Patent Publication Number: US-2022217907-A1

Title: Integrating liquid dispensing control with riding mower steering

Description:
BACKGROUND 
     The beauty and comfort of real estate can often be greatly enhanced by a well-manicured lawn. The basics of a good lawn include suitable soil, proper watering, regular mowing, and maintenance. During the active growing season, good lawn care requires regular mowing perhaps once a week or even more often depending on climate. On the other hand, fertilization and weed control are conventionally performed much less frequently, perhaps only several times a year. The purpose of lawn fertilization is to add proper levels of Nitrogen and other essential nutrients to the soil to support lawn growth. Weed and pest control are often done by applying herbicide or pesticide several times per year to help keep weeds and pests under control. 
     The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some embodiments describe herein may be practiced. 
     BRIEF SUMMARY 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     The principles described herein relate to a riding lawn mower that is configured such that an operator can simultaneously retain directional control of a moving riding lawn mower while selectively applying liquid to the lawn. Thus, an operator can simultaneously mow while selectively applying the liquid to the lawn. The liquid can even be selectively applied many times in a single mow without the operator even needing to move his hands off the steering system. As an example, in the case of the liquid being herbicide, the operator simply mows and watches out for areas that need herbicidal application, such as areas that have weeds. The operator continues to mow seamlessly while applying the liquid to the appropriate portions of the lawn as the mower passes over the problem areas. 
     In one embodiment, this is accomplished by integrating a liquid dispensing control with the mower&#39;s steering system, such that the operator does not need to move his or her control hand from off a control surface of the steering system in order to activate the liquid dispensing control with the same hand. As an example, the liquid dispensing control could be a push button control that is activated by the thumb of the control hand, whilst the fingers and palm of the control hand remain firmly gripped on the control surface of the steering system. As a further example, the liquid dispensing control could be a push button at the end of a steering lever of a zero-turn mower. Alternatively, the actuation control could be placed near the foot of the operator such that the foot is used to activate the liquid dispensing control. 
     This allows the operator to efficiently perform two important tasks of lawn maintenance at a time—lawn mowing and liquid application (e.g., the applying of herbicide). This greatly improves efficiency since mowing and the application of herbicide have typically previously been performed at distinct times. The lawn mower does not even need to stop mowing while the herbicide is being applied. Furthermore, herbicide is more likely to be applied only where weeds are observed, instead of wholesale across larger areas or even the whole lawn. This reduced and more targeted application of chemical agents preserves resources and improves safety due to reduced risk of exposure to chemical agents. Furthermore, the targeted application of liquid has less impact on the environment. Additionally, herbicidal treatment can be performed every mow, leaving weeds little opportunity to get out of control. Once weeds become visible to the operator, herbicide is immediately applied. 
     Additional features and advantages will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the teachings herein. Features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. Features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to describe the manner in which the above-recited and other advantages and features can be obtained, a more particular description of the subject matter briefly described above will be rendered by reference to specific embodiments which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments and are not therefore to be considered to be limiting in scope, embodiments will be described and explained with additional specificity and details through the use of the accompanying drawings in which: 
         FIG. 1  is a component diagram of a conventional riding lawn mower; 
         FIG. 2  is a component diagram of a riding lawn mower in accordance with the principles described herein, and which further includes a tank and liquid dispensing system for applying liquid from the tank through the dispensing system and onto the lawn; 
         FIG. 3  illustrates a right perspective view of a riding lawn mower, that represents a specific embodiment of the riding lawn mower of  FIG. 2 ; 
         FIG. 4  illustrates a schematic diagram of a liquid system that is an example of the liquid dispensing system within the riding lawn mower of  FIG. 3 ; 
         FIG. 5  illustrates a schematic diagram of an electrical system that is an example of the electrical system within the riding lawn mower of  FIG. 3 ; 
         FIG. 6  illustrates a top view of the riding lawn mower of  FIG. 3 ; 
         FIG. 7  illustrates a detailed view of a portion of the riding lawn mower of  FIG. 3 , which detailed view shows liquid system components and electrical system components; and 
         FIG. 8  illustrates a detailed lower rearview of the riding lawn mower of  FIG. 3 , which detailed view shows nozzles spraying liquid from the liquid system to the lawn that the riding lawn mower has just mowed. 
