Abstract:
A chemical concentrate reservoir system for use with a hand held trigger sprayer device and a bottle reservoir includes a chemical reservoir for containing a chemical concentrate; a first adapter connected with the chemical reservoir and having a mixing chamber with at least one inlet and an outlet; wherein the bottle reservoir and the chemical reservoir are in fluid communication with the mixing chamber through said at least one inlet; a first valve at the inlet of the mixing chamber for selective control of fluid flow into said mixing chamber; and a fluid conduit connected with the outlet of the mixing chamber and with the hand held trigger sprayer device.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to a trigger sprayer reservoir system for containing multiple fluids, and more particularly, to a reservoir system allowing for the mixing of a diluent and a chemical concentrate within the reservoir system prior to the mixture entering and being sprayed by a standard trigger sprayer head. 
       BACKGROUND OF THE INVENTION 
       [0002]    Hand held trigger sprayers have been in use and commercially available for decades. Trigger sprayers are typically used to apply a single fluid to a surface by spraying the fluid contained within a bottle through a sprayer head. In such standard sprayer-reservoir systems, a feed tube from a trigger sprayer extends down into a bottle or reservoir. Squeezing the trigger activates a positive displacement pump and evacuates any fluid residing in the pump chamber out through a spray nozzle. Releasing the trigger creates a vacuum which draws fluid from the reservoir into the sprayer pump chamber. The liquids in such reservoirs are generally mixtures of a chemical concentrate and a diluent, such as water. Such mixtures are typically created ahead of time, and deposited within the bottle as needed. 
         [0003]    However, as such hand held trigger sprayers are often used by cleaning or maintenance personnel, a single bottle often has insufficient capacity to hold enough of a mixture to last an entire shift. Thus, when a bottle empties, a worker must stop working and travel back to an often central location where a large amount of pre-mixed solution is kept to refill the bottle. This is an inefficient use of a worker&#39;s time. 
         [0004]    Several sprayers have been created which are designed to hold two separate fluids, such as a chemical concentrate and a diluent (such as water), and to combine such liquids on demand via a specialized spray head. This allows workers to possess enough concentrate for an entire shift, and to refill the water diluent from readily available sources as needed. 
         [0005]    However, such dual fluid sprayer systems are relatively complicated, and often require a complete redesign of standard trigger sprayer heads. Even previous systems which attempt to solve this problem simply, such as that shown in U.S. Pat. No. 5,439,141 to Clark et al., still require some modification to a standard sprayer head. For example, in Clark, the sleeve which press fits into the throat and creates a ball check valve arrangement must be modified or replaced to practice that invention. 
         [0006]    Thus, there is a need for an improved sprayer reservoir system allowing for the mixing of a diluent and a chemical concentrate within the reservoir system that does not require a completely custom trigger sprayer head. 
       SUMMARY OF THE INVENTION 
       [0007]    One aspect of the invention generally pertains to refillable chemical concentrate reservoir that is able to be utilized with standard trigger sprayer heads and bottle reservoir with only minor modifications, if any, required thereto. 
         [0008]    Another aspect of the invention pertains to a chemical concentrate reservoir for use with a trigger sprayer head that provides an enhanced method of refilling that prevents overfilling of the reservoir. 
         [0009]    In accordance with one or more of the above aspects of the invention, there is provided a chemical concentrate reservoir system for use with a hand held trigger sprayer device and a bottle reservoir that includes a chemical reservoir for containing a chemical concentrate; a first adapter connected with the chemical reservoir and the bottle reservoir and having a mixing chamber with at least one inlet and an outlet; wherein the bottle reservoir and the chemical reservoir are in fluid communication with the mixing chamber through the at least one inlet; a first valve at the at least one inlet of the mixing chamber for selective control of fluid flow from the bottle reservoir and the chemical reservoir into the mixing chamber; and a fluid conduit connected with the outlet of the mixing chamber and with the hand held trigger sprayer device. 
         [0010]    There is also provided a chemical concentrate reservoir system for use with a hand held trigger sprayer device and a bottle reservoir that includes a chemical reservoir for containing a chemical concentrate; a first adapter connected with the chemical reservoir and the bottle reservoir and having a mixing chamber with at least one inlet and an outlet; wherein the bottle reservoir and the chemical reservoir are in fluid communication with the mixing chamber through the at least one inlet; a first valve at the at least one inlet of the mixing chamber for selective control of fluid flow from bottle reservoir and the chemical reservoir into said mixing chamber; a fluid conduit connected with the outlet of the mixing chamber and with the hand held trigger sprayer device; and a second adapter connected between the chemical reservoir and the hand held trigger sprayer device and also connected with the fluid conduit and comprising a conduit for allowing the flow of fluid from the fluid conduit to the hand held trigger sprayer device, the second adapter also includes a filling port that is in fluid communication with the chemical reservoir. 
