Abstract:
A lawnmower uses thin, replaceable blades with a hardened cutting edge. Such blades are held by blade holding elements in a horizontally rotating mower blade assembly. The blade assembly and blade assembly housing are configured in a specialized cross-flow mower assembly to reduce grass leave tip damage, increase cut quality and overall aesthetic appeal, while consuming less power and providing a reduced environmental impact.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a non-provisional of U.S. provisional patent application 61/895,859 filed on Oct. 25, 2013. Likewise, the present application claims priority from U.S. non-provisional patent 13/768,856 filed Feb. 15, 2013, and Patent Cooperation Treaty patent application PCT/US14/16319 filed on Feb. 13, 2014. All of said patent applications are incorporated herein in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present Invention is directed generally toward lawnmowers and more particularly to lawnmower blade assemblies and lawnmower housings. 
       BACKGROUND OF THE INVENTION 
       [0003]    Lawnmowers traditionally come in two varieties: rotary mowers, where blades rotate horizontally in a plane; and reel mowers, where helical blades rotate about an axis so that the helical blades can shear grass against a bedknife. 
         [0004]    Rotary mowers have blades with a small cutting area, and the blades require very fast tip speeds to perform well. Typical tip speeds are greater than fifteen thousand feet per minute. This is necessary to achieve an acceptable cut, even when blades are sharp. Foreign objects struck by blades at these velocities can be very dangerous. Even though rotary mower decks and collection bags are required to be designed in accordance with various safety standards to minimize the risk of injury due to flying objects, many injuries still occur from ejected objects even when safety measures are in place. 
         [0005]    In addition, many injuries occur from the blades themselves. Rotary mower blades are very large and heavy and will inflict grievous injury even at low speeds. Furthermore, decks for these blades are completely open underneath to accommodate the circular cut area and the need for the blades to cut at their tips. This large, open area increases the risk of foot, hand, or other body part mutilation, and increases the risk of the blades striking a foreign object. 
         [0006]    Reel mowers have multiple helical blades (usually five or more) that rotate about a horizontal shaft; a stationary bedknife provides a shearing surface for the helical blades. The rotating helical blades of a reel mower typically operate at a lower speed than the blades of a rotary mower, but reel mowers are precision instruments that require frequent adjustment and precise operating conditions such as rotational speed and forward velocity. Reel mowers are also dangerous. Reel mowers must expose the entire front of the rotating helical blades to allow the blades to feed grass against a bedknife. Even while not in operation the helical blades may cause injury. In operation, accidental contact with a spinning helical blade will pull a hand or foot into the bedknife. Consequently, there is a need for a mower with a shielded and less exposed blade assembly to reduce the risk of injury. 
         [0007]    Typical rotary lawnmower blades are generally heavy, flat elongated pieces of steel that rotate symmetrically about a rotatable vertical shaft. Rotary lawn mower blades have a sharpened leading edge, and the outer portion of the trailing edge is curved to create airflow to lift grass and blow clippings into a bag or out of a discharge passage. 
       SUMMARY OF THE INVENTION 
       [0008]    Accordingly, the present invention is directed to a novel lawn mowing apparatus with a shielded blade assembly, configured to use a design configuration where the blade assembly rotates about an axis parallel to the ground. Blades are held by the blade assembly with the cutting edge of each blade oriented in the direction of rotation. This blade orientation requires the flow to be perpendicular to the blade. 
         [0009]    For the present invention as the blade assembly rotates, the grass is sucked up into the blades, is at least cut or marginally cut, and discharged from the blade assembly. In a preferred embodiment the mower blade horizontal cutter assembly acts as a cross-flow fan airfoil. 
         [0010]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention claimed. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention and together with the general description, serve to explain the principles. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The numerous advantages of the present invention may be better understood by those skilled in the art by reference to the accompanying figures in which: 
           [0012]      FIG. 1  is a perspective view of the drive side of a push type lawnmower with a blade assembly guard according to at least one embodiment of the present invention; 
           [0013]      FIG. 2  is a perspective, exploded view, of the non-drive side push type lawnmower shown in  FIG. 1 , having a blade assembly according to at least one embodiment of the present invention; 
           [0014]      FIG. 3  is a perspective, partially exploded view of the push type lawnmower shown in  FIG. 1 , having a blade assembly according to at least one embodiment of the present invention; 
           [0015]      FIG. 4  is a perspective, close up view of the blade assembly positioned with the housing sides and bottom surface; 
           [0016]      FIG. 5  is a perspective view of an embodiment of a horizontal rotary mower blade assembly of the present invention; 
           [0017]      FIG. 6  is a diagrammatic cross-sectional view illustrating a currently preferred crossflow horizontal mower geometry; 
           [0018]      FIG. 7  is an illustration of the airflow pattern as it flows through the crossflow horizontal mower housing in at least one embodiment of the present invention; 
           [0019]      FIG. 8  is a perspective view of a riding type lawnmower according to at least one embodiment of the present invention; 
           [0020]      FIG. 9  is a perspective view of a zero-turning radius mower according to at least one embodiment of the present invention; 
           [0021]      FIG. 10  shows a perspective view of a tow-behind ganged mower deck according to at least one embodiment of the present invention; 
           [0022]      FIGS. 11A ,  11 B, and  11 C are an exploded view of an embodiment of a horizontal rotary mower blade assembly radial blade cartridge and an exploded view of a portion of a rotor; 
           [0023]      FIG. 12  is an exploded, cut away view of a horizontal rotary mower blade assembly axial blade cartridge and rotor connection means; 
           [0024]      FIG. 13  is an exploded, cut away view of a horizontal rotary mower blade assembly axial blade cartridge and an exploded cut away view of an axial rotor blade retention slot; 
           [0025]      FIG. 14A  is an exploded view of a front portion of a wheel driven ganged mower assembly of the present invention on a zero-turning radius type mower; 
           [0026]      FIG. 14B  is an exploded view of a wheel driven tow-behind ganged mower assembly; and 
           [0027]      FIG. 15  is a perspective view of the non-drive side of a push type lawnmower with a blade assembly guard according to at least one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0028]    Reference will now be made to at least one embodiment of the subject matter disclosed, which is illustrated in the accompanying drawings. The scope of the invention is limited only by the claims; numerous alternatives, modifications and equivalents. For the purpose of clarity, technical material that is known in the technical fields related to the embodiments has not been described in detail to avoid unnecessarily obscuring the description. 
