Abstract:
A self-propelled lawn and garden spreader that can be used to apply granular and/or liquid materials to both wide and narrow areas at a constant rate of application per unit area at different ground speeds, such as at a relatively high speed when the operator of the spreader is riding on the spreader, and at a relatively low speed when the operator is walking behind the spreader. The spreader generally includes a frame on which a suitable motor is mounted, wheels mounted to the frame with at least one of the wheels being driven by the motor, and a unit for controlling the ground speed of the spreader, including at least two forward speeds. The spreader further includes a material storage compartment mounted to the frame for containing a material. The material storage compartment has an outlet through which the material exits the material storage compartment and is delivered to a dispenser unit that broadcasts the material outwardly, including away from the sides of the frame. Finally, the spreader includes a device for controlling material flow from the material storage compartment to the dispenser unit. The material flow control device provides at least two flow rates of the material to the dispenser unit, in which the flow rates are synchronized with the at least two forward speeds of the spreader so that the spreader dispenses the material to achieve an approximately constant application rate per unit area at the at least two forward speeds.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/164,466, filed Nov. 10, 1999. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to apparatuses for applying granular and/or liquid materials to lawns and gardens. More particularly, this invention relates to a self-propelled spreader configured to broadcast both granular and liquid materials at multiple rates that are synchronized with multiple forward speeds of the spreader so that the materials are dispensed to achieve an approximately constant application rate per unit area regardless of which of the forward speeds the spreader is operating. 
     2. Description of the Prior Art 
     Lawn and garden maintenance often includes the application of dry (e.g., granular) and liquid materials, including seed, fertilizers, insecticides, herbicides and flingicides. While dry and liquid materials have been broadcast on lawns and gardens using separate equipment, U.S. Pat. No. 5,333,795 to Jessen (incorporated herein by reference) discloses a single spreader unit capable of simultaneously dispensing both liquid or granular materials. Jessen&#39;s spreader unit includes a rotating platter for broadcasting granular materials and multiple spray nozzles for dispensing liquid materials. Though self-propelled to reduce the amount of effort required to apply materials to a lawn or garden, the spreader unit does not provide a platform by which the operator can ride on the unit. Even if so modified, there are circumstances in which the operator of the unit may prefer or be required to walk behind the spreader unit. To complete the application of material more quickly, it is generally typical that the maximum forward speed of a self-propelled spreader unit will be higher than the walking pace found comfortable by its operator, such that different forward speeds are required for the unit to operate under different conditions. Complicating this situation is the importance for the materials, and particularly fertilizers and herbicides that can harm grass and other desired vegetation if applied too heavily, to be applied at an approximately constant application rate per unit area, regardless of the forward speed of the spreader. Another complicating factor is the occasion when the material is to be applied to a relatively restricted or narrow area, necessitating that the extent to which the material is broadcast must be limited by the use of deflectors or by shutting off flow to the appropriate dispensers (e.g., nozzles). However, limiting the broadcast of the material should be done without increasing the application of material on the area being treated to avoid damage to vegetation within the treated area. 
     From the above, it can be seen that further improvements in lawn and garden spreaders would be desirable, and particularly a self-propelled spreader capable of uniformly applying a granular and/or liquid material on a lawn or other ground surface regardless of the speed of the spreader and regardless of the area of the ground surface being treated. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides a self-propelled lawn and garden spreader that can be used to apply granular and/or liquid materials to both wide and narrow areas at a constant rate of application per unit area at different ground speeds, such as at a relatively high speed when the operator of the spreader is riding on the spreader, and at a relatively low speed when the operator is walking behind the spreader. The spreader generally includes a frame on which a suitable motor is mounted, wheels mounted to the frame with at least one of the wheels being driven by the motor, and means for controlling the ground speed of the spreader, including at least two forward speeds. The spreader further includes a material storage compartment mounted to the frame for containing a material. The material storage compartment has an outlet through which the material exits the material storage compartment and is delivered to a dispenser unit that broadcasts the material outwardly, including away from the sides of the frame. Finally, the spreader includes a device for controlling material flow from the material storage compartment to the dispenser unit. According to the invention, the material flow control device provides at least two flow rates of the material to the dispenser unit, in which the flow rates are synchronized with the at least two forward speeds of the spreader so that the spreader dispenses the material to achieve an approximately constant application rate per unit area at the at least two forward speeds. 