     
    
    
     DETAILED DESCRIPTION 
     The principles described herein relate to a riding lawn mower that is configured such that an operator can simultaneously retain directional control of a moving riding lawn mower while selectively applying liquid to the lawn. The liquid can be selectively applied many times in a single mow without the operator even needing to move hands off the steering system. Thus, mowing and the selective application of liquid can be seamlessly done together. As an example, in the case of the liquid being herbicide, the operator simply mows and watches out for areas that need herbicidal application, such as areas that have weeds. The operator continues to mow while seamlessly and simultaneously applying the liquid to the appropriate portions of the lawn as the mower passes over the problem areas. 
     This is accomplished by integrating a liquid dispensing control with the mower&#39;s steering system, such that the operator does not need to move his or her control hand from off a control surface of the steering system in order to activate the liquid dispensing control with the same hand. As an example, the liquid dispensing control could be a push button control that is activated by the thumb of the control hand, whilst the fingers and palm of the control hand remain firmly gripped on the control surface of the steering system. As a further example, the liquid dispensing control could be a push button at the end of a steering lever of a zero-turn mower. Alternatively, the actuation control could be placed near the foot of the operator such that the foot is used to activate the liquid dispensing control. 
     This allows the operator to efficiently perform two important tasks of lawn maintenance at a time—lawn mowing and liquid application (e.g., the applying of herbicide). This greatly improves efficiency since mowing and the application of herbicide have typically previously been performed at distinct times. The lawn mower does not even need to stop mowing while the herbicide is being applied. Furthermore, herbicide is more likely to be applied only where weeds are observed, instead of wholesale across larger areas or even the whole lawn. This reduced and more targeted application of chemical agents preserves resources and improves safety due to reduced risk of exposure to chemical agents. Furthermore, the targeted application of liquid has less impact on the environment. Additionally, herbicidal treatment can be performed every mow, leaving weeds little opportunity to get out of control. Once weeds become visible to the operator, herbicide is immediately applied. 
       FIG. 1  is a component diagram of a conventional riding lawn mower  100 . The component diagram is quite simplified in order to allow attention to focus on the function and interrelationship of the major components and systems of a conventional riding lawn mower. In fact, systems are represented as simple shapes (rectangles and circles) and functional relationships between systems are represented by lines connecting the corresponding simple shapes. 
     Referring to the simple component diagram of  FIG. 1 , the riding lawn mower  100  includes a mower body  101 , a movement system  102 , a cutting system  103 , a power system  104 , and a steering system  105 . The mower body  101  is structured to situate an operator A of the riding lawn mower. As an example, the mower body  101  may have a seat on which the operator sits, or a standing platform on which an operator stands. 
     The movement system  102  is attached to the mower body  101 , as represented by the lines  111 . In operation, the movement system  102  engages a lawn B and allows the mower body  101  to move over the lawn B as represented by arrow C. As an example, the movement system  102  may be wheels rotatably attached to the mower body  101 . 
     The cutting system  103  is attached to the lower portion of the mower body  102 , as represented by line  112 . In operation, the cutting system  103  cuts the lawn B. As an example, the cutting system  103  might typically be mower blades that rotate around an axis that is perpendicular to the lawn, but rotate so as to move in a plane that is parallel to the lawn. 
     The power system  104  is typically housed within and/or on the mower body  101 , as represented by the line  113 . The power system  104  is controlled by the operator A so as to selectively cause (as represented by dashed line  114 ) the movement system  102  to move the mower body  101  over the lawn B, and so as to selectively cause (as represented by dashed line  115 ) the mower blades  103  to cut the lawn B. As an example, the power system  104  may include a combustion engine. 
     The steering system  105  is attached to the mower body  102  as represented by the line  116 . The steering system  105  could be a steering wheel. Alternatively, zero turn riding mowers often have zero turn levers that the operator grasps (one lever with each hand) to independently control the direction of movement of the left side and right side of the riding lawn mower. Thus, the operator can pivot the mower counterclockwise on the lawn by moving the left side of the mower backwards and the right side of the mower forwards, or can pivot the mower clockwise on the lawn by moving the right side of the mower backwards and the left side of the mower forwards. 
