Patent Publication Number: US-2003230641-A1

Title: High viscosity liquid sprayer nozzle assembly

Description:
BACKGROUND OF THE INVENTION  
       [0001] (1) Field of the Invention  
       [0002] The present invention pertains to a nozzle assembly for a hand held and hand operated liquid sprayer typically called a trigger sprayer. In particular, the present invention pertains to a nozzle assembly for a trigger sprayer employed in dispensing viscous liquids. The nozzle assembly produces enhanced dispersion and uniformity in the spray pattern of the viscous liquid dispensed by the trigger sprayer.  
       [0003] (2) Description of Related Art  
       [0004] Hand held and hand operated liquid sprayers commonly known as trigger sprayers are well known in the liquid sprayer art. Trigger sprayers are commonly used to dispense household cleaning or cooking liquids in a stream or spray pattern of the liquid. A trigger sprayer is typically connected to a plastic bottle containing the liquid dispensed by the trigger sprayer.  
       [0005] A typical trigger sprayer is comprised of a sprayer housing that is connected to a neck of the bottle by either a threaded connection or a bayonet-type connection. The sprayer housing is formed with a pump chamber, a liquid discharge passage communicating with the pump chamber and a liquid supply passage communicating with the pump chamber.  
       [0006] A piston is mounted in the pump chamber for reciprocating movements of the piston between charge and discharge positions. A spring is usually provided on the sprayer housing for biasing the piston toward its charge position.  
       [0007] A trigger is mounted on the sprayer housing by a pivot connection at one end of the trigger. The trigger is also connected to the pump piston. Repeating the sequence of manually squeezing the trigger toward the sprayer housing against the bias of the pump spring and then releasing the trigger, oscillates the trigger about its pivot connection and reciprocates the pump piston between its charge and discharge positions relative to the pump chamber.  
       [0008] A pair of check valves or one way valves are positioned in the sprayer housing, one between the pump chamber and the liquid discharge passage and one between the pump chamber and the liquid supply passage. The liquid supply passage includes a dip tube that extends from the sprayer housing into the interior of the bottle, communicating the liquid contained in the bottle through one of the check valves to the pump chamber.  
       [0009] A nozzle assembly having a discharge orifice is assembled to the liquid discharge passage. The liquid discharge passage usually contains a liquid spinner assembly. The spinner assembly has a liquid spinner head at one end adjacent the nozzle orifice and the second of the check valves at its opposite end. The spinner assembly check valve controls the liquid flow from the pump chamber to the liquid discharge passage and prevents the reverse flow.  
       [0010] From the manual oscillating movement of the trigger that reciprocates the pump piston in the pump chamber, the liquid is drawn from the bottle through the dip tube to the pump chamber. The liquid is then pumped from the pump chamber through the liquid discharge passage and through the liquid spinner and discharge orifice and is dispensed from the trigger sprayer in a conical spray pattern.  
       [0011] The typical trigger sprayer described above is well suited for dispensing liquids having a viscosity similar to that of water, for example various types of cleaning liquids. However, when the sprayers are employed in dispensing more viscous liquids like cooking oil, problems are encountered.  
       [0012] With the limited dimensions of the swirl chamber at the head of the spinner assembly and the limited size of the nozzle orifice, an adequate spin cannot be produced in the more viscous liquids dispensed through the typical trigger sprayer to produce an acceptable discharge pattern of the liquid sprayed from the sprayer. Other types of sprayer nozzle assemblies have been developed for more viscous liquids. These other types of sprayer nozzle assemblies do not include a spinner assembly with a swirl chamber that spins the liquid prior to its discharge from the nozzle orifice. Instead, viscous liquid sprayers typically employ a plurality of angled discharge orifices, often two orifices, that direct streams of the viscous liquid discharged from the trigger sprayer at an angle toward each other. The streams of the liquid impact with each other and are dispersed in a spray pattern. However, because the impacting streams of viscous liquid and the spray pattern they produce are outside the discharge orifices of the sprayer nozzle, the sprayer nozzle has no control over the spray pattern produced and the spray pattern of the viscous liquid is often non-uniform.  