         [0029]    In at least one embodiment of the present invention, a lawn mower cut quality is enhanced by airflow optimized for directing grass blades into the blade cutting path for at least one of marginal cutting or cutting before discharge. The invention teaches a unique cross-flow geometry for mowing turf. 
         [0030]    Preventing grass buildup on the blade surface is an issue in turf mowers. The present invention controls the airflow so as to produce fine marginal cuts directed by the cross-flow airflow back into the freshly cut turf for beneficial decomposition. This is achieved by the blade assembly and housing geometry so as to control the flow of air into the blade assembly. This required considerable experimentation to determine the design parameters necessary to prevent this from happening and to also optimize cut performance. In at least one embodiment, a lawnmower utilizes a horizontally rotating blade assembly with the cutting edge of each blade in the blade assembly facing in the direction of rotation. Blades in the blade assembly are thin and have an edge geometry that is at an acute angle to the turf leaves to be cut; therefore, the blades continue to work effectively longer than blades in prior art lawnmowers and produce a healthier and less prone to tip browning cut. Because of the orientation of the blade assembly, the sharpness of the blade edge and the configuration of blades in the blade assembly, the blade assembly may operate at a lower, safer speed as compared to rotary lawnmowers and the blade assembly does not require a stationary straight blade (bed knife, cutter bar, shear bar, or the like) or an open front like a reel mower. The blade assembly may also be largely contained within a blade assembly guard to prevent accidental contact. 
         [0031]    Referring to  FIG. 1 , a perspective view is shown of the right/front side (drive side) of a push type lawnmower  100  with a blade assembly guard according to at least one embodiment of the present invention. The lawnmower includes a foldable handle  102 , a handle hinge  104  to fold the handle for storage and obstacle clearance, two front wheels,  238 ( a ) and  238 ( b ) and two rear wheels  248 ( a ) and  248 ( b ). In one embodiment of the present invention the wheels are adjustable and have mower height adjustment brackets  236 . The mower in one embodiment of the present invention has a battery  306  with a battery charger  308  (for in situ battery pack line current charging or the like). The battery  306  is operably connected to a motor  302  which powers the rotation of the horizontal rotary mower blade assembly (here concealed by front housing  224 ). Alternatively, the mower may be powered by an electric generator (mower powered), gasoline, electricity or by other appropriate means. The motor  302  may engage the horizontal blade assembly through a drive, for example, a chain  312  which may include a belt or chain gear assembly. The drive chain  312  is operatively connected to the rotary drive shaft  124  which engages the rotation of a horizontal rotary mower blade assembly  110  (here concealed by the front housing  224 ). The front housing  224  combined with the rear housing  240  is hinged, for example, to provide access to the blade cartridge  210  and blades  112 , and together define the top of the mower housing  200  according to at least one embodiment of the present invention. The horizontal rotary mower blade assembly (concealed by front housing  224 ) may also include a drive engaging mechanism  314  to facilitate a connection between the shaft  124  and a drive mechanism; for example, the drive engaging mechanism  314  may be a belt wheel to receive a drive belt connected to a motor. 
         [0032]    The mower front foot guard assembly  234  serves multiple purposes. The front foot guard assembly  234  protects people from the blades as well as providing a supportive structure for the framework for the front end of the cross flow horizontal mower and is cable of pushing rocks or other objects away from the mower. The rear housing drive support frame  244  functions as the support frame for the mower  100  and functions as a framework to attach the motor  302 , battery  306  and battery charging system  308  in one embodiment of the present invention. 
         [0033]    Referring to  FIG. 2 , a perspective, exploded view of the push type lawnmower shown in  FIG. 1 , having a horizontal rotary mower blade assembly  110  according to at least one embodiment of the present invention is shown. The drive chain  312  is connected to a horizontal blade assembly shaft  124 . The drive chain  312 , in one embodiment of the present invention may be covered by a drive shield to prevent injuries due to contact with the drive chain  312  and to protect the integrity of the transfer belt  312  during operation. 
         [0034]    The front housing  224  is shown in its open, non-operating position. The front housing  224  may include a hinge  226 . The front housing  224  may include a blade assembly access panel to access the horizontal mower blade assembly  110  for maintenance and replacement of blades  112 . A horizontal rotary mower blade assembly access panel may allow blades to be replaced quickly. In one embodiment of the present invention the front housing  224  may include a handle to allow easy access to the horizontal rotary mower blade assembly. In one embodiment of the present invention the horizontal rotary mower blade assembly may include a quick release option to allow changing the entire horizontal rotary mower blade assembly at one time. The front housing  224  may contain a latch or other similar device to lock the front housing  224  in place upon closing. The latch or locking system may operatively interface with the mower user interface controls  106  to shut down the mower when the front housing  224  is opened or ajar. 