         [0011]    These aspects are merely illustrative of the innumerable aspects associated with the present invention and should not be deemed as limiting in any manner. These and other aspects, features and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the referenced drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    Reference is now made more particularly to the drawings, which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views. 
           [0013]      FIG. 1  is a perspective view of a reservoir system according to a second embodiment. 
           [0014]      FIG. 2  is a side section view of the reservoir system. 
           [0015]      FIG. 3  is a rear section view of the reservoir system showing the trigger sprayer head and filling device to which the system is connected for filling. 
           [0016]      FIG. 4  is a section view of the draw tube adapter of the reservoir system of  FIG. 3 . 
           [0017]      FIG. 5  is a section view of the reservoir system showing the trigger sprayer head and filling device to which the system is connected for filling. 
           [0018]      FIG. 6  is a side section view of the reservoir system showing the trigger sprayer head and filling adapter. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    In the following detailed description numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. For example, the invention is not limited in scope to the particular type of industry application depicted in the figures. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention. 
         [0020]      FIGS. 1-6  illustrate a refillable chemical reservoir system  100  for a trigger sprayer head  200  and bottle reservoir (not shown) containing a diluent according to a preferred embodiment of the present invention. The trigger sprayer head would be attachable to the bottle reservoir by means of a threaded neck on the bottle reservoir and a corresponding threaded collar  201  on the trigger sprayer head  200 . 
         [0021]    The system further includes a chemical reservoir  110 . The chemical reservoir  110  in the illustrated embodiment is provided with an elongated, cylindrically shaped body  112 . The body  112  is advantageously provided with a diameter that is at least marginally smaller than the diameter of the neck of the bottle reservoir so that the chemical reservoir  110  can be inserted through the neck of and into the bottle reservoir. The chemical reservoir  110  incorporates at its bottom end a draw tube  114  that extends toward the bottom of the bottle reservoir. 
         [0022]    The draw tube  114  is connected with the body  112  of the chemical reservoir  110  by a draw tube adapter  116 . The draw tube adapter  116  has a first male tubing nipple  118  located at its bottom end that is arranged to engage and retain one end of the draw tube  114 . The adapter  116  has at its top end a second male tubing nipple  120 , which in some cases may be of a larger diameter than the first tubing nipple  118 , arranged to engage and retain the bottom end of the chemical reservoir body  112 . A flange  122  having a diameter exceeding the inside diameter of at least the bottom end of the chemical reservoir body  112  separates the first  118  and second  120  male tubing nipples. The flange  122  also serves, in combination with a series of ridges  124  encircling the second tubing nipple  120 , to seal the bottom end of the chemical reservoir body  112 . Each of the ridges  124  engages in a sealing contact with the interior of the chemical reservoir body  112 , while the flange  122  engages the end surface of the chemical reservoir body  112 . 
         [0023]    The adapter  116  is also provided with a longitudinal, central passage  126  extending through the length of the adapter  116 . As discussed in more detail below, the adapter&#39;s central passage  126  provides a flow path, which is controlled by other elements discussed below, for diluent from the bottle reservoir, through the draw tube  114 , into the mixing chamber  162 . 
         [0024]    At the middle portion of the adapter  116  there is provided a segmented divider  128 . The segmented divider  128  separates the adapter  116  into top and bottom sections. In the embodiment of  FIG. 4 , the segmented divider  128  takes the form of a circular opening that is coaxial with the central passage  126  and having a series of spokes  130  extending laterally from the edge of the circular opening toward and meeting near the middle of the circular opening. The open areas between the spokes  130  allow for the flow of diluent from the bottom section to the top section of the adapter  116 . 
         [0025]    At the center of the circular opening where the spokes  130  converge, there is provided a central orifice. This central orifice is arranged to accommodate the stem  134  of an umbrella valve  132 . The stem  134  is inserted through the central orifice, which is sized to prevent flow of diluent around the valve stem  134 . The valve flap  136  of the umbrella valve  132  lies over the top side of the segmented divider  128  and completely covers the open areas between the spokes  130 . In a first, sealing position—to which the valve  132  is biased, the valve flap  136  lies against the top surface of the divider  128  to prevent the flow of diluent through the open areas between the spokes  130 . When the valve flap  136  is raised from the top surface of the divider  128 , e.g., by a lowering of ambient pressure above the valve  132 , diluent can flow through the open areas between the spokes  130  and into the top section of the adapter  116 . 
