Classifications

• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01D—HARVESTING; MOWING
  • A01D34/00—Mowers; Mowing apparatus of harvesters
  • A01D34/001—Accessories not otherwise provided for
  • A01D34/005—Mulching means
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01D—HARVESTING; MOWING
  • A01D34/00—Mowers; Mowing apparatus of harvesters
  • A01D34/01—Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus
  • A01D34/412—Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus having rotating cutters
  • A01D34/63—Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus having rotating cutters having cutters rotating about a vertical axis
  • A01D34/73—Cutting apparatus
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01D—HARVESTING; MOWING
  • A01D2101/00—Lawn-mowers

Definitions

• the present invention relates generally to a cutting system for a power rotary lawn mower. More particularly, the present invention relates to baffles that cooperate with a rotary mower blade to finely shred vegetation clippings. Specifically, the present invention relates to a cutting system that includes a plurality of baffles disposed above a rotary cutting blade that cooperate with vertically-oriented mulching cutters that extend from the rotary blade to repeatedly cut vegetation clippings.
• a lawn mower To effectively mulch vegetation clippings, a lawn mower must cut each clipping multiple times.
• One problem with cutting the clipping multiple times is positioning the clippings so that the blade may repeatedly strike them.
• the clipping is forced up by the air flow pattern to the area between the blade and the mower deck.
• the clipping then may swirl above the blade briefly until it falls back down through the plane of the blade towards the ground due to the influence of gravity and air streams.
• the likelihood that the clipping will be cut again by the blade depends on the speed of the blade and the size of the clippings and the random orientation of the clippings when passing through the plane of the blade. As a result, an undesirable number of clippings fall back to the ground without being recut.
• Another object of the present invention is to provide a cutting system, as above, that includes a plurality of baffles that position and temporarily retain the clippings such that they are more likely to be recut by the cutting surfaces of a rotary mower blade.
• Yet another object of the present invention is to provide a cutting system for a rotary lawn mower that includes a plurality of channels that direct clippings into a baffle where the clippings are positioned to be recut by a blade.
• the present invention contemplates a cutting system for a rotary lawn mower having a mower deck including a mower blade rotatably supported substantially within the mower deck, cutters positioned along the mower blade, and at least one baffle assembly carried by the mower deck and extending to a position adjacent to but spaced from the cutters of the mower blade.
• Fig. 1 is a perspective view of a rotary lawn mower blade arm and an exemplary baffle assembly according to the concepts of the present invention.
• Fig. 2 is a top plan view of a mower deck supporting the cutting system of
• Fig. 3 is an end elevational view of the blade arm and baffle assembly taken substantially along the line 3-3 of Fig. 2.
• Fig. 4 is a front elevational view of the blade arm and baffle assembly taken substantially along the line 4-4 of Fig. 2.
• Fig. 5 is a front elevational view of the blade arm taken substantially along line 5-5 of Fig. 2.
• Fig. 6 is an end elevational view similar to Fig. 3 of a blade arm and an alternative configuration for a baffle assembly according to the present invention.
• Fig. 7 is a front elevational view similar to Fig. 4 of the blade arm and baffle assembly depicted in Fig. 6.
• Fig. 8 is a top plan view of a mower deck supporting a second alternative configuration of a cutting system according to the present invention with a portion of the deck top being broken away and portions of the cutting system shown in plan and portions shown in section.
• Fig. 9 is a front elevational view of the blade arm and baffle assembly as well as one of the channeling walls taken substantially along line 9-9 of Fig. 8.
• Fig. 10 is a side view of a channeling wall taken substantially along line 10- 10 of Fig. 8.
• a cutting system according to the concepts of the present invention is depicted as being installed in a typical rotary lawn mower deck, generally indicated by the numeral 10 in Figs. 2 and 4.
• the lawn mower deck 10 has a generally planar or downwardly slightly concave deck top 12 and a substantially cylindrical sidewall 14 extending downward from the periphery of the deck top 12 toward the ground for engagement with grass, leaves, or other vegetation to be mowed (not shown).
• the mower deck 10 functions as the frame of the lawn mower and provides support for a motor (not shown) that drives a mower blade 20.
• the deck 10 also protects the user from the mower blade 20 by at least partially encasing the mower blade 20 within the deck 10.
