Abstract:
A sprayer system includes a pair of tanks, one for storing a dilutent and another for storing a chemical to be mixed with the dilutent in a selected concentration based on the selected orifice of a valve sprayed on the surface. Mixing of chemical with dilutent occurs on the suction side of a diaphragm pump which delivers the mixture to one or more nozzles. Should flow between either tank and the pump be interrupted, flow to the nozzles is automatically interrupted.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to sprayer systems which mix a chemical with a dilutent for application onto a surface. More particularly, the present invention relates to sprayers used to apply chemicals including, but not limited to pesticides, herbicides, fertilizers and other agricultural chemicals. 
         [0002]    Sprayers are used on farms, fields, golf courses and lawns to apply chemicals to crops, grasses, shrubs and other plants. Such chemicals include a variety of pesticides, herbicides, fertilizers and other materials. Such chemicals are often sold in concentrated form and must be diluted with water or some other dilutent prior to or as part of the application process. Sprayers are also used to deliver chemicals to surfaces for cleaning, coating, or the like. 
         [0003]    Prior art sprayer systems have suffered from a number of problems. First, precision and thoroughness in mixing to achieve a consistent concentration of chemical in the mixture has been a problem. Second, a person applying the mixture has had to closely monitor the contents of the separate tanks holding the chemical concentrate and the dilutent to ensure sufficient quantities are present in the tanks. If either tank were to run dry, spraying would continue, but the spray would include either no chemical because the chemical tank ran dry or pure concentrated chemical because the dilutent tank ran dry. Third, pumps used in prior art sprayer systems were susceptible to damage due to overheating if there was an interruption of flow to the pump and the pump continued to operate. The present invention overcomes all of these deficiencies with prior art sprayer systems. 
       SUMMARY OF THE INVENTION 
       [0004]    According to the present invention, a sprayer system is provided which includes a first tank for holding a supply of a chemical concentrate and a second tank for holding a dilutent. Examples of such chemical concentrates include, but are not limited to, pesticides, herbicides and fertilizers. The sprayer system of the present invention can be used to apply other chemicals such as soaps, surfactants, lubricants, coatings and the like. The most typical example of such a dilutent is water. Dilutents other than water can be used. Likewise, the dilutent can be a mixture of water and another chemical. 
         [0005]    Associated with the first tank is a valve regulating the flow of chemical concentrate from the first tank. The valve comprises a first plate and a second plate in face-to-face registration with the first plate. The first plate is stationary and has a first orifice. The second plate has a plurality of orifices of different sizes and is rotatable with respect to the first plate such that any of the orifices of the second plate can be selectively aligned with the orifice of the first plate to control the flow rate of chemical from the first tank through the valve. 
         [0006]    The sprayer system of the present invention also includes a diaphragm pump having a suction port and a pressure port. A mixing connector is operatively coupled to the suction port of the pump, the first tank via the valve and the second tank such that the pump applies suction drawing chemical and dilutent into the mixing connector where the chemical and dilutent are thoroughly mixed before reaching the pump. The pump then delivers the mixture to one or more spray nozzles. 
         [0007]    The concentration of the mixture of chemical and dilutent is determined by the selected port of the valve, i.e., which orifice of the second plate is aligned with the orifice of the first plate. In the event flow of either chemical or dilutent is interrupted because one of the tanks ran dry or for any other reason, the diaphragm pump will immediately lose prime and delivery of fluid by the pump to the nozzles will immediately cease. As such, the user need not worry about applying undiluted chemical or only dilutent. The construction of the pump is such that it will not be damaged to any significant degree if it loses prime. 
         [0008]    The tanks of the sprayer are sufficiently translucent so the level of fluid in the tanks can be observed. The tanks are also graduated so the user can quickly ascertain the quantity of fluid in each tank. Similarly, the valve includes markings indicating its position on the concentration of the mixture. 
         [0009]    The valve, of course, has components in addition to the two disks. For example, a pair of O-rings and a spring cooperate to provide a sealed flow path which passes through the aligned orifices of the first and second plates. 
         [0010]    The apparatus of the present invention can be configured in a number of different ways. For example, the output of the pump can be directed through a wand to a single nozzle. Alternately, the output of the pump can be directed through a manifold or a boom to a plurality of nozzles. 
         [0011]    The apparatus of the present invention can be packaged in a number of ways. It can be mounted to a frame so it can be worn on the back of a user, it can be mounted to a self-powered vehicle such as a truck. It can be mounted to a trailer. It can be mounted for stationary operation. As such, the power to drive the pump can be provided by an electrical motor coupled to a source of electricity, by the power takeoff of a vehicle, or in virtually any other known way to supply power to the pump depending on how the sprayer is to be used. 