     The steering system  105  includes a steering control surface  106  that the operator A situated in the mower body  101  can contact with at least one control hand in order to maneuver the steering system  105  to thereby control (as represented by dashed line  117 ) directional movement of the riding lawn mower  100 . For example, in the case of the steering system  105  being a steering wheel, the control surface includes a portion on the left that conveniently receives the grasp of the left hand, and a portion on the right that conveniently receives the grasp of the right hand. In the case of a zero turn mower, the control surface includes a grasping surface of a left zero turn lever that receives the grasp of the left hand, and a grasping surface of a right zero turn lever that receives the grasp of the right hand. 
       FIG. 2  is a component diagram of a riding lawn mower  200  in accordance with the principles described herein. Again, the component diagram is quite simplified in order to allow attention to be focused on the major components of the system. Furthermore, the general layout of  FIG. 2  is similar to that of  FIG. 1  to allow for comparison of differences as compared to the conventional riding lawn mower  100  of  FIG. 1 . Major systems are again illustrated as simple shapes (rectangles and circles) and physical or functional relationships between those systems are represented by lines between the corresponding simple shapes that represent the related systems. A more specific and concrete embodiment of a riding lawn mower that represents an example of the conventional riding lawn mower  200  will be described further below with respect to  FIG. 3 through 8 . 
     But for now, we stay with the general embodiment of the riding lawn mower  200  of  FIG. 2 . The riding lawn mower  200  also includes a mower body  201 , a movement system  202 , a cutting system  203 , a power system  204 , and a steering system  205 , which may operate as described above for the respective components  101  through  105  of  FIG. 1 . Although not required, the components  201  through  205  of  FIG. 2  may be structured the same as in the corresponding components  101  through  105  of the conventional riding lawn mower  100 . In fact, one specific embodiment of a riding mower described below and built by the inventors takes an existing riding lawn mower and modifies it to be further structured in accordance with the principles described herein. More descriptively, the riding lawn mower  200  in accordance with the principles described herein further includes a tank  211 , a liquid dispensing system  212 , and a liquid dispensing control  207 . 
     The tank  211  is attached to and/or within the mower body as represented by line  221 . The tank  211  holds a liquid to be applied to the lawn B. As an example, the liquid may be herbicide to be used for weed control. The liquid dispensing system  212  is attached to and/or within the mower body  201  as represented by the line  222 , and may even be distributed through the mower body  201 . In operation, the liquid dispensing system  212  is configured to selectively deliver liquid within the tank  211  through at least one delivery nozzle  213  to the lawn C. This delivery path is represented by the dashed line  223  of  FIG. 2 . 
     The liquid dispensing control  207  is configured to be used to actuate and deactivate delivery of the liquid through the at least one delivery nozzle  213 . This actuation and deactivation control is represented by the dashed line  224 . The liquid dispensing control  207  is positioned on the steering system  205  in such proximity to the steering control surface  206  of the steering system  205  such that a control hand of the operator can actuate and deactivate the liquid dispensing control  207  without removing the control hand from the steering control surface  206 . Accordingly, the riding lawn mower  200  is configured such that the operator A can both mow and selectively apply liquid from the tank while retaining directional control of the riding lawn mower. 
     However,  FIG. 2  is just a component diagram of a general embodiment of a riding lawn mower  200 . On the other hand,  FIG. 3  illustrates a right perspective view of a riding lawn mower  300 , that represents a specific embodiment of the riding lawn mower  200  of  FIG. 2 .  FIG. 6  illustrates a top view of the same riding lawn mower  300 . The top view of  FIG. 6  is less detailed than the right perspective view of  FIG. 3 . 
     The riding lawn mower  300  is a zero-turn mower in which the operator stands during operation. Referring to  FIG. 6 , the operator stands on platform  601 . The operator  601  controls the direction of the riding lawn mower  300  by moving left zero turn lever  602 A and right zero turn lever  602 B. Bars  603  and  604  are for the operator to use to maintain balance while standing on the platform  601 . 
