Abstract:
A manually operated trigger sprayer is constructed with a reduced number of parts and in a novel manner in which all of the component parts of the sprayer are constructed of a plastic material. The construction of the trigger sprayer replaces the conventional metal coil spring in the pump chamber with a pair of plastic bowed springs that are integral with the piston rod and are positioned outside the pump chamber. Constructing all of the sprayer parts of a plastic material enables a cost efficient recycling of the parts, which does not require disassembling the parts to remove a metal spring.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     (1) Field of the Invention.  
         [0002]     The present invention pertains to the construction of a manually operated trigger sprayer in which all of the component parts of the sprayer are constructed of a plastic material. The construction of the trigger sprayer replaces the conventional metal coil spring with a plastic bowed spring that is an integral part of the pump piston rod. Constructing all of the sprayer parts of a plastic material enables a cost efficient recycling of the parts that does not require disassembling of the parts to remove the metal spring.  
         [0003]     (2) Description of the Related Art.  
         [0004]     Handheld and hand pumped liquid dispensers commonly known as trigger sprayers are used to dispense many household products and commercial cleaners. Trigger sprayers have been used to dispense household cleaning or cooking liquids and have been designed to selectively dispense the liquids in a spray, stream, or foaming discharge. The trigger sprayer is typically connected to a plastic bottle that contains the liquid dispensed by the sprayer.  
         [0005]     A typical trigger sprayer includes a sprayer housing that is connected to the neck of the bottle by either a thread connection or a bayonet-type connection. The sprayer housing is formed with a pump chamber and a vent chamber, a liquid supply passage that communicates the pump chamber with a liquid inlet opening of the sprayer housing, and a liquid discharge passage that communicates the pump chamber with a liquid outlet opening of the sprayer housing. A dip tube is connected to the sprayer housing liquid inlet opening to communicate the pump chamber with the liquid contents of the bottle connected to the trigger sprayer.  
         [0006]     A nozzle assembly is connected to the sprayer housing at the liquid outlet opening. Some nozzle assemblies include a nozzle cap that is rotatable relative to the sprayer housing between an “off” position where liquid discharge from the trigger sprayer is prevented, and one or more “on” positions where liquid discharge from the trigger sprayer is permitted. In addition, known nozzle assemblies can affect the liquid discharged by the trigger sprayer to discharge the liquid in a spray pattern, in a stream pattern, or as a foam.  
         [0007]     A pump piston is mounted in the sprayer housing pump chamber for reciprocating movement between charge and discharge positions of the piston relative to the pump chamber. When the pump piston is moved to its charge position, the piston is retracted out of the pump chamber. This creates a vacuum in the pump chamber that draws liquid from the bottle, through the dip tube and into the pump chamber. When the pump piston is moved to its discharge position, the piston is moved into the pump chamber. This compresses the fluid in the pump chamber and pumps the fluid from the pump chamber, through the liquid discharge passage of the sprayer housing and out of the trigger sprayer through the nozzle assembly.  
         [0008]     A metal coil spring is positioned in the pump chamber and engages with the pump piston. The coil spring biases the pump piston to the discharge position of the piston.  
         [0009]     A vent piston is often provided with the pump piston and is mounted in the vent chamber. The vent piston moves with the pump piston between a vent closed position and a vent opened position in the vent chamber. In the vent opened position, the interior volume of the bottle attached to the trigger sprayer is vented through the vent chamber to the exterior environment of the trigger sprayer. In the vent closed position, the venting path of air through the vent chamber is closed, preventing leakage of liquid in the bottle through the venting flow path should the bottle and trigger sprayer be inverted or positioned on their sides.  
         [0010]     A trigger is mounted on the sprayer housing for movement of the trigger relative to the trigger sprayer. The trigger is operatively connected to the pump piston to cause the reciprocating movement of the pump piston in the pump chamber in response to movement of the trigger. A user&#39;s hand squeezes the trigger toward the sprayer housing to move the trigger and move the pump piston toward the discharge position of the piston in the pump chamber. The metal coil spring in the pump chamber pushes the piston back to the discharge position of the piston relative to the pump chamber when the user&#39;s squeezing force on the trigger is released.  
