Abstract:
A nozzle assembly having a mixing nozzle that dispenses foam in a particular pattern. A spray tip detachably fixable to the mixing nozzle that produces a foam spray pattern that is different from the spray pattern produced by the mixing nozzle alone

Description:
CROSS REFERENCES TO RELATED APPLICATIONS  
       [0001]     Not Applicable  
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH  
       [0002]     Not Applicable  
       TECHNICAL FIELD  
       [0003]     This invention relates to a multi-component mixing nozzle with removable low cost spray pattern control tips to vary the spray pattern of a plural component mixed material. Two or more fluid components are mixed and processed into a settable plastic through a nozzle and depending on the application are sprayed our poured out of the nozzle. The new designed tip of this invention allows the end user to choose to use the pattern-modifying tip on the mixing nozzle or simply use a nozzle without the modifying tip, depending on the application.  
       DESCRIPTION OF THE BACKGROUND ART  
       [0004]     Manually operable guns are known for dispensing a settable urethane foam. Separate fluid components are fed individually to the gun, passed separately through control valves, and brought into contact with each other upon reaching a mixing chamber of a nozzle from which the mixed components are discharged as foam. Examples of such guns are found in U.S. Pat. Nos. 4,311,254 and 4,399,930 issued to Gary Harding and in U.S. Pat. No. 4,762,253 issued to Steven Palmert.  
         [0005]     The two fluid components are commonly referred to as the “A resin” and the “B resin”. They usually consist of polymeric isocyanate and polyol amine, respectively. The components are supplied separately in two pressurized containers that are attached by hoses to inlets to the guns. When the two fluid components or resins are mixed, the mixture quickly sets up to form a rigid foam product which is substantially insoluble and extremely difficult to remove from surfaces with which it comes in contact. As a result, the nozzles for the guns in which the two components are first mixed are typically designed to be replaceable and disposable so as to avoid the necessity for cleaning the nozzles.  
         [0006]     There are a variety of mixing nozzles available which can produce different dedicated spray patterns depending on the nozzle design. The nature of what nozzle to use depends on the end user&#39;s application. Typically, a supplier includes a number of standard pattern dedicated nozzles with a kit containing the dispenser and foam components. If the user desires a spray pattern different from the standard nozzle included with the system, they must be purchased separately. The spray tip of this invention allow for the supplier to make available to the end users a variety of spray pattern control tips that are inexpensive to produce, easy to stock, inexpensive to distribute and can adapt to the existing mixing nozzles supplied with the system. An inventory of spray nozzles could be kept on site in case they are needed. However, the nozzles are expensive, and the standard nozzles are then wasted.  
         [0007]     A detachable nozzle tip for use with a single component foam dispensing gun is disclosed in U.S. Pat. No. 5,645,199. Single component guns, however, do not include mixing chambers to mix two or more foam components since by definition, single component foam dispensing guns only have one component, and thus do not require mixing. Moreover, the nozzle tip disclosed in U.S. Pat. No. 5,645,199 is not a spray tip that produces a spray pattern. The nozzle tip disclosed in the patent merely extends the length of the nozzle to dispense foam caulk into difficult to reach cracks and crevices.  
       SUMMARY OF THE INVENTION  
       [0008]     The present invention provides a multi-component fluid nozzle assembly including a mixing nozzle and kit including a multi-component fluid mixing nozzle. The assembly and kit include a detachably fixable spray tip that produces a foam spray pattern that is different from the spray pattern produced by the mixing nozzle alone.  
         [0009]     A general objective of the present invention is to provide a multi-component fluid nozzle assembly and a foam dispensing kit which does not require changing a mixing nozzle to change a first spray pattern defined by foam exhausting from the mixing nozzle outlet. This objective is accomplished by provide a spray tip that is detachably fixable to the standard mixing nozzle outlet and foam exhausting from the spray tip outlet defines a second spray pattern, wherein the second spray pattern is different from the first spray pattern.  
         [0010]     The foregoing and other objectives and advantages of the invention will appear from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration a preferred embodiment of the invention. Such embodiment does not necessarily represent the full scope of the invention, however, and reference is made therefore to the claims herein for interpreting the scope of the invention. 