       SUMMARY OF THE INVENTION  
       [0013] The shortcomings of the prior art high viscosity liquid trigger sprayer are overcome by the sprayer nozzle assembly of the present invention which produces a more uniformly dispersed spray pattern of viscous liquids discharged by the nozzle assembly. The trigger sprayer with which the nozzle assembly of the invention is used is formed in the typical configuration including a pump chamber, a liquid discharge passage communicating with the pump chamber, and a liquid supply passage communicating with the pump chamber. A dip tube is assembled to the liquid supply passage and extends into the interior of the bottle when the trigger sprayer is attached to the bottle. The pump piston is mounted in the pump chamber for reciprocating movement of the piston. The trigger is mounted on the trigger sprayer for pivoting movement relative to the sprayer. The trigger is also connected to the pump piston to cause the pump piston to reciprocate between its charge and discharge positions in the pump chamber in response to manual manipulation of the trigger. The trigger sprayer also contains a pair of check valves, one controlling the flow from the dip tube to the pump chamber and preventing the reverse flow. The high viscosity liquid sprayer nozzle assembly of the invention is designed to be used with many types of manual hand held and operated sprayers having this typical construction.  
       [0014] The nozzle assembly of the invention is basically comprised of a nozzle housing containing a flow control member, where the nozzle housing is constructed to be assembled to the liquid discharge passage of most constructions of trigger sprayers. In the preferred embodiment, the nozzle housing and flow control member are both constructed of plastic.  
       [0015] The nozzle housing of the invention has a liquid conduit having a length with opposite upstream and downstream ends. The liquid conduit is dimensioned so that it can be easily attached to the liquid discharge passage of a typical trigger sprayer. The conduit contains a liquid passage having opposite upstream and downstream ends. When assembled to the trigger sprayer, the upstream end of the liquid passage communicates with the liquid discharge passage of the trigger sprayer.  
       [0016] The nozzle housing also has an orifice wall at the downstream end of the liquid conduit. An interior surface of the orifice wall that faces the conduit liquid passage has an axially recessed cavity at its center. A discharge orifice passes through the orifice wall at the center of the cavity. The discharge orifice has a cross-section area with an oblong, preferably rectangular shape.  
       [0017] The interior surface of the orifice wall is conical. A plurality of radial slots are provided in the orifice wall conical surface and extend between the conduit interior surface and the orifice wall cavity, defining a plurality of liquid flow channels that are circumferentially arranged around the recessed cavity.  
       [0018] The flow control member has an axial length with opposite upstream and downstream ends and is positioned in the liquid conduit of the nozzle housing. The flow control member has an elongate stem extending along its length with a flow control head at the downstream end and a valve element at the upstream end of the member. The valve element is designed to seat over an inlet opening to the liquid discharge passage of the trigger sprayer with which the nozzle assembly of the invention is used. In the preferred embodiment, the valve element is a diaphragm or disk valve, although other types of valves may be employed. The flow control head has a conical surface that projects to an apex at the extreme downstream end of the flow control member. With the flow control member positioned in the liquid conduit of the nozzle housing, the conical surface of the head engages against the conical surface of the orifice wall and covers over portions of the plurality of liquid flow channels formed by the slots in the orifice wall. The apex of the flow control head is positioned in the recessed cavity in the orifice wall and is centered relative to the orifice.  
       [0019] In operation of the trigger sprayer employing the nozzle assembly of the invention, viscous liquid pumped from the pump chamber of the sprayer passes through the liquid discharge passage of the trigger sprayer and past the valve element of the flow control member into the liquid conduit of the nozzle housing. The valve element functions to prevent the reverse flow of liquid from the liquid conduit back to the pump chamber. The liquid is pumped through the liquid conduit to the flow control head at the downstream end of the flow control member. The periphery of the flow control head directs the flow of liquid around the head and the conical surface of the flow control head directs the flow of liquid through the plurality of liquid flow channels formed by the radial slots in the orifice wall. Thus, the flow control head and the plurality of liquid flow channels formed by the slots initially break up the flow of viscous liquid into several streams spacially arranged around the orifice and moving toward the orifice. These several separate streams are further directed by the conical surface of the flow control head and the pluralities of liquid flow channels past the apex of the flow control head to a position where the pluralities of streams impact or collide with each other. The position of the point of collision of the plurality of streams is inside the recessed cavity in the orifice wall and at the center of the entrance to the orifice in the orifice wall. The dispersion of the plurality of separate streams of liquid colliding with each other at the entrance of the orifice is shaped by the oblong configuration of the orifice as the liquid dispersed by the collision of the plurality of streams passes through the orifice. The oblong or rectangular configuration of the orifice forms the dispersion pattern of the liquid into a narrow fan spray pattern oriented uprightly or vertically relative to the trigger sprayer held in the hand of the user.  