         [0035]    The horizontal rotary mower blade assembly  110  is enclosed by the housing  200  ( 222 ,  224 ,  240 ) preventing the exposure of blades  112  in the horizontal rotary mower blade assembly  110  (except as necessary for grass cutting as more fully described herein). The front housing  224  together with the rear housing  240  form the top of the crossflow mower housing. The crossflow mower housing may include a left housing side plate  202  and a right housing side plate  204  enclosing the sides of the horizontal rotary mower blade assembly  110 . A portion of the crossflow mower housing including the top piece (front and rear housing interface)  502  ( 412 ,  414 ,  FIG. 6 ) formed by the front housing  224  and the rear housing  240  may connect to the right side plate  204  and left side plate  202 . The crossflow mower housing portion including the front housing  224  and the rear housing  240 , left housing side plate  202  and right housing side plate  204  may closely surround a portion of the horizontal rotary mower blade assembly  110 . An airflow produced by the horizontal rotary mower blade assembly  110  during operation may flow through the horizontal rotary mower blade assembly and may be contained within the boundaries of the right housing side plate  204  and the left housing side plate  202  (as will be more fully be described herein). 
         [0036]    Referring to  FIG. 3 , a perspective cut out view of the front left side of the cross flow mower showing the horizontal rotary mower blade assembly  110  according to at least one embodiment of the present invention is shown. The horizontal rotary mower blade assembly  110  may include a rotary drive shaft  124 . The rotary drive shaft connected to a rotor  114  or a plurality of rotors  114 . The rotors  114  provide attachment surfaces for a plurality of blade clamps  126 . Each blade clamp  126  is configured to hold a blade  112  such that the cutting edge of the blade faces the direction of rotation of the horizontal blade assembly  110  when the blade assembly  110  is in operation (two embodiments are illustrated in  FIGS. 11-13 , for example, other configurations are contemplated by the invention). While  FIG. 3  illustrates a plurality of blade clamps  126 , other blade holding elements may be used to implement embodiments of the present invention. Each blade clamp  126  may hold a single blade  112  or in in some embodiments of the present invention the blade clamp  126  may hold a plurality of blades. Each plurality of blades having a cutting edge ( 112 ). The blade  112  may be straight or curved in cross-section to form a desired airfoil to produce in combination with the housing geometry a desired cross-flow. 
         [0037]    A baffle  216  may define the back bottom part of the cross-flow mower housing. The baffle  216  divides an opening for the intake air and an opening for the exhaust air. The baffle  216  is connected to the right housing (drive side) plate  204  and the left housing (non-drive side) plate  202 , as shown in  FIG. 2 . The baffle extends from left housing side plate to right housing side plate across the back side of the mower. The baffle  216  has an air flow control surface (front surface)  218  herein periodically referred to as the tongue or tongue surface. The baffle  216  has a tongue discharge baffle guide  222 . In one embodiment of the present invention the tongue discharge baffle guide  222  guides or directs the cut grass clippings from the mower. In another embodiment of the present invention a bag or device to capture the cut blades of grass for later disposal may be affixed to the mower. The tongue foot guard  220  protects the mower operator. 
         [0038]    The baffle  216  combined with the front housing  224  and the rear housing  240 , the right housing side plate  204  and the left housing side plate  202  as shown in  FIG. 2  form the horizontal rotary mower blade assembly crossflow mower housing which will be described herein in further detail. 
         [0039]    Referring to  FIG. 4 , a cut away view of a portion of the crossflow mower housing assembly with left housing side part  202  and right housing side part  204  and baffle  216 . The baffle (tongue)  216  extends between left housing side part  202  and right housing side part  204  and is connected therein. The horizontal rotary mower blade assembly  110  as shown in  FIG. 2  and  FIG. 3  is shown. The horizontal rotary mower blade assembly includes a rotary drive shaft  124  (or other non-axle or shaft drive means for rotating the cutter assembly  110 ) extending through and connected to a plurality (or at least a pair) of rotors  114 . The rotary drive shaft  124  spins the rotors  114  about a horizontal axis defined by the rotary drive shaft  124  (or drive means). A plurality of blade clamps  126  are connected to the rotors  114 . A plurality of blades  112  are connected to the plurality of blade clamps  126 . Each blade clamp  126  is configured to hold a blade  112  such that the cutting edge of each blade  112  faces the direction of rotation during normal operation. The said plurality of blades forming an airfoil as the horizontal blade assembly rotates (e.g. about the rotary drive shaft  124 ). 
         [0040]    As described more fully herein, a blade assembly according to the present invention allows for inexpensive, replaceable blades  112 . Whereas the blades of prior art rotary mowers are required to have certain characteristics of mass and ductility based on their mode of operation and tip speed to meet certain safety standards and testing requirements, blades  112  according to at least one embodiment of the present invention essentially comprise only a cutting edge as the blades are thin enough to cut grass without a sharpened edge (while meeting or exceeding best practice guidelines). Blade  112  edges according to at least one embodiment of the present invention may be harder and sharper than prior art blades (preferably having at least two differential hardnesses in cross-section). 
