Abstract:
A rotary lawn mower blade that enhances the process of cutting, grinding, and ejecting lawn debris for the purpose of real-time nutrient recycling and visual aesthetics. The embodiment consists of a leading edge, interrupted transition, and an interrupted trailing face. The leading edge is maintained by sharpening the cutting edge until it intersects the bottom of the embodiment. The transition and trailing face has random interruptions of self-cleaning, sharp, jagged teeth that protrude above the blade surface. The jagged teeth are arranged to optimize the interaction between the clipping and the embodiment for the purpose of shredding and grinding. Centrifugal forces shear and grind the lawn clippings as they translate across the blade surface. The end result is an embodiment that shears and grinds lawn debris into small particles that break down in the environment at an accelerated rate to optimize the recycling process and augment visual appearance.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
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       FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
       [0002]    Not Applicable 
       REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX 
       [0003]    Not Applicable 
       OATHS OR DECLARATION 
       [0004]    Reference US patent Form PTO/SB/01 contained as part of this patent request. 
       BACKGROUND OF THE INVENTION 
       [0005]    In modern times, the practice of collecting lawn clippings when mowing lawn has declined. There are two primary reasons for this; the first is that regulatory requirements have become more stringent to impede the amount of yard waste deposited in landfills. The second is that research has proven that the practice of recycling lawn clippings back into the soil can help to enhance the nutrients and beautify lawn. The practice of recycling lawn clippings reduces the amount of fertilizers needed to maintain a thriving attractive lawn. The problem is that if lawn clippings are not shredded, the roots of the lawn are starved of oxygen and sunlight which are needed for growth; in addition to a poor, unfinished appearance. To overcome this problem, alternative lawn mower blades have been designed and are recognized in the industry as mulching blades. 
         [0006]    The present invention focuses on refining the rotary lawn mower mulching blade by improving the effectiveness of shredding lawn clippings after the initial cut. The invention can be used on any style of rotary lawn mowing apparatus to include electric mowers, hand mowers, tractors, and commercial lawn care equipment which employ a rotary lawn mowing blade. Understand that the invention is not limited in use by equipment specifically designed for mulching blades; rather, this invention can be employed on rear discharge, side discharge, and mulching style lawn mowing decks. 
       SUMMARY OF THE INVENTION 
       [0007]    The objective of this invention is to provide improvements in a rotary lawn mower blade that enhances the way lawn clippings are processed after the initial cut. The present invention grinds post cut clippings in a more efficient and succinct manner to ensure lawn root systems are not shadowed by lawn clippings. The invention functions in all types of lawn cutting conditions to include long, wet, and debris covered scenarios. 
         [0008]    The invention is made of an embodiment that includes a center hole used for mounting to the rotary power equipment. The embodiment includes a leading edge that is sharpened at an angle followed by a trailing face that is bent upward at different rates to alter the amount of vacuum produced by the rotary blade when spinning. The space between the sharpened edge and the trailing lift edge are disrupted with sharp jagged teeth. 
         [0009]    The invention lifts the blades of grass to a vertical stance by the trailing edge vacuum; produced when the blade is rotating at a high rate of speed. The blade of grass is then cut by the sharpened, leading edge of the rotary embodiment. The now cut grass clipping is traveling parallel with the leading edge of the rotary embodiment at a high rate of speed. The grinding occurs as the blade of grass translates across the disrupted, jagged teeth of the embodiment forcing a shear/shredding affect to a post cut clipping. The clipping can either eject upward to allow for the grind process to repeat by the second circumferential cut or the clipping ejects outward along the trailing feature face which includes sharp jagged teeth to precipitate further grinding. An alternate design to this invention can include a trailing edge inflection, which includes a compound angle to improve lawn lift for grinding and clipping ejection which also includes sharp, jagged teeth. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a top view of the lawn mower blade embodying the invention. 
           [0011]      FIG. 2  is a front view perspective of the embodiment shown in  FIG. 1 . 
           [0012]      FIG. 3  is an enlarged top view of one end of the blade shown in  FIG. 1 . 
           [0013]      FIG. 4  is an end view taken along section line  4 - 4  shown in  FIG. 3 . 
           [0014]      FIG. 5  is an enlarged detail view of the end of the blade shown in  FIG. 3 . 
           [0015]      FIG. 6  is an enlarged detailed view identified by as  FIG. 6  with a leader arrow pointing to a detail balloon in  FIG. 3 . 
           [0016]      FIG. 7  is an enlarged detailed view identified as  FIG. 7  with a leader arrow pointing to a detail balloon in  FIG. 3 . 
           [0017]      FIGS. 8 ,  9 , and  10  are simplified (all features not shown) illustrations of an alternate blade end to facilitate the explanation of the trailing edge offset angle and alternate trailing edge configurations for various applications. 
