having a dispensing end and a fill end, a removable and replaceable end-cap adapted to be received in the fill end, a dispensing tip coupled to the dispensing end, and a breakable seal located between the tip and the body, and wherein the body is sufficiently clear throughout its length so as to allow the color of caulk contained within the cartridge to be viewed; providing a mixing tool having a mixer head means having seal means adapted to be brought into static engagement with wall portions of the body adjacent the fill end to lock the head means to the body and to prevent leakage of the caulk from the body during a mixing operation, bore means formed thru the seal means substantially on a longitudinal axis of the body, elongated shaft means mounted thru the bore means for both rotational and axial motion relative to the seal means and the body, the shaft means having a proximal end lying axially outwardly of the seal means and having a distal end lying within the body, mixer impeller means mounted on the distal end and having peripheral portions adapted to lie closely adjacent to an inner surface of the body, power means for rotating the shaft means and impeller means relative to the cartridge; filling the cartridge with the caulk to a level sufficient to allow room for the shaft of the mixing tool to be inserted into the cartridge without causing caulk to overflow from the cartridge; adding coloration for the caulk comprising an amount of paint having the desired color of the caulk, or in the alternative, where paint of the desired color is unavailable, adding color tint corresponding to the desired color of caulk, along with an amount of white paint; affixing the mixing tool to the fill end of the body, when the end-cap is not in place, such that the shaft of the mixing tool is disposed within the cartridge and such that the seal means of the tool sealingly engages the fill end of the body; applying force to the shaft of the mixing tool such that the colorant and caulk in the cartridge is mixed; breaking the seal between the tip and the body of the cartridge; sealingly engaging the end-cap to the fill end of the cartridge; and applying the tinted caulk to an intended substrate.  
         [0011]     In another embodiment of the invention, a caulk product is provided. The product comprises an amount of caulk that is formulated so as to be white in color prior to curing and clear after curing. A cylindrical cartridge contains the amount of caulk, wherein the cartridge comprises a dispensing tip, a substantially cylindrical body, a removable and replaceable end-cap, and a breakable seal located between the tip and the body. A transparent area is disposed within a wall of the cartridge so as to allow the color of the caulk to be viewed, wherein the area defined by the cartridge body is adapted to accommodate the insertion of colorant and a mixing tool without overflow.  
         [0012]     In a further embodiment, the amount of caulk contained in the cartridge is selected so that the caulk occupies no more than 95% of the total volume capacity of the area defined by the cartridge body, seal, and end-cap when the end-cap is in place.  
         [0013]     In a further embodiment, the transparent area extends the length throughout the length of the cartridge.  
         [0014]     Further objectives and advantages, as well as the structure and function of preferred embodiments will become apparent from a consideration of the description, drawings, and examples. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings wherein like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements.  
         [0016]      FIG. 1  depicts a perspective view of a materials container in cartridge form according to an exemplary embodiment of the present invention;  
         [0017]      FIG. 2  depicts a side view in elevation, in partial cross-section and broken away, of the cartridge of  FIG. 1 ;  
         [0018]      FIG. 3  depicts a longitudinal cross-section view of a mixer apparatus according to an exemplary embodiment of the present invention;  
         [0019]      FIG. 4  depicts a cross-section view of the proximal end of the cartridge and a mixing head including a cartridge holder; and  
         [0020]      FIG. 5  depicts a cross-section view of a mixer apparatus according to another embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]     Embodiments of the invention are discussed in detail below. In describing embodiments, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. While specific exemplary embodiments are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations can be used without parting from the spirit and scope of the invention. All references cited herein are incorporated by reference as if each had been individually incorporated.  
         [0022]     Embodiments of the present invention concern a method and apparatus for mixing any of a wide variety of liquid or particulate materials such as colorant, e.g., pigment or organic dye, sand, grout, catalyst for two-part caulking, or the like, preferably in solution or suspension form, into viscous work material, particularly caulking compound, wherein the structural mixing components are of unique but simple design and are adapted to accomplish the mixing very rapidly and directly within the work material retail container, i.e., in-situ.  