• the deck 10 creates a swirl chamber 22 bounded by the plane 24 in which the blade 20 rotates as its lower axial limit, the deck top 12 as its upper axial limit, and the sidewall 14 as its radially outer limit.
• the rotation of the blade 20 causes air flow in the swirl chamber 22 that is generally circular and in the direction of the rotation of the blade 20.
• Grass and leaf clippings that have been cut by the blade 20 are typically caught in the air flow and are held in the swirl chamber 22 until the clippings fall out of the swirl chamber 22 back through the plane of the blade 24. While blade rotation in only one direction is depicted herein, it is to be appreciated that the principles described herein are equally applicable for either direction of rotation of blade 20.
• the cutting system of the present invention includes a plurality of baffle assemblies, generally indicated by the numeral 30, disposed above the rotary mower blade 20.
• Each baffle assembly 30 is supported by the mower deck 10 and extends downward toward the mower blade 20.
• the mower blade 20 includes at least two arms 32 that are supported by an input shaft 34 that transfers rotary motion from a motor (not shown) to the mower blade 20 (Fig. 2).
• a primary cutting surface 40 is formed in the front surface of each arm 32. Each cutting surface 40 is configured to cut through vegetation and create a clipping.
• Each arm 32 has a proximal portion 36 and a distal portion 38, the distal portion 38 being the farthest from the shaft 34 while the proximal portion 36 is closest to the shaft 34.
• Each distal portion 38 of each arm has a deflector 42 formed therein.
• the deflector 42 may be any one of various types that are known in the art.
• the deflector 42 includes a tab 43 disposed angularly above the longitudinal axis 44 of the blade 20.
• the tab 43 is curved upwardly toward the deck top 12 and inwardly toward the shaft 34.
• the curve of the deflector 42 at least partially creates an upward air flow when the mower blade 20 rotates which at least partially creates a circular air flow in the swirl chamber 22. The upward airflow helps direct clippings into the swirl chamber 22.
• a secondary cutting surface 46 is disposed directly behind each deflector 42 on each arm 32.
• the secondary cutting surface 46 is generally parallel to and is disposed in the same blade plane 24 as the primary cutting surface 40.
• the secondary cutting surface 46 provides a second cutting chance at any vegetation that avoids being cut by the primary cutting surface 40.
• a plurality of cutters 48 extend from the top surface of the distal portion 38 of each blade arm 32 behind the primary cutting surface 40.
• Each cutter 48 has a forward facing cutting surface 52 that is configured to cut vegetation.
• Each cutter 48 is configured to cooperate with a respective portion of baffle assembly 30 as will be further explained hereinafter.
• three equal-sized, triangular cutters 48 are disposed in substantially parallel relation on each blade arm 32.
• the size of the cutters 48 may vary, and the position of each cutter 48 with respect to the blade arm 32 may also vary.
• the overall shape of the cutters 48 need not be limited to the triangular cutters 48 depicted in the drawings. Square or rounded cutters 48 may also perform the function required by the present invention.
• the plurality of baffle assemblies 30 are attached to the mower deck top 12 and extend downward toward the blade 20.
• three baffle assemblies 30 are attached to the deck 10 and are circumferentially substantially equiangularly distributed about the deck 10.
• the number of baffle assemblies 30 is in the range from 3 to 7 or more, and it has been found that five baffle assemblies 30 evenly distributed every 72 degrees about the mower deck 10 is a preferred arrangement.
• even a single baffle assembly 30 configured and mounted according to the present invention yields substantially mulching benefits.
• each baffle assembly 30 is angularly disposed with respect to a radius 54 of the mower deck 10. As may be perhaps best seen in Fig. 2, each baffle assembly 30 is disposed at an acute angle, indicated by the numeral 56, with respect to a radius 54 passing through the inner end 58 of the baffle assembly 30. Although each baffle assembly 30 may be mounted parallel to a radius of the deck, it is preferred that the radially outer end of each baffle assembly 30 be angularly offset in the direction of blade approach at an angle 56 in the range of approximately 10 to 30 degrees.
• the angled baffle assemblies 30 help prevent the cutting system from clogging particularly when the mower is used to cut heavy, wet vegetation.
• Each baffle assembly 30 includes a baffle 60 supported by a bracket, generally indicated by the numeral 62.
• Each baffle 60 is configured to be spaced from but adjacent to or in close proximity to the blade 20 so that clippings held by the baffle 60 may be recut by the blade 20 as it passes the baffle 60.