     The illustrated lawn mower  300  was constructed by modifying a commercially available riding lawn mower. Specifically, in this example, the commercially available riding lawn mower is a Scags V-Ride II riding lawn mower commercially provided by Scag Power Equipment. However, the principles described herein are not limited to the riding lawn mower  200  being a modified version of a previously manufactured riding lawn mower. That is, the riding lawn mower could be originally manufactured with the additional systems of  FIG. 2 . Alternatively, or in addition, the riding lawn mower could be a modified version of a riding lawn mower that is not yet designed at the time of the filing of this patent application. 
     In  FIGS. 3, 6 and 8 , three orthogonal axes x, y and z are shown. The x-axis is parallel to the width of the riding lawn mower  300 . The y-axis is parallel to the length of the riding lawn mower  300 . The z-axis is parallel to the height of the riding lawn mower. A “forward direction” is a +y (positive y) direction along the y-axis, and is the same direction as a forward motion of the riding lawn mower  300 . A “backward” direction is a −y (negative y) direction along the y-axis that represents rearward motion of the riding lawn mower  300 . Generally, the riding mower  300  moves in the forward direction when mowing a lawn. But rearward motion is also possible. A +x (positive x) direction is a rightward direction from the left to the right of the riding lawn mower  300  along the x-axis. A −x (negative x) direction is a leftward direction from the right to the left of the riding lawn mower  300  along the x-axis. A +z (positive z) direction is an upward direction from the bottom to the top of the riding lawn mower  300  along the z-axis. That +z direction comes out of the page towards the reader in  FIG. 6 . A −z (negative z) direction is a downward direction from the top to the bottom of the riding lawn mower  300  along the z-axis. 
       FIG. 4  illustrates a schematic liquid diagram of a liquid system  400 , which is an example of fluid components of the liquid dispensing system  212  embodied within the riding lawn mower  300  of  FIGS. 3 and 6 .  FIG. 5  illustrates a schematic electrical diagram of an electrical system  500 , which is an example of electrical and fluid components of the liquid dispensing system  212  embodied within the riding lawn mower  300  of  FIG. 3 . The liquid system  400  and the electrical system  500  will now be described with frequent reference to riding lawn mower  200  of  FIG. 2 , and the riding lawn mower  300  of  FIGS. 3 and 6 . 
     The liquid system  400  includes a tank  401 , a pump  402 , a pressure regulator  403 , a valve  404 , fan nozzles  405 A and  405 B, and various liquid communication devices, including tubes, elbows, and tees. Arrows represent liquid flow directions that occur during various operation times. 
     In the illustrated embodiment, when the riding lawn mower  300  is in operation, the liquid is recirculated from the reservoir tank  401  through the pump  402 , through the pressure regulator  403  and back to the reservoir tank  401 . This recirculation path is from the tank  401 , through the liquid communication path  411 , the pump  402 , the liquid communication path  412 , the pressure regulator  403 , the liquid communication path  413 , and back into the tank  401 . In operation, the pump  402  causes the liquid to be recirculated from the tank, through the recirculation path and back into the tank, regardless of whether the liquid dispensing control system is actually dispensing liquid through the at least one delivery nozzle  405 A and  405 B. 
     In addition, there is an additional one-way liquid path that is selectively activated by the valve  404 , and which taps into a portion  420  of the recirculation path that is fluidly closest to the delivery nozzles  405 A and  405 B. This one-way liquid path may also be referred to as a “terminal path” since liquid that enters the terminal path will exit the system through the nozzles in normal operation. 
     The terminal liquid communication path includes liquid communication path  414  which taps into the recirculation path and is in liquid communication with the inlet of the valve  404 . Furthermore, the outlet of the valve  404  is liquidly coupled via the liquid communication path  415  to the nozzles  405 A and  405 B. Accordingly, when the valve  404  is opened, the liquid is pushed through the liquid communication path  414 , the valve  404 , the liquid communication path  415  and through the nozzles  405 A and  405 B. To the contrary, when the valve  404  is closed, liquid pressure is not significantly applied to the nozzles  405 A and  405 B, and thus liquid flow is largely, if not wholly, prevented from flowing through the nozzles  405 A and  405 B. 