         [0041]    Referring to  FIG. 5 , a close up view of the horizontal rotary mower blade assembly  110  as shown in  FIG. 2 . The horizontal rotary mower blade assembly  110  defines a cylinder having a length and a diameter. The length of the horizontal blade assembly may be described as somewhat less than the distance between the left housing side plate  202  and the right housing side plate  204  as each side is positioned within the crossflow mower. The diameter of the horizontal rotary mower blade assembly may be defined as the diameter of a rotor  114 . The horizontal rotary blade assembly includes a plurality of blade clamps  126 . Each plurality of blade clamps holding blades  112 . Each blade  112  comprising a cutting edge. The horizontal blade assembly  110  is positioned horizontally between the left housing side plate  202  and the right housing side plate  204  as shown in  FIG. 4 . 
         [0042]    Because blades  112  according to at least one embodiment of the present invention are harder and sharper than prior art blades, they may operate at lower speeds, in the range of two thousand to sixty-five hundred feet per minute. In one embodiment, a shaft driving a blade assembly may rotate at an angular velocity of between three thousand and five thousand rotations per minute. Where a blade assembly has a diameter of five inches, such angular velocity may translate to a linear blade tip velocity of two thousand to sixty-five hundred feet per minute. (The current ANSI limit for mower blade tip speed is nineteen thousand feet per minute). 
         [0043]    In one exemplary embodiment, the blades  112  travel at approximately sixty-two hundred feet per minute. Where a blade assembly has a diameter of 5.25 inch, a horizontal rotary mower engine would operate at approximately seventeen hundred rotations per minute. A motor turning at seventeen hundred rotations per minute with a 5.25 inch engine drive pulley driving a blade assembly with a 2.00 inch drive engaging mechanism will drive the blades  112  at approximately sixty-two hundred feet per minute (with the blade assembly rotating at forty-five hundred rotations per minute). Seventeen hundred rotations per minute is a fast idle for most internal combustion four-cycle mower engines. 
         [0044]    Such an exemplary embodiment of the present invention has approximately one-third (⅓) the blade tip speed of a common rotary mower (nineteen thousand feet per minute ANSI limit). A common rotary mower with a vertical engine directly driving a twenty-one inch blade must turn at approximately thirty-three hundred rotations per minute (near some engines maximum operating limit of four thousand rotations per minute) to produce a blade tip speed of approximately eighteen thousand feet per minute. At such engine and blade tip speeds, common rotary mowers produce significant noise and air pollution (ninety dB and as much hydrocarbons and nitrogen oxides as four cars driven for the same length of time). 
         [0045]    Furthermore, because the blades  112  are inserted into a blade clamp  126 , they may be easily replaceable. For example, in at least one embodiment, the blades  112  are modified utility knife blades. 
         [0046]    Rotary blades require a high tip speed, in the range of fifteen to nineteen thousand feet per minute, to adequately cut. Because of the high tip speed, rotary blades must be made from heavy gage, soft, ductile steel to meet ANSI test standards and other safety requirements. Hardness is the primary factor that affects blade sharpness retention, so sharpness of rotary blades degrades quickly because they must be made of ductile steel (less than Rockwell C 40 steel). Typically rotary blades are used for a season or more and are sharpened multiple times during their useful life. Sharpening is not technically difficult but takes time; and if rotary blades are not sharpened regularly, cut quality suffers. 
         [0047]    Because blades  112  in embodiments of the present invention operate at lower tip speed (between two thousand and sixty-five hundred feet per minute in some embodiments of the present invention as compared to nineteen thousand feet per minute in prior art mowers) the power source driving the blades  112  may be less powerful, operate more efficiently and operate at significantly lower engine speed. Less powerful, more efficient power sources may be lighter and more environmentally friendly as compared to motors used in prior art mowers. 
         [0048]    Reel mowers use hardened helical blades but because of the type of cutting action (shearing) they require a technically difficult and time-consuming process to sharpen the blades and adjust the blade alignment. That process usually requires a trained professional. 
         [0049]    Blades  112  according to at least one embodiment of the present invention may be manufactured using a very cost effective process similar to the manufacture of utility knife blades. In at least one embodiment of the present invention, blades  112  may be made of 1095 grade carbon steel. In at least one embodiment of the present invention blades  112  may have a blade thickness maximum of 0.075 inch or 1.9 mm. The core of blades  112  may have a core hardness of less than 50 HRC and the cutting edge of each of said plurality of blades may have a hardness of greater than 50 HRC. 
         [0050]    Referring to  FIG. 6 , a detailed diagram of the crossflow mower housing geometry. One embodiment of the housing design for the cross flow mower is illustrated and described fully herein.  FIG. 6  is an illustration of a cross-section of the crossflow mower housing assembly. The top piece of the crossflow mower housing assembly in one embodiment of the present invention includes the front housing  224  combined with the rear housing  240  to construct the top piece of the housing as shown in  FIG. 1 . The geometry of the top  502  and the baffle  218  are illustrated in  FIG. 6 . The direction of normal movement of the cross flow mower for at least one embodiment of the present invention is in the direction as indicated by the arrow  510 . The direction of movement coincides with the front of the mower. The direction of the air is drawn into the housing as from the front and underside of the crossflow mower. The top of the housing  502  (the front housing  224  and the rear housing  240  as shown in  FIG. 1 ) and the baffle  216  define the intake opening  402  and the exhaust opening  404 . 