           [0018]      FIG. 8  is a top view of the simplified (all features not shown) embodiment. 
           [0019]      FIG. 9  is an end view of the simplified (all features not shown) embodiment. 
           [0020]      FIG. 10  is a front view of the simplified (all features not shown) embodiment. 
           [0021]      FIG. 11  is an isometric of the embodiment shown in  FIG. 1 . 
       
    
    
       [0022]    Prior to a detailed description of the embodiment, let it be recognized that the invention is not limited in its&#39; application, details of fabrication, and arrangements of the components set forth by the description or illustrations. The invention is adept of other embodiments and employed in alternative methods. Therefore, the terminology used herein is for the purpose of explanation and should not limit the present invention. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    The present invention is made from tuff; durable material such as steel that is processed in a series of sequences to form critical geometry. This geometry includes provisions for mounting, shearing, lifting, and grinding post cut lawn clippings and debris. The invention is reliable, durable, and performs in all mowing conditions to increase the speed in which post cut lawn clippings break-down into the soil. This invention effectively improves the look and finish of freshly cut lawn in addition to enhancing the cutting process in future weeks of the mowing season by reducing the amount and size of the lawn clippings. 
         [0024]      FIGS. 1-7  illustrate the embodiment of the present invention.  FIG. 8  is a simplified view (all features not shown) to illustrate an angle  22  at which the trailing edge is bent with respect to the leading edge  11  which will be explained in more detail later.  FIG. 9  is a simplified view (all features not shown) to illustrate the trailing face angle and alternative designs of the embodiment to include a trailing edge with a compound bend angle which includes an inflection; again to be explained later.  FIG. 10  is a simplified view (all features not shown) to illustrate alternate trailing edge face designs to be explained later. An isometric of the embodiment is represented by  FIG. 11 . 
         [0025]      FIG. 1  is a top view of the rotary lawn mower blade  14  to include a through hole  1  to precipitate mounting to a rotating arbor shaft which is not shown in any of the provided figures. The embodiment  14  can be directly coupled to an internal combustion (IC) engine, electric motor, or mowing deck where the embodiment is driven by a power take off (PTO). Generally, item  14  will have a mounting arbor pass through hole  1  and will be clamped to the arbor utilizing a compression washer and bolt; not shown. The embodiment is generally clamped between a bolt/washer and arbor flange by applying a compressive force in the form of torque applied to the bolt head. 
         [0026]    The embodiment  14  is rotated in a clockwise direction at a rate of speed necessary to perform work. The speeds will vary depending on the application and the device used to rotate the embodiment. The embodiment  14  is symmetrical at each end  7 ,  9 ,  10  of the blade and across the entire embodiment. This is necessary to facilitate both a static and dynamic balance which is essential to minimize vibration and uneven loads on arbor bearings when rotating. Edge  7 ,  9 ,  10  includes a radius at or larger than the overall length of the embodiment to provide end clearance necessary for rotation in what is referred to as the cutting deck. 
         [0027]    Edge  13  in  FIGS. 1-2  can be square (as shown), chamfered, have a radius, or include any suitable edge treatment. Edge  13  transitions into edge relief  12  and ultimately to the leading edge  11  which can be machined, ground, formed, stamped, or shaped using any process necessary to produce an angle that intersects the bottom edge of the blade. The leading edge  11  angle illustrated in  FIGS. 3-6  is preferably between 20-45 degrees referenced from the bottom side of the embodiment. This edge is generally maintained to produce the cleanest cut possible by grinding, machining, or filing the edge. 
         [0028]      FIG. 3  is an enlarged view of one end of the embodiment; with an understanding that each end of the blade is a mirror image, further description of the embodiment will focus on  FIGS. 3-7  detailing one end of the blade and simplified (all features not shown) views  FIGS. 8-10 . 
         [0029]    Primary cutting edge  11  intersects the top side of the embodiment  16 . The top side  16  includes sharp, jagged teeth  9  that reside behind the primary cutting edge  11 . The teeth  9  can be produced by forming, shaving, broaching, stamping, machining, or casting. The teeth arrangement may be uniform, random, offset, or any suitable arrangement to facilitate the most effective post cut clipping. The shape of each tooth  9  includes a vertex of material which stands proud of the top side  16  of the embodiment. The arrangement of the cutting teeth  9  can be uniform, random, offset, or any suitable arrangement to facilitate self-cleaning and shredding of the clipping. The shape of the tooth  9  size can be 0.100 inch wide by 0.068 inch tall, but the width and height can be any suitable size. The face of the tooth  9  employs sharp edges which are in direct line of action to the leading cutting edge  11 . The jagged cutting teeth  9  can be sharpened using any suitable process such as filling, grinding, or honing. 
