Patent Publication Number: US-6910799-B2

Title: Mixing apparatus and method

Description:
This application is a continuation-in-part of applicants Ser. No. 09/563,465 of same title and filed on May 2, 2000, now abandoned, and further is a continuation-in-part of applicants pending Ser. No. 10/115,330 of same title and filed on Apr. 2, 2002. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field 
     This invention concerns 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. 
     In the use of certain materials such as caulking or other sealing materials which are sold in plastic dispensing tubes such as “DAP® Acrylic Latex Caulk Plus Silicone”, 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 has been applied. In that event, the white caulking has to be painted over as the final step. 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 present invention provides a quick, effective, convenient and cleaner method and apparatus for substantially automatically performing the mixing operation. 
     2. Prior Art 
     Applicant is unaware of any prior apparatus or method of the type disclosed and claimed herein which is designed to mix colorant directly into caulking compound or the like contained in its retail tube. 
     SUMMARY OF THE INVENTION 
     The present invention, in one of its preferred embodiments comprises a mixer head means having a mixer shaft rotatably or non-rotatably mounted axially therethrough and having a mixing impeller or blade means affixed to a distal end thereof, a proximal end of said shaft being adapted for engagement with a power source for reciprocating said shaft and impeller means axially, said head means having a first annular sealing surface adapted for making a sealing connection to a second annular sealing surface on an open filler end portion of a tube of viscous caulking compound or the like whereby the combination of said head means and tube is completely portable and independent of other structure, and wherein said shaft with said mixing impeller or blade means is adapted to be reciprocated thru the viscous compound contained in the tube substantially the entire length of the tube to rapidly and intimately mix the compound with colorant or other additive material placed in the tube. 
     In certain preferred embodiments: 
     (a) the blade means is provided at its periphery with a wiping surface adapted to rotatably and longitudinally slide against or in close proximity to the inner surface of the tube whereby no significant amount of unmixed compound or colorant remains; 
     (b) a colorant supply means is provided to inject the colorant into the compound during reciprocation of the shaft and blade means thru the compound; 
     (c) the supply means of (b) above comprises passage means extending longitudinally thru the shaft whereby colorant can be either pressure injected or gravity fed at a desired rate therethrough into the compound either before or during rotation and/or longitudinal mixing movement of the shaft thru the compound; 
     (d) the shaft with mixer blade means is rotatably mounted and supported on rotative power means in a longitudinally stationary position wherein mixer head means is provided for holding the tube filler end and wherein linear power means is provided for longitudinally reciprocating said head means and tube relative to the shaft and mixer blade means; 
     (e) power means is provided for selectively reversing rotation of the shaft and blade means during the mixing operation to afford maximum mixing turbulence to the compound; 
     (f) said head means includes rotative power means connected to said proximal end of said shaft for rotating said shaft; and 
     (g) said head means is provided with structure for connecting it to an apparatus which can reciprocate the head and tube relative to said shaft and impeller. 