         [0051]    One of ordinary skills in the art may describe this housing as being made from two circular arcs one with the center at the rotor center and the other being larger with its center located in the blade interior at the bottom. One of ordinary skills in the art would recognize such a housing as being described as a log spiral housing with very small radial width. The front end housing is extended closer to the ground and the baffle  216  or tongue, as it may be referred to by one of ordinary skill in the art, has been reconfigured to provide optimum performance of the crossflow mower. 
         [0052]    The Bold dotted lines  500  ( FIG. 6 ) are the datum reference lines for purposes of demonstrating the geometry of the crossflow mower housing assembly. One embodiment of the present invention defines the larger circular arc as the rear wall leading edge to end of log spiral arc angle  412  to be 210 degrees. The rear wall leading edge to rotor vertical axis angle  414  is optimally 7 degrees. The rear wall height angel  418  is optimally 101 degrees. In one embodiment of the present invention, the rear wall height angle may be described as the angular distance from the leading edge  410  to the point where the clearance between the horizontal rotary blade assembly and the housing wall increase shown at point  442  in  FIG. 6 . One of ordinary skill in the art would recognize point  442  as being the ending of the small radial width and the commencing of the logarithmic distance when referring to the log spiral housing. 
         [0053]    The blade clearance at the vortex wall  440  is optimally, mathematically described as 0.02×D2. Where D2 defines the outside diameter of the horizontal rotary blade assembly. The blade clearance at the leading edge  422  is optimally 0.04×D2. The distance  426  from the tongue wall top edge to the blade top tangent line  428  is mathematically described as 0.26×D2. Where D2 defines the outside diameter of the horizontal rotary blade assembly. The measured angle  430  describing the tongue wall inside edge to the zero datum angle is measured in at least one embodiment of the present invention in the range of 15 degrees to 20 degrees. The blade trailing edge angle  432  it optimally 70 to 80 degrees. The blade leading edge angle  434  is optimally 31 to 35 degrees. 
         [0054]    The tongue wall or baffle  218  leading edge to the end of log spiral arc angle  436  is optimally 28 degrees. The tongue or baffle  218  thickness angle  438  is optimally 52 degrees. 
         [0055]    For optimal flow and efficiency conventional theory recommends that the blade angles range from β 1 =60 to 90 degrees with 90 degrees optimal and β 2 =20 to 40 degrees with 26 degrees optimal. Whereby the angle β 2  is defined as the blade leading edge angle and the angle β 1  is defined as the blade trailing edge angle as shown in the figure herein. Performance variation is slight for values of β 2  between 60 and 90, but a variation of β 1  does have an impact on flow and efficiency. Experiments for this invention were run for values of β 2  from 18 degrees to 44 degrees and it was determined for at least one embodiment that 33 degrees provided the best cut quality with acceptable flow and efficiency. In at least one embodiment of the present invention a range of 31 degrees to 35 degrees for β 2  is acceptable with the optimum value of 33 degrees. The value for β 1  was purposely changed from approximately 60 to 175 degrees in conjunction with variation to other parameters including β 2 . In at least one embodiment of the present invention the value of β 1  functions well in the range of 60 to 95 degrees with the optimal angular measurement of 70 to 80 degrees. 

 
         [0056]    A width distance for the fan ranging from 1.3 to 1.55 times the D2 outer diameter of the blade assembly is employed. The spacing for the rotors  114  must be approximately this ratio or greater. The ratio of D1 to D2 should be between 0.7 and 0.85 with 0.84 being optimal for the design of one embodiment of the present invention. Most of the invention embodiments were either on the high end of this range or slightly over. Embodiments with values as high as 0.9 performed well during trials. 
         [0057]    The rotor  114  as shown in  FIG. 5  has a width W. The width W of the rotor  114  is optimal for at least one embodiment of the present invention when it is based on the ratio of a length L of a horizontal rotary mower assembly  110  as shown in  FIG. 5  and a diameter D2. A diameter D2, as described previously is the outer diameter of the horizontal rotary mower blade assembly. The optimum ratio, mathematically L divided by D2 is optimally 1.46. 
         [0058]    The rotational velocities for this embodiment to achieve optimum cut performance were approximately 3200 RPM for a 2 blade arrangement and 2500 RPM for a 6 blade arrangement. The 2500 RPM equates to a blade tip speed of approximately 3,900 feet per minute (fpm) which is significantly lower than a typical rotary mower that have a tip speed between 15,000 and 19,000 fpm. 
         [0059]    Referring to  FIG. 7 , an illustration of the airflow pattern as it flows through the crossflow mower housing  200  in one embodiment of the present invention. The crossflow mower is traveling forward which is defined as the normal direction of operation and is indicated by arrow  510 . The crossflow mower housing top surface  502  (which is the combination of the front housing  224  and rear housing  240  as shown in  FIG. 1 .) and the baffle  216  substantially cover at least a portion of the horizontal rotary blade assembly  110 . The mower housing top surface  502  and the mower housing bottom surface or baffle  216  define the intake opening  402  and the exhaust opening  404 . In one embodiment of the present invention the intake opening  402  has a width of 50 percent to 75 percent of the diameter of the horizontal rotary blade assembly. In one embodiment the exhaust opening,  404  has a width of 50 to 70 percent of the diameter of the horizontal rotary blade assembly. 
