A spreader assembly with surface-clearing blower includes a rotary or broadcast spreader mounted on a frame for distribution and deposition of granular material in an area proximate the spreader assembly, a blower also mounted on the frame and with one or more ducts or hoses for conveying forced air to a surface proximate the spreader assembly to be cleared of deposited material. Granular material may include seed, ice-melt compound or salt, or fertilizer or other lawn or garden amendment or additive. The frame is mounted on the powered drive unit of a walk-behind mower to replace the mower deck.

BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a motorized apparatus for spreading granular material such as dry fertilizer and, in particular, to a spreader assembly with forced air blower mounted to the front of a walk behind motorized drive assembly. 
         [0003]    2. Description of the Related Art 
         [0004]    Devices for evenly spreading granular materials, such as de-icing compounds, seed, fertilizer, pesticide, or soil amendments such gypsum, are known in the prior art and include broadcast spreaders and drop spreaders. Drop spreaders generally drop material straight down in a width equal to that of the spreader hopper and are useful for covering areas than can be traversed in straight lines, in which case they generate little waste. Considerable care must be used, however, to avoid overlapping or failing to adjoin application lanes. If lanes fail to adjoin, gaps are created where material is not deposited. If lanes overlap, twice the amount of material may be deposited as desired. In the case of fertilizer or grass seed, such misapplication will become evident and long term as the lawn develops over a season. Broadcast spreaders, also referred to as rotary spreaders since the device usually uses a rotating wheel, disc or other form of rotary impeller to distribute material radially outward from the spreader, avoid some of these problems since they are designed to provide overlapping application of material, often in non-parallel application lanes. The material in the broadcast spreader hopper drops at a selected rate, governed typically by setting the size of a hopper aperture, from the hopper onto the spinning rotary impeller that then disperses the material over the desired surface, such as a lawn. Overlapping application lanes assure complete coverage to avoid missing any portions of the application surface. The method of material distribution typically scatters material in an arc of 360° or less about the axis of the rotary impeller and, therefore, often deposits material in undesired locations such as sidewalks, driveways or parking lots adjacent to the application surface. 
         [0005]    After application of fertilizer to a lawn, for example, a user must typically sweep adjacent paved areas to remove fertilizer granules that otherwise would be walked upon and tracked into buildings. Removal of fertilizer granules from sidewalks and other pedestrian walkways in a commercial setting is particularly important as the granules present an unkempt appearance, are unpleasant for customers and visitors to walk upon, and in high traffic areas can result in significant deposition of fertilizer material upon carpeting and other interior floor surfaces, perhaps scratching, staining or otherwise marring or damaging the surfaces. In addition, state or local law may require that granules containing pesticide be removed from paved surfaces. What is needed in the art is a spreader that can provide an automated means of clearing surfaces adjacent to an application surface of unwanted deposited material. 
       SUMMARY OF THE INVENTION 
       [0006]    An embodiment of a spreader assembly may include a mobile support element or base, a spreader attached to and conveyed by the support element, and means for directing a stream of air to a portion of the surface proximate the support element to substantially clear the surface of granular material deposited on the surface by the spreader. 
         [0007]    More specifically, the spreader assembly may include a mobile frame assembly comprising a typically rectangular, horizontally disposed frame, a rotary or broadcast spreader mounted to and above the frame, a means for producing a directed stream of air flowing at relatively high velocity, such as a forced-air blower, and one or more means for directing the stream of air downward toward a surface to be cleared of granular material deposited by the spreader, such as a hose or duct with a opening located distal from the blower and located proximate the surface to be cleared. The spreader assembly may include means for selectively opening or closing one or more of such means for directing, such as valves controlling the flow of air through hoses or ducts. Wheels are attached to the frame to allow the spreader assembly to be rolled along the ground and a source of power is provided to power the blower. 
         [0008]    The spreader assembly with surface-clearing blower may further include a powered drive unit including an engine and driven wheels. The powered drive unit is typically provided by removing the mower deck from a walk-behind mower and replacing the mower deck with the spreader frame assembly described above. In such case, the frame is typically provided with two, freely rotating, swiveling wheels attached to the front end of the frame. The back end of the frame is bolted to the powered drive unit of the walk-behind mower, which is typically provided with two, transverse, engine-driven wheels. The spreader assembly is therefore supported by two driven wheels at the rear of the spreader assembly and two swiveling wheels at the front of the spreader assembly. 