     The present mixing method in one preferred embodiment employing a retail, off-the-shelf tube of caulking material wherein the tube has a puncturably sealed dispenser end section, a filler end section having surface portions defining a fill opening into the tube, a thrust cap sealingly, slidably mounted in said filler end section, and further employing a mixer head means adapted to seal against said surface portions of said filler end section during the mixing operation, wherein said head means has mixer shaft means rotatably and axially slidably mounted therethrough, and wherein a mixer impeller means is fixed to a distal end of said mixer shaft means for rotation and axial movement therewith, said method comprising the steps of (a) removing said thrust cap from said tube, (b) adding additive into said tube, (c) connecting said head means to and sealingly against said surface portions of said filler end section to seal said fill opening with said blade means inside of said tube and to provide a portable independent combination of said head means and tube, (d) starting rotation and relative reciprocation of said mixer shaft means within said tube and continuing the rotation and reciprocation for a desired mixing period, (e) removing said tube and the colored compound therein from said shaft, impeller means and head means, and (f) replacing said thrust cap in said filler end section to retain the mixed compound and additive in said tube until use. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be further understood from the following description and drawings herein wherein the structures depicted are not drawn to scale or actual relative proportions and wherein portions thereof are cross-sectioned or broken away for clarity, wherein: 
         FIG. 1  is a partially sectioned schematic view of an overall mixer apparatus-including a fluid, air or hydraulic cylinder for reciprocating the mixing head means and caulking tube; 
         FIG. 2  is a longitudinal partial cross-sectional view of one preferred type of mixing head means for carrying out the present mixing operation wherein the head means and tube are in the up position and wherein the head means has just-tripped the top limit switch to reverse the hydraulic cylinder stroke; 
         FIG. 3  is a view taken along line  3 — 3  of  FIG. 1  in the direction of the arrows with portions broken away for clarity; 
         FIG. 4  is a top view of one useful type of worm gear transmission power means for driving the mixing shaft means taken along line  4 — 4  of  FIG. 2 , with the gear housing top removed for clarity; 
         FIG. 5  is an enlarged, for clarity, distal end portion of the mixing blade means and colorant injector piston of  FIG. 2 ; 
         FIG. 6  is a cross-sectional view taken along line  6 — 6  of  FIG. 2  in the direction of the arrows and showing the mixer blade means; 
         FIG. 7  is a cross-sectional view taken along line  7 — 7  in  FIG. 6  in the direction of the arrows; 
         FIG. 8  is a view of the filler end of a typical off-the-shelf caulking compound tube such as DAP® with portions broken away to show the thrust cap in place and which, when pressured further into the tube (down in  FIG. 8 ) by a caulking gun, forces the compound out thru the dispenser nozzle of the tube; 
         FIG. 9  is a side view, partially sectioned, of a rack and pinion type power means for reciprocating the tube; 
         FIG. 10  is a view of the mixer head means taken along line  10 — 10  of  FIG. 2  in the direction of the arrows with portions broken away for clarity; 
         FIG. 11  is a view of the mixer head means on the tube filler end as in  FIG. 2  showing a hand held variation of the colorant injection means; 
         FIG. 12  is a cross-sectional view of the proximal end of the tube and a variation of the mixing head means including a tube holder section; 
         FIG. 13  is a view as in  FIG. 12  showing a more preferred type of mixer head means; 
         FIG. 14  is a top view of the head means of  FIG. 13  taken along line  14 — 14  thereof in the direction of the arrows; 
         FIG. 15  is a cross-sectional view taken along line  15 — 15  of  FIG. 13  in the direction of the arrows; 
         FIG. 16  is a partially sectioned side elevation view of an electrical motor powered reciprocation apparatus with the present preferred mixing head structure mounted on a carriage means; 
         FIG. 17  is an elevation view of a useful means for quickly connecting the mixer shaft to a rotative power source; 
         FIG. 18  is a view taken generally along line  18 — 18  of  FIG. 16  in the direction of the arrows; 
         FIG. 19  is a view as in  FIG. 16  of a variation in the connection of the carriage means to the mixer head means; 
         FIG. 20  is a longitudinal cross-section of a preferred head means; 
         FIG. 20A  is an enlarged cross sectional view of the portion of head  23  which clamps onto carriage  77 ; 
         FIG. 21  is a cross-sectional view taken along line  21 — 21  of  FIG. 20  in the direction of the arrows and showing only a portion of body  56  in elastomeric cross-section; 
         FIG. 22  is a view of a highly preferred impeller taken along line  22 — 22  in  FIG. 20  in the direction of the arrows; 
         FIG. 23  is a cross-sectional view of the impeller taken along line  23 — 23  in  FIG. 22  in the direction of the arrows; 
         FIG. 24  is a cross-sectional view of a preferred shaft seal mounted in the bushing; 
         FIG. 25  is a perspective view of the bushing of  FIG. 20 ; 
         FIG. 26  is a top view of a multiple head carrying carriage; 
         FIG. 27  is a partial view of the head means of FIG.  20  and showing a variation in the structure of seal body  56 ; 
         FIG. 28  shows a variation in mixing head structure; 
         FIG. 29  shows in an alternative tightening means structure for knob means  69  in  FIG. 20 ; 
         FIG. 30  is a cross-sectional view of a variation of the tapered seal construction of  FIG. 28  wherein inner portions of the tube filler end wall provide a component of the seal; and 
         FIG. 31  is essentially the same as  FIG. 20  but wherein the shaft is provided with a handle for non-rotative mixing. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Referring to the drawings and with particular reference to the claims hereof, the present apparatus in one preferred form and generally designated  10  is well adapted for mixing liquid, solid or suspension colorant or other material with viscous work material  12  such as caulk which is contained in a reservoir  14  of an elongated tube  16 , typically of plastic, between a puncturably sealed dispensing end  18  and a filler end  20  normally sealed by a thrust cap seal such as  17 . The reservoir is provided by a cylindrical inner surface  22  of the tube and has a substantially uniform diameter throughout its length. One typical caulk tube size is approximately 1⅞ O.D. and 8½ in., long. 