     In view of the above, it can be appreciated that the spreader of this invention can be used to perform at least two types of treatments, either separately or simultaneously. In a preferred embodiment, the material storage compartment includes at least one tank of liquid treatment material. Hoses define fluid paths that connect the tank to multiple frame-mounted nozzles, and valves enable the operator to selectively cause fluid to flow to one or more of the nozzles. A pressure control device is also provided to maintain a constant pressure within the tank and hoses, regardless of which nozzle or nozzles are selected by the operator. The excess flow generated by the material flow control device is bypassed back into the tank, providing mixing of the contents. The nozzles are preferably grouped into at least two sets, each with a right and left nozzle that when operated together preferably cover the entire broadcast width desired for the liquid treatment material. The nozzles of each set also preferably have different flow rate capacities that, through proper selection of the nozzles, produce a constant rate of application per unit area at different ground speeds. 
     Also in a preferred embodiment, the spreader includes at least one bin as a material storage compartment for a granular treatment material, and a dispenser for dispersing the granular material on the ground surface being treated. Also preferably included is a deflector that can be used to prevent the granular material from being dispersed to either side of the spreader at the discretion of the operator, and a device for controlling the flow of the granular material to provide multiple sets of at least two flow rates. The granular flow control device is calibrated so that the flow rates of each set enable the spreader to dispense the granular material at an approximately constant application rate per unit area at the different forward speeds of the spreader. 
     Other preferred features of the invention include configuring the spreader to have drive wheels on a front section that includes the frame, with a sulky equipped with wheels mounted to the frame as a rear section of the spreader. The sulky provides a platform on which the operator can ride. The front and rear sections of the spreader can be connected together by an articulating joint linkage that enables the sections to bend side to side laterally for steering, and to rotate radially. To provide a method for treating small, difficult to reach or remote areas of a lawn or garden, the spreader is also equipped with a flexible squeeze bottle that can be filled from the storage compartment on the spreader, and then hand-operated remote from the spreader. The bottle is preferably equipped with a nozzle body that prevents fluid from splashing directly out of the nozzle body when the bottle is held upright and shaken. 
     Other objects and advantages of this invention will be better appreciated from the following detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a self-propelled spreader in accordance with a preferred embodiment of this invention. 
     FIG. 2 shows an articulating joint mechanism by which a rear sulky is mounted to a front frame of the spreader in accordance with the preferred embodiment of the invention. 
     FIG. 3 represents a handle latching assembly in accordance with the preferred embodiment of this invention. 
     FIG. 4 represents a liquid storage and dispensing system in accordance with this invention. 
     FIG. 5 is a bottom view of a bin for containing a granular material dispensed by the spreader of FIG.  1 . 
     FIG. 6 shows a handheld spot sprayer in accordance with the preferred embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 represents a self-propelled spreader  10  in accordance with a preferred embodiment of this invention. The spreader  10  is shown as including a granular storage bin  12 , a tank  14  and a handle assembly  16  mounted to a chassis frame  18 . The frame  18  may be formed of tube metal, though other forms for the frame  18  are foreseeable. A transaxle (not shown) is preferably mounted to the frame  18  for driving a pair of drive wheels  20  located near a forward end of the frame  18 . A sulky  22  is mounted to a rearward end of the frame  18 , and includes a platform  24  with a non-skid surface upon which the operator of the spreader  10  may stand. The sulky  22  is supported by a fixed axle  26  to which a pair of wheels  28  are mounted. The axle  26  and wheels  28  can be of any suitable type, and preferably include a braking mechanism (not shown), such as a band brake that can be hydraulically operated by a hand-activated hydraulic master cylinder  30  located on a handle bar  32  of the handle assembly  16 . The master cylinder  30  is preferably equipped with a locking mechanism (not shown) by which the brake can be held to serve as a parking brake. 