         [0009]    The blower is typically powered by a belt and pulley drive system that includes an engine-powered pulley on the powered drive unit. The engine-powered or driving pulley is typically the same pulley previously used to power the belt-driven mower blade of the disengaged mower deck. A belt runs between the powered driving pulley and a driven pulley attached to the shaft of the blower fan. Controls on the powered drive unit previously used to engage and disengage power to the mower blade, such as via a slack belt clutch, are now used to engage and disengage power to the blower. The blower may therefore be selectively operated during a spreading operation. 
         [0010]    Because the mower deck is removed and replaced with the lighter-weight frame that supports the spreader and blower, the machine is much lighter overall and is easier to use on hillsides because the reduced weight requires less force from the powered drive unit engine to drive the driven wheels and requires less operator force when manipulating the powered drive unit handle or handles to make turns. In addition, the blower enables the operator to remove deposited granules from selected portions of an application surface without requiring additional equipment. 
         [0011]    Other advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example an embodiment of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a front, right perspective view of an embodiment of spreader blower having three, selectable, flexible air ducts. 
           [0013]      FIG. 2  is a left, side view of an embodiment of a spreader blower having a single air duct and showing a slack belt clutch system. 
           [0014]      FIG. 3  is a left, side view of an embodiment of a spreader blower having a single air duct and having an electric clutch mounted below the engine and above the driving pulley. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    As required, a detailed embodiment of the present invention is disclosed herein; however, it is to be understood that the disclosed embodiment is merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. 
         [0016]    Referring now to the drawings, there is shown an embodiment of the spreader assembly with surface-clearing blower of the present invention indicated by the reference numeral  100 . The spreader assembly  100  includes a mobile support element or base such as a metal frame  105 . The metal frame  105  is typically horizontally disposed and generally rectangular. The frame  105  has a horizontally disposed longitudinal axis running from the front  110  of the frame  105  to the back  115  of the frame  105 , and a horizontally disposed transverse axis perpendicular to the longitudinal axis. A rotary spreader  120 , otherwise known as a broadcast spreader, is mounted to and above the frame  105  by any sufficiently operable means such as a metal post  125  attached to and projecting upward from the frame  105 . Metal brackets or flanges  130  may be used to attach the spreader  120  to the post  125 . A rotary spreader  120  of the type shown in the figures typically includes a hopper  135  for storing granular material to be distributed by the spreader  120 . An aperture (not shown) at or near the bottom of the hopper  135  allows the stored material to drop under force of gravity to a rotary impeller  140 . The rotary impeller  140  rotates about a vertical axis and includes fins or flanges  145  for flinging granular material radially outward from the rotary impeller  140  as it rotates at sufficient speed. The rotary impeller  140  may therefore distribute granular material from the hopper  135  in an approximately 360° radial arc about the spreader  120  and upon a selected application surface such as a lawn. Shields (not shown) placed proximate the impeller  140  may be used to narrow the arc and, in particular, to prevent material from being directed toward the operator. A sliding gate or other apparatus (not shown) located at the bottom of the hopper  135  may be provided to adjust the hopper aperture size for varying the material feed rate from the hopper  135  to the rotary impeller  140 . The rotary impeller  140  is typically rotated under power provided by an electric motor  165 . 
         [0017]    Since a rotary spreader  120  will typically distribute material from the hopper  135  in relatively wide arc about the spreader  120 , the spreader assembly  100  of the present invention provides a means for producing a directed stream of air flowing at relatively high velocity, such as a forced-air blower  150 , and one or more means for directing the stream of air downward toward a surface to be cleared of granular material deposited by the spreader  120 , such as a hose  155  or duct  160  with a distal opening  280  located proximate the surface to be cleared. The spreader assembly  100  may include means for selectively opening or closing one or more of the hoses  155  or ducts  160 , such as valves  170  controlling the flow of air through hoses  155  or ducts  160 . 
         [0018]    The spreader assembly  100  with surface-clearing blower  150  may further include a powered drive unit  200  including an engine  205  and driven wheels  210  powered by the engine  205 . The powered drive unit  200  is typically provided by removing the mower deck from a conventional walk-behind mower and replacing the mower deck with the spreader frame  105  described above. In such case, the frame  105  is typically provided with two, freely rotating, swiveling, front wheels  175  attached to the front end  110  of the frame  105 . The back end  115  of the frame  105  is bolted or otherwise attached to the powered drive unit  200 , which is typically provided with two, transverse, engine-driven wheels  210 . The spreader assembly  100  is therefore supported by two driven wheels  210  at the rear of the spreader assembly  100  and two swiveling wheels  175  at the front of the spreader assembly  100  that allow the spreader assembly  100  to be rolled along the ground. 
