WO2018057552A1 - Lames de tondeuse compactes - Google Patents

Lames de tondeuse compactes Download PDF

Info

Publication number
WO2018057552A1
WO2018057552A1 PCT/US2017/052384 US2017052384W WO2018057552A1 WO 2018057552 A1 WO2018057552 A1 WO 2018057552A1 US 2017052384 W US2017052384 W US 2017052384W WO 2018057552 A1 WO2018057552 A1 WO 2018057552A1
Authority
WO
WIPO (PCT)
Prior art keywords
blade
elongate
mower
curved portion
elongate blade
Prior art date
Application number
PCT/US2017/052384
Other languages
English (en)
Inventor
Gerald Hobrath
Amit Saha
Robert Jira
Original Assignee
Mtd Products Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US29/578,374 external-priority patent/USD816445S1/en
Application filed by Mtd Products Inc filed Critical Mtd Products Inc
Priority to EP17777748.9A priority Critical patent/EP3515171A1/fr
Priority to CA3041627A priority patent/CA3041627A1/fr
Priority to AU2017332128A priority patent/AU2017332128A1/en
Priority to CN201780070700.XA priority patent/CN109952020A/zh
Publication of WO2018057552A1 publication Critical patent/WO2018057552A1/fr
Priority to AU2021200853A priority patent/AU2021200853A1/en