         [0012]    The invention is further described and explained below with reference to the drawings which show one example of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a perspective view of a sprayer system constructed in accordance with the present invention; 
           [0014]      FIG. 2  is a left side view of the sprayer system shown in  FIG. 1 ; 
           [0015]      FIG. 3  is a right side view of the sprayer system shown in  FIG. 1 ; 
           [0016]      FIG. 4  is a front view of the sprayer system shown in  FIG. 1 ; 
           [0017]      FIG. 5  is a rear view of the sprayer system shown in  FIG. 1 ; 
           [0018]      FIG. 6  is a top view of the sprayer system shown in  FIG. 1 ; 
           [0019]      FIG. 7  is a bottom view of the sprayer system shown in  FIG. 1 ; 
           [0020]      FIG. 8  is an exploded side view showing the chemical tank and valve assembly used to meter chemical from the chemical tank of the sprayer system shown in  FIG. 1 ; 
           [0021]      FIG. 9  is an exploded view of the valve assembly used to meter chemical from the chemical tank of the sprayer system shown in  FIG. 1 ; 
           [0022]      FIG. 10  is a cross-sectional view of the valve assembly shown in  FIGS. 8 and 9 ; and 
           [0023]      FIG. 11  is a cross-sectional view showing a valve assembly located between the larger tank and mixing connector of the sprayer system shown in  FIG. 1  to prevent backflow of chemical from the smaller tank into the larger tank. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0024]    As depicted in the drawings, the sprayer system  10  is mounted on a trailer  12  supported by a pair of wheels  14  and  16  mounted to opposite ends of an axle  18 . The trailer  12  has a bed  20  which supports the sprayer system  10  and a hitch  22  enabling the trailer  12  to be coupled to a tractor or other vehicle (not shown) so the trailer can be towed. 
         [0025]    A large tank  24  is mounted to the bed of the trailer. The tank  24  can be made of any suitable plastic or metal such as polyethylene or of stainless steel. The tank  24  has a relatively large diameter threaded fill port  26  at the top and two drain ports  28  and  30  near the bottom. The drain port  28  is typically threaded and sealed by a movable cap  29  having matching threads except when the tank  24  is being drained or cleaned. A hose  31  is connected to the drain port  30 . As will be explained below with reference to  FIG. 11 , the hose  31  can also be coupled to the drain port  30  of tank  24  via one or more valves and a pick-up tube  186 . The larger tank  24  is typically used to store a dilutent such as water. The tank  24  has a series of graduated markings  32  on a translucent or transparent wall section  34  of the tank so the quantity of fluid in the tank can be easily ascertained. 
         [0026]    A smaller tank  40  is mounted to the larger tank  24 . More specifically, the smaller tank  40  is coupled to a threaded cap which is used to seal the fill port  26  of the tank  24 . The smaller tank  40  sits within the fill port  26  as shown in the drawings. 
         [0027]    The smaller tank  40  is intended to hold a chemical concentrate. Tank  40  can be made of any suitable glass, plastic or metal. The tank  40  must be sturdy and should be made of a material which is generally non-reactive with the chemical concentrate to be stored in the tank  40 . 
         [0028]    The tank  40  has a wall section  44  which is transparent or translucent and graduated so the quantity of concentrate in the tank can be easily ascertained. The tank  40  also has a threaded fill port  46  at the top. A valve assembly  50 , comprising a threaded cover  52 , is also shown in the drawings. The threaded cover  52  of the valve assembly  50  enables the valve assembly  50  to be removably coupled to the fill port  46  of the tank  40 . 
         [0029]    The construction of the valve assembly  50  is best shown in  FIGS. 8-10 . As shown, the threaded cover  52  of the valve assembly  50  has a plate  54  and a wall  56  having internal threads which cooperate with the threads  47  of the fill port  46  of the tank  40 . The plate  54  has an orifice  58  extending through the plate  54 . The orifice  58  is an opening surrounded by one end of a cylindrical wall  60  projecting downwardly from the plate  54  and terminating in a bottom flange  62 . A pair of locking members  64  project upwardly from the plate  54 . Each locking member terminates in an outwardly projecting lip  66 . 
         [0030]    The cylindrical wall  60  and flange  62  are provided to secure conduit  70  to the orifice  58 . The conduit  70  extends from the orifice  58  to the bottom of the tank  40  and is provided to draw concentrate up from the bottom of the tank  40  to the orifice  58 . The conduit  70  has a connector  72  which includes a flange  74  and a slot  76  for receiving an O-ring  78 . When assembled, a spring  80  is passed over the conduit  70  into contact with the flange  74 . The bottom of the conduit is then passed through the top of the orifice  58  so the spring  80  resides between the flange  74  of the connector  72  and the flange  62  of the cylindrical wall  60  projecting from the plate  54 . 