         [0019]    The electric motor  165  receives power to drive the rotary impeller  140  from the powered drive unit  200  electrical system which may comprise a battery or engine-powered electrical generator. As shown in  FIG. 1 , a switch  215  is typically mounted on the powered drive unit console  220  or handle  225  for turning the electric motor  165  on or off, causing the rotary impeller  140  to rotate or cease rotating, respectively. 
         [0020]    A lever  227 , mounted on or near the console  220  or handle  225 , is attached through linkages to the above-referenced gate so that the operator may move the lever  227  to open or close the gate, thereby providing a ready means for initiating or halting distribution of the granular material by the spreader  120 . 
         [0021]    A source of power is provided to rotate the fan  250  of the blower  150 . This may comprise an electric motor or other means, however, the blower  150  is typically powered by a belt and pulley drive system that engages an engine-powered driving pulley  230  on the powered drive unit  200  (see  FIGS. 2 and 3 ). The driving pulley  230  is typically the same pulley previously used to power the mower blade of the disengaged mower deck and is provided with the powered drive unit  200 . A belt  235  runs between the powered pulley  230  and a driven blower pulley  240  attached to the shaft of the blower fan  250 . See  FIG. 2  wherein the housing of the blower  150  is partially broken away to show the fan  250  inside the blower  150 . Controls, such as a control lever  255 , on the powered drive unit  200  previously used to engage and disengage power to the mower blade are now used to engage and disengage power to the blower  150 . The blower  150  may therefore be selectively operated during a spreading operation to initiate or halt airflow from the blower  150  as desired. 
         [0022]    Typical means for engaging or disengaging power to the blower  150  include an electric clutch  260  (see  FIG. 3 ) positioned in the power train between the power drive unit engine  205  and the driving pulley  230 . The same controls on the power drive unit  200  provided for engaging or disengaging power to the previously attached mower deck may be used to control the electric clutch  260 . 
         [0023]    Another means for engaging or disengaging power to the blower  150  includes a tensioning or idler pulley  270  (see  FIG. 2 ) that may be moved relative to the belt  235  running between the engine pulley  230  and blower pulley  240 . The tensioning pulley  270  may be moved to a first position wherein tension is increased upon the belt  235  thereby tightening the belt  235  upon the engine and blower pulleys sufficiently to cause the belt  235  to grip both the engine and blower pulleys so that rotation from the engine pulley  230  is transmitted from the rotating belt  235  to induce rotation in the blower pulley  240 . The tensioning pulley  270  may be moved to a second position wherein tension is released upon the belt  235  thereby loosening the belt's frictional engagement with the engine pulley  230  and blower pulley  240  so that one or both pulleys slip relative to the belt  235  and rotation is not transmitted from the engine pulley  230  to the blower pulley  240 . The tensioning pulley  270  is typically selectively moved between the first position and second position by moving the lever  255  engaged via linkages with the tensioning pulley  270  and mounted near the handle  225  and/or console  220  of the powered drive unit  200 . 
         [0024]    The blower  150  includes a casing or housing that houses the fan  250  or impeller. A first opening (not shown) in the blower housing allows air to enter the housing as the fan  250  is rotated. A second opening (nozzle aperture  280 ) allows air to be expelled from the blower  150  as the fan  250  is rotated. The second opening  280  is generally located at the terminal or distal end of an air duct  160  or air hose  155 . Therefore, as the fan  250  is rotated air is expelled from the blower  150  through the nozzle aperture  280  and replacement air is drawn into the blower  150  from the first opening proximate the fan  250 . The fan  250  and blower housing are typically arranged to form what is generally known in the art as a squirrel cage fan or blower. 
         [0025]    In one embodiment of the spreader assembly  100 , a duct  160  is attached to the blower  150  and extends generally transversely outward to the lateral edge of the frame  105 . The duct  160  is also angled downward to direct a stream of air produced by the blower  150  at an area of the application surface selected to be cleared of deposited granular material. As the spreader assembly  100  is rolled past the selected surface, the nozzle aperture  280 , passes over or in close proximity to the selected area and the force of the stream of air emitted from the nozzle aperture  280  blows the deposited granular material off of the proximate selected area. For example, after using the spreader assembly  100  to distribute and deposit granular fertilizer upon a lawn, the spreader assembly  100  may be passed near a sidewalk adjacent to the lawn so that the blower cleans the sidewalk of deposited fertilizer granules. 