         [0026]    The adapter  116  is also provided with an insert  142  positioned within the top section of the adapter  116 . In the illustrated embodiment, the insert  142  slidingly engages with the top section of the adapter  116 . Advantageously, the outer diameter of the insert  142  is sized to have a press fit with the interior diameter of the top section of the adapter  116  to secure the insert into place. The insert  142  has an annular flange  144  at its upper, outside edge to limit the depth of insertion of the insert  142  into the adapter  116 . 
         [0027]    The insert  142  is provided with two upwardly facing cavities. The first of these cavities  146  is in communication with and remains open to the interior of the chemical reservoir body  112 . The second cavity  148  is intended to communicate with an inner draw tube  140  as described in more detail below. An interior dividing wall  150  separates the first and second cavities from one another, and a bottom wall  152  partially encloses the bottom end of the insert  142  and the cavities. 
         [0028]    At the bottom of the first cavity  146 , there is provided a metering orifice  154  in the bottom wall  152  that communicates with the first cavity  146  and allows for the flow of chemical concentrate from the chemical reservoir through the first cavity  146 . Flow of chemical concentrate through the metering orifice  154  is controlled by a second umbrella valve  156 . As with the first umbrella valve  132  described above, the second such valve is provided with a stem  158  and valve flap  160 . The valve stem  158  is inserted into a vertical opening in the bottom wall  152  of the insert  142  to secure the valve  156  in place. The valve flap  160  is positioned to lie against the bottom surface of the bottom wall  152  and seal the metering orifice  154  in the valve&#39;s biased position. When the valve flap  160  is allowed to move away from the bottom wall  152 , chemical concentrate is able to flow through the bottom wall  152  of the insert  142  via the metering orifice  154 . 
         [0029]    As can be seen most clearly in  FIG. 4 , there is an open area within the adapter  116  located between the bottom wall  152  of the insert  142  and the top of the segmented divider  128 . This open area represents a mixing chamber  162 . It is in the mixing chamber  162  that diluent flowing through the segmented divider  128  and chemical concentrate flowing through metering orifice  154  are intermingled to create the desired dispensing product. The ratios of diluent and chemical concentrate that are mixed together in the mixing chamber  162  are controlled by adjusting the size of the open areas between the spokes  130  of the segmented divider  128  and the flow area of the metering orifice  154 . Alternately, or in combination with adjustment of the respective flow areas of the segmented divider  128  and metering orifice  154 , the ratio of diluent and chemical concentrate can be adjusted through the use of different valve types in the segmented divider  128  and metering orifice  154  or by using valves having different performance characteristics, for example, varying durometers and/or cracking pressures. 
         [0030]    While the illustrated embodiment makes use of umbrella valves in connection with the segmented divider  128  and metering orifice  154 , those of skill in the art will recognize that other types of valves may be utilized with the present invention. 
         [0031]    In the bottom wall  152  of the insert  142  there is provided an opening into the second cavity  148 . In the illustrated embodiment, this opening remains open to the mixing chamber  162  at all times and permits the flow of mixed diluent and chemical concentrate from the mixing chamber  162  into the second cavity  148 . 
         [0032]    The chemical reservoir  110  also incorporates an inner draw tube  140  that is largely contained within the chemical reservoir body  112 . The inner draw tube  140  is oriented longitudinally within the chemical reservoir body  112  and is connected at one end with the trigger sprayer  200  and at its other end with the insert  142 . The inner draw tube  140  provides a conduit for the flow of a diluent/chemical mixture to the trigger sprayer  200  for dispensing. 
         [0033]    The first cavity  148  of the insert  142  is advantageously formed to slidingly accommodate the bottom end of the inner draw tube  140 . The top of the first cavity  148  is provided with the upwardly extending circular wall  164 . An O-ring seal  168  is arranged to sealingly engage the outer surface of the inner draw tube  140  and prevent flow of mixed diluent/chemical concentrate around the outside of the inner draw tube  140  back into the interior of the chemical reservoir body  112 . In alternate embodiments, an annular groove is provided along the interior surface of the circular wall  164  to accommodate the O-ring seal  168 . 