     
    
     BRIEF SUMMARY OF THE DRAWINGS  
       [0011]      FIG. 1  is a view in elevation of a foam dispensing gun in accordance with the present invention with a detachable spray tip removed;  
         [0012]      FIG. 2  is a view in horizontal section taken in the plane of the line  2 - 2  of  FIG. 1 ;  
         [0013]      FIG. 3  is a detailed partial view in vertical section taken in the plane of the line  3 - 3  in  FIG. 2  showing the valve members in an open position;  
         [0014]      FIG. 4  is a detailed view of the spray tip detachably fixed to the nozzle of  FIG. 2 ;  
         [0015]      FIG. 5  is a cross sectional view of  FIG. 4 ;  
         [0016]      FIG. 6  is a rear view of the spray tip of  FIG. 3 ;  
         [0017]      FIG. 7  is a sectional view along line  7 - 7  of  FIG. 6 ;  
         [0018]      FIG. 8  is a sectional view along line  8 - 8  of  FIG. 6   
         [0019]      FIG. 9   a  is a perspective view of the spray tip of  FIG. 4 ;  
         [0020]      FIG. 9   b  is a front view of the spray tip of  FIG. 9   a;    
         [0021]      FIG. 9   c  is a sectional view along line  9   c - 9   c  of  FIG. 9   b;    
         [0022]      FIG. 9   d  is a top view of the spray tip of  FIG. 9   a;    
         [0023]      FIG. 10   a  is a perspective view of an alternative spray tip;  
         [0024]      FIG. 10   b  is a front view of the spray tip of  FIG. 10   a;    
         [0025]      FIG. 10   c  is a sectional view along line  10   c - 10   c  of  FIG. 10   b;    
         [0026]      FIG. 10   d  is a top view of the spray tip of  FIG. 10   a;    
         [0027]      FIG. 11   a  is a perspective view of an alternative spray tip;  
         [0028]      FIG. 11   b  is a front view of the spray tip of  FIG. 11   a;    
         [0029]      FIG. 11   c  is a sectional view along line  11   c - 11   c  of  FIG. 11   b;    
         [0030]      FIG. 11   d  is a top view of the spray tip of  FIG. 11   a;    
         [0031]      FIG. 12   a  is a perspective view of an alternative spray tip;  
         [0032]      FIG. 12   b  is a front view of the spray tip of  FIG. 12   a;    
         [0033]      FIG. 12   c  is a sectional view along line  12   c - 12   c  of  FIG. 12   b  with a hose attached; and  
         [0034]      FIG. 12   d  is a top view of the spray tip of  FIG. 12   a   
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0035]     The foam dispensing gun disclosed herein is substantially identical to the foam dispensing gun disclosed in U.S. Pat. No. 5,462,204 with the exception that it includes, as described below, a detachable spray tip for producing a spray pattern different than the spray pattern produced by a nozzle forming part of the gun. U.S. Pat. No. 5,462,204 is assigned to the assignee of the present invention, and is fully incorporated herein by reference. Although the foam dispensing gun having a modified standard mixing nozzle disclosed herein is preferred, any multi-component mixing nozzle can be modified to include a detachable spray tip without departing from the scope of the invention.  
         [0036]     Referring to  FIGS. 1-3 , in general, the foam dispensing gun includes a body  10  with a handle  11  that may be formed integral with the body  10 . The body  10  and handle  11  may be molded from a synthetic resin material. The body  10  is formed with a pair of longitudinal, parallel passageways  12  and  13 . The passageways  12  and  13  are divided into forward and rearward portions by an intermediate chamber  14 . The rearward portions of the passageways  12  and  13  mount brass connectors  15  that have a ribbed end for attachment to hoses connected to pressurized containers for fluid components that are used to form the foam.  
         [0037]     The connectors  15  are hollow and define passageway inlets leading from the tanks of components. The bushings  22  are also hollow and mount duck-bill valves  25  in their center. The duck-bill valves  25  are formed of a rubber or other elastomeric material and function as one-way valves to permit fluid under pressure to enter a passageway  12  or  13 .  
         [0038]     Each bushing  22  is disposed against a bellville spring  26  which bears against an end of the respective connector  15  thereby urging the bushing  22  inwardly in the passageway  12  or  13  until it abuts against a shoulder  27 . A coiled spring  30  is disposed in each of the passageways  12  and  13 . The spring  30  bears at one end against an end of a respective bushing  22 . The other ends of the springs  30  bear against the ends of brass needle valve members  31  also disposed in the passageways  12  and  13 .  
