Abstract:
A portable, battery-powered sprayer for dispensing two liquid products at the same time includes first and second nozzles which receive first and second liquids and first and second air supplies. The nozzles are arranged to dispense the liquids at different flow rates, with different droplet sizes, and into different target zones. A low battery sensor prevents operation when the batteries have insufficient power to produce the intended flow rates and droplet sizes.

Description:
BACKGROUND OF THE INVENTION 
   This invention relates to a portable sprayer and is particularly concerned with a sprayer for treating an area with two different products in a single pass. The sprayer is particularly adapted for applying mosquito control products, although its use is not limited to this application. 
   The most effective treatment of an area for mosquito control results from the application of two products. The first product, known as a knockdown product or knockdown treatment, is designed to kill mosquitoes already in a treatment zone. It is most effective when applied as an ultra low volume (ULV) spray or fog with small, lightweight droplet sizes. The second product, known as a barrier product or barrier treatment, is designed to prevent mosquitoes from entering the treatment zone. It is best applied in larger, heavier droplet sizes that impinges on plants and foliage with a material that repels and/or kills mosquitoes. The difference in required droplet sizes for the knockdown product and barrier product dictates that two separate nozzles be used to distribute the two products. This has been done commercially with a variety of units, all having separate sprayers. 
   Some prior art ULV sprayers of this type are mounted on a truck and are engine-powered. Similarly, truck-mounted mist blowers having very large blasts of air are powered by gasoline engines. With these types of units mounted on trucks there is ample space to accommodate separate nozzles and ample power available to drive them. Such is not the case with sprayers intended for household or consumer use. Other prior art sprayers have ULV nozzles in a hand-held unit powered by a small gasoline engine or an electric motor using a power cord. There are also prior art barrier product sprayers that supply a liquid stream only. That is, there is no air mixed with the liquid. These are available for nursery and household use in both truck-mounted and hand-cart mounted units. They are powered both by gasoline engines and electric motors, including battery powered motors. 
   Household sprayers need to be portable, preferably hand-held units which do not require an electrical cord. Because of these limitations in portable units, the conventional practice in household sprayers has been to make two separate passes with two separate nozzles, one for applying the knockdown product and one for applying the barrier product. Obviously, this is not the most convenient arrangement since making two passes takes twice as long as making one pass. Also, with this conventional practice either two entirely separate sprayers must be used or a single sprayer must have its nozzle and product supply reservoir changed after the first pass. Neither of these arrangements is optimal. 
   Furthermore, it is desirable to use battery power for household sprayers because rechargeable batteries are more convenient to use compared to units powered by gasoline engines or household current, the latter requiring a long, unwieldy extension cord. While hand-held, battery-powered sprayers are preferable from a convenience standpoint, the batteries are limited in the amount of power they can supply so the sprayer must be designed to minimize power use and make changing the battery pack simple and quick. It has not previously been feasible to have a dual-output sprayer including a ULV nozzle in a hand-held, battery-powered unit. 
   SUMMARY OF THE INVENTION 
   A primary object of the present invention is a portable sprayer having dual output nozzles for applying two separate products at the same time. 
   Another object of the invention is a sprayer of the type described in which the nozzles produce different droplet sizes. 
   Yet another object of the invention is a sprayer which is battery powered. 
   A further object of the invention is a sprayer having dual product chambers with quick connect fluid connectors between the chambers and the fluid lines supplying product to the pump. 
   Still another object of the invention is a sprayer of the type described which detects a low voltage condition in the batteries and prevents operation of the unit under such conditions. 
   These and other desired benefits of the invention, including combinations of features thereof, will become apparent from the following description. It will be understood, however, that a device could still appropriate the claimed invention without accomplishing each and every one of these desired benefits, including those gleaned from the following description. The appended claims, not these desired benefits, define the subject matter of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of the sprayer of the present invention. 
       FIG. 2  is a side elevation view of the sprayer and charging cradle assembly, with some parts in section and one half of the housing case removed to expose the interior components. 
       FIG. 3  is a perspective view of the reservoir cartridge connectors and supply lines. 
       FIG. 4  is an exploded perspective view of the ULV nozzle which dispenses the knockdown product. 
       FIG. 5  is an exploded perspective view of the wind tunnel of the barrier dispensing nozzle, shown rotated about its axis 90° from its installed position. 
       FIG. 6  is an exploded perspective view of the barrier dispensing nozzle shroud, also shown rotated about its axis 90° from its installed position. 