       [0020] By the operation of the novel construction of the liquid spray nozzle assembly of the invention described above, the nozzle assembly disperses viscous liquid in a uniform fan sprayed pattern that is easily employed by a user of the nozzle assembly of the invention to direct the spray of viscous fluid where desired. 
     
    
    
     DESCRIPTION OF THE DRAWINGS  
     [0021] Further features of the invention are revealed in the following detailed description of the preferred embodiment of the invention and in the drawing figures wherein:  
     [0022]FIG. 1 is a side sectioned view of the viscous liquid sprayer nozzle assembly of the invention employed on the liquid discharge passage of a typical hand held and operated trigger sprayer;  
     [0023]FIG. 2 is a side sectioned view of the sprayer nozzle assembly of the invention removed from the trigger sprayer liquid discharge passage;  
     [0024]FIG. 3 is an end cross-sectioned view of the nozzle assembly of FIG. 2 from the plane of line  3 - 3  in FIG. 2;  
     [0025]FIG. 4 is a side sectioned view of the nozzle housing of the nozzle assembly;  
     [0026]FIG. 5 is an end section view of the nozzle housing from the plane of line  55  of FIG. 4;  
     [0027]FIG. 6 is an end view of the nozzle housing from the plane of line  6 - 6  in FIG. 4; and,  
     [0028]FIG. 7 is a perspective view of the flow control member of the nozzle assembly of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0029]FIG. 1 is a partial, side-sectioned view of a sprayer apparatus comprising the nozzle assembly  12  of the present invention assembled to a conventional trigger sprayer  14  of the type disclosed in U.S. Pat. No. 4,958,754, assigned to the assignee of the present invention and incorporated herein by reference. Generally, the portions of the trigger sprayer shown in FIG. 1 include a portion of the trigger sprayer housing  16  and a portion of a covering shroud  18  assembled over the housing. Because the constructions of conventional trigger sprayers are well known in the art, only a portion of the trigger sprayer  14  with which the nozzle assembly  12  of the invention is used is shown in FIG. 1.  
     [0030] Contained inside the sprayer housing  16  is a tubular, vertical riser  22  shown at the right in FIG. 1. The lower end of the riser communicates with a dip tube (not shown) that extends downwardly into the liquid contained in the bottle container (not shown) to which the trigger sprayer  14  is attached. Together, the riser  22  and dip tube form a portion of the liquid supply passage that supplies the liquid of the container to the trigger sprayer pump chamber (not shown). As seen in FIG. 1, the upper end of the riser  22  is formed with an annular valve seat  24  on which rests a ball valve  26 . The ball valve  26  and valve seat  24  form the check valve that controls the flow of liquid from the bottle container through the dip tube and riser  22  to the pump chamber, but prevent the reverse flow of liquid.  
     [0031] A vertical fluid conducting column  28  of the sprayer housing  16  surrounds the tubular riser  22 . The interior passage of the fluid column  28  communicates with the trigger sprayer pump chamber. In addition, the interior of the fluid column  28  communicates with the liquid discharge passage  32  of the trigger sprayer defined by a tubular duct  34  of the sprayer housing  16 . The tubular duct  34  has an inlet opening  36  at the right end of the duct as viewed in FIG. 1 that communicates the liquid discharge passage  32  within the duct with the liquid passage of the fluid column  28 . An outlet opening  38  is provided at the opposite end of the duct  34 . The duct  34  has a cylindrical interior surface  42  that surrounds the discharge passage  32 . The inlet opening  36  and the outlet opening  38  are coaxial with a center axis  44  of the discharge passage  32 . On operation of the trigger sprayer pump (not shown) liquid is drawn into the pump through the fluid column  28  and past the ball valve  26  and valve seat  24 , and then is pumped to the liquid discharge passage  32  through the interior passage of the fluid column  28  and through the inlet opening  36  of the discharge passage.  