     With reference to all of the embodiments shown herein the apparatus in its generic sense comprises mixer head means of metal or plastic material and generally designated  23  having a tube end seal means generally designated  24  adapted to be brought into static engagement by pressure cap means generally designated  41  with wall portions such as the top rim  26  or the upper portions  27  of the interior or outer surfaces of the filler end  20  of the tube to prevent leakage of the work material from the tube during the mixing operation. Bore means  28  is formed thru the seal means  24  substantially on a longitudinal axis  30  of the tube, and an elongated mixer shaft means  32  is mounted thru  28  for both rotational and axial motion with respect to the seal means  24  and tube  16 . This shaft means has a proximal end  34  lying axially outwardly of the seal means and has a distal end  36  lying within the reservoir  14 . Mixer impeller means  38  is mounted on said distal end and has a periphery  40  adapted to lie closely adjacent to or in sliding contact with cylindrical inner surface  22  of the tube. The above seal means  24 , bore means  28 , shaft means  32 , impeller means  38  and pressure cap means  41  constitute the basic structure of the head means  23 . Power means such as  42  is provided for axially moving, in a relative sense, shaft means  32  and impeller  38  substantially completely thru the reservoir of material in a reciprocating manner and power means such as  44  is provided for rotating the shaft  32  and impeller  38  as they are being moved axially thru the material. 
     In the embodiment shown in  FIGS. 1 and 2  the pressure cap means  41  comprises a cylindrical holder section  46  and a pressure cap section  50 . The caulking tube is dropped, dispensing end  18  first, with a loose fit between the holder section and tube to allow easy removal of the tube after mixing. In the embodiment of  FIG. 2 , the top rim  26  of the tube preferably extends slightly above the top rim  48  of the holder section whereby when a pressure cap section  50  is forced down onto the seal means  24 , the seal means will seal the tube filler end  20  and said cap section will clamp the ends  20  and  18  of the tube between the seal  24  and a circular ledge  54  on the holder section interior wall. This clamping will prevent rotation of the tube during the mixing operation wherein rotation of the mixer impeller and compound tends to drag the tube into rotation. 
     In the embodiment of  FIG. 11  a special type of tube end seal means is shown wherein the seal body  56  thereof can be glass, preferably tempered and tough, or clear plastic, and the pressure cap section  50  is formed with a large opening  58  such as to afford a visual inspection of the progress and extent of the colorant mixing operation. An annular cushion  60  of elastomeric material, preferably silicone lubricated, is provided, but not essential, and which, in cooperation with annular elastomeric seal ring  62  cushions the seal body  56 . It is noted that where glass is not used, cushion  60  still has utility in providing a slippery surface to facilitate tightening of cap section  50  where threads are employed as shown in  FIG. 11 , without tending to rotate the seal body  56  and seal ring  62 . One or more additional seals such as O-rings  63  may be mounted on  56  if needed. 
     Shaft means  32  is rotatably mounted thru seal body  56  in all of the embodiments shown, which body is preferably provided with a mixer shaft seal  64  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 during reciprocating of the caulking tube. 