       FIG. 7  is an exploded perspective view of the battery pack. 
       FIG. 8  is a perspective view of the underside of the battery pack, showing the latch. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The portable sprayer of the present invention is shown generally at  10  in  FIG. 1 . The sprayer includes a housing  12  in which most of the sprayer components are contained. The most prominent components visible on the exterior of the housing are the shrouds  14 ,  16  of the first and second spray nozzles. The shrouds protrude from the housing  12 . They have a ledge that engages the interior of the housing to keep the shrouds from being pulled out of the housing. Knurled collars  18 ,  20  engage the shrouds to prevent them from being pushed into the housing. The liquid emitter mounting brackets  22 ,  24  of the first and second nozzles are partially visible within the shrouds  14 ,  16 . The liquid emitters themselves are described more fully below. Beneath the second nozzle shroud  16  there is a door  26  that provides access to a liquid reservoir compartment. This door may also function as a lever for actuating a reservoir support tray. 
   Other externally-visible features of the sprayer include a handle  28  and a control switch  30  on the top of the handle. In front of the switch there are a pair of openings or windows  32 ,  34  through which operational indicators can be viewed. The indicators may be as simple as an LED which shows when the battery is charging. Or the indicators could include a more complicated readout showing the user the battery charge level, the amount of liquid left in the product chambers, or similar information. 
   The housing  12  is split vertically into two case-like halves.  FIG. 2  illustrates the sprayer resting in its charging cradle  36  with one housing half removed so the internal components are visible. The housing half  12 A includes a top wall  38 , a bottom wall  40 , a rear wall  42  and a side wall  44 . The top wall  38  curves upwardly toward the front of the housing so that together with the handle  28  it defines an opening  46  that receives a user&#39;s hand. At its peak the top wall  38  slopes downwardly at an angled wall  48  to meet with the front wall  50 . The door  26  forms much of the front wall. It will be noted that the handle  28  is hollow so a wiring harness (not shown) can be run through it to the control switch  30  and the indicators on top of the handle. The front of the housing has a pair of nozzle openings  52  and  54  through which the first and second nozzle  14  and  16  extend. 
   The housing has a plurality of internal walls or partitions that define various compartments. Front and rear vertical partitions  60 ,  62  each have a cutout portion  64 . The cutouts receive the wind tunnel  66  as will be explained. Beneath the wind tunnel and between the vertical partitions  60 ,  62  there is a pump compartment  68 . A divider wall  70  extends from the rear vertical partition  62  to the rear wall  42 . It defines a battery compartment  72  and a control circuit compartment  74 . Top and bottom horizontal walls  76 ,  78  join the front vertical partition  60  and extend to the front of the housing to define the liquid reservoir compartment  80 . The bottom wall  78  has an opening that receives a connector support beam  82  for a quick-connect fluid connector. The female mating half of the fluid connector (not shown) is mounted in the bottom of the reservoir cartridge. Just underneath the corner of the bottom wall  78  and front vertical partition  60  are passages (one of which is shown at  84 ) for the fluid supply lines. 
   Near the junction of the rear vertical partition  62  and the bottom wall  40  there is an indentation in the bottom wall that forms a charging receptacle  86 . Electrical connectors are located here to electrically connect the battery pack to a charging electrode extending upwardly from the cradle  36 . At the lower left corner of the charging receptacle the bottom wall has a catch  88 . The catch is engageable with a latch on the battery pack to retain the battery pack in the battery compartment  72 . In this regard it will be noted that the bottom wall  40  does not extend to meet with the rear wall  42 . Instead, the battery pack  120  forms the bottom rear corner of the sprayer unit when it is installed. This construction allows a user to remove and replace the battery pack with just one hand, as will be explained more fully below. 
   The other housing half is similar. The housing halves may be fastened together with screws or the like. Each housing half will also include a plurality of mounting posts or pads which receive screws for attachment of the various components in their respective compartments. 