     Because of the recirculation in the recirculation path, air bubbles and sediment cannot easily accumulate in significance within that recirculation path. Thus, liquid can more evenly flow since blockages are prevented, and air bubbles are mitigated. In addition, this recirculation prevents the pump  402  from power cycling or air locking, thereby extending the life of the pump  402 . Instead, the pump  402  might power cycle as few as just one time for an entire lawn, or perhaps just when the lawn mower itself power cycles. 
     In addition, such recirculation means that there is liquid present at the inlet of the valve  404 . When the valve  404  is opened, the liquid pressure quickly propagates to the nozzles  405 A and  405 B for delivery of the liquid to the lawn. Thus, there is no substantial time lag between the time that the valve  404  is opened, and the time that the liquid is delivered to the lawn, or at least that time lag is short enough to be taken into account by the operator when applying liquid to the lawn. Stated a different way, the nozzle reaction time is reduced, allowing the operator to take more intuitive aim of the herbicide at weeds. 
     The tank  401  is an example of the tank  211  of  FIG. 2 . A specific example of the tank  401  is represented as the tank  311  of  FIGS. 3 and 6 . Referring to  FIG. 4 , the operator can place the liquid (such as herbicide) within the reservoir tank  401  via an opening at the top that is covered by a cap  410 . In the concrete examples of  FIGS. 3 and 6 , the tank  311  includes removable cap  312 , which covers an opening in which herbicide may be poured. In the example of  FIG. 3 , the tank  311  may have a 6 gallon capacity, though the principles described herein are not limited to the capacity of the tank. 
     Since the liquid is not applied to all of the lawn, but only on selective areas, this capacity is sufficient for even large lawns. As a general average, liquid usage may be at about 1 gallon per acre, though the selective activation while mowing means that this usage can vary as there is need. If the inventive concept has been applied to a given lawn every mow over an extended period of time, there may be times when no herbicide at all is needed, since the lawn has been well maintained with herbicide selectively applied each mow. After all, the principles described herein allow the operator to get well ahead of any weed problem since herbicide can be applied as soon as the operator can see a weed while mowing. 
     More details regarding example components of the liquid system  400  will now be described. Referring again to  FIG. 4 , the pump  402  draws liquid from the reservoir tank  401  through the liquid communication path  411 , through the pump  402 , through the liquid communication path  412 , through the pressure regulator  403 , through the liquid communication path  413 , and back into the reservoir tank  401 . 
     The pump  402  may be, for example, any pump that is compatible with the liquid being applied, and which can pump at a sufficient flow rate through the nozzles  405 A and  405 B, and which can preferably be powered by a riding lawn mower battery (which is typically 12 volts). As an example only, the riding lawn mower  300  has a pump  313 , which is a PENTAIR® SHURFLO® Model 2088-343-136, which is powered by 12 volts DC, is rated for flows up to 3 gallons per minute, and is rated for pressures up to 45 pounds per square inch (PSI). All pressures mentioned herein are relative pressures with respect to atmosphere, rather than absolute pressures with respect to a vacuum. The liquid communication paths  411 ,  412 ,  413 ,  414  and  415  may be composed of ½ inch (inside diameter) PVC tubing with corresponding PVC fittings (elbows, tees, and nozzles). 
     The pressure regulator  403  ensures that a proper pressure is maintained within the liquid communication paths  411  through  414  (and within liquid communication path  415  when the valve  404  is open). In one embodiment, the pressure regulator  403  is set at 30 PSI, which is high enough to ensure significant flow through the nozzles  405 A and  405 B, but low enough that the nozzle spraying is controlled at predictable spray angles and not randomly and unpredictably sputtering. Thus, the 30 PSI level of pressure does allow the herbicide to land with sufficient flow on predictable portions of the lawn, at least with the riding lawn mower  300  depicted in  FIG. 3 . However, the precise optimal pressure will differ depending on the dimensions, properties and components of the liquid dispensing system. In one embodiment, the pressure is regulated to be at a pressure between 15 and 40 PSI. 