     The upper or proximal end  34  of the shaft preferably is mounted thru a rotative power means  44  which can rotate the shaft  32  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. One preferred power means is shown in  FIG. 4  as a worm gear transmission  66  having a worm shaft  68  rotatably mounted in a housing  70  affixed to a base or frame means  72  of any desired construction which supports the structural components of the present apparatus. Shaft  32  is affixed to a worm gear  74  which mates with shaft  68  and is rotatable thereby. Shaft  68  may be driven by an electric motor  76 , preferably variable speed, or by, e.g., reversible electric hand held drill or the like, either house current or battery powered, with its chuck coupled to shaft extension  78 , or by a hand crank coupled to  78 , all such shaft rotating means being termed herein as power means. 
     The outermost end  80  of shaft  32  preferably is funnel shaped for facilitating the loading of colorant into passage  82  which is generally axially provided thru shaft  32  and exits thru the inner end  84  of  32 . A colorant injection piston rod  88  and annular seal ring  90  affixed to the inner end portion  92  thereof is slidable down into passage  82  and may be employed to forcibly eject colorant which has been loaded into passage  82 , into the work material. Rod  88  is preferably provided with a stop means such as collar  94  affixed thereto to allow ring  90  to substantially completely wipe passage  82  clear of colorant but not to allow  90  to pass beyond end  84  of  32  and become damaged. Shaft portion  34  is preferably split and provided with a socket  35  and set screw  37  to allow removal of the shaft from  44  for facilitating cleaning or replacement with a different size impeller blade means  38  and seal means  24 . 
     The mixer impeller or blade means  38  preferably has multiple, e.g., 2-5 blades  96  of any desired shape such as shown in  FIGS. 6 and 7  and having their radially inner portions  98  affixed to shaft means  32  and their outer radial portions  99  affixed to cylindrical rim  100 . This rim provides peripheral surface  40  which functions to smoothly slide on inner surface  22  of the tube rotationally and linearly to stabilize  32  and  38  and to wipe surface  22  of compound and colorant during the mixing operation. Rim  100  preferably extends slightly above the blades  96  at their upper portions  102  and slightly below the blades at their lower portions  104  such that at the ends of the reciprocation travel, rim  100  will, in the event said travel is slightly unintentionally over extended, engage dispensing end  18  or seal means  24  before the rotating blades can make contact with either or both of  18  or  24  and cause damage thereto or to the blades. It is noted that end  18  is typically of thin plastic such that an operator can easily puncture it with a nail or the like pushed thru the opened nozzle tip  106  when ready for use. 
     Referring to  FIGS. 1-3 , the power or lift means  42  preferably is the piston  43  and an automatically two way operating hydraulic or air cylinder  108 , and is connected to the base  110  of the holder  46  preferably by a quick disconnect coupling such as pin  112  and socket  114 . Compression spring  116  urges pin  112  into  114 . Such a coupling allows a quick change of holder  46  to accommodate tubes of different sizes. 
     In this embodiment, cylinder  108  is mounted on a foot member  118  which is clamped to a stanchion  120  of base or frame means  72  by bolt means  122  slidable thru an aperture in leg  124  and threaded thru a threaded aperture in leg  126 . When  122  is loosened, member  118  and attached cylinder  108  and holder  46  can be rotated to the side to allow easy removal or loading of a tube in holder  46 . Member  118  can also be slid up or down on stanchion  120  to position holder  46  in the precise vertical position to receive a tube. In this regard, ruler markings  128  can be provided on the stanchion to make easier the proper vertical positioning of  118  for each size tube. 
     It is apparent that for this embodiment, where tubes of different lengths are used, the travel of piston  43  must be adjusted to give the proper reciprocating stroke length to holder  46 , relative to the vertically stationary mixer impeller  38 . For this purpose, a cylinder  108  is selected which can readily give the maximum piston stroke required for the longest retail caulking tube which might be used by tradesmen. At the time of this writing about 12 to 14 inches of piston stroke would appear to be more than is needed for the most common reservoir length of retailed tubes of caulking material. 