   Turning now to the components mounted in the housing, a description of the liquid reservoir cartridge will be given first. The liquid reservoir cartridge itself is partially visible at  90 . The reservoir is a replaceable, twin-chamber cartridge or package. Preferably the cartridge has relatively stiff side walls, a top and a floor. Inside the cartridge are two chambers. Preferably each chamber comprises a plastic bag capable of retaining liquid therein. One of the bags will contain the chemistry for the knockdown product and the other bag will contain the chemistry for the baffler product. The floor of the reservoir cartridge has two quick-connect, female connector halves (not shown). There is one female connector for each bag and they are in fluid communication with the interior of each bag. The female connector halves mate with corresponding male quick-connect connectors  92 A,  92 B ( FIG. 3 ). These connectors are mounted in the support beam  82  which in turn is fixed to the bottom wall  78  in the bottom of the reservoir compartment  80 . The quick connectors may be of a type supplied by IPN of Peachtree, Ga. under their trademark Clean Clic System®. When the male and female connectors are separated, valves in the connectors prevent liquid flow through the connector halves. As seen in  FIG. 3 , fluid supply lines  94 A,  94 B are attached to the male connectors  92 A,  92 B. The supply lines extend through the openings  84  in the front vertical partition  60 . Check valves  96  are included in the supply lines. Filters may also be incorporated in the supply lines. Elbows  98  direct the supply lines to the liquid pump heads as described below. 
   Inside the reservoir compartment  80  there is a tray  100  that mounts the reservoir cartridge  90 . The tray has a floor  102 , side walls  103  and a top wall  104 . The floor is attached to a cam  106  that is pivoted to the housing walls. The cam is also connected to the front door  26 . The door serves as a lever that actuates the cam  106 . Opening the door through a clockwise motion (as seen in  FIG. 2 ) about the cam&#39;s pivot causes the floor  102  to move upwardly in a linear motion. This linear motion disengages the female fluid connectors of the reservoir cartridge from the compartment&#39;s male connectors  92 A,  92 B. Disengaging the fluid connectors causes them to close and prevent any fluid flow through them. With the connectors disengaged, an empty reservoir cartridge can be removed from the tray  100  and replaced with a full one. Then the door  26  is closed by means of a counterclockwise motion about the cam&#39;s pivot. This causes the tray floor  102  to move downwardly. The female fluid connectors of the new, full reservoir cartridge engage the male fluid connectors  92  at the bottom of the reservoir compartment  80  to establish fluid communication between the twin chambers of the new cartridge and the fluid supply lines  94 A,  94 B. This provides a safe, effective and reliable way to make fluid connections without the user having to handle any of the fluid lines, connectors or the products themselves. 
   The next major area of the housing is the pump compartment  68 . It contains a low-energy air pump  108  which is driven by an air pump motor  110 . A bracket  109  mounts the air pump  108  to the housing. The air pump  108  supplies pressurized air to the first nozzle through an air pipe  112 . Behind the air pump is a low energy liquid pump  114  which is driven by a liquid pump motor. The liquid pump motor is hidden in  FIG. 2  behind the air pump motor  110 . The liquid pump  114  is preferably a dual head diaphragm pump. Thus, one motor drives one dual head pump that supplies two separate fluids to two separate nozzles. The heads of the liquid pump are connected to the reservoir cartridge  90  by liquid supply lines  94 A,  94 B and the elbows  98 , as seen in  FIG. 3 . The pump outlets are connected to nozzle supply lines or tubes. Knockdown spray line  116  connects to the first nozzle and barrier spray line  118  connects to the second nozzle. 
   The battery compartment  72  contains a battery pack shown generally at  120 . Further details of the battery pack are described below. Connectors in the battery pack electrically connect the battery pack to the control circuit  122  which is mounted in the control circuit compartment  74 . The control circuit is mounted on a printed circuit board. The printed circuit board has a power supply section that includes connectors for wires that supply electric power to the air pump motor  110  and the liquid pump motor, as well as to the fan motor  158  in the second nozzle. The printed circuit board also connects to the switch  30  in the handle and to the indicator LED&#39;s in the handle. A microcontroller is included on the printed circuit board to provide a level of intelligence that, for example, prevents operation when the battery voltage drops to a level that is incapable of producing the proper droplet sizes, when the reservoir cartridge is empty or not installed, or when the sprayer is mounted in the charging cradle. Also, the microcontroller is programmed to turn the air supply motors on before the liquid pump is activated and turn the air supply motors off after the liquid pump is shut down. This assures that liquid never flows without an accompanying air supply and any residual liquid in the emitters is blown out the nozzles and will not remain in the unit after it is turned off. 