     The valve  404  may be any valve that is compatible with the underlying liquid, and which can operate at the mentioned pressures, and with sufficient flow. In one embodiment, the valve  404  is a TEEJET® AA144-1 DirectoValve rated for flows up to 10 gallons per minute, and up to 100 PSI. 
     The nozzles  405 A and  405 B may be fan spray nozzles designed to spray in a fan shape. It is preferred that the nozzles  405 A and  405 B be arrayed perpendicular to the direction of movement of the riding lawn mower, and such that there is slight overlap of the spray from neighboring fan nozzles. This reduces the chance that there will be a lawn area that is missed by the nozzle spray. 
       FIG. 5  illustrates a schematic electrical diagram of an electrical system  500  that is used to control the liquid dispensing system  400  of  FIG. 4 . Specifically, the electrical system  500  controls the pump  402  and the valve  404  of the liquid dispensing system  400 . Thus, the pump  402  and valve  404  are also shown as part of the electrical system  500  in  FIG. 5 . The electrical system  500  uses the battery  501  as an electrical power source. The battery  501  could be, for example, a 12 volt battery that is also used for all other electrical power systems of the riding lawn mower (such as engine ignition). The electrical system also includes a four terminal solid state relay  502 . The electrical system  500  also includes two switches  511  and  512  that are controlled by the operator of the riding lawn mower. 
     The on-off switch  511  turns the pump  402  itself on and off by applying the battery voltage  501  across the pump  402  via the solid state relay  502 . This causes the liquid to recirculate through the recirculation path. The inventors expect that this on-off switch  511  will not be cycled on and off very often. For example, the on-off switch  511  might be turned on when lawn mowing begins, and off when lawn mowing ends. When the on-off switch is off, battery power is prevented from being provided to the valve  404  as well. Because of the lower frequency of activation of the on-off switch  511 , this switch  511  need not be located on the steering system because it is not necessary that the operator turn this switch on and off while simultaneously driving the riding lawn mower. 
     The spray pushbutton switch  512  closes to open the valve  404  by applying the battery  501  voltage via the solid state relay  502  across the valve  404 . The spray pushbutton switch  512  opens to thereby close the valve  404  by ceasing application of the battery voltage across the valve  404 . Thus, the operator applies the liquid (e.g., herbicide) to the lawn by pressing the pushbutton switch  512 , and ceases application of the liquid to the lawn by releasing the pushbutton switch  512 . The inventors expect that the operator of the riding lawn mower will operate the spray pushbutton switch  512  whenever the operator spots weeds in the lawn, perhaps many times during the mowing of a lawn (or few or no times if the lawn is already relatively weed-free). 
     The pushbutton  512  may be placed within convenient reach of the operator even when then operator still has the control hand firmly on the control surface of the steering system. As an example, referring to  FIG. 6 , the pushbutton  512  may be a button  605  that is at the end of the right zero turn lever  602 B of the riding lawn mower  300 . Accordingly, the operator of the riding lawn mower can easily press and release the spray pushbutton switch  512  without stopping or even perhaps slowing down the lawn mowing operation. For example, referring to  FIG. 6 , an operator mowing the lawn will have a left hand grasping the left zero turn lever  602 A, and a right hand grasping the right zero turn lever  602 B. The operator&#39;s right thumb may press and release the pushbutton control  605  without even removing the right hand from off the right zero turn lever  602 B. Thus, the operator can mow while selectively applying herbicide to the lawn. 
     In an alternative embodiment, the pushbutton control may be a thumb button positioned at the end of the left zero turn lever. Alternatively, there may be a thumb button at the end of each of the left zero turn lever, and the right zero turn lever. This gives the operator convenience as to how to activate the herbicide spray. Thus, in accordance with the principles herein, there may be two liquid dispensing controls—a first liquid dispensing control that is in such proximity to a first control surface of the steering system such that a first hand of the operator need not be removed from the first control surface in order to activate the first liquid dispensing control, and a second liquid dispensing control that is in such proximity to a second control surface of the steering system such that a second hand of the operator need not be removed from the second control surface in order to activate the second liquid dispensing control. In this case, the liquid dispensing control activated by the left hand might activate nozzles on the left side of the riding lawn mower, and the liquid dispensing control activated by the right hand might activate nozzles on the right side of the riding lawn mower. 