     In order to adjust and control the piston stroke length and direction, electrical limit switches  130  and  132  vertically adjustably mounted on frame  72  are adapted to engage their arms  131  and  133  respectively with the bottom  134  and top  136  respectively of holder  46  at the prescribed limits of its reciprocation and, by means of solenoid valves in the hydraulic or air system which are electrically connected to the switches, reverse the direction of hydraulic or air fluid flow and the direction of the piston stroke. Control means are also provided to adjust the speed of the piston reciprocation. In practice, a stroke speed of from about 4 to about 20 seconds per complete up-and-down cycle is desirable, but slower or faster speeds may, of course, be used. 
     In the operation of the apparatus, a holder  46  of proper dimensions for receiving a particular size caulking tube is connected to piston  43 . Foot member  118  is vertically adjusted on stanchion  120  to vertically position the holder where the piston stroke can accommodate the required full up-and-down travel of the holder with room to spare such that impeller  38  can, be extracted from the tube after mixing is complete. The limit switches  130 ,  132  are then vertically adjusted on stanchion  120  of frame  72  and locked into position for being actuated by the bottom and top alternately of the holder at the precise moment that impeller  38  is at the prescribed ends of its reciprocation stroke or travel. The device is now ready to receive a caulking tube  16  from which a thrust cap seal  17  has been removed by, e.g., applying pressure to the tube sides which pops  17  out of the tube. 
     In order to facilitate vertical loading of the tube into the holder and removing it therefrom, the foot member  118 , after loosening bolt  122 , is swung to the side  123  such that the holder and tube can clear impeller  38  and any other structure of the device which might be in the way. When it is desirable to maintain the precise vertical position of  118  such as when the device is needed to mix several tubes of the same size, a positioning collar  140  as shown by dotted line in  FIG. 1  may be employed to support  118  while it is being rotated. 
     As shown in  FIG. 9  other types of reciprocating power means may be employed such as rack  142  and pinion gear  144  wherein  144  may be driven by reversible motor means and the travel of  142  controlled by switches such as  130  and  132 . Gear  144  may also be fitted within a hand crank  146  if desired. 
     In the embodiment of  FIG. 11 , the colorant fluid may be contained in a syringe  148  and a plastic tube  149  provided and connecting the syringe nozzle  150  to a pipe  152  fixed thru the seal body  56 . The syringe can be used to inject colorant into the tube before the mixing starts or during the mixing, or both. 
     In a related embodiment, tube  149  may be rigid or semi-rigid plastic, or metal or ceramic and used, e.g., by inserting it down into the open caulk tube and substantially all the way thru the work material, and the syringe then actuated to inject the colorant into the material as tube  149  is slowly withdrawn therefrom to leave a column of colorant longitudinally in the material. The mixer head means  23  may then be fixed into the open tube end by, e.g., the mechanism of  FIG. 13 , and the mixing process started by any power means such as a hand drill chucked directly onto shaft portion  34 . 
     It is noted that the configuration of the head means  23 , the seal means  24  and the pressure cap means  41  can be varied in accordance with the present invention, such as, for example those shown in  FIGS. 2 ,  11 - 15  and  20 . In  FIG. 2 , cap section  50  is provided with two or more spring arms  51  which are formed with shoulders  53  adapted to snap in under a shoulder ring  55  affixed around holder  46  as cap section  50  is pushed down over the open neck of the holder with sufficient force to compress seal  62  to a sealing condition. These arms  51  are readily removed from  55  by an outward pull on their lower ends. 
     In  FIG. 11 , cap section  50  and the holder section  46  are provided with mating threads  52  such that adequate sealing pressure can be applied to  62  by a small rotating force applied to the cap. Cap section  50  is preferably knurled as at  47  for allowing hand tightening. 
