The present invention relates to lawn mowers and, more particularly, to baffle systems for use lawn mower cutting decks.
In one embodiment, the invention provides a cutting deck for a lawn mower. The cutting deck includes a cutting deck pan having an upper wall, sidewalls extending downwardly from the upper wall, and a discharge opening defined in the sidewalls. A first cutting blade is rotatably mounted beneath the upper wall. The first cutting blade is configured to rotate within a first rotation zone. A second cutting blade is rotatably mounted beneath the upper wall. The second cutting blade is configured to rotate within a second rotation zone. The first and second cutting blades are configured to cut vegetation and form clippings beneath the cutting deck pan. A baffle system is coupled to the cutting deck pan and extends downwardly from the upper wall. The baffle system has a baffle wall that at least partially surrounds the first cutting blade and the second cutting blade to define a first cutting chamber and a second cutting chamber. The baffle wall includes a front baffle wall portion having a front guide surface configured to guide the clippings from the first and second cutting chambers towards the discharge opening, and a rear baffle wall portion having a concave guide surface and an end positioned between the first cutting chamber and the discharge opening. A discharge transition area is positioned between the first cutting chamber and the discharge opening. The discharge transition area is defined by a linear segment of the baffle wall that extends from the end of the rear baffle wall portion to the discharge opening in a direction away from the front baffle wall portion and a contoured segment of the baffle wall formed on the front guide surface that extends from approximately midway within the first cutting chamber to the discharge opening. The contoured segment curves away from the rear baffle wall portion. The contoured segment is positioned opposite the linear segment such that a size of the discharge opening increases away from the first and second cutting chambers.
In another embodiment, the invention provides a cutting deck for a lawn mower. The cutting deck includes a cutting deck pan having an upper wall, sidewalls extending downwardly from the upper wall, and a discharge opening defined in the sidewalls. A first cutting blade is rotatably mounted beneath the upper wall. The first cutting blade is configured to rotate within a first rotation zone. A second cutting blade is rotatably mounted beneath the upper wall. The second cutting blade is configured to rotate within a second rotation zone. A baffle system is coupled to the cutting deck pan and extends downwardly from the upper wall. The baffle system has a baffle wall that at least partially surrounds the first cutting blade and the second cutting blade to define a first cutting chamber and a second cutting chamber. The baffle wall includes a rear baffle wall portion having a concave guide surface that forms a peak between the first cutting chamber and the second cutting chamber, and a front baffle wall portion having a front guide surface having a transition area positioned between the second cutting chamber and the first cutting chamber and a curved segment that extends from the transition area to form an apex approximately midway within the first cutting chamber and proximate the first rotation zone. The curved segment being convex away from the first rotation zone.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.
As shown in
As shown in
The baffle system 34 is coupled to the deck pan 26 and extends downwardly from the upper wall 38. The baffle system 34 is composed of baffle walls 50 that at least partially surrounds the first cutting blade 30, the second cutting blade 31, and the third cutting blade 32 to define a first cutting chamber 62, a second cutting chamber 58, and a third cutting chamber 54. In the illustrated embodiment, the first cutting chamber 62 is formed around the first cutting blade 30, which is closest to the discharge opening 46. The second cutting chamber 58 is formed around the middle or second cutting blade 31. The third cutting chamber 54 is formed around the third cutting blade 32, which is furthest from the discharge opening 46.
As shown in
The rear baffle wall portion 52 includes a concave guide surface 86. The concave guide surface 86 forms a first abrupt peak 60 between the first cutting chamber 62 and the second cutting chamber 58. The concave guide surface 86 also forms a second abrupt peak 64 between the second cutting chamber 58 and the third cutting chamber 54. The concave guide surface 86 is constructed to conform with or be concentric to the rear portion of the blade rotation zones 36, 40, 44 to direct clippings in the rear portion of the baffle system 34 towards the front baffle wall portion 56. The rear baffle wall portion 52 includes an end 68 positioned between the first cutting chamber 62 and the discharge opening 46. In the illustrated embodiment, the concave guide surface 86 is formed of three curved segments or a half circles that terminate at the first and second abrupt peaks 60, 64. In other embodiments, the entire rear baffle portion wall 52 may be formed of a single piece of material that defines the rear section of each cutting chamber 54, 58, 62. In some embodiments, the entire baffle system 34 may be formed of a single piece.