         [0034]    A filling adapter  170  is positioned at the top of the chemical reservoir  110 . The filling adapter  170  is advantageously arranged to cooperate with a novel filling station, described in more detail below, to allow nearly automated refilling of the chemical reservoir  110  with chemical concentrate. As with many of the other components described herein, the filling adapter  170  is connected to the body  112  of the chemical reservoir by means of a nipple section  172  having a series of ridges  174  and a flange  176 . Each of the ridges  174  engages in a sealing contact with the interior of the chemical reservoir body  112 , while the flange  176  engages the end surface of the chemical reservoir body  112 . The filling adapter is divided into a top portion  178  and a bottom portion  180 , which are divided by a wall  182 . The bottom portion  180  is in largely open fluid communication with the interior of the chemical reservoir body  112 , while the top portion  178  is isolated from the chemical reservoir body  112  by dividing wall  182 . 
         [0035]    The filling adapter  170  includes two interior tube structures. The first is a fluid tube  184 , into which the top end of the inner draw tub  140  is inserted. The fluid tube  184  passes through wall  182  and extends upwardly through the top portion  178  of the filling adapter  170 . The second tube is a float check valve tube  186  and houses a float check valve  188 , which is involved in the filling operation as described in more detail below. The float check valve tube  186  terminates at an orifice in wall  182 , which allows selective fluid communication between the top portion  180  of the filling adapter  170  and the float check valve tube  186  as described in more detail below. 
         [0036]    In the illustrated embodiment, the float check valve  188  is formed by a generally cylindrical valve body with a seal mounted on the top end of the valve body. The valve body has a diameter larger than that of the orifice in wall  182  but smaller than the inside diameter of the float check valve tube  186 . This arrangement keeps the float check valve from passing through the orifice at the top of the float check valve tube  186 . At the bottom end of the float check valve tube  186 , a retainer keeps the float check valve  188  from falling out of the float check valve tube  186 . 
         [0037]    When the float check valve  188  is positioned at the top of the float check valve tube  186 , the seal of the float check valve  188  engages the orifice in wall  182  to seal the orifice and prevent fluid communication from the top portion  178  of the filling adapter to the float check valve tube  186  and into the chemical reservoir body  112 . As the float check valve  188  drops away from the wall  182 , fluid communication is possible between the top portion  178  of the filling adapter and the interior of the chemical reservoir body  112 , with fluid, including air, being able to pass through the orifice, between the valve body and the interior of the float valve check tube  186  and out the bottom end of the float valve check tube  186 . 
         [0038]    The filling adapter  170  also includes two ports in one of its exterior walls: a filling port  190  and an air port  194 . In a preferred embodiment, the filling port  190  and air port  194  are arranged on the same side of the filling adapter  170 , one above the other. More particularly, the air port  194  is oriented above the filling port  190 . The air port  194  is positioned in the top portion  178  of the filling adapter above wall  182 , while the filling port  190  is in the bottom portion  180  of the filling adapter and below wall  182 . In this arrangement, the filling port  190  is in direct fluid communication with the interior of the chemical reservoir body  112 . As can be seen in  FIG. 5 , the filling port  190  is outside of the float check valve tube  186 . In one embodiment, the filling port  190  is positioned at a vertical level higher than the bottom of the float check valve tube  186 . In another embodiment, the air port  194  is positioned further above the filling port  190  and in a position that places it outside of the bottle reservoir when the chemical reservoir system is inserted therein. 
         [0039]    A trigger sprayer adapter  198  is positioned at the top of the filling adapter  170 . The trigger sprayer adapter  198  is formed primarily from a cylindrical fluid passage. At its bottom end, the trigger sprayer adapter  198  is arranged to engage the top end of the fluid tube  184  of the filling adapter. At its top end, the trigger sprayer  198  engages the trigger sprayer  200 . The trigger sprayer adapter  198  serves two primary purposes: it conveys the concentrate/diluent mixture from the fluid tube  184  of the filling adapter  170  to the trigger sprayer head  200 ; and it seals the top portion  178  of the filling adapter  170 . 