     In  FIG. 12  the seal means  24  comprises an elastomeric gripping body  160  having a circular periphery  162  which is dimensioned in diameter to slide down into the filler end  20  of a caulking tube. A bushing  164  having threads  165  is axially mounted thru bore  28  in body  160  and has its inner end  161  non-rotatably fixed to a plate  166  as by welding at  167 . Shaft  32  is rotatably, slidably mounted thru a bore  168  in the bushing. A washer  170  preferably of low friction metal or plastic material is mounted over the bushing and a nut  172  is threaded over the bushing. The upper end  171  of bushing  164  extends an exaggerated amount above nut  172  to provide wrench flats  173  for holding  164  and body  160  from rotating as nut  172  is tightened against washer  170 . 
     In use, shaft  32  is mounted thru bore  168  with the mixer impeller lying adjacent plate  166 . With the mixer impeller then inserted into a tube thru the tube filler end thereof, body  160  is slid into the filler end to a desired position therein. A wrench is then mounted on flats  173  to hold bushing  164  and washer  166  stationary, and nut  172  is tightened sufficiently to bulge the body  160  radially outwardly to seal and grip against inner surface  22  of the caulking tube. 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 . 
     With the seal means  24  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  77 , and the shaft  32  rotated either by a power means such as  44  or, e.g., an electric drill having its chuck fixed to  32 . Reciprocation of the mixer head thru the work material relative to the caulking tube can be done by power means such as  42  or by hand. 
     Referring to  FIGS. 13 ,  14  and  15  wherein structure substantially equivalent to that of  FIG. 12  are numbered the same, bushing  164  is 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  as at  59 . 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. 
     Referring to  FIGS. 16-31 , the best modes presently known for practicing the present invention are shown therein and wherein certain structures are numbered as in  FIGS. 1-15 . 
     In the embodiments of  FIGS. 16  thru  31 , the tube  16  is locked to head means  23  in a manner similar to  FIGS. 12 and 13 . Referring to  FIG. 20 , head  23  comprises pressure cap means  41  formed to provide a cylindrical recess wall  57  dimensioned for snugly, slidably receiving the filler end  20  of tube  16 . The elastomeric body  56  of seal means  24  is substantially cylindrical in shape in its uncompressed condition but is bulged laterally as shown at  59  in its compressed sealing condition wherein the upper portion  27  of the tube  16  is pressured against the bulge  59  to lock the tube to the head means  23 . 
     Head means  23  further comprises a bushing such as  164  but having a substantially oblong cross-section stem  73  threaded as at  165  and having flats  61  for preventing rotation of the bushing in the mating and substantially oblong aperture  65  provided thru the top  67  of cap means  41  and thru which the bushing can longitudinally slide. A circular tightening knob  69  having internal threads  71  is adapted to be threaded onto bushing  164  and tightened against proximal pressure surface  159  of cap top  67  such that the pressure plate portion or second shoulder means  166  of the bushing and distal pressure surface  175  of top  67  will compress body  56  between its top  182  and bottom  184  surfaces and bulge it radially to frictionally lock against the inner wall surface  188  of the tube and bulge it radially to frictionally lock and seal the tube between body  56  and recess wall  57 . It is noted that body  56  may have various cross-sectional configurations and constructions such as the elastomeric, resilient air filled doughnut  75  shown in a compressed operational condition in FIG.  27 . 
     As shown in  FIG. 16  head means  23  with the tube  16  locked thereto is removably affixed to a carriage means  77  of any desired configuration and preferably provided with a retractable positioning pin  79  or equivalent which is adapted to fit within a recess  81  in the wall portion  87  of cap  41  (see  FIG. 20 ) to removably lock head  23  and tube  16  to the carriage  77  in a desired position. Compression spring  83  is compressed between a plug  85  threaded into  77  and a shoulder  86  affixed to pin  79  to continually urge the pin toward an aperture  89  in the carriage, in which aperture the cap  41  is to be locked as hereinafter described. 