The front baffle wall portion 52 includes a front guide surface 72 that forms a continuously curved surface from the third cutting chamber 54 to the discharge opening 46. In the illustrated embodiment, the front guide surface 72 is constructed to direct clipping from the third cutting chamber 54 to the second cutting chamber 58, from the second cutting chamber 58 to the first cutting chamber 62, and from the first cutting chamber 62 towards the discharge opening 46.
The front guide surface 72 includes a first transition area 74 positioned adjacent the first transition zone 48 between the third cutting chamber 54 and the second cutting chamber 58. The first transition area 74 directs the clippings from the third cutting chamber 54 to the second cutting chamber 58. The first transition area 74 includes an extended, contoured segment 94. The extended, contoured segment 94 is initially linear as the segment extends out of the third cutting chamber 54 and is then convex toward the second cutting chamber 58. The first transition area 74 is devoid of any abrupt peaks that extend towards the rear baffle wall portion 52 within the first transition zone 48. The absence of abrupt peaks and the geometry of the extended contoured segment 94 in the first transition area 74 reduces the amount of clippings that may form clumps within or fail to exit the third cutting chamber 54. As a result, the third cutting blade 32 is able disperse the clippings from the third cutting chamber 54 through the first transition zone 48 and into the second cutting chamber 58 for processing through the cutting deck 22.
The front guide surface 72 includes a second transition area 78 positioned adjacent the second transition zone 49 between the second cutting chamber 58 and the first cutting chamber 62. The second transition area 78 directs the clippings from the second cutting chamber 54 to the first cutting chamber 62. The second transition area 78 includes a drooped, contoured segment 98. The drooped, contoured segment 98 is slightly concave away from the second cutting chamber 58 and transitions to being convex away from the third cutting chamber 62. A curved segment extends from the drooped, contoured segment 98 and forms an apex 100 positioned approximately midway within the first cutting chamber 62 and proximate to a front portion of the blade rotation zone 36 of the first cutting blade 30. It should be appreciated that the apex 100 may form a relative extrema or an absolute extrema of the front baffle wall portion 56. In some embodiment, the apex 100 may be the portion of the front baffle wall portion 56 that is closest to the rear baffle wall portion 52 (i.e., an absolute extrema). In other embodiments, the apex 100 may be the portion of the front baffle wall portion 56 adjacent that first cutting chamber 62 that is closest to the rear baffle wall portion 52 (i.e., a relative extrema.), In the illustrated embodiment, the apex 100 is a relative extrema. It should also be appreciated that while the first and second transition areas 74, 78 are illustrated as curved surfaces, that the first and second transition area 74, 78 may be flat.
With continued reference to
In the illustrated embodiment, the center point A of the first rotation zone 36 is offset the center point B of the baffle circle 104 a first distance 108 (e.g., a left-to-right direction or side-to-side direction that is perpendicular to a direction of travel of the lawn mower 10 and the cutting deck 22) and a second distance 112 (e.g., a front to back direction). The first and second distances 108, 112 may vary based on the size of the mower deck 22. For example, the first distance 108 may be relatively small (e.g., offset approximately three inches). In the illustrated embodiment, the center point A is closer to the discharge opening than the center point B. In other embodiments, center point B may be positioned closer to the discharge opening 46 than the center point A or approximately in line with the center point A (e.g., the first distance 108 is approximately zero).
The second distance 112 may vary so the apex 100 of the front baffle wall portion 56 is proximate the outer circumference of the first rotation zone 36. For example, the apex 100 may be positioned less than approximately three inches from the outer circumference of the first rotation zone 36. In some embodiments, the distance between the apex 100 and the first rotation zone 36 may be proportional to the diameter of the cutting deck 22. For example, the distance may be approximately less than five percent of the diameter of the cutting deck 22. In other embodiments, the apex 100 may be positioned greater than approximately three inches from the first blade rotation zone.
In the illustrated embodiment, a tangential surface of the curved surface (e.g., at the apex 100) is parallel to a tangential surface of the first blade rotation zone 36 proximate to the apex 100. In other words, the front baffle wall portion 56 is devoid of any portions that are concentric with and convex towards the blade rotation zone 36. Rather, the curved segment of the front baffle wall portion 56 that defines apex 100 is convex away from first rotation zone 36 and concave towards the center point B of the baffle circle 104.
