Abstract:
A manually operated trigger sprayer has an integral plastic spring and pump piston rod that are connected by a breakable connection, whereby the spring and piston rod can be assembled to the trigger sprayer as one piece and are subsequently broken into two separate pieces in response to their assembly to the trigger sprayer, or subsequent manual operation of the trigger sprayer.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention pertains to the construction of a manually operated trigger sprayer in which the conventional metal coil spring and separate piston rod are replaced with an integral plastic spring and pump piston rod that are connected by a breakable connection, whereby the spring and piston rod can be assembled to the trigger sprayer as one piece and are subsequently broken into two separate pieces in response to their assembly to the trigger sprayer, or subsequent manual operation of the trigger sprayer. 
     2. Description of the Related Art 
     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 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. 
     A typical trigger sprayer includes a sprayer housing that is connected to the neck of the bottle by either a screw thread connection or a bayonet-type connection. The sprayer housing is formed with a pump 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. 
     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. 
     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 pumps the liquid from the pump chamber, through the liquid discharge passage of the sprayer housing and out of the trigger sprayer through the nozzle assembly. 
     A metal coil spring is positioned in the pump chamber and engages with the pump piston. The coil spring biases the pump piston toward the discharge position of the piston. Some known trigger sprayers have plastic springs in their pump chambers or mounted on the exterior of the sprayer housing. 
     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 spring pushes the piston back to the charge position of the piston relative to the pump chamber when the user&#39;s squeezing force on the trigger is released. 
     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. 
     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. In the typical trigger sprayer construction where most of the component parts are molded of a plastic material, there is a cost associated with the molding of each of the individual parts and a cost associated with assembling each of the individual parts into 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, for example by reducing the number of component parts of the trigger sprayer or reducing the assembly steps required in manufacturing the trigger sprayer could result in a significant overall reduction in the cost of manufacturing large numbers of trigger sprayers. 
     SUMMARY OF THE INVENTION 
     The trigger sprayer of the present invention achieves the desired result of reducing the manufacturing costs of a trigger sprayer. This is achieved by reducing the number of separate component parts of the typical trigger sprayer construction, and reducing the separate assembly steps required by the typical trigger sprayer construction. 
     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. 
     The sprayer housing also includes a pump chamber. The pump chamber communicates with the liquid supply passage. 
     The sprayer housing also has a liquid discharge tube just above the pump chamber. A liquid discharge passage extends through the liquid discharge tube to a liquid outlet opening on the sprayer housing. The liquid discharge passage communicates the pump chamber with the liquid outlet opening. 
     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. 
     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. 
     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 to the exterior of the sprayer, and to open the liquid flow path through the liquid discharge passage and the outlet opening to the exterior of the sprayer. 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. 
     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. 
     A manually operated trigger actuator 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. 
     The novel construction of the trigger sprayer of the invention includes a piston rod that is operatively connected between the trigger and the piston assembly. The piston rod has a length with opposite first and second ends. The first, distal end of the piston rod engages with the trigger. The second, proximal end of the piston rod is connected to the piston assembly. 
     The novel construction of the trigger sprayer also includes a spring having a pair of spring arms that are integrally connected with the piston rod by a pair of breakable connections between the spring arms and the distal end of the piston rod. The pair of spring arms, the pair of breakable connections, and the piston rod are one monolithic piece of plastic material. The pair of spring arms each have the same curved lengths with opposite first and second ends. The first ends of the spring arms engage with the trigger and the second ends of the spring arms engage with the sprayer housing. The distal end of the piston rod extends from the piston assembly, between the pair of spring arms and toward the trigger. A pivoting connection is provided between the distal end of the piston rod and the trigger. 
     The pair of breakable connections between the piston rod and the spring arms of the spring enable the spring and the piston rod to be molded as one piece, thereby reducing the number of separate parts of the trigger sprayer. In addition, with the breakable connections connecting the pair of spring arms of the spring to the piston rod, the spring and the piston rod can be assembled as one piece to the trigger sprayer, thereby reducing the number of separate assembly steps for the trigger sprayer. Thus, the desire to reduce the number of separate component parts and to reduce the number of separate assembly steps to reduce the manufacturing costs of a trigger sprayer are achieved. 