Links

Classifications

    • 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

Definitions

  • the present disclosure relates to lawn and garden equipment, and more particularly, to a low-profile cutting blade for a mower.
  • Currently available lawn mowers such as walk-behind mowers, riding mowers, garden tractors, and the like include a cutting deck having at least one cutting blade configured to cut grass and other vegetation.
  • the blade When using a cutting blade with a bagging attachment, the blade often includes an inclined surface to create lift under the deck to stand the grass upright and provide an airstream to move grass clippings into the bagging attachment such as the cutting blade shown in U.S. Pat. No. 6,301,868.
  • usage of this type of cutting blade in situations involving soils containing a relatively high sand content can erode the inclined surface portion of the cutting blade. After time, the inclined surface may be entirely removed, thereby eliminating the lift functionality of the blade. This can require relatively frequent blade replacement.
  • a mower blade for a lawn maintenance device includes an elongate blade having opposed end edges and opposed side edges.
  • the elongate blade is adapted for mounting onto a rotary mower for rotation about a center axis extended transverse to the elongate blade and separating the elongate blade into opposed elongate end portions extended from said center axis.
  • the elongate blade has a blade major axis.
  • the elongate blade defines a curved portion such that the curved portion is opposite a cutting edge. The curved portion extends from the elongate blade in an upward direction where the two meet and curves toward a lower face of the elongate blade.
  • a mower blade for a lawn maintenance device includes an elongate blade having opposed end edges and opposed side edges.
  • the elongate blade is adapted for mounting onto a rotary mower for rotation about a center axis extended transverse to the elongate blade and separating the elongate blade into opposed elongate end portions extended from the center axis.
  • the elongate blade has a blade major axis.
  • the elongate blade defines a curved portion such that the curved portion is opposite a cutting edge.
  • the curved portion extends from the elongate blade in an upward direction where the two meet and curves toward a lower face of the elongate blade.
  • a distal portion of the curved portion is offset vertically from a cutting edge to develop lift during rotation.
  • a mower blade for a lawn maintenance device includes an elongate blade having opposed end edges and opposed side edges.
  • the elongate blade is adapted for mounting onto a rotary mower for rotation about a center axis extended transverse to the elongate blade and separating the elongate blade into opposed elongate end portions extended from the center axis.
  • the elongate blade has a blade major axis.
  • the elongate blade defines a curved portion such that the curved portion is opposite a cutting edge.
  • the curved portion extends from the elongate blade in an upward direction where the two meet and curves toward a lower face of the elongate blade.
  • the curved portion has a constant cross-section over most of the blade major axis.
  • FIG. 1 is an isometric view of an exemplary low profile mower blade according to at least one embodiment of the present disclosure
  • FIG. 2 is an elevation view of the low profile mower blade of FIG. i;
  • FIG. 3 is a top view of the low profile mower blade of FIG. 1;
  • FIG. 4 is a cross-section view taken along line 4— 4 of FIG.1;
  • FIG. 5 is a cross-section view taken along line 5— 5 of FIG. 1;
  • FIG. 6 is an isometric view of a low profile mower blade showing an alternative mounting arrangement.
  • Example embodiments that incorporate one or more aspects of the present disclosure are described and illustrated in the drawings. These illustrated examples are not intended to be a limitation on the present disclosure. For example, one or more aspects of the present disclosure can be utilized in other embodiments and even other types of devices. Moreover, certain terminology is used herein for convenience only and is not to be taken as a limitation on the present disclosure. Still further, in the drawings, the same reference numerals are employed for designating the same elements.
  • the low profile mower blade 20 includes an elongate blade 24 having a first end edge 26 and a second end edge 28 that are opposed to one another.
  • a first side edge 30 and a second side edge 34 are also opposed to one another, and together, the first end edge 26, the second end edge 28, the first side edge 30, and the second side edge 34 generally form the four sides of the low profile mower blade 20.
  • the low profile mower blade 20 is adapted for mounting onto a lawn maintenance device (e.g., a rotary mower) (not shown) for rotation about a center axis 36 extended transverse to the elongate blade 24.
  • the center axis 36 separates the elongate blade 24 into opposed elongate end portions 38, 40 extending from the center axis 36.
  • the elongate blade 24 also includes a blade major axis 44.
  • the elongate blade 24 can be configured with a pair of sharpened cutting edges 46.
  • the sharpened cutting edges 46 are located on the first and second side edges 30, 34 such that when the low profile mower blade 20 rotates in the direction shown by arrow 48, the sharpened cutting edges 46 are each on a leading edge of the elongate blade 24 to cut grass and/or vegetation.
  • the sharpened cutting edges 46 can be two inches to six inches in length.
  • the central portion 50 of the low profile mower blade 20 can include structure for mounting the low profile mower blade 20 to a rotating shaft, such as a spindle, engine shaft, etc. such that the low profile mower blade 20 can be rotated by a power source on a rotary mower (not shown).
  • the power source can be any suitable power source including, but not limited to, a gasoline powered engine, a corded electric motor, a battery-powered electric motor, etc.
  • the low profile mower blade 20 can define one or more apertures to cooperate with physical features located on the rotary mower to attach the low profile mower blade 20 to structure on the rotary mower. Any suitable attachment structure or definition is contemplated with the present disclosure.
  • FIG. 2 the exemplary low profile mower blade 20 is shown in an elevation view. As seen in the figure, one sharpened cutting edge 46 is shown on the lower right side of the low profile mower blade 20.