         [0060]      FIG. 7  show a horizontal rotary blade assembly  110  having a plurality of blades  112 . The horizontal rotary blade assembly rotates (e.g., about the rotary drive shaft  124 ) as shown in  FIG. 1 . The direction of rotation of the horizontal blade assembly  110  is opposite the direction of the rotation of the wheels ( 238 ,  248 ) in a mowing operation. The arrow  520  represents the rotation of the horizontal rotary blade assembly in its normal operation. The arrows ( 720 ,  722 ,  724 , and  728 ) are illustrative of the flow pattern which the air travels from the intake opening  402  through the exhaust opening  404 . 
         [0061]    The design of the crossflow mower housing in one embodiment of the current invention allows for the optimum location and size of the internal vortex  726 . The vortex  726  is being pushed down by the low radius log spiral housing. It is also being directed down and back by the large shaped baffle (tongue)  216 . The large shaped baffle  216  size and shape is primarily responsible for the size and position of the vortex. The greatest inflow of air is closest to the front end of the intake opening. 
         [0062]    The main air flow moves transversely across the blade assembly. A phenomenon particular to the crossflow fan is that, as the blades rotate, the local air incidence angle changes. The result is that in certain positions the blades act as compressors (pressure increase), while at other azimuthal locations the blades act as turbines (pressure decrease) this causes air to travel through the crossflow fan cylindrical blade assembly entering on one side and exiting on the opposite side of the blade assembly. An objective of the present invention is cut quality. Another objective is controlling grass buildup on the blade surface due to the location of the suction or in flow of air into the blade assembly. A typical crossflow fan uses an impeller with 25 to 35 forward curved blades, placed in a housing consisting of a rear wall and vortex wall (tongue). Some of the embodiments of the present invention used 2, 3, 4, 6, and 8 blade arrangements. This is fewer than convention dictates. The airflow and efficiency performance increases as does the production and maintenance costs as the number of blades increase. The present invention achieved acceptable performance with two blades and exceptional performance with six and eight blade configurations. The number of blades considered for the cross flow mower range from two to thirty-six with the optimal number of eight. 
         [0063]    In one embodiment of the present invention the horizontal rotary mower blade assembly may be defined as a cylinder (as shown in  FIG. 5 ) with a length and a diameter of the rotor  114 . As shown in  FIG. 5  the horizontal blade assembly may have a circumference having an arc length of 360 degrees defined by 360 radii with top most radius being approximately zero. The housing  200  ( FIG. 6 ) including the front housing  224  and the rear housing  240  ( FIG. 1 ) and the baffle  216  may substantially surround the horizontal blade assembly. The front housing  224  and baffle  216  combining to define an intake opening  402  ( FIG. 4 ). The rear housing  240  and baffle  216  ( FIG. 3 ,  FIG. 4  and  FIG. 6 ) define the housing exhaust opening  404 . The housing intake opening  402  beginning between 225 and 200 radii degree radii of the horizontal rotary mower blade assembly  110  and ending at between 170 and 150 degree radii of said horizontal rotary mower blade assembly  110 . Said housing exhaust opening  404  beginning at between the 60 and 80 degree radii of said horizontal rotary blade assembly  110  and ending between the 120 and 130 degree radii of said horizontal rotary blade assembly  110 . 
         [0064]    In one embodiment of the present invention is further defined as having the housing intake opening  402  has an arc length of between 60 and 70 degrees and said exhaust opening  404  having an arc length of between 40 and 70 degrees. 
         [0065]    In one embodiment of the present invention  100  the baffle  218  as shown in  FIG. 3  and  FIG. 6  where said baffle having at least one dimension approximately equal to the radius of said horizontal rotary mower blade assembly  110 . The baffle (tongue)  216  maybe defined as having a curved surface nearest the rotational arc of said horizontal rotary blade assembly  110  which varies in distance from the rotational arc (axis). The baffle  216  defines as a substantially equal annular space  232  between the housing and the horizontal rotary blade assembly  110  by forming a substantially constant radius from approximately 220 degree to 355 degrees. The opening distance to the horizontal rotary mower blade assembly  110  blade arc varies between the arc length defined by the housing bottom surface between approximately 350 and 60 degrees. 
         [0066]    The design of the crossflow mower housing  200  in one embodiment of the present invention  100  closely surrounding the horizontal rotary blade assembly  110 , may be configured to maintain and direct an airflow produced by the rotation of the blade assembly  110  to direct grass clippings toward a clippings bag or an opening where grass clippings are ejected. 
         [0067]    In at least one embodiment of the present invention, the mower  100  has a blade assembly configured to rotate horizontally. The blade assembly may include a shaft  124 , rotors  114  connected to the shaft  124 , and blade clamps  126  holding blades  112  connected to the rotors as shown in  FIG. 3  and  FIG. 4 . As the shaft  124  (or the like) turns, the cutting edge of each blade  112  cuts the grass in its path of travel. Because the blade assembly rotates substantially faster than the forward velocity of any mower, the action of the blade assembly may create a gradient in the length of grass in the immediate vicinity of the blade assembly. For example, grass may be shortest directly below the shaft  124  where the cutting edge of each blade  112  passes closest to the ground, and progressively longer as the blades  112  rotate until the blades  112  reach a point in the rotation when they are no longer cutting any grass. Such mowing action may progressively remove several portions of each blade of grass until the grass is cut to its shortest length. A mower according to at least one embodiment of the present invention effectively mulches grass clippings, and smaller clippings are easier to transport through airflow. The cut ends of grass are substantially similar to those achieved with a reel mower. 