         [0011]     The metal coil spring is compressed between a rear wall of the pump chamber and the pump piston when the piston is moved to the discharge position. The compressed spring pushes the pump piston back to the charge position when the user&#39;s squeezing force on the trigger is released. The metal coil spring is typically the only component part of the trigger sprayer that is constructed of metal. The remaining component parts are all plastic.  
         [0012]     Inlet and outlet check valves are assembled into the respective liquid supply passage and liquid discharge passage of the trigger sprayer. The check valves control the flow of liquid from the bottle interior volume through the liquid supply passage and into the pump chamber, and then from the pump chamber and through the liquid discharge passage to the nozzle assembly of the trigger sprayer.  
         [0013]     The typical construction of the trigger sprayer discussed above has several separate component parts. The manufacturing of each of these individual component parts contributes to the overall cost of manufacturing the trigger sprayer. Because trigger sprayers are manufactured and sold in very large numbers, even a slight reduction in the manufacturing costs of a trigger sprayer can result in a significant overall reduction in the cost of manufacturing a large number of trigger sprayers. As a result, it is desirable to reduce the number of component parts that go into the assembly of a trigger sprayer to thereby reduce the manufacturing costs of the trigger sprayers.  
         [0014]     In addition, further cost savings related to the manufacturing of trigger sprayers can be achieved by recycling the plastic of previously manufactured sprayers. However, the cost of recycling prior art trigger sprayers is substantially increased by the need to disassemble a trigger sprayer to remove the metal coil spring. The metal spring must be removed before the remaining plastic parts are recycled. Trigger sprayers could be more cost efficiently recycled if the need to remove the metal coil spring from the trigger sprayer is eliminated.  
       SUMMARY OF THE INVENTION  
       [0015]     The trigger sprayer of the present invention achieves the desired objectives of reducing the total number of component parts that go into a trigger assembly, and eliminating the metal coil spring from those component parts. As a result, the trigger sprayer of the invention can be manufactured more cost efficiently, and the recycling of the trigger sprayer is more economical.  
         [0016]     The trigger sprayer of the invention has a sprayer housing construction that is similar to that of prior art trigger sprayers. The sprayer housing basically includes an integral cap that attaches to the neck of a separate bottle that contains the liquid to be dispensed by the trigger sprayer. A liquid inlet opening is provided on the sprayer housing inside the cap, and a liquid supply passage extends upwardly through the sprayer housing from the liquid inlet opening.  
         [0017]     The sprayer housing also includes a pump chamber having a cylindrical pump chamber wall. The pump chamber communicates with the liquid supply passage.  
         [0018]     A liquid discharge passage extends through a liquid discharge tube on the sprayer housing. The liquid discharge passage communicates the pump chamber with a liquid outlet opening on the sprayer housing.  
         [0019]     A valve assembly is inserted into the liquid supply passage and separates the liquid supply passage from the liquid discharge passage. The valve assembly includes an input valve that controls the flow of liquid from the sprayer housing inlet opening to the pump chamber, and an output valve that controls the flow of liquid from the pump chamber and through the liquid discharge passage to the liquid outlet opening.  
         [0020]     A valve plug assembly is assembled into the liquid supply passage of the sprayer housing. The valve plug assembly includes a valve seat that seats against the input valve, and a vent baffle that defines a vent air flow path through the pump chamber to the interior of the bottle attached to the trigger sprayer.  
         [0021]     A nozzle assembly is assembled to the trigger sprayer at the sprayer housing liquid outlet opening. The nozzle assembly is rotatable relative to the trigger sprayer to close the liquid flow path through the liquid discharge passage and the liquid outlet opening, and to open the liquid flow path through the liquid discharge passage and the outlet opening. The nozzle assembly has several open positions relative to the sprayer housing that enable the selective discharge of a liquid in a stream pattern, a spray pattern, and a foaming discharge.  
         [0022]     A piston assembly is mounted in the pump chamber for reciprocating movements between charge and discharge positions of the piston assembly relative to the sprayer housing. The piston assembly includes a pump piston and a vent piston both mounted in the pump chamber. As the pump piston moves to its charge position, the vent piston is moved to a closed position where a venting air flow path through the pump chamber and through the venting air baffle is closed. As the pump piston is moved to its discharge position, the vent piston is moved to an open position in the pump chamber. This opens the venting air flow path through the pump chamber and the venting air baffle to the interior volume of the bottle attached to the trigger sprayer.  
