Patent Publication Number: US-7222802-B2

Title: Dual sprayer with external mixing chamber

Description:
BACKGROUND OF THE INVENTION 
   This invention relates generally to a manually operated dual trigger sprayer, and more particularly to such a sprayer having an externally mounted mixing manifold for combining separate liquids issuing from the sprayer upon sprayer actuation. 
   Dual trigger sprayers are known having a pair of side-by-side pistons operating in side-by-side pump cylinders for simultaneously drawing liquids separately stored and discharging the liquids through separate discharge passages issuing as separate sprays from the sprayer assembly for intermingling at or on the target. Examples of such sprayers can be found in U.S. Pat. No. 5,857,591, FIG. 6, and in U.S. Pat. No. 5,535,950, FIG. 10. Otherwise, the dual liquids are combined internally of the sprayer assembly at or upstream of the sprayer nozzle for commingling in a spin chamber or the like prior to discharge as a combined spray through a single discharge orifice in the nozzle. Examples of such sprayers can be found in the U.S. Pat. No. 5,857,591 patent, FIG. 10, in the U.S. Pat. No. 5,535,950 patent, FIG. 9, and in U.S. Pat. No. 6,550,694. 
   It has been found that commingling of disparate sprays at or on the target may be ineffectual as the outer fines of each spray become airborne before they can possibly be entrained into the center. This is due to the outer edge of each spray cone having the highest velocity compared to the velocities of the spray particles nearer the center. This, therefore, results in incomplete mixing of the dual spray liquids which is undesirable and could be harmful depending on the chemical nature of the sprays combined. 
   BRIEF DESCRIPTION OF THE INVENTION 
   It is therefore an object of the present invention to provide a dual sprayer having an external mixing manifold to assure intimate commingling of spray particles of separate liquids issuing through separate discharge orifices each provided with its own spin mechanics assembly. The mixing manifold may be in the form of an external attachment mounted at the downstream end of a nozzle cap containing a pair of discharge orifices for the separately issuing liquids. The manifold has a single discharge port through which the combined liquids issue as a spray, stream or foam. The manifold may define a smooth-walled mixing chamber so arranged relative to the discharge orifices that the spray particles impact against the smooth walls causing spray particles of both liquids to intimately commingle before issuing as a combined spray or stream from a discharge port of the adaptor. For foaming, an air aspiration opening may be defined by the attachment permitting ingested air to mix with the commingling separate sprays so as to issue through the discharge port of the attachment as a foam. A foaming screen may be provided at the discharge port for foaming. And, an external guide tube or ring on the attachment at its discharge port can be provided for directing the spray or foam to a selected area of a target. Swirl vanes may be provided on the inner wall of such a tube or ring to even further enhance a commingling of the two separately issuing liquids. And, the external mixing chamber may include some type of baffled geometry such as ribs, vanes, bumps, grooves, a rough surface finish, etc., to enhance turbulence in the mixing chamber to provide for a more intimate combining of the dual liquids before issuing through the attachment nozzle. 
   Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the invention when taken together with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an expanded, perspective view illustrating the essence of the invention; 
       FIG. 2  is an expanded perspective view showing various details of the invention not found in  FIG. 1 ; 
       FIG. 3  is a sectional view taken substantially along the line  3 — 3  of  FIG. 2 ; 
       FIG. 4  is a sectional view taken substantially along the line  4 — 4  of  FIG. 2 ; 
       FIG. 5  is a sectional view taken substantially along the line  5 — 5  of  FIG. 2 ; 
       FIG. 6  is a view similar to  FIG. 2  showing the external mixing manifold mounted to the spray nozzle of the sprayer; and 
       FIG. 7  is a view of spray mechanics assemblies in accordance with one embodiment employed for the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Turning now to the drawings wherein like reference characters refer to like and corresponding parts throughout the several views, the dual piston trigger sprayer according to the invention, generally designated  10  and partially shown in  FIGS. 1 ,  2  and  6 , is part of a dual sprayer as fully shown in U.S. Pat. No. 5,535,590 , commonly owned herewith, and the entirety of the disclosure of which being specifically incorporated herein by reference. Thus, the dual sprayer comprises the side-by-side pump units simultaneously actuated by a single trigger lever for suctioning first and second liquids separately stored into the pump chambers of the pumping mechanisms and discharging the separate liquids through separate side-by-side discharge barrels for issuance as separate sprays to a separate spin mechanics assemblies as shown in FIG. 10 of the U.S. Pat. No. 5,535,950 patent. The dual sprayer of the invention, prior to mixing, is essentially the same in function and operation as that disclosed in the &#39;950 patent. Thus, in the invention, a pump body or housing of the dual dispenser has a dual pump which includes a pair of side-by-side pump pistons respectively reciprocable in a pair of side-by-side pump cylinders configured so that reciprocation of the pistons draw disparate liquids from the liquid compartments into the pump chambers and discharges the liquids through separate discharge passages defined by discharge barrels  11  and  12 . The discharge barrels terminate in a common discharge nozzle, or in separate discharge nozzles, although not shown here. Spin mechanics assemblies are associated with each barrel such that the disparate liquids are separately swirled and are discharged through a pair of discharge orifices  13  and  14  respectively associated with the two discharge barrels, in a manner well known in the art. The liquids issue as spray cones which mix and are combined downstream of nozzle cap  15  which contains the discharge orifices and portions of the respective spin mechanics assemblies. 
   An externally mounted mixing manifold having a single discharge port is provided according to the invention to ensure intimate intermingling of spray particles of the disparate liquids so as to be delivered to the target as a thoroughly admixed dual liquid. An attachment  16  open at its upstream end defines a mixing chamber or manifold  17  by its five interconnected walls  18 ,  19 ,  21 ,  22 ,  23  ( FIGS. 2 to 4 ). The interior of the mixing chamber may be smooth walled and corner rounded as at  24  to avoid the formation of entrapped eddies at the internal corners formed during bombardment of the swirling sprays against the smooth walls for admixing. Otherwise, opposing walls  19 ,  22 , for example, may be provided with suitable arcuate vanes  25  or the like within the interior of mixing chamber  17  to enhance turbulent flow so that the conical spray plumes of disparate liquids issuing from their respective discharge orifices  13  and  14  are induced to swirl in unison in a common direction or in opposing directions, depending on the direction of the vanes. The particles of each of the sprays, from their outer peripheries to their centers, thoroughly and intimately intermingle externally to the dual sprayer. Attachment  16  is shown in  FIG. 6  mounted to the front face  34  of nozzle  15 , in its operative position. 
   Front wall  18  of the attachment has a central discharge port  26  ( FIG. 4 ) surrounded by an external nozzle  27  which may be in the form of a collar or the like. The admixed liquids issue from mixing chamber  17  through discharge port  26  and nozzle  27  to the intended target. To effect foaming, with one or both of the liquids containing a foaming agent, a fine mesh screen  28  ( FIG. 4 ) may be provided spanning discharge port  26  to enhance foaming at the time of discharge, in a manner known in the art. Also, with or without the mesh screen, mostly during the former, it may be desirable to further swirl the admixed liquids to increase the forward and spinning velocities thereof by the provision of swirl vanes  29  on the inner wall of nozzle  27  acting in a common direction. Otherwise, vanes  29  acting in opposing directions would further enhance turbulence of the mixture before exiting the nozzle. 
   Nozzle cap  15  may be provided with corner openings  31  ( FIG. 2 ) for the reception of mounting legs  32  extending in an upstream direction from the four corners of attachment  16 . The mounting legs may have shoulders  33  such that in the  FIG. 6  mounted position of the attachment, the legs are snapped into openings  31  and their shoulders  33  bear against front face  34  of the nozzle cap so as to maintain gaps  35  between the legs in the fully mounted position. The gaps define air aspiration openings through which ambient air is ingested during operation of the dual sprayer as the disparate liquids issue from their discharge orifices  13  and  14  into the mixing manifold. The ingested air aerates the mixture and, if one or more of the disparate liquids includes a foaming agent, enhances foaming by creating air bubbles before or during impact with the inner walls of the chamber and/or upon passing through mesh screen  28 . 