         [0068]    The aesthetic quality and health of a lawn cut with a reel mower is far superior to that of a rotary mower. Rotary mowers leave the cut ends ragged while the reel mower&#39;s shearing cut leaves cut ends relatively clean. A ragged edge leaves grass more prone to disease. In at least one embodiment of the present invention, the cut quality produced by a horizontal rotary mower  100  may be significantly better than a rotary mower and closely match the cut quality of a reel mower. 
         [0069]    Referring to  FIG. 8 , a perspective view of riding type lawnmower  600  according to at least one embodiment of the present invention is shown. In at least one embodiment of the present invention, a riding type lawnmower  600  includes an operator seat  108  with mower user interface controls  106  in close proximity to the operator seat  108 . In one embodiment of the present invention, the riding type lawnmower may include a motor  302 , a battery  306 , a drive assembly  300  (concealed beneath and behind the driver seat), front wheels  238  and rear wheels  248  which propel the riding type lawnmower across the surface. In other embodiments of the present invention means for powering the riding type mower may be by gasoline or other appropriate means. One embodiment of the present invention includes a plurality of horizontal rotary blade assemblies  110  (concealed within the housing front  224 , and left housing side plate  202 ). The horizontal rotary blade assembly  110  has a motor  302  powered by a battery  306  which is operably connected to a battery charger  308 . Alternatively, the horizontal rotary motor blade assembly  110  could be powered by gasoline or other appropriate means. The motor  302  may engage the horizontal rotary mower blade assembly  110  through some type of drive chain  312  which may include a belt or chain gear assembly. The drive chain  312  is operatively connected to the rotary drive shaft  124  engaging the rotation of a horizontal rotary blade assembly  110  (concealed by the front housing  224 ). The front housing  224  combined with the rear housing  240  define the housing top piece  502  ( FIG. 6 ) of the crossflow mower housing according to at least one embodiment of the present invention. The blade assembly (concealed by front housing  224 ) may also include a drive engaging mechanism  314  to facilitate a connection between the shaft  124  and a drive mechanism; for example, the drive engaging mechanism  314  may be a belt wheel to receive a drive belt connected to a motor. In another embodiment ( FIG. 14A ), the ganged belly mower assembly (for use on a tractor or zero-turn radius mower) may be driven from the mower deck wheels or vehicle wheels (via a mechanical or electrical connection). Likewise, a gas powered electric generator on a towing vehicle or a large battery may be utilized to power each individual mower deck assembly. 
         [0070]    The horizontal rotary mower blade assembly  110  may be connected to the riding type lawnmower within an undermounted bracket system  606 . The horizontal rotary mower blade assembly  110 , in one embodiment of the present invention may include an access panel in the front housing  224  having quick access to allow maintenance and replacement of blades in the blade assembly. A blade assembly useful in this embodiment of the present invention may be as described herein. 
         [0071]    Referring to  FIG. 9 , a perspective view of a zero-turning radius mower  700  according to at least one embodiment of the present invention. The zero-turning radius mower  700  includes an operator seat  108  with mower user interface controls  106  in close proximity to the operator seat  108 . In one embodiment of the present invention, the riding type mower may include a motor  302 , a battery  306  and a battery charger  308  (concealed beneath the driver seat). In other embodiments of the present invention means for powering the zero-turning radius mower  700  may be by gasoline or other appropriate means. A plurality of horizontal rotary mower blade assemblies  110  are concealed within the housing front  224 , and left housing side plate  202 . The horizontal rotary mower blade assembly  110  has a motor  302  powered by a battery  306  which is operably connected to a battery charger  308 . Alternatively, the horizontal rotary mower blade assembly could be powered by gasoline or other appropriate means. The motor  302  may engage the horizontal rotary mower blade assembly  110  through some type of drive chain  312  which may include a belt or chain gear assembly. The drive chain  312  is operatively connected to the rotary drive shaft  124  engages the rotation of a horizontal rotary mower blade assembly  110  (concealed by the front housing  224 ). The front housing  224  combined with the rear housing  240  define the housing top piece  502  ( FIG. 6 ) of the crossflow mower. The horizontal rotary mower blade assembly  110  (concealed by front housing  224 ) may also include a drive engaging mechanism  314  to facilitate a connection between the shaft  124  and a drive mechanism; for example, the drive engaging mechanism  314  may be a belt wheel to receive a drive belt connected to a motor. 
         [0072]    The horizontal rotary mower blade assembly  110  may be operatively connected to the zero-turning radius mower  700  by a framework  604 . The horizontal rotary mower blade assembly  110  is operatively connected to the zero-turning radius mower  700  and controlled by the user through the mower user interface/controls  106 . The horizontal blade assembly  110 , in one embodiment of the present invention may include an access panel in the front housing  224  having quick access to allow maintenance and replacement of blades in the blade assembly. A blade assembly useful in this embodiment of the present invention may be as described herein. 
         [0073]    Referring to  FIG. 10 , a perspective view of a tow-behind ganged mower deck  800  according to at least one embodiment of the present invention is shown. The tow-behind ganged mower deck  800  may be pulled behind a tractor or like vehicle in one embodiment of the present invention. The tow-behind ganged mower deck  800  may be connected to a tractor or like vehicle by means of a hitch mechanism on the tractor (not shown) and attached by a towing connector  602 . The tow-behind ganged mower deck  800  connected through a towing connector  602  may include a power transfer mechanism such as a power take-off. Alternatively, the towing connector  602  may connect a tractor or like vehicle to the tow-behind gang mower deck  800  for towing while one or more horizontal rotary mower blade assemblies  110  are powered through other means such as the motor  302 , battery  306  and drive train system  312  as shown in  FIG. 10 . The tow-behind ganged mower deck deck  800  in one embodiment of the present invention is operatively connected to the tractor or like vehicle (not shown). In one embodiment of the present invention a plurality of horizontal rotary mower blade assemblies  110  are connected to the mower deck framework  604  or connected to one or more undermounted bracket systems  606 . In another embodiment ( FIG. 14B ), the ganged towable mower assembly may be driven from the mower deck wheels or vehicle wheels. Likewise, a gas powered electric generator on a towing vehicle or a large battery may be utilized to power each individual mower deck assembly. 