         [0040]    The trigger sprayer head  200  is of a generally conventional design utilizing a trigger actuated pump cylinder  204  and a dispensing path  206  fluidly connected with the pump cylinder and leading to a nozzle  208 . The nozzle  208  may be of the spinning adjustment type or fixed. The trigger sprayer head  200  also incorporates an entry cylinder  202  to which the top end of the trigger sprayer adapter connects to fluidly connect the trigger sprayer head  200  to the inner draw tube  140  via the fluid tube  184  of the filling adapter  170 . A check valve  203  in the entry cylinder  202  prevents back flow of fluid once drawn into the trigger sprayer head  200  during the compression stroke of the pump cylinder  204 . The trigger sprayer head  200  operates in a known manner to draw fluid from the fluid path formed by the entry cylinder  202 , trigger sprayer adapter  198 , fluid tube  184 , and inner draw tube  140  into the trigger sprayer head  200  during the return stroke of the trigger. During the compression stroke of the trigger, check valve  203  closes in reaction to the increase in pressure created by the stroke of the pump cylinder  204 . Fluid trapped with the trigger sprayer head  200  is forced into the dispensing path  206  and out nozzle  208 . 
         [0041]      FIGS. 1 ,  3 , and  5  illustrate a novel filling station  210  suitable for use with this embodiment of the chemical reservoir system  100 . The filling station  210  is contained within a housing  218  that may be wall mounted and is arranged with supporting elements to hold one or more chemical reservoir systems  100  for the purpose of refilling the reservoirs. These supporting elements include upper supporting arms  212 , lower supporting arms  216 , and a securing clip  214 , which keeps the chemical reservoir system in place during the refilling operation. In alternate embodiments, the securing clip  214  may be incorporating into the upper supporting arms  212 . The refilling station  210  further incorporates a bulk chemical concentrate source (not shown) and a vacuum source, e.g., a pump, (also not shown) of known design. The bulk chemical concentrate source and vacuum source may be located within housing  212  or located remotely and connected by tubes, piping or similar means. Within the housing  212  is a manifold comprised of a chemical outlet  220  with a chemical nipple  222  for attachment of a tube or pipe leading from the bulk chemical concentrate source. The manifold also includes an air outlet  224  having a nipple  226  for connection to the vacuum source. The outer ends of the chemical  220  and vacuum  224  outlet paths are provided with outlet seals  221 ,  225  (preferably O-ring seals) that sealingly engage with the filling  190  and air  194  ports of the filling adapter  170 . 
         [0042]    When chemical reservoir system  100  is placed into the filling station  210 , the filling  190  and air  194  ports of the filling adapter are aligned with the chemical  220  and air  224  outlets, respectively, of the filling station  210 . Advantageously, the upper  212  and lower  216  supporting arms and securing clip  214  are arranged to position the chemical reservoir system  100  in a manner that aids the alignment of the ports of the respective components. When the outer ends of the chemical  220  and air  224  outlet paths engage the filling  190  and air  194  ports of the filling adapter  170 , the filling port  192  and air port  196  check valves are pushed open to create a continuous conduit between the filling port  190  and chemical outlet  220  and between the air port  194  and the air outlet  224 . Seals  221 ,  225  engage with the filling  190  and air  194  ports to prevent leaks during the filling process. In alternate embodiments, one or both of the chemical  220  and air  224  outlets may also be provided with check valves  223  to prevent possible back flow of fluid or air and allow for the chemical  220  and air  224  outlets to be shut off when no chemical reservoir system  100  is docked. This positive shut off feature allows multiple filling stations  210  to be connected together in series and operated from a single vacuum source and/or bulk chemical concentrate source. 
         [0043]    Having described the structure of the illustrated embodiment, the filling and dispensing operations of the system will now be explained. 
       Filling/Refilling Operation 
       [0044]    As can be seen from the figures and above description, a reservoir is formed within the chemical reservoir body  112  for the retention of chemical concentrate in preparation for mixing with a diluent and subsequent dispensing. In order to fill or refill this reservoir with chemical concentrate, the system  100  is first placed into the filling station  210  in the manner described above. As noted above, this places the top portion  178  of the filling adapter  170  into fluid communication with the vacuum pump via the air port  194  and air outlet  224 . In addition, the bottom portion  180  of the filling adapter is placed into fluid communication with the bulk chemical concentrate source via the filling port  190  and chemical outlet  220 . At this point, the system  100  is ready for filling or refilling. 
         [0045]    First, the vacuum source is activated. Activation of the vacuum source may occur manually or automatically as result of the chemical reservoir system  100  being placed into the filling station  210 , for example by means of a trigger switch activated by contact with the system  100 . The vacuum source acts to draw air from the reservoir through the float check valve tube  186 , which is open at this stage due to the downward biasing of the float check valve  188  and the absence of any counteracting buoyant force. As air is removed from the reservoir, the pressure within the reservoir drops thereby drawing chemical concentrate from the bulk source through the chemical outlet  220  and fluid port  190  and into the reservoir. 