         [0039]     The needle valve members  31  span the chamber  14  and are received in both the forward and rearward portions of the passageways  12  and  13 . The needle valve members  31  have a rear portion provided with a radial recess  32  that mounts an O-ring  33  to seal with the rearward portion of the passageway  12  or  13 . The forward portion of each valve member  31  is formed as a conical needle valve portion  35  terminating in a circular cylindrical tip  36 . The conical needle valve portion  35  and tip  36  mate with a conical valve seat  37  having a circular cylindrical extension  38  and formed in the body  10  at the front terminus of the passageways  12  and  13 .  
         [0040]     The valve seats  37  define passageway outlets, and open directly through the front face of a nose  40  on the body  10 . The valve members  31  have an annular recess  39  behind the conical needle valve portion  35 . The recess  39  mounts an O-ring  41  that seals the junction of the needle valve portion  35  and the conical valve seat  37  when the valve is closed, as shown in  FIG. 4 . The valve members  31  have an additional annular recess  45  that mounts an O-ring  46  that seals with the forward portions of the passageways  12  and  13 .  
         [0041]     The chamber  14  mounts a yoke  50  formed at the top of a trigger lever  51 . The yoke  50  has a pair of arms  52  terminating in lateral bosses  53  that are received for pivotal movement in holes  54  in the two sides of the body  10 , as shown in  FIG. 3 . The yoke  50  also includes a central rib  55  which, with the arms  52 , defines two spaced cradles  56  that receive necked down portions  57  intermediate the ends of the valve members  31 . The springs  30  normally urge the valve members  31  forwardly to close the needle valves  35  against the valve seats  37 . The trigger lever  51  can be rotated to withdraw the valve members  31  against the urgings of the springs  30  to open the valves.  
         [0042]     Each valve member  31  has a central internal passage  60  that terminates in a transverse port  61  that extends to the surface of the valve member at a point between the O-rings  40  and  46 . As shown in  FIG. 5 , when the trigger lever  51  is squeezed to open the valves, fluid from the pressurized containers can pass through the central passages  60  in the valve members  31 , out the ports  61 , through the valve seats  37 , and out of the front nose  40  of the body  10 . The O-rings  46  prevent fluid from moving rearwardly along the passageways  12  or  13 . As the valves are closed, the conical needle valve portions will extrude materials forwardly out of the valve seats. The seating of the needle valve in the valve seat combined with the O-rings  40  will seal off the interior of the passageways and prevent air from reaching the fluid resins in such passageways.  
         [0043]     A disposable mixing nozzle  65  is mounted on the front of the gun. The nozzle  65  has a hollow interior that defines a mixing chamber  66  and interposed between an inlet chamber and an outlet  67 . A helical static mixer  68  of known construction is mounted in the mixing chamber  66 . The rear end of the nozzle upstream of the mixing chamber  66  has an enlarged circular cylindrical portion  69  which surrounds the nose  40  of the body  10  and is sealed thereto by an O-ring  70 . The cylindrical portion  69  also defines the open inlet chamber. An annular ring  80  formed around the nozzle  65  proximal the outlet  67  provides grasping surfaces for securely grasping the nozzle  65  when attaching and detaching the nozzle  65  from the gun body  10 . External threads  82  are formed on the nozzle  65  forward of the annular ring  80  for threadably engaging a detachable spray tip  84 , such as shown in  FIGS. 4-8 .  
         [0044]     A pair of resilient arms  71  extend along either side of the nozzle rearwardly from the enlarged cylindrical portion  69 . The resilient arms  71  are adapted to engage ears  72  that extend from opposite sides of the body  10  adjacent the nose  40 . The resilient arms  71  have a curved portion  73  adjacent their ends which terminates in a notch  74  that mates with an ear  72 . The nozzle can be quickly attached to the body  10  by sliding the resilient arms  71  beneath the ears  72 . The curved portions  73  will cam the arms  71  so that the arms will slide easily past the ears  72  until the notches  74  engages with the ears  72 . The nozzles  65  can be easily removed by manually depressing the curved ends  73  of the arms  71  to release the notches  74  from the ears  72  and allow the arms  71  to slide past the ears  72 . Although detachably fixing the nozzle to the body is preferred, as described above, the nozzle can form an integral and/or permanent part of the body, or be detachably fixed to the body using other methods, such as by using a threaded engagement, snap fit, friction fit, fasteners, and the like, without departing from the scope of the invention.  