         [0026]    In another embodiment of the spreader assembly  100 , a manifold  285  is connected to the blower  150  for distributing air flow from the blower  150  to several ducts or hoses  155  (see  FIG. 1 ). If three hoses  155  are used, as shown in  FIG. 1 , they are typically positioned so that a first hose  155   a  projects forward of the spreader assembly frame  105 , a second hose  155   b  projects leftward of the frame  105  (as viewed from the front of the spreader assembly  100 ), and a third hose  155   c  projects rightward of the frame  105 . The terminal end of each hose  155  may be referred to as a nozzle. Each nozzle is positioned within approximately 12 inches of the selected surface. Air flow may be selectively directed to any or all of the three hoses  155  by manipulating valves  170  placed along each hose  155 . In  FIG. 1 , ball valves  170  are shown positioned along each hose  155  so that valve actuators or levers  290  associated with each valve  170  project upward from the valve  170 . Each lever  290  may be turned to move the valve  170  from an open to a closed position or any selected intermediate position. Alternatively, the valves  170  may be controlled electronically by electromechanical devices known in the prior art such as solenoids. 
         [0027]    In one embodiment, the rotations per minute (RPM) of the powered drive unit engine  205  is approximately 3300, the engine pulley  230  is about 7″ in diameter, the blower pulley  240  is about 5″ in diameter, and the blower fan's 250 RPM are between approximately 4,400 and 5,500, as determined by engine RMP and the pulley diameter ratios. The blower fan  250  is approximately between 9 and 10″ in diameter and typically has between 40 and 60 blades. This embodiment will provide sufficient air flow to move most granular material typically applied by broadcast spreaders when the nozzle or nozzles are positioned within about 10″ of the selected surface. 
         [0028]    The spreader assembly  100  may be used to spread granular material, such as fertilizer, insecticide, or various soil amendments, upon an application surface, such as a lawn, while clearing nearby surfaces, such as sidewalks and driveways, of deposited material according to the following steps. Note that certain steps may be performed in an order varying from those given here, as long as the objective of clearing selected surfaces is accomplished. 
         [0029]    First, the hopper  135  is partially filled with material to be distributed by the spreader  120 . Before adding the material to the hopper  135 , lever  227  should be moved as required to close the hopper gate. Next, the engine  205  of the powered drive unit  200  is started and power is provided to the driven wheels  210  to begin forward motion of the spreader assembly  100  along a selected application lane upon an application surface. As the spreader assembly  100  moves forward, the operator typically walks behind the powered unit  200 , holding onto the handle(s)  225 . The switch  215  controlling power to the spreader motor  165  is turned, pushed, pulled or otherwise manipulated to an “on” position so that the spreader motor  165  is energized and begins turning the rotary impeller  140 . The gate lever  227  is manipulated to open the gate so that material may flow from the hopper  135 , through the hopper aperture and gate, and onto the rotary impeller  140 . 
         [0030]    While material is flung from the rotary impeller  140 , some material may land on surfaces adjoining the application surface. To clear material from such surfaces, the blower  150  is engaged with the engine  205  by manipulating the clutch lever  255 . If an electric clutch  260  is used, proper manipulation of the clutch lever  255  (or electrical switch as may be provided) causes the electric clutch  260  to engage the driving pulley  230  with the engine  205 . If a slack clutch is used, proper manipulation of the lever  255  moves the tensioning pulley  270  against the belt  235  to increase belt tension against the driving and driven pulleys  230  and  240 . In either case, power from the engine  205  is thereby provided to the blower fan  250 . The operator may then position the spreader assembly  100 , and particularly the hose or duct nozzle apertures  280 , proximate a surface to be cleared of deposited material. This operation may occur while spreading material with the spreader  120  or afterwards, after the spreading operation is complete. If a spreader assembly  100  with multiple hoses  155  is used, the hose valves  170  may be set to open or closed positions as needed. For example, to clear a surface to the right of the spreader assembly  100 , hose  155   b  would be utilized and the associated valve  170  opened. To clear a surface to the left of the spreader assembly  100 , hose  155   c  would be similarly used. To clear a surface directly in the path of the spreader assembly  100 , hose  155   a  would be used. 
         [0031]    In a further embodiment of the spreader assembly  100 , the blower  150  and duct  160  shown in  FIGS. 2 and 3  are mounted upon the frame  105  so that the blower  150  and associated duct  160  may be swiveled about an axis typically coincident or parallel to the fan axis to direct the duct nozzle any selected radial position. 
         [0032]    It is to be understood that while certain forms of this invention have been illustrated and described, it is not limited thereto except insofar as such limitations are included in the following claims and allowable equivalents thereof.