Abstract:
An elongated air intake screen is provided for vehicles such as commercial mowers that operate in conditions having substantial airborne foreign materials that tend to clog the screen. The exterior surface of the screen is provided with intake openings throughout its 360 degree surface to draw air over a substantial area. It is located at the upper edge of the vehicle to separate it from the cutting decks and area where airborne grasses and similar foreign materials are encountered. Air drawn into the screen is used to cool the engine and hydraulic fluid heat exchangers and provide for engine combustion needs.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to vehicles used to mow grass and similar vegetation and more specifically to an air intake screen used with such vehicles.  
         BACKGROUND OF THE INVENTION  
         [0002]    Vehicles such as commercial mowers are commonly used for extended periods in warm climates. Since these vehicles typically utilize liquid cooled engines, they have fans and radiators for cooling the liquid. Similarly, they generally use hydraulic oil to power lift cylinders and related power needs on the vehicle. This oil is also cooled by passing it through an oil cooler.  
           [0003]    As the blades of the implements drawn by the mower cut grass and similar vegetation, the drier cut grass particles and similar foreign materials become airborne. Typically air intake screens are provided in front of the heat exchangers, that is the radiator and oil cooler, to minimize the build up of such foreign materials on the heat exchangers and the consequent effect on the cooling of the water and oil. These intake screens also serve to minimize the amount of foreign material being drawn into the engine combustion system.  
           [0004]    It has been common to place air intake screens directly in front of the cooling fan and heat exchangers at the rear of the engine compartment. Generally these screens are oriented vertically. Since the dust and airborne particles are more predominate near the cutting decks and lower portions of the mower, such placement frequently results in the screens becoming filled with foreign material, thereby requiring frequent servicing.  
           [0005]    One attempt in reducing the accumulation of material on the screen of a front mount mower was to place the screen at the front of the engine compartment and directly behind the operator seat. While this located the screen further from the dust and swirling airborne materials at the lower portions of the mower, it still used a smaller screen which resulted in frequent cleanings.  
           [0006]    Accordingly, it would be desirable to provide an air intake screen for use with a mower that extended the time between required cleanings. Further, it would be desirable to provide an air intake screen that provided sufficient filtered air for the liquid coolant radiator, the oil cooler and the engine combustion system.  
           [0007]    It would as well be desirable to provide an air intake screen that reduced engine overheating, hydraulic oil overheating, and lost time for screen cleanings.  
         SUMMARY OF THE INVENTION  
         [0008]    Toward these ends, there is provided a tubular air intake screen that draws air in throughout its 360 degree exterior surface. The screen is placed above the engine compartment to minimize exposure to the dry grass particles and similar foreign materials generated by the mower blades. The screen is sealed at its forward end and open at its rearward end to funnel filtered air to a vertical duct work that leads to a fan and engine air intake duct. The fan moves filtered air over the liquid and oil heat exchangers.  
           [0009]    With the present invention, a large volume of filtered air is available and the cleaning cycle for servicing the screen is substantially extended. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is a rear elevated perspective view of a front mount mower utilizing the tubular screen subject of the present invention. In this view, the rear duct is removed to expose the cooling fan and engine air intake duct.  
         [0011]    [0011]FIG. 2 is a side view of the commercial front mower with the side panels removed to expose the engine compartment. At the rear of the mower is carried the vertical duct that directs air from the screen to the cooling fan and engine air intake duct.  
         [0012]    [0012]FIG. 3 is an enlarged front view of the air intake screen. FIG. 3 a  is a yet further enlarged and partial view illustrating that the screen is provided with openings throughout its full 360 degree tubular surface.  
         [0013]    [0013]FIG. 4 is an enlarged schematic partial view of the sealing interface between the rear duct and screen.  
         [0014]    [0014]FIG. 5 is a left front elevated perspective view of the mower illustrating the forward and of the screen. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0015]    Looking first to FIG. 1, there is illustrated a rear elevated perspective view of a front mount mower  10  utilizing the tubular air intake screen  12  subject of the present invention. It will be understood that not all of the operator station elements are shown nor are the side and front cutting deck implements.  
         [0016]    The mower  10  includes a frame  14  supported by front and rear wheels  16  and  18 . The frame  14  further supports left and right implement lift structures, only one portion of the left structure  20  being shown. Carried in the rear portion of the frame  14  is an engine  22 . Looking as well to FIG. 2, it can be seen that the engine compartment  24  is carried in the mid portion of the frame  14 , behind the operator station  26  and enclosed in a hood  28  having sides  30  and a top surface  32 . The engine  22  in the preferred embodiment is liquid cooled and is provided with a radiator  34  at the rear portion of the engine compartment  24 . The engine  22  is further provided with a combustion air intake duct  36  that leads to an air filter  38  above the engine  22 .  