   In operation, with the mixing manifold attachment  16  mounted against front face  34  in  FIG. 1 , and as shown in  FIG. 6  for the  FIG. 2  variant, and assuming the dual pump to be primed, each pull of the trigger lever (not shown) pressurizes the liquids in their respective side-by-side pumping units and simultaneously discharges the disparate liquids separately through their respective discharge barrels  11  and  12  whereupon they pass through their spin mechanics assemblies (not shown) within nozzle cap  15  for particle breakup in the normal manner of the two liquids while separated for issuance through their respective discharge orifices  13  and  14  as conical spray plumes of first and second disparate liquids. The spray particles enter mixing manifold  17  where the sprays are intimately mixed together during the turbulent flow pattern created within the mixing chamber which provides an impact obstruction to knock down the fines at the outer edges of the sprays moving at highest velocity on entering the chamber to thereby focus them into the primary mix. The spray particles of the two liquids impact against the five inner walls of the attachment colliding with one another as induced by the inner contoured walls of the chamber. Swirl vanes  25  may be provided to enhance the intimate intermingling of the two sprays prior to discharge through nozzle  27  and/or to effect further turbulence. Swirl vanes  29  may be provided on the inner wall of the nozzle  27  to enhance the swirling velocity and the force at which the combined spray exits the nozzle and/or to even further enhance turbulence. Foaming of the admixed sprays, assuming one or both the sprays containing a foaming agent, can be enhanced by the provision of mesh screen  28  through which the admixture passes and collides with the strands of the mesh to effect a fine particle breakup and produce foam. 
   Other measures can be taken to ensure an even more intimate mixing of the two sprays within the mixing chamber. For example, as shown in  FIG. 5 , discharge orifices  13   a  and  14   a , respectively associated with discharge barrels  11  and  12 , can be oriented in front face  34  of nozzle cap  15  so as to be angled toward one another as shown by the arrows in  FIG. 5  so that upon exiting these orifices the sprays directly collide with one another within the mixing manifold as well as with the inner walls of the manifold to effect intimate commingling of the spray particles prior to discharge. 
   And, as shown in  FIG. 7 , the spin mechanics for each of the spray nozzles of nozzle cap are of known construction as, for example, a swirl chamber  36  and  37  associated with orifices  13  and  14  into which liquid is channeled via tangentials  38  and  39 , respectively, thus inducing swirls of the liquids entering the swirl chambers which issue through orifices  13  and  14  in the form of conical sprays. Optionally, tangentials  38  and  39  can be disposed to effect swirling in opposite directions to enhance the mixing of the liquids in mixing chamber  12 . 
   External mixing chamber  17  according to the invention functions to contour and/or incorporate the outer fine particles from each spray into the mix. Without the mixing chamber, the outer fines of each spray become airborne before they can possibly be entrained into the center. This is because the highest velocity is at the outer edge of the spray cone. The mixing chamber according to the invention provides an impact obstruction to knock them down and focus them into the primary mix. In accordance with the invention, disparate fluids are spray atomized from separate discrete swirl chambers and orifices whereafter they are force commingled in an atomized state within an external mixing manifold located downstream of the discrete swirl chambers and sprayer discharge orifices. The external mixing chamber may be of a predetermined geometry to control the degree of mixing depending on the specific spray liquids. The external mixing chamber of the invention is intended to admix separate atomized liquids prior to their hitting the target. 
   Obviously, many modifications and variations of the present invention are made possible in the light of the above teachings. For example, rather than legs on attachment  16  which provide gaps therebetween when mounted to nozzle  15 , one or both of the attachment and the nozzle cap could be provided with notches  30  ( FIG. 1 ) to define air aspiration openings. And, the external mixing chamber  17  can include some type of baffled geometry such as ribs, vanes, bumps, grooves, a rough surface finish, etc., to enhance turbulence in mixing chamber  17  and therefore provide for a more intimate combining of the two liquids before issuing through nozzle  27 . The foaming consistency can be varied by varying the size of the air aspiration openings, and screens other than mesh screens could be provided for foaming. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.