• the bracket 62 may be supported from the deck top 12 by a plurality of nut and bolt assemblies 64, as is depicted in the drawings. However, the present invention also contemplates that the brackets 62 may be attached by other connectors. For instance, the brackets 62 may be welded to the deck top 12. If desired, the deck top 12 may be contoured to facilitate placement and seating of brackets 62. Additionally, the brackets 62 may be supported in whole or in part by the sidewall 14 of the deck 10.
• Each bracket 62 includes an attachment portion 70 connected to a mounting portion 72.
• the mounting portion 72 is tilted forward in the direction of blade 20 rotation, such that the mounting portion 72 and the attachment portion 70 form an acute angle, indicated by the numeral 74.
• the attachment portion 70 of the bracket 62 may be reversed, such that the angle between the mounting portion 72 and the attachment portion 70 is obtuse.
• the acute angle 74 between the mounting portion 72 and the attachment portion is in the range of approximately 60 to 80 degrees.
• a third portion 76 of bracket 62 extends from the lower edge of the mounting portion 72.
• the third portion 76 is also tilted forward in the direction of blade 20 rotation, such that the third portion 76 forms an acute angle, indicated by the numeral 78, with the mounting portion 72 of the bracket 62.
• the third portion 76 is spaced from the baffle 60 and provides support when the blade 20 causes the baffle 60 to bend and contact the third portion 76.
• a baffle 60 is attached to each bracket 62 by a suitable connector, such as a plurality of nut and bolt assemblies 80 having flat, broad heads 82.
• the configuration of the heads 82 provides support to the baffle 60 when the baffle 60 is subjected to bending forces.
• the baffle 60 may be a solid unitary member fabricated from a variety of materials such as metal, rubber, or plastic. In this respect, an elastomer, such as neoprene, with a single thin reinforcing layer encapsulated therein constituting one example.
• the baffle 60 may include a plurality of bristles 84, as depicted in Figs.
• a slot 90 is formed in the baffle 60 that corresponds with the contour of each cutter 48 on the blade arm 32.
• the slots 90 allow the cutters 48 to pass through the baffle 60 without contacting or at least deflecting the baffle 60 to any substantial extend.
• the slots also prevent the baffles 60 from being destroyed by the blade.
• the slots 90 may be preformed by removing sections of bristles or the blade 20 may be used to form the slots 90 as it rotates through the baffle 84.
• Each slot 90 is configured to allow the cutter 48 to pass through the baffle
• the slots 90 are generally triangularly shaped to allow the angled, triangular cutters 48 to pass therethrough. In other embodiments of the present invention where the cutters 48 are configured differentially, or are perpendicularly disposed to the blade axis 44, the configuration of the slots 90 would change to accommodate the cutters 48.
• the present invention operates in the following manner.
• the blade 20 rotates at a relatively high rate of speed that is suitable for cutting vegetation.
• the primary cutting surface 40 contacts a piece of vegetation such as a blade of grass or leaf, the vegetation is cut and the clipping is thrown above the blade 20 toward the cutters 48. If the clipping contacts the cutters 48 solidly, the clipping is immediately recut. Not all clippings, however, are recut by the cutters 48.
• FIG. 9 An alternative embodiment of a cutting system according to the concepts of the present invention is depicted as being installed in a typical rotary lawn mower deck, generally indicated by the numeral 100 in Figs. 8-10.
• the lawn mower deck 100 has a generally planar or downwardly slightly concave deck top 112 and a substantially cylindrical sidewall 114 extending downward from the periphery of the deck top 112 toward the ground for engagement with grass, leaves, or other vegetation to be mowed (not shown).
• the mower deck 100 functions as the frame of the lawn mower and provides support for a motor (not shown) that drives a mower blade 120.
• the deck 100 also protects the user from the mower blade 120 by at least partially encasing the mower blade 120 within the deck 100.
• the deck 100 By encasing the blade 120, the deck 100 creates an inner spindle grass compression swirl chamber 122 bounded by the plane 124 in which the blade 120 rotates as its lower axial limit, the deck top 112 as its upper axial limit, and the sidewall 114 as its radially outer limit.