         [0074]    A tow-behind ganged mower deck  800  may include a plurality of horizontal rotary mower blade assemblies  110 . The horizontal rotary mower blade assembly  110  may have a motor  302  powered by a battery  306  which is operably connected to a battery charger  308 . Alternatively, the horizontal blade assembly could be powered by gasoline or other appropriate means. The motor  302  may engage the horizontal rotary mower blade assembly through some type of drive chain  312  which may include a belt or chain gear assembly. The drive chain  312  is operatively connected to the rotary drive shaft  124  which engages the rotation of a horizontal rotary mower blade assembly  110  here concealed by the front housing  224 . The front housing  224  combined with the rear housing  240  define the top piece of the crossflow mower housing according to at least one embodiment of the present invention. The blade assembly (concealed by front housing  224 ) may also include a drive engaging mechanism  314  (as shown in  FIG. 1 ) to facilitate a connection between the shaft  124  and a drive mechanism; for example, the drive engaging mechanism  314  may be a belt wheel to receive a drive belt connected to a motor. 
         [0075]    The horizontal blade assembly  110 , in one embodiment of the present invention may include an access panel in the front housing  224  having quick access to allow maintenance and replacement of blades in the blade assembly. A blade assembly useful in this embodiment of the present invention may be as described herein. 
         [0076]    In at least one embodiment of the present invention  100  ( 600 ,  700 ,  800 ) the horizontal rotary mower blade assembly  110 ,  210  may be removably replaced from the housing  200 . For example, a quick axle release  322  may be utilized to allow the rotary drive shaft  124  to be removed from the bearings ( 206 ,  208 ) such that the blade cartridge  210  may be removed from the housing  200  via the front housing  224 . Once removed the rotary blade cartridge  210  may be replaced with a fresh blade cartridge  210  having replaced blades (or sharpened blades, or for blade replacement or the like. Additionally, in another configuration of a removable blade cartridge  210  embodiment, one or both of the housing side plates ( 202 ,  204 ) may be quickly and safely removed from the frame  244  (via, for example, quick release fasteners or the like) such that the blade cartridge  210  may be rapidly and safely removed from the housing  200 . In this fashion the blade cartridge  210 , for example, may be slid from the drive shaft  124  from the rotor axle slot  116  for replacement or the like. In operation a user may also replace individual blades via the front housing  224 . 
         [0077]    Referring to  FIGS. 11A ,  11 B, and  11 C, an exploded view of a radial blade cartridge  210  is shown and an exploded cut out portion of a rotor  114  as shown in  FIG. 5 . In one embodiment of the present invention the radial blade cartridge may have a spring  804  attached to a locking mechanism  802  whereby the rotary blade cartridge  210  may be placed into the radial rotor blade retention slot  120 . The radial rotary blade cartridge  210  may be pushed down into the radial rotor blade retention slot  120  whereby activating the spring loaded locking mechanism  802 . In at least one embodiment of the present invention the radial rotary blade cartridge may include a tool designed to push the radial rotary blade cartridge  210  into the radial rotor blade retention slot  120 . 
         [0078]    Referring to  FIG. 12 , an exploded view of an axial rotary blade cartridge  810  is shown as placed in an axial rotary blade retention slot  904  and  FIG. 13  an exploded cut out view of a rotor  114  and with an exploded view of the blade cartridge  810 . The axial rotary blade cartridge  810  may have a length substantially similar to the distance between two rotors of the plurality of rotors  114  as shown in  FIG. 5 . The rotary blade cartridge  810  may include a blade or a plurality of blades  112 . The rotary blade cartridge  810  may have a plurality of bottom brackets  812 . The bottom bracket  812  may define a hole substantially similar in diameter to the locking pin  902 . The locking pin  902  may be operatively connected to a spring loaded locking mechanism  808 . The axial rotary blade cartridge  810  may be connected to the axial rotary blade retention slot  904  as shown in  FIG. 13 . For example, in one embodiment of the present invention, the horizontal rotary mower blade assembly  110  may be opened at the front housing  224  when the mower is in the off position and the blades  112  may be quickly and easily replaced using the axial rotary blade cartridge  810 . The axial rotary blade cartridge  810  may be disposable for example. In another example the blade cartridge may be reused with replacement blades or sharpened blades. 
         [0079]    In a presently preferred embodiment, motor operation is restricted to a mowing configuration, for example, all or at least some of the following conditions must be determined to exist by the controller  304 : two hands on the push handle  102  dead man switch or the like, no motion detected on or near the mower, housing  200  and assemblies secure and in operational configuration, and mower wheels rotating ( 238 ,  248 ). 
         [0080]    It is believed that the present invention and many of its attendant advantages will be understood by the foregoing description of embodiments of the present invention, and it will be apparent that various changes may be made in the form, construction, and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely an explanatory embodiment thereof, it is the intention of the following claims to encompass and include such changes.