     In  FIG. 16  an apparatus is shown for reciprocating the carriage  77  and tube and comprises a base  91  to which is affixed a stanchion  93  which is slidably mounted thru the carriage and supports at its upper end a header means  95 . A threaded spindle  97  is rotatably mounted on base  91  and is threaded thru the carriage and rotatably passes thru a bearing  101  in  95 . An electric motor  45  or equivalent is mounted on  95  and its output shaft is connected to spindle  97 . This motor is preferably adapted to rotate the spindle at any desired speed and to reverse its rotational direction in order to cycle the carriage and tube up and down at a rate to achieve good mixing. Another electric motor  105  or equivalent is mounted on  95  and is adapted for connection to shaft  32  by a bayonet type connector  103  or equivalent as shown in  FIG. 17  wherein pin  107  is on shaft  32  and slot  109  is on the output shaft  111  of the motor. 
     The assembly of the head  23  on the carriage  77  with tube attached in operating condition with shaft  32  extending outwardly a desired extent is carried out by positioning the neck portion  113  of the head into channel  115  in the carriage, pulling pin  79  outwardly from aperture  89 , moving  113  inwardly until wall portion  87  is laterally within the perimeter of aperture  89 , thrusting the head upwardly until shoulder  117  thereon abuts the underside  119  of the carriage, releasing pin  79  to allow it to engage against wall portions  87 , and rotating the head until the pin automatically inserts into recess  81  by way of spring  83 . At this point the shaft  32  can be extended upwardly by the operators hand force to make the connection shown in FIG.  17 . It is noted that where reverse rotation of shaft  32  is desired, a type of connector other than  103  should be used such as, e.g., a set screw. The length of stroke of the carriage is preferably regulated by limit switches or the equivalent in the manner shown in  FIGS. 1 and 2 . Other types of regulatory means such as light or other radiation sensing devices may, of course, be employed. 
     It is noted that for any of the embodiments shown herein the head  23 , carriage  77  and tube  16  may be held stationary while the shaft  32  and motor  105  are reciprocated. Such a variation is readily made, for example, by attaching the carriage  77  in fixed position on a lower portion of stanchion  93  and disconnecting it from spindle  97 , and removing motor  105  from header  95  and affixing it to a carriage such as  77  as the carriage and its mounting are shown in FIG.  16 . 
     Referring to  FIGS. 19 through 20A , the phantom lines of  77  in  FIG. 20 , and to  FIG. 20A , the assembly of head  23  with carriage  77  can be done by way of (1) making the aperture  89  of a diameter approximately the same as the width of channel  115  which preferably is only slightly wider than the diameter of neck  113  of the tightening knob  69 , (2) dimensioning the head components and the thickness  121  of the carriage such that with the tube  16  clamped by an initial force to the head, the neck  113  can be slid thru channel  115  to aperture  89  and the knob  69  then further tightened a small but sufficient degree to clamp the carriage between the underside  127  of the knob and the top  67  of the pressure cap  41 , and (3) employing a compressible pressure element such as  153  comprised of an annular metal washer component  154  and an annular elastomeric buffer component  155  wherein bushing  164  is slidable thru the center opening  156  of said element and wherein said buffer component is less compressible than body  56  such that seal body  56  will bulge tightly against the tube wall before said buffer component compresses to the point where the underside  157  of knob  69  tightly engages carriage  77 . It is preferred that  154  and  155  be adhesively affixed to each other and that  156  be adhesively affixed to the top  67  of pressure cap means  41 . 
     The most preferred shaft seal  64  is shown in  FIG. 24  wherein an annular metal housing  135  is adhesively affixed to an annular or ring seal  137  of elastomeric material. The most preferred impeller  38  is disc shaped as shown in  FIGS. 22 and 23  wherein the mixing blades are in the form of slots  138  tapered from about 30 to about 50 degrees, and wherein the direction of rotation of shaft  32  is clockwise. The construction greatly reduces the whipping of air into the caulk mass during mixing. The bottom  139  of the impeller disc is slightly concaved such that the tube seal  141  will not be damaged if the impeller comes into contact with the tube bottom. 
     As shown in  FIG. 26  multiple channels  115  and apertures  89  may be provided in the carriage  77  for simultaneous multiple mixings. Stanchion slide guides such as  143  against which the carriage is vertically slidable may be provided to prevent rotation of the carriage during mixing. In  FIG. 29  an alternative to knob  69  is shown as a pair of opposed arms having smooth hemispherical ends  145  for easy gripping and rotation. 