     The transaxle preferably provides multiple forward gears, a reverse gear, neutral and a differential, and is operated in combination with a suitable clutch mechanism, preferably a centrifugal clutch of a type well known in the art. The transaxle is preferably driven by a motor  34 , such as a four-cycle gasoline engine, through an appropriate drive system, preferably a belt and pulley system (not shown). A generator (not shown) is also preferably driven by the motor  34  to provide electrical power to the spreader  10 , as will be discussed below. The motor  34  is mounted to the frame  18 , along with an appropriate fuel reservoir, starter, throttle and other accessories conventional in the art. A shift lever  36  is shown as being located within easy reach of the operator. A stop bracket (not shown) can be used to locate the normal working gears of the transaxle. The shift lever  36  pivots about its lower end and is operably connected to the transaxle with a suitable shift linkage (not shown ). The motor throttle has preset run positions and controls the engine speed of the motor  34 . Referring to FIG. 1, the throttle is remotely operated by means of a cable (not shown) which is operably connected to a lever  40  on the handle bar  32 . The lever  40  has several detents or stops that establish an idle speed, a running speed and a choke setting. The throttle is returned to the idle position by a spring (not shown). 
     Referring to FIG. 2, the front frame  18  is connected to the rear sulky  22  by an articulating joint mechanism comprising an upper connecting link  42  with spherical rod ends at each end affixed by bolts or pins to the frame  18  and to the sulky  22 . A lower pivot spherical rod end  44  protrudes from a tongue  46  of the sulky  22 , and is secured to the frame  18  with a bolt or pin. A pair of separating columns  48  and  50  space the rod ends of the link  42  from the rod end  44  and tongue  46 , respectively, of the sulky  22 , to maintain a parallel relationship between the connecting link  42  and the tongue  46 . The front spherical rod end of the upper connecting link  42  and the lower pivot spherical rod end  44  are axially aligned on the column  48  so as to permit the frame  18  and the sulky  22  to rotate about the axis of the column  48 . The rear spherical rod end of the link  42  permits the sulky  22  to rotate about the axis of the tongue  46 , through the lower pivot rod end  44  located at the bottom of the column  48 . Two stops  52  made of, as an example, tubular metal are welded or otherwise secured at either side of the column  48  to limit the degree of rotation of the sulky  22  about the column  48 . 
     The handle assembly  16  is mounted to the frame  18  with bolts, clevis pins or the like, to provide a pivot for the assembly  18  at its lower end. The handle assembly  16  is configured to have at least two operating positions, with a mechanism to adjust the operating positions and a mechanism to quickly reposition and secure the handle bar  32 , so as to allow the operator to maintain complete control of the spreader  10  as he or she steps onto the sulky  22  for riding the spreader, and off of the sulky  22  for walking behind the spreader  10 . Referring to FIG. 3, the handle assembly  16  includes one or more extensions  54 , with a guide  56  affixed to one or more of the extensions  54  by welding, bolting, or other means. The guides  56  are formed, as an example, of round tube through which a round latch  58  passes. Each latch  58  projects from both ends of its guide  56 . An extension spring  60  is connected to each guide  56  and an upper portion of each latch  58  with brackets, screws, or bolts to automatically return the latch  58  to its original position when pulled and then released. When the handle assembly  16  is in a forward position, the latch  58  contacts a forward edge of a latch striker  62  secured to the frame  18 , so that the handle assembly  16  is secured in a position most appropriate for riding the spreader  10 . A top edge of the striker  62  is inclined downward toward the rear of the spreader  10 , forming a track upon which the lower end of the latch  58  rides as it travels downwardly and rearwardly when the handle assembly  16  is pivoted rearward, thereby lowering the handle assembly  16  to a position most favorable for walking behind the spreader  10 . As seen from FIG. 1, the upper end of the latch  58  is connected with a connecting rod  64  to a handle release lever  66  located near the handle bar  32 . A lower end of the connecting rod  64  forms a stop to control the downward motion of the latch  58  by contacting the top of the guide  56  and, in the preferred embodiment, also provides the attachment point for the spring  60 . Adjustment screws  68  are provided at the forward and rearward ends of one or both of extensions  54  to limit the travel of the handle assembly  16  by striking the frame  18 . Other forms of latch mechanisms are foreseeable. 