         [0023]     In  FIG. 1 , an embodiment of the present invention is shown as a caulking tube or container  10  in the form of an elongated tubular housing  12  which is preferably cylindrical in shape, but which could take a variety of cross-section geometric shapes, if desired. Tubular housing  12  has a generally hollow interior  14  that is closed at one end, a dispensing end, by an end wall  16  including a nozzle assembly  18 , as is known in the art. Nozzle assembly  18  includes an elongated dispensing tip  20 . Housing  12  is enclosed at an end opposite end wall  16 , a fill end, by a end cap  22  which is slideably received in interior  14  so that it has a peripheral edge surface  24  that abuts the interior surface  48  of surrounding side wall  26  that forms tubular housing  12 . As described more thoroughly below, at least a portion of side wall  26  is transparent.  
         [0024]     The construction of container  10  is shown in greater detail in  FIG. 2 . As is shown in  FIG. 2 , container  10  receives a caulking compound  32  which is preferably opaque and, in one embodiment, consists of an acrylic terpolymer including ethylacryate, acrylonitrile, and acrylic acid which physically vulcanizes by immobilization into a clear substance. The caulking compound is also preferably greater than 60% solids. The caulking compound is tintable such that the caulk is colored by the addition of a colorant. Housing  12  is enclosed at the dispensing end by end wall  16  which, in one embodiment, is in the form of a metal cap having a lip  34  that is secured onto the edge of housing  12  as is known in the art. End wall  16  has a central port  36 , shown in phantom, and is provided with nozzle assembly  18  that includes elongated tip  20 . Tip  20  has a passageway  38  extending longitudinally therethrough with tip  20  being somewhat conical in shape so that side wall  40  of tip  20  diminishes in cross-section from end wall  16  to free end  42  of tip  20 . Passageway  38  is in fluid communication with the interior  14  of housing  12 , but a seal  21  interrupts this fluid communication. Prior to use, however, seal  21  is broken to establish the outlet path for the compound  32 . The provision of seal  21  allows for more complete mixing of the caulk in the container, as described below.  
         [0025]     In the illustrated embodiment, an end cap  22  seals the caulking material in the interior  14  of the housing  12 . The end cap  22  is removable so that colorant can be mixed with the caulk in the housing  12 . As mentioned above, at least a portion of the housing  12  is sufficiently clear so that the color of the caulk contained within the interior  14  can be viewed. The housing  12  may be clear along its entire length. A label including product information may be applied to the side wall  26 . The label may include a window  28  extending along the length of the housing  12 , through which the color of the caulk can be viewed. The user can also observe through the window or through the clear housing if the colorant is uniformly mixed and distributed throughout the caulk.  
         [0026]     The end cap  22  can be replaced on the housing after the colorant is added and can act as a piston member slideably received in the open interior  14  of housing  12 . As is shown in  FIG. 2 , end cap  22  is cup-shaped in configuration so that it has a flat base plate  44  which bears against caulking material  32 . To this end, end cap  22  has a side wall  46  which slideably engages interior surface  48  of side wall  26 . Accordingly, the outer surface of side wall  46  defines peripheral surface  24  which slideably engages surface  48 .  
         [0027]     It should thus be appreciated that, when tip  30  is severed at a selected location along its length, a circular or oval outlet is formed for caulking material  32  since passageway  38  is in fluid communication with hollow interior  14  through port  36  in end wall  16 . Accordingly, when end cap  22  is forcibly moved from the upstream location shown in  FIG. 2  to the downstream location shown in phantom in  FIG. 2 , caulking material  32  is expelled as a rope-like bead from the outlet formed in tip  20 . This rope-like bead has dimensions which correspond to the dimensions of the outlet. Since surrounding side wall  26  is transparent, the material which remains in cartridge  10  is defined by the position of base plate  44 .  