   The first nozzle for dispensing the knockdown product is shown generally at  124  in  FIG. 4 . The term nozzle as used herein includes not only a liquid emitter but also a plenum for the air that is mixed with the liquid. The first nozzle is mounted in the upper portion of the housing. The axis of the nozzle is disposed at about a 45° angle to the bottom and top walls of the housing. Obviously when the housing is in its normal orientation wherein the bottom wall is parallel to the ground, then the first nozzle will dispense the knockdown product at about 45° above the ground. The nozzle  124  includes the first shroud  14  which is in the form of a generally cylindrical tube. The shroud  14  fits through the housing opening  52  and is fixed to the housing by the knurled collar  18  and the ledge on the interior of the shroud. A pair of opposed blisters  126  on the outer end of the shroud locate an emitter mounting shell  128 . The shell fits telescopically into the shroud. Protrusions  130  engage the blisters  126  to provide an anti-rotation feature. The shell  128  mounts an emitter  132 . This is an ultra low volume (ULY) emitter. As seen in  FIG. 4 , the emitter includes a body  134  with an internal passage. An air inlet  136  connects to the internal passage and the air feeder line  112  coming from the air pump  108 . A liquid inlet  138  connects to the internal passage and the liquid feeder line  116  coming from one of the heads of the liquid pump  114 . Downstream of the air and liquid inlets the emitter passage has a venturi (not shown). The venturi, combined with the effect of the high pressure air, breaks the knockdown liquid into droplets whose average volume median diameter is about 15 to 30 microns. This creates a fog that is ejected from the emitter in a cone-shaped pattern and permeates the surrounding area, resulting in delivery of the insecticide to mosquitoes in the vicinity. The emitter design allows creation of the small droplet sizes with a minimal power requirement. The motors driving the pumps supplying the ULY nozzle of the present invention use much less power than in prior designs. The motors supplying air and liquid to the ULV nozzle draw only about 2 to 3 amps. This is important in a portable sprayer whose only available power supply is a rechargeable battery pack. 
   The second nozzle for dispensing the barrier product is shown generally at  140  in  FIGS. 5 and 6 . The second nozzle is mounted in the housing in the cutouts  64  and extends fully across the width of the housing. It includes a wind tunnel  66  formed by two semi-cylindrical halves  142 . Each wind tunnel half has a plurality of hooks  144  which engage catches  146  formed on the other half. Mounting tabs  148  are also provided for engagement with screws (not shown) which fix the wind tunnel to the housing. Slots  150  provide apertures for the barrier supply line  118  and for a motor wiring harness  152 . A grating  154  is mounted near one entrance to the wind tunnel  66 . The grating has a lattice of bars that permits air to enter the wind tunnel but prevent solid objects from entering. A fan  156  is mounted in the wind tunnel  66 . The fan is driven by a fan motor  158 . The fan motor mounts a fan shroud  160 . The fan shroud is made of two shroud halves, each of which includes a body portion  162  and a wing  164  ( FIG. 6 ). The body and wing direct air through the wind tunnel  66 . The barrier supply line  118  extends through the interior of the fan shroud  160 . The barrier supply line has a radial portion that extends through the aperture  150  in the wind tunnel to connect to the liquid pump. An axial portion of the barrier supply line  118  runs through the fan shroud  160  to a nozzle tube support member  166 . The support member is clamped between the edges of the wind tunnel. The support member  166  mounts a barrier fluid emitter  168  that is in fluid communication with the end of the axial portion of the barrier supply line  118 . The emitter  168  produces a fan-shaped spray pattern in a vertical orientation. The end of the wind tunnel  66  communicates with a cylindrical second nozzle shroud  16 . The shroud is axially aligned with the wind tunnel. Shroud  16  is fixed to the housing by the knurled collar  20 . The axis of the second nozzle is disposed parallel to the bottom and top walls of the housing. Thus, when the housing is in its normal orientation wherein the bottom wall is parallel to the ground, the second nozzle will dispense the barrier product in a generally horizontal direction. The combination of the air flow through the wind tunnel  66  and the liquid emitter  168  produces a barrier product spray having droplet sizes of about 80 to 200 microns in volume median diameter. This droplet size allows the barrier product droplets to penetrate a greater distance than the ULV spray and it also allows the barrier product to coat area foliage with a repellant layer that discourages mosquitoes from entering the protected zone. 