• the rotation of the blade 120 causes air flow in the swirl chamber 122 that is generally circular and in the direction of the rotation of the blade 120. Grass and leaf clippings that have been cut by the blade 120 are typically caught in the air flow and are held in the swirl chamber 122 until the clippings fall out of the swirl chamber 122 back through the plane 124 of the blade 120. While blade rotation in only one direction is depicted herein, it is to be appreciated that the principles described herein are equally applicable for either direction of rotation of the blade 120.
• the cutting system of the alternative embodiment of the present invention includes a plurality of baffle assemblies, generally indicated by the numeral 130, disposed above the rotary mower blade 120.
• Each baffle assembly 130 is supported by the mower deck 100 and extends downwardly toward the mower blade 120.
• the mower blade 120 includes at least two arms 132 that are supported by an input shaft 134 that transfers rotary motion from a motor (not shown) to the mower blade 120.
• a primary cutting surface 140 is formed in the front surface of each arm 132. Each cutting surface 140 is configured to cut through vegetation and create a clipping.
• a plurality of cutters 148 extend upwardly from the top surface of the outer portion of each blade arm 132 behind the primary cutting surface 140. Each cutter 148 has a forward facing cutting surface 152 that is configured to cut vegetation.
• Each cutter 148 is configured to cooperate with a respective portion of the baffle assembly 130, as will be further explained hereinafter.
• three equal-sized triangular cutters 148 are disposed in substantially parallel relation on each blade arm 132.
• the size of the cutters 148 may vary, and the position of each cutter 148 with respect to the blade arm 132 may also vary.
• the overall shape of the cutters 148 need not be limited to the triangular cutters 148 depicted in the drawings. Square or rounded cutters 148 may also perform the function required by the present invention.
• the plurality of baffle assemblies 130 are attached to the mower deck top 112 and extend downwardly toward the blade 120.
• four baffle assemblies 130 are attached to the deck 100 and are circumferentially, substantially equiangularly distributed about the deck 100.
• the number of baffle assemblies 130 is in the range from three to seven or more, and it has been found that four baffle assemblies 130 evenly distributed every 90 degrees about the mower deck 100 is a preferred arrangement.
• each baffle assembly 130 is disposed substantially parallel to a radius of the mower deck 100.
• Each baffle assembly 130 includes a baffle 160 supported by a bracket, generally indicated by the numeral 162.
• Each baffle 160 is configured to be spaced from but adjacent to or in close proximity to the blade 120 so that clippings held by the baffle 160 may be recut by the blade 120 as it passes the baffle 160.
• the bracket 162 may be supported from the deck top 112 by a plurality of nut and bolt assemblies 164, as is depicted in the drawings. However, the present invention also contemplates that the brackets 162 may be attached by other connectors. For instance, the brackets 162 may be welded to the deck top 112. If desired, the deck top 112 may be contoured to facilitate placement and seating of the brackets 162. Additionally, the brackets 162 may be supported in whole or in part by the sidewall 114 of the deck 100.
• Each bracket 162 includes slotted portion 170 connected to a mounting portion 172.
• the mounting portion 172 is substantially flat and is configured to abut the inner surface of the deck top 112.
• the slotted portion 170 extends downwardly from the mounting portion 172 and is configured to slidingly receive the upper end of the baffle 160.
• the baffle 160 is held by slotted portion 170 through the engagement of a pair of lips 174 extending inwardly from the bottom of the slotted portion 170 with a rail 176 disposed at the top of the baffle 160.
• the rail 176 and lips 174 are configured such that the rail 176 may slide within the slot 178 in the slotted portion 170 without falling through the bottom of the slotted portion 170.
• the rail 176 may be formed by clamping slotted length of metal around a bar 180 about which individual bristles 184 are wrapped. When the rail 176 is clamped on the bristles 184 and bar 180, the bristles 184 are substantially retained by the rail 176 and cannot be removed without being broken.
• each slotted portion 170 abuts the sidewall 114 of the deck 100 such that the baffles 160 cannot move radially outwardly out of the slotted portions 170.
• the sidewall 114 cooperates with a pin 182 that is received through holes in the slotted portion 170 to hold the baffle 160 in the bracket 162.
• the pin 182 is removed when one desires to remove the baffle 160 from the bracket 162.
• the baffle 160 is then slid inwardly until free of the bracket 162. A new baffle 160 may then be inserted and the pin 182 replaced.
• the baffle 160 may be a solid, unitary member fabricated from a variety of materials, such as metal, rubber, or plastic.
• an elastomer such as neoprene, with a single thin reinforcing layer encapsulated therein, constitutes one example.