     The breakable connections between the pair of spring arms and the piston rod are constructed to break, separating the pair of spring arms from the piston rod. In variant embodiments of the invention, the breakable connections between the pair of spring arms and the piston arm can be constructed to break in response to the piston rod being connected by the pivoting connection to the trigger. Additionally, the breakable connections can be constructed to break in response to relative movement between the piston rod and the spring. Still further, the breakable connections between the pair of spring arms and the piston rod can be designed to break in response to movement of the trigger relative to the sprayer housing. 
    
    
     
       DESCRIPTION OF THE DRAWINGS FIGURES 
       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: 
         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; 
         FIG. 2  is a perspective view of the disassembled component parts of the trigger sprayer; 
         FIG. 3  is a front view of the trigger actuator; 
         FIG. 4  is a side sectioned view of the trigger and integral spring and piston rod of the invention; 
         FIG. 5  is a top sectioned view of the spring and piston rod monolithically connected by a pair of breakable connections; and, 
         FIG. 6  is a top view similar to that of  FIG. 5 , but after the breakable connections between the spring and piston rod have been broken. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Several component parts of the trigger sprayer of the invention 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. 
     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 . An air vent opening  26  is also provided on the sprayer housing  12  in the interior of the connector cap  14 . 
     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 . 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 larger interior diameter portion of the pump chamber  32  with a bottle connected to the trigger sprayer. A pair of openings  44 ,  46  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  44  is the liquid input opening to the pump chamber  32 , and the second of the openings  46  is the liquid output opening from the pump chamber. 
     A liquid discharge tube is also formed on the sprayer housing  12  and provides the liquid discharge passage  48  of the sprayer housing. One end of the liquid discharge passage  48  communicates with the liquid supply passage  18  in the liquid column  22 , and the opposite end of the liquid discharge passage  48  exits the sprayer housing  12  through a liquid outlet opening  52  on the sprayer housing. 
     A valve assembly comprising an intermediate plug  54 , a resilient sleeve valve  56  and a resilient disk valve  58  is assembled into the liquid supply passage  18 . The valve assembly is inserted through the liquid inlet opening  16  and the valve assembly plug  54  seats tightly in the liquid supply passage  18  between the pump chamber input opening  44  and the pump chamber output opening  46 . Thus, the plug  54  separates the liquid inlet opening  16  into the pump chamber  32  from the liquid outlet opening  52  from the pump chamber  32 . The disk valve  58  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  56  is positioned to control the flow of liquid from the pump chamber  32  and through the liquid discharge passage  48  and the liquid outlet opening  52 , and to prevent the reverse flow of liquid. 
     A valve plug assembly comprising a valve seat  62 , a dip tube connector  64 , and an air vent baffle  66  is assembled into the liquid inlet opening  16  inside the connector cap  14 . The valve seat  62  is cylindrical and seats against the outer perimeter of the valve assembly disk valve  58 . A hollow interior bore of the valve seat  62  allows liquid to flow through the bore and unseat the disk valve  58  from the seat  62  as the liquid flows from the inlet opening  16  to the pump chamber  32 . The periphery of the disk valve  58  seats against the valve seat  62  to prevent the reverse flow of liquid. The dip tube connector  64  is a cylindrical connector at the center of the plug assembly that connects to a separate dip tube (not shown). The air vent baffle  66  covers over but is spaced from the vent opening  26  in the connector cap  14 . The baffle  66  has a baffle opening  68  that is not aligned with the vent opening  26 , but communicates with the vent opening through the spacing between the air vent baffle  66  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  68  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  68  are not directly aligned, the air vent baffle  66  prevents liquid in the bottle from inadvertently passing through the baffle opening  68 , 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. 
     A nozzle assembly  72  is assembled to the sprayer housing  12  at the liquid outlet opening  46 . The nozzle assembly  72  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  72  has a rotatable nozzle cap  74  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. 