   The battery pack  120  is illustrated in  FIGS. 7 and 8 . It has a case including a top  170 , a bottom  172 , and a false bottom  174 . The top  170  is closed on three sides and one end. The fourth, open side  176  of the top receives a contact support member  178 . Battery contact strips  180  are attached to the support member  178 . The contact strips provide electrical connection to a package of battery cells shown at  182 . Most of the cell package fits into the top  170  of the case. The remainder fits into the false bottom  174 . The false bottom is a four-sided structure with open ends. The bottom portion  172  is fastened to the false bottom  174  by screws  184 . The bottom  172  is a tray having a curved edge  185  and openings on it lower surface and on one side edge. A latch  186  is slidably mounted in the bottom portion  172 . A spring  188  urges the latch  186  outwardly of the bottom  172  but only a beveled edge  190  of the latch can fit through the side opening of the bottom portion. The remainder of the latch is retained in the bottom portion  172 . When the beveled edge  190  protrudes from the bottom it is engageable with the catch  88  on the sprayer housing to retain the battery pack in the battery compartment  72 . The latch  186  can also be retracted fully into the bottom portion  172  so as to release the battery pack  120  from the sprayer housing. The latch  186  includes a series of grooves  192  that are accessible to a user through the lower opening in the bottom portion. The user can place a thumb on the curved edge  185  and two or three fingers in the grooves  192  to enable the user to squeeze the latch and retract it for the purpose of releasing the battery pack from the sprayer housing. Installing a replacement battery pack simply requires pushing the battery pack into the compartment  72 . The beveled edge of the latch will allow it to retract upon contact with the catch  88  during insertion. Once the latch clears the catch, the spring  188  will push the latch back into its extended position where it will engage the catch and hold the battery pack in the battery compartment. 
     FIG. 2  illustrates an auxiliary battery pack  194  resting in a charge receptacle  196  in the cradle  36 . The cradle also includes a depression  198  for receiving the sprayer. The auxiliary battery pack  194  will be charged and ready to swap with a discharged battery in the sprayer. Obviously it is intended that the discharged pack will be placed in the charge receptacle  196  so it can be recharged. As mentioned above, when the sprayer is returned to the depression  198  in the cradle  36 , the battery pack that is mounted in the sprayer will also be recharged. Thus, two fully charged battery packs should be available at the start of most uses of the sprayer. Two charged batteries will be sufficient to treat the yards of most homeowners. 
   The use and operation of the sprayer are as follows. With a fully charged battery pack and a full liquid reservoir cartridge, the user grasps the sprayer by the handle  28  and removes it from the cradle  36 . The sprayer is transported to the area to be treated and, after assuring that conditions are safe for treating the area, the user acutates the control switch  30 . This activates the microcontroller which first verifies that a non-empty liquid reservoir is present in the reservoir compartment  80  and that sufficient battery voltage is available to generate the required air and liquid flow rates and pressures. If so, the microcontroller activates the air pump motor  110  and the fan motor  158 . Shortly thereafter the microcontroller activates the liquid pump which sends the knockdown liquid to the emitter  132  and the barrier liquid to the emitter  168 . The user then traverses the perimeter of the area to be treated. If the microcontroller senses that the battery voltage has fallen below a level needed to assure proper droplet formation it will shut down the liquid pump and then the air motors. The user can then change the battery pack as described above to continue the treatment process. Similarly, if the microcontroller senses that the liquid reservoirs are empty, it will shut down the liquid pump and then the air motors. The user can then change the liquid reservoir cartridge as described above. When the entire area to be treated has been treated the user releases the control switch. The liquid pump shuts off, followed by the air motors. The user returns the sprayer and auxiliary battery pack to the charging cradle so the batteries will recharge and be ready for the next application. 
   While the preferred form of the invention has been shown and described herein, it should be realized that there may be many modifications, substitutions and alterations thereto. For example, instead of using a single liquid pump with dual heads, separate pumps could be provided, one for each product. Alternately, the pump could be replaced entirely by one or more aerosol pressure cans. If aerosol cans are used, they would be a replacement item just like the liquid reservoir cartridge. Also, while various components of the sprayer are referred to as being in the housing, it will be understood that this is meant in a general sense that the components are connected, attached or mounted on, in or to the housing. In other words, portions of the components may protrude outside of a boundary wall of the housing and still be considered in the housing. A further alternate construction may include a separate lever inside the door  26 . Thus, instead of the door actuating the reservoir cam  106 , a lever just inside the door would be connected to the cam to actuate it. Also, while a hand-held sprayer has been shown and described, other arrangements are possible that would still allow the sprayer to be portable. For example, the housing might have wheels incorporated therein or the housing could be mounted on a ground-engaging cart.