     The bin  12  is intended to store a granular material, such as a fertilizer, herbicide or other granular treatment material, while the tank  14  is intended to contain a liquid treatment material, such as a liquid fertilizer, herbicide or fungicide. Accordingly, both the bin  12  and the tank  14  are formed of materials compatible with the material they are intended to contain. The bin  12  has an opening at its top and a bottom portion with a sloped or trough shape to ensure that granular material contained in the bin  12  will readily flow by gravity to the bottom of the bin  12 . The bin  12  may also be fitted with a hinged or removable lid (not shown) to close the opening. The bin  12  includes at least one outlet  38  (FIG. 5) through which the granular material within the bin  12  will flow by gravity for dispensing, as will be discussed below. 
     With further reference to the bin  12 , FIG. 5 is a bottom view of the bin  12  and shows a sliding gate  70  for opening and closing the bin outlet  38 . One end of a lever  72  is connected to the sliding gate  70 , while a wire  74  is connected to the opposite end of the lever  72 . The wire  74  is actuated with a bell crank control rod  76  that extends across the handle bar  32 , as shown in FIG.  1 . At either end of the control rod  76 , a rod extension  78  is in close proximity to the handle bar  32  to permit opening and closing of the gate  70  with the operator&#39;s thumb or forefinger of either hand. An arm  80  projects from the control rod  76  so as to encounter an adjustable stop  82  that limits the amount of rotation of the control rod  76 , and therefore the movement of the sliding gate  70 . The adjustable stop  82  consists of a round dial with a helical ramp around the circumference, such that the relative distance between the arm  80  and helical ramp changes as the dial is rotated to control the opening of the sliding gate  70 . In the preferred embodiment, the stop  82  is calibrated to provide multiple sets of positions for the gate  70  to achieve different flow rates of granular material from the bin  12 . The flow rates for each set are calibrated for each of the different forward speeds provided for the spreader  10 , so that the spreader  10  dispenses the granular material at an approximately constant application rate per unit area at the different forward speeds. For example, if the spreader  10  has two established forward speeds, to apply a specified amount of granular material per unit area, the stop  82  has two settings for the desired application rate, one for each forward speed. Various other configurations for controlling and calibrating the opening provided by the gate  70  are foreseeable. 
     As shown in FIG. 1, a spinner platter  84  is positioned below the outlet  38  of the bin  12 . The rotatable platter  84  is driven by a shaft  86 , which in turn is driven by the motor  34  through an appropriate drive system, such as the belt and pulley system discussed above. A wire (not shown) may be attached to the upper end of the shaft  86  and extend into the bin  12  to agitate the granular material and prevent plugging of the outlet  38  of the bin  12 . The spinner platter  84  spins to radially distribute the granular material. In accordance with known practice, a pivoting diffuser plate  88  actuated by wire  89  (FIG. 5) is preferably located between the bin  12  and the gate  70  to balance the spreader pattern between the right and left lateral directions by directing the granular material to specific areas of the platter  84 . A hinged flap or deflector  90  is shown in FIG. 1 as being held in position above and out of the granular path by a spring  92 , but capable of being pivoted into the granular path with a handle  94  to intercept and deflect the granular material to reduce the width of the spreader pattern for edging property. 
     Referring now to FIG. 4, the tank  14  is connected with a hose or other suitable passage to diaphragm pump  96 . Additional hoses are shown as connecting the pump  96  to four separate spray nozzles  98 , each of which is configured to dispense the liquid contained within the tank  14  as a spray directed toward the front and sides of the spreader  10 . Valves  100  located in the fluid paths defined by the hoses enable the operator to select which nozzle  98  or nozzles  98  are supplied with liquid from the pump  96 . The nozzles  98  are shown as being divided into two separate broadcast pairs, with one pair  102  being located above the second pair  104  on the frame  18 . The nozzles  98  of the first pair  102  have a higher output capacity and are used when operating the spreader  10  at a higher of two forward speeds, such as when the operator is riding on the sulky  22 , while the nozzles  98  of the second pair  104  have a lower output capacity and are used when operating the spreader  10  at a lower of two forward speeds, such as when the operator is walking behind the sulky  22 . The flow capacities of the nozzles  98  of the different pairs  102  and  104  are chosen so that, for a given amount of pressure generated by the pump  96 , the same application rate per unit area is achieved when only the high-capacity pair  102  are used at the faster of two forward speeds as when only the low-capacity pair  104  are used at the slower of the two forward speeds. Either nozzle  98  of either nozzle pair  102  or  104  can be turned off by the valves  100  to reduce the width of broadcast spray and align the spray pattern with the granular spread pattern determined with the deflector  90 . A return hose  106  allows the unused output of the pump  96  to be bypassed back to the tank  14 , which advantageously provides mixing of the liquid within the tank  14 . The hose  106  terminates with a pressure relief valve  108  that maintains a predetermined pressure within the flow path between the pump  96  and the nozzles  98 . The pump  96  is preferably operated by a switch (not shown) mounted on the handle bar  32  to allow the spray from the nozzles  98  to be turned on and off. Power for the pump  96  can be provided by a generator (not shown) driven by the motor  34 , as discussed above. 