     Referring to  FIG. 28 , the seal means  24  comprises a slightly tapered, e.g., 1-5 degrees cylindrical recess wall  57  into which the open filler end of tube  16  is pushed. The frictional contact of the tube with wall  57  is sufficient to seal the tube end and stabilize the shaft  32  axis and impeller within the tube such that rotation and reciprocation of the shaft can proceed smoothly without dislocation of the head  23  from the tube. In  FIG. 30  the tapered wall  158  provides the seal and frictional lock of the head to the tube. 
     For these embodiments which afford quick and easy on-the-job mixing, the cap  41  is preferably provided with ridge projections  39  spaced around the cap for gripping such that in addition to pushing or pulling the tube, rotation of the cap on the tube can be facilitated to ensure proper sealing and to assist in removal of the tube from the head. Also for this embodiment the rotative power means preferably comprises a hand or palm held and small size battery operated electrical motor with its output shaft integral with shaft  32  such that all of the structures of head means  23  desired for convenient and expeditious mixing are integrated into a single hand held unit falling within the ambit of “combination” as used herein. 
     In another and highly preferred embodiment of the present invention, particularly the fully hand held and hand operated version as shown in  FIG. 31 , shaft  32  is provided with a handle  147  by which the operator can reciprocate shaft  32  and impeller  38  without having to rotate the shaft and impeller to intimately mix the caulk and colorant. It is preferred that for this operation, after the colorant is added thru the open top of tube  16 , the following procedure is followed:
         1. Insert shaft  32  and impeller  38  all the way down into the tube thru the caulk wherein  38  is proximate dispensing end  18  of the tube;   2. Position and tighten head means  23  in the tube fill end to seal the tube whereby the pressure within the tube is ambient;   3. Withdraw the shaft and impeller to proximate the tube fill end whereby the pressure within the tube becomes less than ambient, e.g., 7-10 psi., and whereby air which was originally entrained within the caulk now tends to escape therefrom; and   4. Reciprocating, e.g., 10-50 times, the shaft and impeller within the tube between said fill end and said dispensing end whereby the pressure within said tube cycles between ambient, e.g., 14.7 psi., and less than ambient, e.g., 7-10 psi and whereby said colorant is intimately mixed into the caulk.       

     It is apparent, of course, that the above procedure can be carried out by the use of automatic or semi-automatic type reciprocating equipment such as that shown in  FIG. 16  but without the need for a motor  105 , wherein the outer end of shaft  32  simply could be clamped in a non-rotative position on stanchion  93  during the mixing operation. 
     It is noted that the head variations of  FIGS. 28 ,  30  and  31  may be provided with means for mounting them on carriage  77  such as recess  81  formed in the sides thereof for receiving a pin such as  79 . 
     In order for the preferred and best mode embodiments of the present invention to work properly and to produce the most convenient and expeditious mixing results, the pressure cap means  41  must be so constructed that it does not interfere with or impede the operators hand gripping of the tube  16  as the operator is assembling or disassembling the head  23  and tube and, if desired, as the operator is holding the tube during the mixing operation. To this end and with the cap affixed to the tube, the downwardly depending wall  178  or other portions of the pressure cap should allow at least about a hands width of at least about four inches of the tube dispensing end  18  to protrude beyond wall  178 . Therefore, it is preferred that a total length of the cylindrical recess wall  57  of pressure cap means  41  does not exceed three inches even where a reciprocating apparatus as shown in  FIG. 16  is employed since proper placement of the head and tube in the carriage means  77  is greatly facilitated where the operator can hand grip the tube. It is noted that an experienced operator by hand gripping a tube  16  can remove thrust cap seal  17 , feed additive thru the tube filler end  20 , assemble the head  23  onto the filler end  20 , run and/or reciprocate the shaft  32  and impeller  38  to mix the components, remove the head from the tube, and replace seal  17  in the tube in less than 30 seconds, particularly when the combination is only hand supported during the mixing operation. 
     The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications will be effected with the spirit and scope of the invention.