     In an alternative embodiment, the pushbutton control  512  is situated in the mower body  201  so as to be activated by a foot of the operator A. This permits that hands of the operator to be used to steer the riding lawn mower, and a foot of the operator to be used to control spraying. 
       FIG. 7  illustrates a detailed view of a portion  320  of the riding lawn mower  300  of  FIG. 3 , which detailed view shows liquid system components and electrical system components. Also,  FIG. 8  illustrates a detailed lower rearview of the riding lawn mower  300  of  FIG. 3 , which detailed view shows nozzles spaying liquid from the liquid system to the lawn that the riding lawn mower has just mowed. Accordingly, an example of the liquid system  400  of  FIG. 4  and the electrical system  500  of  FIG. 5  will now be described with respect to the riding mower  300  of  FIGS. 3 and 6 , as well as the detailed views of  FIGS. 7 and 8 . 
     Referring to  FIG. 4 , when the pump  402  is on, liquid flows from the reservoir tank  401  through the liquid communication path  411 , through the pump  402 , through the liquid communication path  412 , through the pressure regulator  403 , through the liquid communication path  413  and back into the reservoir tank  401 . In the example riding lawn mower  300  of  FIG. 3  (and the more detailed view in  FIG. 7 ), the liquid is drawn by the pump  313  from the bottom (not shown) of the tank  311 , through the tube  321 , through the pump  313 , through the pressure regulator  314 , through the tube  323  and back into the tank  311 . 
     Also referring to  FIG. 4 , the valve  404 , when opened draws liquid from point  420  of the recirculation path through the liquid communication path  414 , through the valve  404 , through the liquid communication path  415  and to the nozzles  405 A and  405 B. Referring to  FIG. 3  and the more detailed views of  FIGS. 7 and 8 , the valve  315  draws the liquid through the tube  324 , through the valve  315  and through the liquid communication path  325  which leads towards the back of the riding lawn mower. 
     In  FIG. 8 , it can be seen that the liquid communication path  325  delivers liquid to the nozzles  316 A,  316 B, and  316 C. Thus, in the riding lawn mower  300 , the delivery nozzles are arrange side to side in a width direction (along the x-axis) of the riding lawn mower, and along the back of the riding lawn mower. Thus, a wide swath of liquid can be applied to the lawn. In the illustrated case of  FIG. 3 , the riding lawn mower has a 48 inch cutting width, the three nozzles  316 A,  316 B, and  316 C are spaced in intervals of 18 inches, are positioned about 6 inches about the lawn, and have a spray angle of 110 degrees. This permits overlap in the spray of neighboring nozzles. 
     Referring to  FIG. 5 , the battery  501  selectively delivers electrical power through the solid state relay  502 , to the valve  404  and pump  402  as previously described, in accordance with the state of the on/off switch  511  and the spray button switch  512 . Referring to  FIGS. 3 and 6 , the thumb button control in the right zero turn lever  602 A is an example of the pushbutton switch  502  of  FIG. 5 . The switch  606  is an example of the on/off switch  511  of  FIG. 5 . Referring to  FIG. 7 , the relay  701  is an example of the solid state relay  502  of  FIG. 5 . Electrical wiring to and from the spray button switch  512  can be pulled through a hollow center along the length of the right zero-turn lever  602 A. 
     Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the described features or acts described above. Rather, the described features and acts are disclosed as example forms of implementing the claims. 
     For the processes and methods disclosed herein, the operations performed in the processes and methods may be implemented in differing order. Furthermore, the outlined operations are only provided as examples, and some of the operations may be optional, combined into fewer steps and operations, supplemented with further operations, or expanded into additional operations without detracting from the essence of the disclosed embodiments. 
     The present invention may be embodied in other specific forms without departing from its spirit or characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicate by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.