     A piston assembly comprising a liquid pump piston  76  and a vent piston  78  is mounted in the pump chamber  32  for reciprocating movement. The pump piston  76  reciprocates between a charge position and a discharge position in the pump chamber  32 . In the charge position, the pump piston  76  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  76  moves in an opposite rearward direction into the pump chamber toward the pump chamber rear wall  38 . This forces the liquid drawn into the pump chamber  32  through the output opening  46 , past the sleeve valve  56  and through the liquid discharge passage  48  and the liquid outlet opening  52 . As the pump piston  76  reciprocates in the pump chamber  32  between the charge and discharge positions, the vent piston  78  reciprocates between a vent closed position where the vent piston  78  engages against the interior surface of the pump chamber wall  34 , and a vent open position where the vent piston  78  is spaced inwardly from the interior of the pump chamber wall  34 . In the vent open position of the vent piston  78 , air from the exterior environment of the sprayer can pass through the pump chamber opening  42 , past the vent piston  78  to the vent opening  26 , and then through the spacing between the baffle  66  and the connector cap  14 , through the vent baffle opening  68  and to the interior of the bottle connected to the trigger sprayer. 
     A center post  82  extends axially from the piston assembly to a distal end  84  of the post. A vertically oriented slot  86  extends axially into the post distal end  84 . A pair of horizontal pivot pins  86  project radially outwardly from opposite sides of the post distal end  84 . The pins  88  are positioned on opposite sides of the axial slot  86 . Thus, the slot  86  allows the pivot pins  88  to resiliently flex radially inwardly toward each other. 
     A manually operated trigger actuator  92  is mounted on the sprayer housing  12  for movement of the trigger relative to the sprayer housing. The trigger  92  has a pair of pivot pins  94  that project from opposite sides of the trigger and mount the trigger to the sprayer housing  12  for pivoting movement. 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. The construction of the trigger includes a finger engagement surface  96  that is engaged by the fingers of a user&#39;s hand. Opposite the finger engagement surface  96 , the trigger has an interior surface  98  that faces toward the sprayer housing  12 . A pair of connection posts  102  are provided on the interior surface  98 . The connection posts  102  are axially aligned and are axially spaced from each other on opposite sides of the trigger  92 . This is best seen in  FIG. 6 . 
     The novel construction of the trigger sprayer of the invention includes a spring and a piston rod that are interconnected by a breakable connection and are formed as one monolithic piece, thereby reducing the number of separate component parts that go into the construction of the trigger sprayer, and reducing the number of assembly steps required in manufacturing the trigger sprayer. 
     The spring is comprised of a pair of spring arms  104 ,  106  that are mirror images of each other and are spaced from each other, defining a void  108  between the spring arms. Each of the spring arms  104 ,  106  has a narrow, elongate length that extends between opposite first  112 ,  114  and second  116 ,  118  ends of the spring arms. In assembling the spring to the trigger sprayer, the spring arm first ends  112 ,  114  engage against the interior surface  98  of the trigger  92 . From the first ends  112 ,  114 , the lengths of the spring arms  104 ,  106  curve upwardly away from the trigger  92  and toward the sprayer housing  12 . The curved lengths of the spring arms  104 ,  106  extend over the pump chamber  32  to the second ends  116 ,  118  of the spring arms that engage with the sprayer housing  12 . The spring arm second ends  116 ,  118  engage with the sprayer housing  12  between the pump chamber  32  and the liquid discharge tube  48  of the sprayer housing. The bowed or curved configurations of the spring arms  104 ,  106  bias the trigger  92  away from the sprayer housing  12 . Manually squeezing the trigger  92  compresses the spring arms  104 ,  106  between the trigger  82  and the sprayer housing  12 , and increases the curvature of the intermediate portions of the spring arms  104 ,  106 . When the squeezing force on the trigger  82  is removed, the resiliency of the spring arms  104 ,  106  pushes the trigger away from the sprayer housing  12 . 