         [0045]     The static mixer  68  includes a wall portion  76  which is located in the open inlet chamber defined by the enlarged cylindrical end  69  of the nozzle. As shown in  FIG. 2 , the wall portion  76  divides the inlet chamber and is positioned between the valve seats  37  so that complete mixing of the two fluid components does not occur immediately at the nose  40 . If the nozzle  65  should become clogged with foam and not be replaced, the subsequent opening of the valves could result in the fluid of higher pressure being forced from the mixing chamber through the valve seat for the other component in the reverse direction. The duckbill valves  25  prevent such cross-contamination which would result in set-up of the components within the gun if allowed to occur.  
         [0046]     Referring now to  FIGS. 4-9   d,  the nozzle outlet  67  exhausts into the detachable spray tip  84  fixed to the nozzle  65 . The spray tip  84  includes a hollow interior having a spray tip inlet  86  in fluid communication with a spray tip outlet  88 . Preferably, the spray tip inlet  86  includes internal threads  90  that threadably engage the external threads  82  formed on the nozzle  65  to detachably fix the spray tip  84  to the nozzle  65 . Although threadably engaging the spray tip with the nozzle is preferred, other means for detachably fixing the spray tip to the nozzle outlet end, such as a twist lock engagement, friction fit, snap fit, and the like, can be used without departing from the scope of the invention. Moreover, fasteners, such as set screws, hose clamps, bands, and the like, can be used to more securely fix the spray tip to the nozzle outlet end.  
         [0047]     The spray tip outlet  88  can be any shape to produce the desired spray pattern. Preferably, the spray pattern produced by the spray tip outlet  88  is different from the spray pattern produced by the nozzle outlet  67  without a spray tip  84  affixed thereto. In the embodiment disclosed in  FIG. 6 , the spray tip outlet is a small generally rectangular aperture  94  in fluid communication with the hollow interior and exhausting between a pair of diverging walls  92 . Preferably, the walls  92  diverge at an angle of no more than 28° to control the foam spray exiting from the spray tip outlet  88 . Other exhaust shapes can include a plurality of apertures in fluid communication with the inlet, an elongated slit, a tubular opening having any desired diameter, a conical aperture having an increasing diameter, and the like, without departing from the scope of the invention.  
         [0048]     Opposing wings  96  extending radially from the spray tip  84  provide engagement surfaces for rotating the spray tip  84  to threadably engage the internal threads  90  with the external threads  82 . Of course, other means can be provided for securely grasping the spray tip to detachably fix the spray tip to the nozzle end, such as a single wing, a knurled exterior surface, a geometric external cross section for engaging a wrench, and the like, without departing from the scope of the invention.  
         [0049]     In other embodiments of the present invention, spray tips  184 ,  284  shown in  FIGS. 10   a - 11   d  have spray tip outlets  188 ,  288  that are different from the spray tip outlet  88  disclosed in  FIGS. 4-9   d  above. As in the first embodiment disclosed herein, the spray tip outlets  188 ,  288  disclosed in  FIGS. 10   a - 11   d  produce a spray pattern that is different from the spray pattern produced by the nozzle outlet  67  without a spray tip.  
         [0050]     In yet another embodiment of the present invention shown in  FIG. 12   a - 12   d , a replaceable spray tip  384  includes a flexible hose  385  for modifying the foam spray pattern. The spray tip  384  is detachably fixed to the nozzle outlet  67  and includes external barbs  387  for attaching the hose  385  thereto. The spray tip  384  including the flexible hose  385  affixed thereto has an outlet  388  that can produce spray patterns different from the spray pattern produced by the nozzle outlet  67  without a spray tip affixed thereto. Advantageously, a plurality of spray tips  384 , each having different sized barbs  387  can be provided to accommodate different diameter flexible hoses without replacing the nozzle.  
         [0051]     The detachable spray tip disclosed herein provides a user with increased flexibility. The user can spray foam through the nozzle without the spray tip to produce a foam spray having a known spray pattern, or the user can affix a spray tip to the nozzle to produce a different foam spray pattern without replacing or purchasing a different nozzle. This saves time and money by reducing waste and increasing inefficiency. Moreover, the spray tips can be provided at a larger variety and lower cost than an entire nozzle which allows a user to maintain an inventory of spray tips for use.  
         [0052]     While there has been shown and described what is at present considered the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention defined by the appended claims.