The second transition area 78 is also devoid of any abrupt peaks that extend towards the rear baffle wall portion 52 within the second transition zone 49. Rather, the drooped, contoured segment 98 forms a continuous surface that extends towards the apex 100 and is angled towards the end 68 of the rear baffle portion 52. The absence of abrupt peaks and the geometry of the drooped, contoured segment 98 and the apex 100 reduces the amount of clippings that may form clumps within or fail to exit the second cutting chamber 58. As a result, the second cutting blade 31 is able disperse the clippings from the second cutting chamber 58 through the second transition zone 49 and into the first cutting chamber 62.
With continued reference to
The discharge transition area 76 is further defined by a contoured segment 90 of the baffle wall 50 in the second discharge area 70 that is formed on the front guide surface 72. The contoured segment 90 extends from the apex 100 of the curved surface approximately midway within first cutting chamber 62 to the discharge opening 46. The contoured segment 90 is positioned opposite the linear segment 82 in the discharge transition area 72 and curves away from the rear baffle wall portion 52 to also increase the size (e.g., width or volume) of the discharge opening 46 as the discharge transition area 76 extends away from the first cutting chamber 62. The contoured segment 90 is initially conforms with the outer circumference of the baffle wall circle 104 that is convex towards the first cutting chamber 62 and becomes concave away from the first cutting chamber 62 (e.g., curves towards the front of the cutting deck 22) the contoured segment 90 approaches the discharge opening 46. The second discharge area 70 helps reduce clipping clumping and improve distribution of clippings from the first cutting chamber 62 out of the discharge opening 46.
In conventional cutting decks, clippings C may be biased toward the front of the discharge opening when being expelled from the cutting deck, as schematically shown in
The cutting deck 22 with the baffle system 34 described above helps evenly disperse the clippings C across the entire width or area of the discharge opening 46, as shown in
With reference to
The second cutting blade 31 guides the clippings formed in the second cutting chamber 58 along the concave guide surface 86 of the second chamber 58 and towards front baffle wall portion 56. The clippings that entered the second cutting chamber 58 from the third cutting chamber 54 and the clippings from the second cutting chamber 58 mix together (e.g., along the flow path 102). The second cutting blade 31 guides the combined clippings along the front baffle wall portion 56 and towards the second transition area 78. The drooped, contoured segment 98 of the second transition area 78 guides the combined clipping in the second cutting chamber 58 into the first cutting chamber 62. The geometry of the drooped, contoured segment 98 and the curved segment that forms the apex 100 approximately midway within the first cutting chamber 62 directs the combined clippings in a rearward direction towards the rear baffle wall portion (e.g., towards the end 68 of the rear baffle wall portion 50). As, a result, the first cutting blade 30 in the first cutting chamber 62 is able to processes the combined clipping from the third and second cutting chambers 54, 58 towards the discharge opening 46.
The first cutting blade 30 guides the clippings formed in the first cutting chamber 62 along the concave guide surface 86 of the first cutting chamber 62, beyond the apex 100, and towards the contoured segment 90 of the discharge transition area 76. At the same time, the combined clippings from the third and second cutting chambers 54, 58 enter the first cutting chamber 62 along the drooped, contoured segment 98 via the flow path 102. The construction of the first cutting chamber 62 allows the majority of the clippings cut in the first cutting chamber 62 to disperse towards the contoured segment 90 of the discharge transition area 76 while the combined clippings are moving along the flow path 102 from the third and second cutting chambers and towards the linear segment 82 of the discharge transition area 76. As a result, the first cutting blade 30 interacts with the combined clipping to eject the clippings (C) out of the discharge opening 46 between the contoured segment 90 and the linear segment 82 of the discharge transition area 72. The clippings are dispersed generally along the entire width of the discharge opening 46, rather than only a portion of the discharge opening 46.
Various features and advantages of the invention are set forth in the following claims.
This application claims priority to U.S. Provisional Patent Application No. 62/803,676, filed Feb. 11, 2019, the entirety of which is hereby incorporated by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/US20/17741 | 2/11/2020 | WO | 00 |
Number | Date | Country | |
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62803676 | Feb 2019 | US |