         [0023]     A manually operated trigger is mounted on the sprayer housing for pivoting movement. The trigger is engaged by the fingers of a user&#39;s hand holding the trigger sprayer. Squeezing the trigger causes the trigger to move toward the pump chamber, and releasing the squeezing force on the trigger allows the trigger to move away from the pump chamber.  
         [0024]     The novel construction of the trigger sprayer of the invention includes a piston rod that is operatively connected between the trigger and the pump piston. The piston rod has a length with opposite first and second ends, with the first end engaging with the trigger and the second end being connected to the pump piston.  
         [0025]     The novel construction of the trigger sprayer also includes a pair of springs that are formed integrally with the piston rod. In the preferred embodiment, the pair of springs and the piston rod are one monolithic piece of plastic material. The pair of springs each have a length with opposite proximal and distal ends. The length of each spring is curved or formed in a bowed configuration. The proximal end of each spring is connected to the piston rod intermediate the piston rod first and second ends. From the proximal ends of the springs, the springs extend away from the piston rod and curve over the exterior of the pump chamber wall. The curved lengths of the springs extend across opposite sides of the sprayer housing discharge tube as the springs extend from the piston rod. As the spring lengths extend along opposite sides of the discharge tube, the spring lengths then curve back toward the pump chamber of the sprayer housing. The spring lengths end at free distal ends of the springs, whereby both of the bowed springs cantilever from the piston rod. The distal ends of the springs engage against the sprayer housing and are the only portions of the springs to engage with the sprayer housing.  
         [0026]     The bowed configurations of the springs bias the piston rod and the pump piston away from the pump chamber. This biases the pump piston toward its charge position relative to the pump chamber and the sprayer housing. By manually squeezing the trigger of the trigger sprayer, the proximal ends of the springs are moved toward the distal ends of the springs, increasing the curvature of the bowed springs. When the squeezing force on the trigger is removed, the resiliency of the springs pushes the trigger away from the pump chamber and moves the pump piston back to its charge position relative to the pump chamber.  
         [0027]     By providing the bowed springs as an integral part of the pump piston rod in lieu of the conventional coiled metal spring positioned in the pump chamber, the component parts of the trigger sprayer are reduced. This results in reduced manufacturing costs.  
         [0028]     In addition, by providing the pair of springs as an integral part of the pump piston rod, the springs are constructed of the same piece of material as the pump piston rod. This eliminates the need for a metal coil spring and enables all of the component parts of the trigger sprayer to be constructed of plastic material. With all of the sprayer parts being constructed of plastic, the trigger sprayer can be recycled more economically. 
     
    
     DESCRIPTION OF THE DRAWING FIGURES  
       [0029]     Further features of the invention are set forth in the following detailed description of the preferred embodiment of the invention and in the drawing figures wherein:  
         [0030]      FIG. 1  is a side sectioned view of the trigger sprayer of the invention with the trigger in a forward position relative to the sprayer housing;  
         [0031]      FIG. 2  is a perspective view of the disassembled component parts of the trigger sprayer;  
         [0032]      FIG. 3  is a front view of the trigger sprayer;  
         [0033]      FIG. 4  is a top view of the trigger sprayer with the shroud removed; and,  
         [0034]      FIG. 5  is a side sectioned view of the trigger sprayer along the line  5 - 5  of  FIG. 4  and with the trigger in a rearward position relative to the sprayer housing. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0035]     As stated earlier, the novel design of the trigger sprayer of the present invention enables each of the component parts of the trigger sprayer to be constructed of a resilient, plastic material. In addition, the novel construction enables several component parts to be constructed of one, monolithic piece of material, that were in the past constructed of several separate pieces. This results in a reduction in the manufacturing costs. The all plastic construction of the trigger sprayer enables the sprayer to be more economically recycled after use.  