  • Many cutting blades and mower blades incorporate a ramped surface or sail opposite the sharpened cutting edge 46 in order to produce lower air pressure above and higher air pressure below the rotating cutting blade so as to effectively create lift of the grass, other vegetation, and subsequent clippings.
  • This lift can be used to straighten the grass and vegetation prior to cutting and provide a force to move the clippings to a collection bag or out a discharge chute (not shown).
  • the ramped surface or sail is constantly experiencing an impingement of sand particles along the length of the ramped surface. This, in turn, effectively sandblasts or wears away the ramped surface within a relatively short time.
  • the low profile mower blade includes the elongate blade 24 having end portions 38, 40 extending from the center axis (represented by a dot at 36).
  • the elongate blade 24 also includes a blade major axis 44 and is configured with a pair of sharpened cutting edges 46.
  • the sharpened cutting edges 46 are located on the first and second side edges 30, 34 such that when the low profile mower blade 20 rotates in the direction shown by arrow 48, the sharpened cutting edges 46 are each on a leading edge of the elongate blade 24 to cut grass and/or vegetation.
  • FIG. 4 a cross-section view of the elongate blade 24 is shown.
  • the elongate blade 24 defines a curved portion 54 such that the curved portion 54 is opposite the sharpened cutting edge 46.
  • the curved portion 54 extends from the elongate blade 24 in an upward direction from where the sharpened cutting edge 46 and the curved portion 54.
  • the term "upward direction” is used to define the direction that is perpendicular to a driven surface (e.g., the turf) that is generally considered “up,” as the lawn maintenance device is normally operated.
  • the curved portion 54 then curves to point downward toward a lower face 56 of the elongate blade 24.
  • the curved portion 54 provides significantly less air turbulence as the low profile mower blade 20 revolves around the center axis 36. This reduction in air turbulence encourages objects (e.g., grains of sand) to flow over and behind the rotating low profile mower blade 20 rather than striking a portion of the low profile mower blade 20 such as a sail or ramped portion and subsequently destroying the sail or ramped portion.
  • the airflow pattern is generally represented by arrow 58 in FIG. 4.
  • the curved portion 54 defines a concave space 60 on the lower face 56 of the elongate blade 24.
  • the concave space 60 also encourages the development of a lower air pressure above the grass and/or vegetation in order to urge the grass and/or vegetation to an upright position for cutting by the rotating low profile mower blade 20.
  • the curved portion 54 of the elongate blade 24 includes a distal portion 64 is offset vertically from the sharpened cutting edge 46. As shown in FIG. 3, the distal portion 64 offset from the sharpened cutting edge 46 is measured along a line that is generally parallel to the center axis 36.
  • the distal portion 64 of the curved portion 54 is higher in elevation from the driven surface (e.g., the turf) than the sharpened cutting edge 46.
  • This offset distance is represented by dimension 66. Similar to the geometry of the curved portion 54, the offset distance 66 helps develop lift during rotation of the low profile mower blade 20. In one example, the offset distance 66 is less than about one-half inch (1.2 cm). In another example, the offset distance 66 is greater than about one-quarter inch (0.6 cm).
  • FIG. 5 another cross-section view of the elongate blade 24 is shown.
  • FIGS. 4 and 5 are identical apart from the reference numerals. The comparison is useful to show that over most of the blade major axis 44, the elongate blade 24 has a constant cross-section. This can be of particular use when scaling the low profile mower blade 20 to different mower applications. For example, if a walk- behind mower requires a 30-inch long blade, and there is a 28-inch long blade already designed, the designer can merely add another inch to each of the end portions 38, 40 to create the 30-inch long blade. Similarly, to design a low profile mower blade 20 with a shorter length, a designer merely removes a desired length from each of the end portions 38, 40. This can save design and engineering time, and thus cost.
  • the curved portion 54 develops flexion stability between the central portion 50 and the end portions 38, 40 of the low profile mower blade.
  • a flat piece of metal stock is sharpened on either side to function as a mower blade.
  • these known flat blades often lack a flexion stability and can flex according to arrows 68 in FIG. 2.
  • this type of flexion can create undesired variability in grass cutting height and results in a rough grass cut that is often undesirable.
  • the added stiffness provided by the curved portion 54 to the elongate blade 24 can be beneficial.
  • FIG. 6 an alternate mounting structure is shown.
  • any suitable mounting structure or definition can be used with the low profile mower blade 20 of the present disclosure.
  • FIG. 6 shows apertures 70 and embossed areas 74 suitable for use with a quick-change attachment scheme as described in U.S. Patent Application No. 14/847,909 and its family members.
  • the apparatus of the present disclosure can have several benefits.
  • the low profile mower blade can increase the lifespan of the mower blade when used over soils or surfaces having a relatively high sand content.
  • the low profile mower blade can last as much as four times as long as a typical lawn mower blade having a sail or ramped surface to develop lift. In other examples, the blade can last three times as long as a typical lawn mower blade.
  • the low profile mower blade can present a greater surface area upon which to deflect objects such as grains of sand in comparison to typical sail-employing mower blades. The greater surface area not withstanding, the low profile mower blade also can eliminate a significant amount of blade wear caused by object impingement simply by having the low profile. This lower profile can also significantly reduce the drag forces operating on the low profile mower blade. In some cases, the drag can be reduced by as much as 12.5% in comparison to a standard mower blade.
  • Other benefits can include a constant cross-section profile that is easily scalable to other mower applications (e.g., longer or shorter blade lengths).
  • the described low profile mower blade can also provide flexion stability or stiffness along the blade major axis to reduce and/or eliminate rough cuts due to the mower blade ends moving up and down relative to the center portion during operation.