         [0046]    The vacuum source continues to operate, and chemical concentrate continues to be drawn into the reservoir, until the reservoir is nearly filled. As chemical concentrate fills the reservoir and reaches the level of the float check valve  188 , it forces the float check valve  188  upward until the check valve seal engages the orifice in wall  182 . This disconnects the reservoir from the vacuum pump, resulting in the pressure within the reservoir equalizing. At this point, chemical concentrate ceases to be drawn from the bulk source. As can be readily seen, this particularly advantageous arrangement automatically results in complete filling of the reservoir while eliminating the possibility of overfilling and damage to the chemical reservoir system  100 . It should be noted that the filling port  190  in the illustrated embodiment is advantageously arranged at a higher vertical position than the bottom of the float check valve tube  188 . As the vertical positioning of the filling port  190  will directly impact the fill level of the reservoir, this higher positioning allows for more complete filling of the reservoir. 
         [0047]    In one embodiment, the vacuum source utilized with the filling station  210  is sensitive to changes in its air intake and automatically shuts off in reaction to the increase in resistance experienced once the float check valve  188  closes. Such a system provides the added benefit of minimizing the need for operator involvement and the possibility of damage to the vacuum pump. 
         [0048]    In an alternate embodiment, a positive pressure pump is utilized to push chemical concentrate from a bulk source into the reservoir. In such an embodiment, air within the reservoir is forced out of the reservoir through the air port as chemical concentrate fills the reservoir. 
         [0049]    When filling is complete, the chemical reservoir system  100  may be removed from the filling station  210 , whereupon the filling port check valve  192  and air port check valve  196  automatically close to seal the reservoir. The system is ready for dispensing at this point. 
         [0050]    It should be noted that while a preferred embodiment of a filling station has been described herein, the chemical reservoir system  100  may be utilized without such a station. Further, it is possible to use variants of the described filling station. For example, a pump may be incorporated into the chemical supply path of the filling station such that fluid is pumped into the chemical reservoir, resulting in air being forced out of the chemical reservoir body through the air port instead of a vacuum pump being used. 
       Mixing/Metering Operation 
       [0051]    As previously noted, the trigger sprayer head  200  draws fluid upward from the inner draw tube  140  in a known manner through the action of the pump cylinder  204 . The manner in which fluid is introduced into the inner draw tube  140  is now described. Prior to an initial dispense after refilling, chemical concentrate is stored within the chemical reservoir body  112  while diluent is stored within the bottle reservoir. The inner draw tube  140  and mixing chamber  162  are generally empty. 
         [0052]    Upon operation of the pump cylinder  204  with a first depression of the trigger followed by the return stroke of the pump cylinder  204 , air is drawn from the space in the inner draw tube  140  and mixing chamber  162 , thereby reducing the pressure within this space. This reduces the pressure exerted on the surfaces of the valve flaps  136 ,  160  of the first and second umbrella valves  132 ,  156  relative to the pressure present within the bottle reservoir and the chemical reservoir, respectively, which allows the valve flaps,  136 ,  160  to move away from their biased closed positions. This motion opens flow paths from both the bottle reservoir and the interior of the chemical reservoir body  112 —through the segmented divider  128  and metering orifice  154 , respectively to allow diluent and chemical concentrate to flow into the mixing chamber  162 . 
         [0053]    As the return stroke of the pump cylinder  204  is completed, the pressure within the inner draw tube  140  and mixing chamber  165  is allowed to equalize relative to the pressure within the bottle reservoir and the chemical reservoir. This equalization of pressure forces the valve flaps  136 ,  160  back into their sealing positions, thereby preventing additional diluent and chemical concentrate from flowing into the mixing chamber  162  and inner draw tube  140 . 
         [0054]    With subsequent return strokes of the pump cylinder  204 , mixed chemical concentrate and diluent are drawn up the inner draw tube  140  and into the trigger sprayer for dispensing through the nozzle  208  as the mixing chamber  162  is simultaneously filled with fresh chemical concentrate and diluent. 
         [0055]    As will be appreciated by those of skill in the art, the chemical reservoir systems described herein provide a system that allows for the use of generally standard trigger sprayer components, in particular, trigger sprayer heads and reservoir, while rendering those components readily refillable with predetermined quantities of chemical concentrate. This allows for the use of bulk chemical sources while ensuring a consistently proper concentrate/diluent ratio. 
         [0056]    The preferred embodiments of the invention have been described above to explain the principles of the invention and its practical application to thereby enable others skilled in the art to utilize the invention in the best mode known to the inventors. However, as various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.