         [0030]      FIG. 3 , jagged teeth surface  16  transitions into radius  8  where trailing edge  5  is bent upward. This is to provide vacuum and lift which draws the lawn blade into a vertical stance prior to being cut by leading edge  11  of the embodiment. The height of edge  5  can range from 0.5-2.5 inches tall when referenced from the bottom face depending on the lift required for use. Generally, the trailing edge  5  is the same height along the entire surface.  FIG. 10  is a simplified view illustrating an alternate design where the trailing edge angle  23  can increase or decrease for different cutting situations. The trailing edge  5  shown in  FIG. 4 . can have any suitable bend angle but preferably from 30-90 degrees and is bent about radius  8 . To facilitate the ease of bending,  FIG. 4  radius  8  intersects radius  3   FIG. 3 . Radius  3  reduces internal stresses induced by the bending process. The bend angle  22  is represented in simplified view  FIG. 9 . Simplified view  FIG. 9  also represents an alternate design to include bend angle  21  and bend angle  22  which results in a compound angle in face  19 . This compound angle is used to cup clippings as they traverse along face  19  and are routed off the blade face. Either design trailing face  17 ,  19  include a bend radius  8  preferably at a 10 degree angle, but can be at any suitable angle between 5-15 degrees to the leading edge  11  which is represented in the simplified embodiment  FIG. 8  detail  20 . 
         [0031]      FIG. 7 , jagged teeth  6  are similar to  9  and reside on surface  17 ,  19  which are placed at preferably 45 degrees but can be at any suitable angle between 30-90 degrees to edge  11 . The teeth  6  are produced by forming, shaving, broaching, stamping, machining, or casting. The shape of the tooth  6  includes a vertex of material which stands proud of the top side  17 ,  19  of the embodiment. The cutting teeth  6  can be uniform, random, offset, or any suitable pattern to facilitate self-cleaning and shredding of the clipping. Generally the tooth  6  can have a root width of 0.100 of an inch wide and peak of 0.068 of an inch tall, but the width and height can be any suitable size. The face of the tooth  6  employs sharp edges which shred the clipping. The jagged cutting teeth  6  can be sharpened using and suitable process such as filling, grinding, or honing. 
         [0032]    The blade thickness  13  in  FIG. 2  can be any suitable amount but generally between 3/16-⅜ of an inch thick. The blade width  FIG. 3  edge  13  to  13  can be any suitable dimension but generally ranges from 2-4 inches. The shear and grind  FIG. 3  which encompasses cutting edge  11 , jagged teeth  9  and surface  16 , include jagged teeth  6  and surface  17 ,  19  generally increase in width toward the outward edge  10 ,  8 , and  7 . This width can be any suitable dimension, but generally ranges from 2-6 inches. The blade  14  can be made from any suitable material, but generally made from a high carbon, alloy steel. Processes used for fabrication can include, but are not limited to powdered metal, stamping, broaching, machining, or casting. The embodiment  14  can be treated with any suitable metal heat treatment to maintain edge wear, tooth wear, and toughness to withstand impact/fracture. The embodiment  14  can be treated with any suitable wear coating treatment or plating to aid with tooth life  6  and  9  and the leading edge  11 . The embodiment  14  can be treated with any suitable corrosion protection to ensure robust and reliable service. 
         [0033]    The present invention described above ( FIGS. 1-11 ) defines an embodiment  14  that works when rotated at a high rate of speed. The surfaces  17 ,  19  and trailing edge  5  produce a vacuum which generates lift. The vacuum forces the lawn blade to stand perpendicular to sharped edge  11 . Edge  11  shears the top section of the grass blade (not shown) off at the specified height. The post cut lawn clipping (not shown) translates from a perpendicular stance to a parallel stance to face  16 . The clipping traveling parallel along face  16  is interrupted by jagged teeth  9  nested on transition face  16  which initiates the grinding process of the post cut clipping. The grind process occurs as the lawn blade impacts each tooth  9  as the blade of grass translates along face  16 . 
         [0034]    The post cut clipping (not shown) diminishes in size and shape as it traverses along face  16 . The clipping velocity is translated upward to face  17  or  19  by radius  8 . The clipping impacts jagged teeth  6  at an alternate angle to jagged teeth  9  which continues to grind the post cut clipping. Upon reaching face  17  or  19 ; the post cut clipping has two possible paths. Path one is that gravitational forces applied to the clipping maintain the material against face  17 ,  19  until it is ultimately ejected upward allowing it to be ground a third and fourth time as it intersects the opposite embodiment side two of the blade making a second circumferential cut. Path two; is that centrifugal forces act on the clipping by the rotating blade which cups the material and translates it along  17  or alternate design  19  where it continues to be ground up by jagged teeth  9  until ultimately is ejected to the side discharge or mulching deck baffles. 
         [0035]    In general, the features of the embodiment can be, but are not limited to the following fabrication processes: powdered metal, casting, stamping, coining, broaching, and machining.