     A piston rod  122  is operatively connected between the trigger  92  and the liquid pump piston  76  and vent piston  78 . A circular flange  124  is provided at the rearward end of the piston rod  122 . A top flange  126  and bottom flange  128  extend forwardly from the circular flange  124  and converge toward each other. A center flange  132  connects the top flange  126  and bottom flange  128 . The circular flange  124  has a center opening  134  and the center flange  132  extends across the opening  134 . The center post distal end  84  of the piston assembly extends through the circular flange opening  132 . The center post pins  88  engage against the opposite side of the circular flange  124  from the liquid pump piston  76  and vent piston  78 , and the piston rod center flange  132  engages in the slot  86  in the piston assembly center post  82 , thereby providing a pivoting connection between the piston rod  122  and the liquid pump piston  76  and vent piston  78 . 
     The top flange  126  and bottom flange  128  of the piston rod extend forwardly toward the trigger  92  and converge to a projecting distal end  136  of the piston rod. The piston rod distal end  136  extends through the void  108  between the spring arms  104 ,  106 . Referring to  FIG. 5 , the piston rod distal end  136  is integrally connected to the spring arms  104 ,  106  by a pair of breakable connections  138 ,  142 . The breakable connections,  138 ,  142  together with the piston rod distal end  136  and the interconnected spring arms  104 ,  106  are formed as one monolithic piece as shown in  FIG. 5 . The breakable connections  138 ,  142  are specifically designed to break on relative movement between the piston rod distal end  136  and the pair of spring arms  104 ,  106 , thereby separating the piston rod  122  from the spring arms  104 ,  106 . There are several equivalent ways in which the breakable connections  138 ,  142  can break to separate the piston rod  122  from the spring arms  104 ,  106 . 
     The piston rod top flange  126  and bottom flange  128  converge toward each other and meet at a pair of piston rod sockets  144 ,  146 . The piston rod sockets  144 ,  146  are axially aligned and face in opposite directions from the opposite sides of the piston rod  122 . The piston rod distal end projects forwardly from the pair of sockets  144 ,  146 . The sockets  144 ,  146  are dimensioned to receive the trigger connection posts  102  in the sockets in assembling the piston rod  122  to the trigger sprayer. 
     In assembling the spring arms  104 ,  106  and the piston rod  122  to the trigger sprayer, the piston rod distal end  136  is moved toward the trigger interior surface  98  until the trigger connection posts  102  are positioned opposite the piston rod sockets  104 ,  106 . The resilience of the material of the trigger  92  causes the trigger connection posts  102  to snap into the piston rod sockets  144 ,  146 , thereby providing a pivoting connection between the trigger  92  and the piston rod  122 . As the piston rod  122  is moved toward the trigger interior surface  98 , the spring arms  104 ,  106  engage against the trigger interior surface  98 . Further forward movement of the piston rod  122  causes the breakable connections  138 ,  142  between the piston rod distal end  136  and the spring arms  104 ,  106  to break, thereby separating the piston rod  122  from the spring. 
     Alternatively, if connecting the piston rod  122  to the trigger  92  in the manner described above does not result in the breakable connections  138 ,  142  breaking, relative movement between the spring arms  104 ,  106  and the piston rod  122  when the trigger  92  is manually reciprocated will result in breaking the breakable connections  138 ,  142 . Furthermore, relative movement between the spring arms  104 ,  106  and the piston rod  122  as the piston rod  122  is assembled to the trigger sprayer can result in breaking the breakable connections  138 ,  142 . 
     Thus, providing the spring arms  104 ,  106  with the breakable connections  138 ,  142  to the piston rod  122  provides the spring and piston rod as a single, monolithic component part of the trigger sprayer. This reduces the number of separate component parts required to manufacture the trigger sprayer, and thereby reduces manufacturing costs. Furthermore, with the spring arms  104 ,  106  interconnected by the breakable connections  138 ,  142  to the piston rod  122 , this single component part is assembled to the trigger sprayer in the manufacturing of the trigger sprayer, thus reducing the assembly steps. This further reduces the manufacturing costs of the trigger sprayer. 
     Although the trigger sprayer of the invention has been described above by reference to a specific embodiment of the trigger sprayer, 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.