         [0036]     Several component parts of the trigger sprayer are found in the typical construction of a trigger sprayer, and therefore these component parts are described only generally herein. It should be understood that although the component parts are shown in the drawing figures and are described as having a certain construction, other equivalent constructions of the component parts are known. These other equivalent constructions of trigger sprayer component parts are equally well suited for use with the novel features of the invention to be described herein.  
         [0037]     The trigger sprayer includes a sprayer housing  12  that is formed integrally with a connector cap  14 . The connector cap  14  removably attaches the trigger sprayer to the neck of a bottle containing the liquid to be dispensed by the trigger sprayer. The connector cap  14  shown in the drawing figures has a bayonet-type connector on its interior. Other types of equivalent connectors may be employed in attaching the trigger sprayer to a bottle. A liquid inlet opening  16  is provided on the sprayer housing  12  in the interior of the connector cap  14 . The inlet opening  16  provides access to a liquid supply passage  18  that extends upwardly through a cylindrical liquid column  22  formed in the sprayer housing  12 . The column  22  has a center axis  24  that is also the center axis of the liquid supply passage  18 . An air vent opening  26  is also provided on the sprayer housing  12  in the interior of the connector cap  14 . A cylindrical sealing rim  28  projects outwardly from the connector cap interior and extends around the liquid inlet opening  16  and the vent opening  26 . The rim  28  engages inside the neck of a bottle connected to the trigger sprayer to seal the connection.  
         [0038]     The sprayer housing includes a pump chamber  32  contained inside a cylindrical pump chamber wall  34  on the sprayer housing  12 . The pump chamber cylindrical wall  34  has a center axis  36  that is perpendicular to the liquid supply passage center axis  24 . The interior surface of the pump chamber wall  34  has a smaller interior diameter section adjacent a rear wall  38  of the pump chamber, and a larger interior diameter section adjacent an end opening  42  of the pump chamber. The smaller interior diameter portion of the pump chamber  32  functions as the liquid pump chamber, and the larger interior diameter portion of the pump chamber  32  functions as a portion of a venting air flow path through the sprayer housing  12 . The vent opening  26  in the sprayer housing connector cap  14  communicates the interior of the larger interior diameter portion of the pump chamber  32  with a bottle connected to the trigger sprayer. A pair of openings  46 ,  48  pass through the pump chamber rear wall  38  and communicate the interior of the pump chamber with the liquid supply passage  18 . The first of the openings  46  is the liquid input opening to the pump chamber  32 , and the second of the openings  48  is the liquid output opening from the pump chamber.  
         [0039]     A liquid discharge tube  52  is also formed on the sprayer housing  12 . The liquid discharge tube is cylindrical and has a center axis  54  that is parallel with the pump chamber center axis  36 . The liquid discharge tube  52  defines the liquid discharge passage  58  of the sprayer housing. One end of the liquid discharge passage  58  communicates with the liquid supply passage  18  in the liquid column  22 , and the opposite end of the liquid discharge passage  58  exits the sprayer housing  12  through a liquid outlet opening  62  on the sprayer housing.  
         [0040]     The sprayer housing  12  is also formed with a pair of exterior side walls or side panels  64  that extend over opposite sides of the pump chamber wall  34  and over opposite sides of the discharge tube  54 . The side walls  64  extend over the pump chamber wall  34  in the area of the pump chamber rear wall  38 , but do not extend in the forward direction the full extent of the pump chamber wall  34  to the end opening  42 . The side walls  64  are spaced outwardly from the pump chamber wall  34  and the discharge tube  54  forming voids  66  between the side wall  64  and the pump chamber wall  34  and the discharge tube  54 . The side walls  64  have lengths on the opposite sides of the liquid discharge tube  54  that extend substantially the entire length of the discharge tube. Rear walls  68  of the sprayer housing  12  extend outwardly from opposite sides of the liquid column  22  and connect to the rearward edges of the side walls  64 .  