         [0017]    The mower  10  is also provided with a hydraulic oil system for powering the mower deck lift cylinders  40  and related other power needs of the mower  10 . The mower&#39;s hydraulic fluid reservoir is provided with a line  42  that leads to an oil cooler  44  at the rear of the engine compartment  24 . These heat exchangers, that is the radiator  34  for the liquid or water and the oil cooler  44  for the hydraulic oil system are vertically stacked in the preferred embodiment. Both heat exchangers  34  and  44  are positioned in front of a cooling fan  46  at the rear of the engine compartment  24 .  
         [0018]    Looking as well to FIG. 5, it can be seen that the forward end of the mower  10  is provided with the operator station  26  including a seat  48  and a rollover protection device (ROPS)  50 . Although not shown, the operator station  26  would be equipped with forward and reverse foot controls, brakes, steering wheel, throttle, and other related controls.  
         [0019]    Looking now to FIG. 3, it will be seen that the tubular air intake screen  12  is generally elliptical in configuration and fore and aft elongated. In the preferred embodiment, the screen  12  is constructed of perforated steel and includes air inlet openings  52  over its full 360 degree exterior surface. At the forward end of the screen  12 , there is a cover  54  blocking the entry of air. The rear end of the screen  12  is open and in communication with a bezel or vertical duct work  56  that is removably attached to the rear of the vehicle  10 . Looking back to FIG. 2, it can be seen that when the duct work structure  56  is attached to the rear of the vehicle  10 , it encloses the cooling fan  46  and the engine combustion air intake duct  36 . An airtight seal is provided between the ductwork structure  56  and the frame structure  58  of the vehicle  10 .  
         [0020]    The screen  12  is sealingly received, as is best illustrated in FIG. 4, between an inside flange  60  of the framework  58  carried at the rear of the vehicle  10  and an outer lip  62  of the duct  56  when it has been attached. A similar inner and outer flange arrangement is provided to secure the forward end of the screen  12  where the cover  54  is provided to prevent intake of unfiltered air.  
         [0021]    In operation, the front mount mower  10  is utilized to carry left and right as well as forward decks for cutting grass and similar vegetation. As the mower  10  is used, the cutting blades will lift and cut the grass. In doing so, the blades generate a substantial air movement which causes dryer grass clippings and foreign material to swirl around the decks and lower portion of the vehicle  10 . Because the air intake screen  12  is located at the upper portion of the vehicle  10 , less of the clippings and foreign material will be drawn into the screen  12 .  
         [0022]    The screen  12 , which is spaced above and apart from the engine compartment  24 , will draw air into its duct like interior channel from all around its 360 degree exterior surface. With such a large intake surface area and with the screen  12  located well above the decks, there will be less of a tendency for the screen  12  to become clogged.  
         [0023]    As the cooling fan  46  rotates, it draws air through the screen  12 , rearwardly through the tubular structure of the screen  12  and then downwardly within the vertical duct work  56 . The cooling fan  46  is located rearwardly of the vertically stacked oil and liquid heat exchangers  34  and  44 . In the preferred embodiment, the radiator  34  for the water is on the top and the oil cooler  44  for the hydraulic oil is positioned there beneath.  
         [0024]    Since the air intake screen  12  draws air throughout its 360 degree exterior tubular surface, the likelihood of foreign material filling its openings  52  and clogging it during daily operation is reduced. The elevated location of the screen  12  further serves to reduce its exposure to the airborne foreign matter as well. When the operator needs to clean the screen  12 , he simply uses an air hose to blow foreign material particles from the openings  52 .  
         [0025]    The hood or engine cover  30  swings open to allow access to the cooling fan  46 , heat exchangers  34  and  44  and the interior portion of the screen  12 . For further access to the interior portion of the screen  12 , the duct work  56  can be removed.  
         [0026]    With the present invention, there is provided an air intake screen  12  with a substantial surface area that permits substantial volumes of air to be provided to the cooling fan  46  to cool the heat exchangers  34  and  44  and provide clean air to the engine  22 . With the elevated location of the screen  12 , it is removed from much of the airborne foreign material and thereby reduces the rate at which the material accumulates within the openings  52  of the screen  12 . Accordingly, overheating of the engine  22  and/or hydraulic system is minimized and time between servicing requirements for cleaning the screen  12  is substantially extended.  
         [0027]    Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.