     [0032] The nozzle assembly  12  of the invention is shown assembled to the trigger sprayer  14  in FIG. 1, and is shown disassembled from the trigger sprayer in FIG. 2. The nozzle assembly  12  is basically comprised of the nozzle housing  46  and the fluid control member  48  contained in the nozzle housing. In the preferred embodiment, the nozzle housing and flow control member are both constructed of plastic. The nozzle assembly  12  of the invention is designed to be used with many types of manual handheld and operated sprayers having the typical construction of a trigger sprayer described earlier.  
     [0033] The nozzle housing  46  has a tubular conduit  52  with a cylindrical exterior surface  54  and a cylindrical interior surface  56 . The conduit exterior surface  54  is dimensioned to fit through the discharge passage outlet opening  38  and tightly against the interior surface  42  of the discharge passage in mounting the nozzle housing  46  to the trigger sprayer  14 . The conduit interior surface  56  defines a liquid passage  58  extending through the conduit from an upstream end  62  of the conduit to a downstream end  64  of the conduit. The conduit upstream end  62  is opened so that the conduit liquid passage  58  communicates with the discharge passage  32  of the trigger sprayer. The conduit  52  also has a center axis  66  that is coaxial with the center axis  44  of the trigger sprayer discharge passage.  
     [0034] The nozzle housing  46  also includes an orifice wall  68  at the conduit downstream end  64 . The orifice wall  68  has an exterior surface  72  that faces the exterior environment of the trigger sprayer, and an opposite interior surface  74  inside the liquid passage  58  of the conduit. A cylindrical, exterior cavity  76  is recessed axially into the orifice wall exterior surface  72  to an exterior cavity surface  78  in the cavity. The cylindrical exterior cavity  76  is coaxial with the conduit center axis  66 . On the opposite side of the orifice wall, a cylindrical interior cavity  82  is recessed axially into the orifice wall interior surface  74  to an interior cavity surface  84  in the orifice wall. The cylindrical interior cavity  82  is concentric with the conduit center axis  66 .  
     [0035] A liquid discharge orifice  86  passes through the reduced thickness portion of the orifice wall  68  between the exterior cavity  76  and the interior cavity  82 . As best seen in FIGS. 5 and 6, the discharge orifice  86  has a cross sectional area that is oblong with a length of the discharge orifice being larger than a width of the discharge orifice. FIGS. 5 and 6 show the length of the discharge orifice  86  oriented vertically relative to the trigger sprayer  14 . In a variant embodiment, the length of the discharge orifice  86  could be oriented horizontally relative to the trigger sprayer. The discharge orifice  86  is centered relative to the exterior cavity  76 , the interior cavity  82  and the conduit center axis  66 .  
     [0036] The portion of the orifice interior surface  74  that surrounds the interior cavity  82  is conical. As seen in FIGS. 1 and 2, as the interior surface  74  extends radially outwardly from the interior cavity  82  it also tapers axially toward the conduit upstream end  62 . As best seen in FIG. 5, a plurality of slots  92  are formed axially into the orifice wall interior surface  74 . The slots are circumferentially spaced around the conduit center axis  66  and extend radially outwardly from the interior cavity  82  to the conduit interior surface  56 . As best seen in FIGS. 1 and 2, each of the slots  92  has a triangular interior area when viewed in cross section. As best seen in FIG. 5, at least a pair of the slots  92  are aligned with the oblong length of the discharge orifice  86 . Each of the slots  92  forms a liquid channel directing the flow of liquid from the conduit liquid passage  58  toward the interior cavity  82  and the discharge orifice  86  as will be explained.  