         [0041]     A valve assembly comprising an intermediate plug  72 , a resilient sleeve valve  74  and a resilient disk valve  76  is assembled into the liquid supply passage  18 . The valve assembly is inserted through the liquid inlet opening  16  and the valve assembly plug  72  seats tightly in the liquid supply passage  18  between the pump chamber input opening  46  and the pump chamber output opening  48 . Thus, the plug  72  separates the liquid inlet opening  16  into the pump chamber  32  from the liquid outlet opening  62  from the pump chamber  32 . The disk valve  76  is positioned in the liquid supply passage  18  to control the flow of liquid from the liquid inlet opening  16  into the pump chamber  32 , and to prevent the reverse flow of liquid. The sleeve valve  74  is positioned to control the flow of liquid from the pump chamber  32  and through the liquid discharge passage  58  and the liquid outlet opening  62 , and to prevent the reverse flow of liquid.  
         [0042]     A valve plug assembly comprising a valve seat  78 , a dip tube connector  82 , and an air vent baffle  84  is assembled into the liquid inlet opening  16  inside the connector cap  14 . The valve seat  78  is cylindrical and seats against the outer perimeter of the valve assembly disk valve  76 . A hollow interior bore of the valve seat  78  allows liquid to flow through the bore and unseat the disk valve  76  from the seat  78  as the liquid flows from the inlet opening  16  to the pump chamber  32 . The periphery of the disk valve  76  seats against the valve seat  78  to prevent the reverse flow of liquid. The dip tube connector  82  is a cylindrical connector at the center of the plug assembly that connects to a separate dip tube (not shown). The valve plug assembly positions the dip tube connector  82  so that it is centered in the connector cap  14  of the sprayer housing. The air vent baffle  84  covers over but is spaced from the vent opening  26  in the connector cap  14 . The baffle  84  has a baffle opening  86  that is not aligned with the vent opening  26 , but communicates with the vent opening through the spacing between the air vent baffle  84  and the interior surface of the connector cap  14 . This allows air to pass through the vent opening  26  and through the baffle spacing and the baffle opening  86  to vent the interior of the bottle connected to the trigger sprayer to the exterior environment of the sprayer. Because the vent opening  26  and baffle opening  86  are not directly aligned, the air vent baffle  84  prevents liquid in the bottle from inadvertently passing through the baffle opening  86 , the baffle spacing and the vent opening  26  to the exterior of the trigger sprayer should the trigger sprayer and bottle be inverted or positioned on their sides.  
         [0043]     A nozzle assembly  92  is assembled to the sprayer housing  12  at the liquid outlet opening  62 . The nozzle assembly  92  can have the construction of any conventional known nozzle assembly that produces the desired discharge pattern of liquid from the trigger sprayer. In the preferred embodiment of the invention, the nozzle assembly  92  has a rotatable nozzle cap  94  that selectively changes the discharge from a “off” condition where the discharge is prevented, to a “spray” condition, a “stream” condition and/or a foaming discharge.  
         [0044]     A piston assembly comprising a liquid pump piston  102  and a vent piston  104  is mounted in the pump chamber  32  for reciprocating movement along the pump chamber axis  36 . The pump piston  102  reciprocates between a charge position and a discharge position in the pump chamber  32 . In the charge position, the pump piston  102  moves in a forward direction away from the pump chamber rear wall  38 . This expands the interior of the pump chamber creating a vacuum in the chamber that draws liquid into the pump chamber, as is conventional. In the discharge position, the pump piston  102  moves in an opposite rearward direction into the pump chamber toward the pump chamber rear wall  38 . This compresses the liquid drawn into the pump chamber  32  and forces the liquid through the output opening  48 , past the sleeve valve  74  and through the liquid discharge passage  58  and the liquid outlet opening  62 . As the pump piston  102  reciprocates in the pump chamber  32  between the charge and discharge positions, the vent piston  104  reciprocates between a vent closed position where the vent piston  102  engages against the interior surface of the pump chamber wall  34 , and a vent open position where the vent piston  104  is spaced inwardly from the interior of the pump chamber wall  34 . In the vent open position of the vent piston  104 , air from the exterior environment of the sprayer can pass through the pump chamber opening  42 , past the vent piston  104  to the vent opening  26 , and then through the spacing between the baffle  84  and the connector cap  14 , through the vent baffle opening  86  and to the interior of the bottle connected to the trigger sprayer.  