         [0028]     A mixing apparatus that may be used to mix the colorant with the caulk is described in co-pending U.S. patent application Ser. No. 10/293,850, which is incorporated herein by reference. With reference to the embodiments shown in  FIGS. 3 and 4 , the mixing apparatus in its generic sense comprises mixer head means of metal or plastic material and generally designated  50  having a housing end seal means generally designated  52  adapted to be brought into static engagement by pressure cap means generally designated  54  with wall portions such as the top rim  56  of the interior or outer surfaces of the fill end of the housing  12  to prevent leakage of the caulking material from the housing  12  during the mixing operation. Bore means  58  is formed thru the seal means  52  substantially on a longitudinal axis  60  of the housing, and an elongated mixer shaft means  62  is mounted thru  58  for both rotational and axial motion with respect to the seal means  52  and housing  12 . This shaft means  62  has a proximal end  64  lying axially outwardly of the seal means and has a distal end  66  lying within the interior  14 . Mixer impeller means  68  is mounted on the distal end  66  and has a periphery  70  adapted to lie closely adjacent to or in sliding contact with cylindrical inner surface  48  of the tube. The above seal means  52 , bore means  58 , shaft means  62 , impeller means  58  and pressure cap means  54  constitute the basic structure of the head means  50 . Power means may also be provided for rotating the shaft  62  and impeller  68  as they are being moved axially thru the caulking material.  
         [0029]     In the embodiment shown in  FIGS. 3 and 4  the pressure cap means  54  includes a pressure cap section  70 . In the embodiment of  FIG. 4 , when pressure cap section  70  is forced down onto the seal means  52 , the seal means  52  will seal the housing  12 .  
         [0030]     Shaft means  62  is rotatably mounted through seal body  72  in the embodiment shown, which body is preferably provided with a mixer shaft seal  74  such as an O-ring or other annular ring type seal of composition and configuration which affords an axially sliding seal as well as one which wipes the viscous material from the shaft while reciprocating in the caulking tube.  
         [0031]     The upper or proximal end  64  of the shaft preferably is mounted through a rotative power means which can rotate the shaft  64  selectively and substantially instantly in either direction and at any desired rpm, e.g. 600-800 rpm, such that maximum mixing turbulence can be imparted to the work material. Alternatively, the shaft can be reciprocated through the housing by hand, as is described in more detail below.  
         [0032]     In  FIG. 4  the seal means  52  comprises an elastomeric gripping body  160  having a circular periphery  162  which is dimensioned in diameter to slide down into the end of the housing  12 . A bushing  164  having threads  165  is axially mounted thru bore  58  in body  160  and has its inner end  161  non-rotatably fixed to a plate  166  as by welding at  167 . Shaft  62  is rotatably, slidably mounted thru a bore  168  in the bushing.  
         [0033]     In use, shaft  62  is mounted thru bore  168  with the mixer impeller lying adjacent plate  166 . With the mixer impeller then inserted into a tube through the fill end thereof, body  160  is slid into the fill end to a desired position therein. Bushing  164  may be provided with a flat  174  over which a pressure cap  176  of special configuration is mounted. This cap is dimensioned and shaped to slide down over bushing  164  and the open neck  163  of a tube and be held by hand from rotating while nut  172  is tightened against the upper surface  169  of the cap to bulge seal body  160 . The outer cylindrical wall  178  of the cap prevents excessive outward bulging of the tube neck wherein such bulging might be a problem for some tubes having thin or weak walls. Torque arms  180  on nut  172  allow hand tightening thereof. Nut  172  is tightened sufficiently to bulge the body  160  radially outwardly to seal and grip against inner surface  48  of the housing  12 . The elastomeric material of body  160  is selected to allow it to sealingly bulge under just a few pounds of pressure from the tightening nut  172 .  
         [0034]     With the seal means  52  and mixer impeller means thus positioned in the tube, and with the colorant injected, e.g., deposited in the tube, on or into the work material by drop bottles, syringe, spatula, gel capsules, color packets, mechanical dispenser, or the like, the tube can be hand held or placed within a holder or carriage, and the shaft  62  rotated either by a power means such as an electric drill having its chuck fixed to  62 . Reciprocation of the mixer head through the work material relative to the caulking tube can be done by power means or by hand to thoroughly mix the colorant and the caulk.  
         [0035]     In another embodiment of the invention illustrated in  FIG. 5 , shaft  62  is provided with a handle  147  by which a user can reciprocate shaft  62  and impeller  68  without having to rotate the shaft  62  to mix the colorant and the caulk.  