• the baffle 160 as depicted in Fig. 9, may 7/49276 PC17US97/11487
• baffles 160 include a plurality of bristles 184 that form a baffle 160 having a thickness on the order of one-half inch.
• a polycarbon material of the type used in utility brushes constitutes one example.
• the baffles 160 are fabricated such that each baffle 160 has a slot 190 that corresponds with a cutter 148.
• the slots 190 allow the cutters 148 to pass through the baffle 160 without contacting or at least deflecting the baffle 160 to any substantial extent.
• the slots 190 also prevent the baffles 160 from being destroyed by the blade 120.
• the slots 190 may be preformed by removing sections of bristles, or the blade 120 may be used to form the slots 190 as it rotates through the baffle 160.
• a plurality of channeling walls 200 extend downwardly from deck top 112 to form tapered channels 202.
• Each tapered channel 202 becomes narrower or tapers in the direction of blade rotation, with only one direction being depicted for purposes of example.
• a baffle assembly 130 is disposed at the narrow portion of each channel 202.
• the tapered channels 202 function to direct the clippings contained in the swirl chamber 122 into the baffle assemblies 130 where the clippings may be recut by cutters 148.
• Each channeling wall 200 is arcuate and has a first end 204 and a second end 206. As may be perhaps best seen in Fig. 10, the first end 204 of each channeling wall 200 is substantially shorter than the second end 206 of the channeling wall 200. That is, first end 204 of channeling wall 200 does not extend downwardly from deck top surface 112 as far as the second end 206 of a channeling wall 200 extends downwardly. In the embodiment of the invention disclosed in Figs. 8-10, the second end 206 of the channeling wall 200 extends downwardly, such that it is substantially even with the lower ends of the bristles 184 and does not contact the blade 120.
• the height of the first end 204 is indicated generally by the numeral 210 and is approximately one-third of the height of the second end 206 which is generally indicated by the numeral 212.
• the first end 204 of the channeling wall 200 may be substantially the same height as the second end 206 of the channeling wall 200.
• the first end 204 may be substantially even with the interior surface of the deck top 112.
• This alternative embodiment of the present invention operates in the following manner.
• the blade 120 rotates at a relatively high rate of speed that is suitable for cutting vegetation.
• the primary cutting surface 140 contacts a piece of vegetation, such as a blade of grass or leaf, the vegetation is cut, and the clipping is thrown above the blade 120 toward the cutters 148. If the clipping contacts the cutters 148 solidly, the clipping is immediately recut. Not all clippings, however, are recut by the cutters 148.
• Both the whole clippings and the recut clippings are then trapped in the inner spindle grass compression swirl chamber 122 by the air flow created by the blade rotation.
• the air flow carries these clippings into one of the tapered channels 202 that directs the clippings into a baffle assembly 130 where the clippings are supported by a baffle 160.
• the blade 120 continues to rotate and drives the cutters 148 against the clippings that are lying over or projecting into the slots 190 in the baffle 160.
• the cutters 148 recut these clippings into smaller pieces until the clippings are small enough to avoid the baffles 160 and fall down through the plane 124 of the blade 120 where they may be recut again.
• the cutting systems disclosed herein fulfill the various objects of the present invention set forth above and otherwise constitute an advantageous contribution to the art.
• modifications can be made to the preferred embodiments of the present invention disclosed herein without departing from the spirit of the invention.
• the cutting system disclosed herein may be used with mower configurations having two, three, or more, blades that are disposed next to each other.
• Such mowers cut substantially wider swaths than mowers with a single cutting blade, and it is just as desirable in these mowers to recut clippings as in single-blade mowers.
• the scope of the invention is thus limited solely by the scope of the attached claims.

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• Life Sciences & Earth Sciences (AREA)
• Environmental Sciences (AREA)
• Harvester Elements (AREA)

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• 1997
  • 1997-06-26 CA CA 2259040 patent/CA2259040A1/en not_active Abandoned
  • 1997-06-26 WO PCT/US1997/011487 patent/WO1997049276A1/en not_active Application Discontinuation
  • 1997-06-26 AU AU38796/97A patent/AU3879697A/en not_active Abandoned
  • 1997-06-26 EP EP97936028A patent/EP0929210A4/de not_active Withdrawn

Patent Citations (2)

Non-Patent Citations (1)

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