         [0045]     A manually operated trigger  112  is mounted on the sprayer housing  12  for movement of the trigger relative to the sprayer housing. The trigger  112  has a pair of pivot posts  114  that project from opposite sides of the trigger and mount the trigger to the sprayer housing  12  for pivoting movement. A pair of abutments  116  project outwardly from the pivot posts  114  and limit the pivoting movement of the trigger  112  toward the sprayer housing  12 . The construction of the trigger includes a finger engagement surface that is engaged by the fingers of a user&#39;s hand. Squeezing the trigger causes the trigger to pivot rearwardly toward the pump chamber  32 , and releasing the squeezing force on the trigger allows the trigger to pivot forwardly away from the pump chamber.  
         [0046]     The novel construction of the trigger sprayer of the invention includes a piston rod  122  that is operatively connected between the trigger  112  and the pump piston  102  and vent piston  104 . The piston rod  122  has a length with a cylindrical collar  124  at one end of the rod length. The cylindrical collar  124  is assembled to the pump piston  102  and vent piston  104 . The opposite end  126  of the piston rod  122  engages with and is operatively connected to the trigger  112 .  
         [0047]     The novel construction of the trigger sprayer also includes a pair of springs  132  that are formed integrally with the piston rod  122 . Together the springs  132  and the piston rod  122  are one, monolithic piece of plastic material, thereby reducing the number of separate component parts that go into the construction of the trigger sprayer. The pair of springs  132  each have a narrow, elongate length that extends between opposite proximal  134  and distal  136  ends of the springs. The intermediate portions  138  of the springs between the proximal ends  134  and distal ends  136  have the same, curved or bowed configuration. The spring proximal ends  134  are connected to the piston rod  122  intermediate the opposite ends  124 ,  126  of the piston rod. From the proximal ends  134 , the lengths of the springs curve upwardly away from the piston rod  22  and the pump chamber center axis  36  through the intermediate portions  138  of the springs. As the lengths of the springs continue along the spring intermediate portions  138 , the springs extend along opposite sides of the liquid discharge tube  154  and over the pump chamber wall  34 . The springs then extend downwardly toward the pump chamber center axis  36  as the springs extend to their distal ends  136 . Each of the springs  132  is cantilevered from the piston rod  122  from the spring proximal ends  134 , with the spring distal ends  136  being free ends. The spring distal ends  136  engage against the sprayer housing rear walls  68 , with the spring distal ends  136  being the only portions of the springs that engage with the sprayer housing  12 .  
         [0048]     The bowed or curved configurations of the springs  132  bias the piston rod  122  and the connected pump piston  102  and vent piston  104  outwardly away from the pump chamber rear wall  138 . This biases the pump piston  102  toward its charge position relative to the pump chamber  32  and the sprayer housing  12 . By manually squeezing the trigger  112 , the spring proximal ends  134  move toward the spring distal ends  136 , increasing the curvature of the bowed intermediate portions  138  of the springs. When the squeezing force on the trigger  112  is removed, the resiliency of the springs pushes the trigger  112  away from the pump chamber rear wall  38  and moves the pump piston  102  back to its charge position relative to the pump chamber  32 .  
         [0049]     A shroud  142  is attached over the sprayer housing  12  to provide an aesthetically pleasing appearance to the trigger sprayer. The shroud  142  has a lower edge  144  that is positioned below the pair of springs  132 . Thus, the shroud  142  protects the springs  132  from contact with portions of the hand or other objects exterior to the trigger sprayer when the trigger sprayer is being operated.  
         [0050]     By providing the bowed springs  132  as an integral part of the pump piston rod  122  in lieu of the conventional coiled metal spring positioned in the pump chamber, the component parts of the trigger sprayer are reduced. This results in reduced manufacturing costs for the trigger sprayer.  
         [0051]     In addition, by providing the pair of springs  132  as an integral part of the pump piston rod  122 , the springs are constructed of the same piece of material as the pump piston rod. This eliminates the need for a separate metal coil spring and enables all of the component parts of the trigger sprayer to be constructed of a plastic material. With all the sprayer parts being constructed of plastic, the trigger sprayer can be recycled more economically after use.  
         [0052]     Although the trigger sprayer of the invention has been described above by reference to a specific embodiment, it should be understood that modifications and variations could be made to the trigger sprayer without departing from the intended scope of the following claims.