         [0036]     Accordingly, the caulking tubes and mixing apparatus described above may be using in a method for tinting caulk. The general procedure for tinting the caulking compound in the preprepared packages of caulking tubes is to first remove the end-cap  22  and add the colorant to the caulk in the housing. It is preferred that the size of the interior of the housing and the amount of caulk provided in the housing are selected to allow the colorant to be added without overflow from the housing. Typically, a standard size housing is filled with about 9.4 ounces of caulk. If there is not sufficient volume in the housing to permit the addition of tinting material, some caulk is removed before adding the colorant. However, care must be taken not to remove too much caulk from the housing. If the total volume of the caulk applied to the substrate is more than about 5% colorant, the quality of the caulk is degraded to a commercially meaningful extent. Preferably, the caulk is about 3% to about 4% colorant. The colorant and the caulk are then mixed, for example with the use of the above-described mixing apparatus. The end cap is replaced and the tinted caulk is dispensed from the tube.  
         [0037]     In an exemplary method of the invention, an amount of caulk is provided in a container, for example a caulking tube as described above. The caulking tube should include a transparent portion through which the color of the caulk can be observed. In one embodiment, the tube is substantially opaque as to allow brand information, manufacturer information, and product information to be displayed thereon, except for a transparent window that extends throughout the length of the tube. Also, a seal is provided between the interior of the housing and the dispensing tip. The seal prevents caulk from entering the dispensing tip during mixing, such that the colorant can be evenly mixed through all of the caulk. The caulk may be of a type that is initially opaque or white in color prior to curing and clear after curing. When color is added to the caulk, the caulk takes on the color of the colorant after curing.  
         [0038]     The end cap  22  is removed from the container, allowing the colorant to be added to the caulk. Typically a tube contains about 9.4 ounces of caulk. About 7.5 to 10 ml of colorant is used to color this amount of caulk. The cartridge is filled with the caulk to a level sufficient to allow room for colorant and the shaft of the mixing tool to be inserted into the cartridge without causing caulk to overflow the cartridge. The colorant for the caulk may comprise an amount of paint having the desired color of the caulk, or in the alternative, where paint of the desired color is unavailable, a color tint corresponding to the desired color of the caulk. If necessary, an amount of white paint may be added to the caulk to fine tune its color. Of course, any other kind of colorant that is compatible with the caulk may be used to color the caulk.  
         [0039]     A mixing tool having a shaft, such as the mixing apparatus described above, is also provided. The mixing tool is affixed to the end of the cartridge with the end-cap removed, such that the shaft of the mixing tool is disposed within the cartridge and such that the circumference of the base of the tool sealingly engages the end of the cartridge. A rotational force is applied to the shaft of the mixing tool such that the colorant and caulk in the cartridge are mixed together. The rotational force may be generated by an electric drill having its chuck affixed to the shaft, by hand, or by other motive force. The shaft may also be reciprocated through the housing. In a hand-operated embodiment, the shaft is rotated as it is reciprocated through the housing, for example, in a screw-like manner.  
         [0040]     If a hand-operated mixer is used, the following method may be used to tint the caulk. The shaft  62  and impeller  68  are inserted all the way down into the housing  12  through the caulk such that impeller  68  is proximate end  18 . The shaft  62  and impeller  68  are withdrawn to fill end of the housing, whereby air that was originally entrained in the caulk escapes. The shaft  62  and impeller  68  are reciprocated within the housing between the fill end and the dispensing end about 10-50 times, whereby the colorant is mixed into the caulk.  
         [0041]     After mixing, the mixing apparatus is removed from the housing  12  and the end-cap  22  is sealingly engaged to the end of the housing. The seal between the dispensing tip and the interior of the housing is broken, allowing the caulk to pass out of the housing. The tinted caulk can then be dispensed from the container in a manner know in the art and applied to an intended substrate.  
         [0042]     Accordingly, an apparatus and method which allows the contractor or the home hobbyist to purchase tubes of caulk and add colorant to the caulk to duplicate the color of their paint, tile, laminate, or the like is provided. There is also provided a quick, effective, convenient and cleaner method and apparatus for substantially automatically performing the mixing operation.  
         [0043]     The embodiments illustrated and discussed in this specification are intended only to teach those skilled in the art the best way known to the inventors to make and use the invention. Nothing in this specification should be considered as limiting the scope of the present invention. All examples presented are representative and non-limiting. The above-described embodiments of the invention may be modified or varied, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, with the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described.