         [0031]    Overlying the plate  54  is a plate  82 . The plate  82  has a center opening  84  defined by a wall  86  so that the plate  82  can be passed over the locking members  64 . The wall  86  of the center opening  84  engages various other projections extending upwardly from the plate  54  to register and align the plates  54  and  82  with respect to each other. The registration is such that the plate  82  can easily be rotated in face-to-face registration with plate  54 . The plate  82  has corrugations  88  in its outer wall  90  to assist in rotating plate  82  with respect to plate  54 . Located between the walls  86  and  90  of the plate  82  are a plurality of orifices  92   a - 92   n  of different sizes. These openings  92   a - 92   n  are individually and selectably alignable with the orifice  58  in the plate  54  to control the flow of concentrate through the valve. 
         [0032]    Overlying the plate  82  is a connector member  100 . The connector member has an integrally formed conduit  102  extending from an entrance  104  positioned adjacent the point where an orifice  92   a - 92   n  of the plate  82  is aligned with the orifice  58  of the plate  54  such that the entrance  104  is in fluid communication with the conduit  70 . As shown, the conduit  102  terminates at a male member  106  designed to accept a quick connect adapter  108  attached to a hose  110 . 
         [0033]    The connector member  100  also includes channel(s)  112  which permit the connector member  100  to be passed over the locking members  64  during assembly. 
         [0034]    The valve assembly also includes a locking cap  114  overlying the connector member  100  and having slots (not shown) engaging the lips  66  of the locking members  64  to secure the components of the valve assembly  50  in place. 
         [0035]    As best shown in  FIG. 2 , the sprayer system also includes a mixing connector  120 . The mixing connector includes two input ports  122  and  124  and an output port  126 . Typically, the mixing connector  120  will have a T or a Y shape. The shape used should ensure thorough mixing of the materials received at the input ports  122  and  124 . As shown, the hose  31  extending from tank  24  is connected to input port  122  and the hose  110  extending from the valve assembly  50  is connected to the input port  124 . The output port  126  is connected either directly or by a hose to the suction port  132  of a diaphragm pump  130 . 
         [0036]    The diaphragm pump  130  is self-lubricating such that it will not be significantly damaged if it continues to run for a reasonable period of time after losing prime. This is particularly beneficial because the pump  130  will lose prime in the event flow is interrupted from either tank  24  or tank  40 . In this way, flow from the pump stops virtually immediately should either tank  24  or  40  become empty. This feature ensures only the desired mixture exits the pump and eliminates the risk that only the contents of one of the two tanks will exit the pressure port  134  of the pump  130 . 
         [0037]    As shown in  FIG. 2 , the pressure port  134  of the pump  130  is connected to the input  142  of manifold  140 . The manifold has four outputs  144   a - 144   d . Manifold output  144   a  is coupled to a pressure gauge  145 . Manifold output  144   b  is coupled via a shutoff valve  146  to a hose  148  which, when the valve  146  is open, carries the mixture from the manifold to two nozzles  150  secured to a boom  152 . The boom is attached to the trailer  12  by a pair of supports  154 . The manifold output  144   c  is coupled by a shutoff valve  156  to a return hose  158  leading to tank  24 . The manifold output  144   d  is sealed by a threaded cap  160 . Manifold output  144   d  can be used to attach a separate hose (not shown) to the sprayer system. Such a hose can, in turn, be connected to a spray wand or other type of nozzle arrangement thus permitting the sprayer system of the present invention to be employed in a variety of ways. 
         [0038]    To prevent the mixture formed in the mixing connector from flowing into the larger tank  24 , a pair of valves is can be provided. These are illustrated in  FIG. 11 . As shown in  FIG. 11 , one of these valves is a check valve comprising a housing  180 , a compression spring  182  and a check ball  184 . The check valve is positioned between a pick-up tube  186  joined to the drain port  30  of the larger tank  24  and the hose  31  leading to the mixing connector  120 . The spring  182  forces the check ball  184  against a seat of the housing  180  to hold the valve closed until sufficient suction is provided by the pump  130  to overcome the force applied by spring  182  to unseat the check ball  184 . This suction force also ensures any fluid will flow away from tank  24  toward the pump  130 . If the suction force ever drops below the spring force applied to the check ball  184  by the spring  182 , the ball immediately resets within housing  180  to prevent backflow of liquid into the larger tank  24 . Further, a shutoff valve  188  can also be provided to manually close off the tank  24  from the rest of the system. 
         [0039]    The above description has been provided to comply with the applicable patent laws and is not intended to be limiting the scope of the invention which includes all subject matter falling within the scope of the claims set forth below and equivalents.