     As shown in FIG. 4, an additional valve  110  is provided that enables the tank  14  to be drained, as well as enables filling of a small handheld spot sprayer  112 , shown in FIG.  6 . The sprayer  112  consisting of a flexible plastic bottle  114  with a removable cap  116  penetrated by a nozzle body  118 . The nozzle body  118  has an inlet  120  on its interior end so as to be in communication with the fluid contents of the bottle  114  when assembled with the bottle  114 , and an outlet  122  on its exterior end. The nozzle body  118  further has a flange  124  and threads on its exterior end. An o-ring  126  forms a compression seal between the flange  124  and the cap  116  when an external nut  128  is tightened on the nozzle body  118 . A strainer  130  and nozzle  132  are provided at the nozzle body outlet  122 , and are secured to the nozzle body  118  with a nozzle cap  134 . The nozzle  132  preferably creates a fan-shaped pattern with the liquid dispensed from the bottle  114 , the width of the pattern increasing with the pressure exerted on the bottle  114 . Light pressure creates a narrow spray for spot treating, such as applying herbicide to individual weeds, while higher pressures disperse the spray in a wider spray pattern for treating larger turf areas. Different nozzles  132  can be used to shape the spray pattern, adjust the angle of spray and change the flow rate. The strainer  130  protects the nozzle  132  from becoming clogged by particles present in the fluid, which might otherwise distort the spray pattern, cause fine droplets to be discharged that can drift in the wind, or misdirect the spray off target. In lieu of or in addition to the strainer  130 , the inlet  120  can be formed to comprise a number of openings facing the sidewall of the bottle  114 , with the openings being sufficiently small to prevent particles from entering the nozzle body  118 . 
     According to the invention, the inlet  120  to the nozzle body  118  is offset from the outlet  122  to define a fluid flow path that significantly reduces the amount of fluid that is ejected from the nozzle  132  when the sprayer  112  is held upright and shaken. As shown in FIG. 6, the inlet  120  is at a right angle to the outlet  122  of the body  118 , which causes the inlet  120  to be disposed facing a sidewall of the bottle  114 . The resulting bend in the flow path acts as a baffle to prevent unintentional flow through the path, even if the sprayer  112  is shaken while in an upright position or remains inverted for an extended period of time. The sprayer  112  is preferably mounted to the spreader  10  with any suitable bracket (not shown). In use, the operator removes the sprayer  112  from its bracket, inverts the bottle  114 , and then squeezes to dispense the liquid. When the sides of the bottle  114  are released, the liquid remaining in the flow path is forced back into the bottle  114  by the incoming air. Thereafter, the liquid will not flow through the nozzle body  118  as long as the pressure within the bottle  114  is substantially equal to the pressure outside of the bottle  114 , i.e., the bottle  114  is not squeezed. Similar results can be achieved with sprayers configured differently from that shown in FIG.  6 . For example, the functions of the nozzle body  118 , strainer  130 , nozzle  132  and/or nozzle cap  134  could be combined into a single component, which defines a circuitous (i.e., nonlinear) flow path that acts as a baffle to prevent unintentional flow from the sprayer. Furthermore, a sufficiently circuitous flow path can be defined simply by providing a flow path with two passages having adjacent portions that are parallel but offset from each other, thereby defining two ninety-degree turns in the flow path. Accordingly, such modifications are within the scope of this invention. 
     While the invention has been described in terms of a preferred embodiment, it is apparent that other forms could be adopted by one skilled in the art. Accordingly, the scope of the invention is to be limited only by the following claims.