     [0037] The fluid flow control member  48  is shown assembled in the nozzle housing  46  and trigger sprayer  14  in FIG. 1 and is shown removed from the nozzle housing and trigger sprayer in FIG. 7. The flow control member  48  has an elongate stem  94  with an axial length between a first, downstream end  96  of the member and a second, upstream  98  of the member. A valve element  102  in the form of a resilient disk valve is provided on the stem upstream end  98 . The diameter of the valve element  102  is dimensioned to overlie the inlet opening  36  of the discharge passage  32 . The valve element  102  also functions as a spring, exerting a pushing force on the stem  94  to the left or in the downstream direction through passage  32 . A flow control head  104  is provided at the first, downstream or opposite end  96  of the stem  94 . The flow control head  104  has a circular peripheral surface  106  that gives the head a circular cross section. From the peripheral surface  106 , the flow control head has a conical surface  108  that projects in a downstream direction from the stem to an apex  112  of the cone formed by the surface. With the fluid control member  48  positioned in the trigger sprayer discharge passage  32  and the nozzle housing conduit  52 , the length of the stem  94  positions the valve element  102  against the discharge passage inlet opening  36  and positions the head conical surface  108  in engagement with the orifice wall conical interior surface  74 . The head conical surface projects in a downstream axial direction to the apex  112  of the surface that is positioned in the volume of the orifice wall interior cavity  82 . The engagement of the periphery of the head conical surface  108  with the orifice wall conical interior surface  74  causes the head conical surface  108  to extend over portions of the radially extending slots  92  formed in the orifice wall interior surface  74 . This defines a plurality of fluid flow breakup channels in the conduit liquid passage  58  that extend from the peripheral surface  106  of the flow control head, through the plurality of slots  94  and across the conical surface  108  of the flow control head toward the discharge orifice  86 . In the example of the preferred embodiment of the invention, the four radially extending slots  92  will break up fluid flow through the discharge passage  32  and conduit liquid passage  58  into four streams of liquid that are directed toward each other and impact adjacent the apex  112  of the flow control head conical surface  108 .  
     [0038] In operation of the trigger sprayer  14  employing the nozzle assembly  12  of the invention, viscous liquid is pumped from the pump chamber (not shown) of the sprayer upwardly through the annular space between the housing fluid column  28  and the tubular riser  22 . The viscous liquid passes through the inlet opening  36  of the sprayer discharge passage  32  and unseats the valve element  102  of the flow control member. The viscous liquid enters the discharge passage  32  and flows in a downstream direction or to the left as viewed in FIG. 1 over the exterior surface of the stem  94  of the flow control member toward the flow control head  104  at the downstream end of the flow control member. The peripheral surface  106  of the flow control head directs the flow of liquid around the head and the liquid enters the plurality of slots  94  in the orifice wall conical interior surface  74  at the periphery of the flow control head. The conical surface  108  of the flow control head engaging with the orifice wall conical interior surface  74  directs the flow of liquid through the plurality of liquid flow channels formed by the radial slots  92  in the orifice wall. Thus, the flow control head  104  and the plurality of liquid flow channels formed by the slots  92  initially break up the flow of viscous fluid into several streams, in this example four streams, spatially arranged around the discharge orifice  86  and moving toward the orifice. These several separate streams of liquid are further directed by the flow control head conical surface  108  and the plurality of slots  92  toward the conical surface apex  112  where the pluralities of liquid streams impact or collide with each other inside the interior cavity  82  of the orifice wall  68 . The impact of the liquid streams inside the orifice wall interior cavity  82  occurs at the entrance to the discharge orifice  86 . The impact or collision of the liquid streams at the entrance to the discharge orifice  86  causes the liquid to disburse as it passes into the orifice and the dispersion of the liquid is shaped by the oblong configuration of the orifice as the liquid passes through the orifice. The oblong or rectangular configuration of the orifice  86  forms the dispersion pattern of the liquid into a narrow fan spray pattern oriented uprightly or vertically relative to the trigger sprayer held in the hand of the user. In the alternate embodiment where the oblong shape of the discharge orifice  86  is positioned horizontally, the dispersion pattern of the liquid would be a narrow fan spray pattern oriented horizontally relative to the trigger sprayer held in the hand of the user.  
     [0039] From the operation of the liquid spray nozzle assembly  12  of the invention described above, the nozzle assembly disperses viscous liquid in a more uniform fan sprayed pattern that is easily employed by the user of the nozzle assembly and trigger sprayer to which it is attached to direct the spray of viscous liquid where desired.  
     [0040] While the present invention has been described by reference to a specific embodiment, it should be understood that modifications and variations of the invention may be constructed without departing from the scope of the invention defined in the following claims.