Landscapes

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

Abstract

La présente invention concerne une lame de tondeuse (20) pour un dispositif d'entretien de pelouse qui comprend une lame allongée (24) ayant des bords d'extrémité opposés (26, 28) et des bords latéraux opposés (30, 34). La lame allongée (24) est adaptée pour montage sur une tondeuse rotative pour rotation autour d'un axe central (36) s'étendant transversalement par rapport à la lame allongée (24) et séparant la lame allongée (24) en parties d'extrémité allongées opposées (38, 40) s'étendant depuis l'axe central (36). La lame allongée (24) a un grand axe de lame (44) et définit une partie incurvée (54) de sorte que la partie incurvée (54) soit opposée à un bord tranchant aiguisé (46). La partie incurvée (54) s'étend depuis la lame allongée (24) dans une direction ascendante où les deux se rencontrent et est courbée vers une face inférieure (56) de la lame allongée (24). D'autres exemples de la lame de tondeuse (20) comprennent la partie incurvée (54) étant décalée verticalement par rapport à un bord tranchant aiguisé (46) pour développer une portance pendant la rotation et une section transversale constante sur la majeure partie du grand axe de lame (44).
PCT/US2017/052384 2016-09-20 2017-09-20 Lames de tondeuse compactes WO2018057552A1 (fr)

Priority Applications (5)

Application Number Priority Date Filing Date Title
EP17777748.9A EP3515171A1 (fr) 2016-09-20 2017-09-20 Lames de tondeuse compactes
CA3041627A CA3041627A1 (fr) 2016-09-20 2017-09-20 Lames de tondeuse compactes
AU2017332128A AU2017332128A1 (en) 2016-09-20 2017-09-20 Low profile mower blades
CN201780070700.XA CN109952020A (zh) 2016-09-20 2017-09-20 低轮廓割草机刀片
AU2021200853A AU2021200853A1 (en) 2016-09-20 2021-02-10 Low profile mower blades

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US201662397177P 2016-09-20 2016-09-20
US62/397,177 2016-09-20
US29/578,374 2016-09-21
US29/578,374 USD816445S1 (en) 2016-09-21 2016-09-21 Cutting blade

Publications (1)

Publication Number Publication Date
WO2018057552A1 true WO2018057552A1 (fr) 2018-03-29

Family

ID=59997489

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2017/052384 WO2018057552A1 (fr) 2016-09-20 2017-09-20 Lames de tondeuse compactes

Country Status (4)

Country Link
CN (1) CN109952020A (fr)
AU (2) AU2017332128A1 (fr)
CA (1) CA3041627A1 (fr)
WO (1) WO2018057552A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI695673B (zh) * 2019-09-25 2020-06-11 何炳梓 刀片及包括該刀片之割草機

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2799985A (en) * 1954-05-26 1957-07-23 Motor Wheel Corp Rotary lawn mower safety blade
GB2050792A (en) * 1979-05-25 1981-01-14 Goebler H Lawnmower blades
US5775078A (en) * 1996-07-19 1998-07-07 Warren; Richard C. Rotary lawn mower
EP0894427A1 (fr) * 1997-07-29 1999-02-03 JAVERLHAC, Jean-Charles Lame de gyro-broyeur
US6301868B1 (en) 1999-08-26 2001-10-16 James D. Siplinger Vortex reducing mower blade
EP2636296A1 (fr) * 2012-03-07 2013-09-11 SABO-Maschinenfabrik GmbH Barre porte-lames

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105075497A (zh) * 2014-04-21 2015-11-25 苏州宝时得电动工具有限公司 割草机切割刀片

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2799985A (en) * 1954-05-26 1957-07-23 Motor Wheel Corp Rotary lawn mower safety blade
GB2050792A (en) * 1979-05-25 1981-01-14 Goebler H Lawnmower blades
US5775078A (en) * 1996-07-19 1998-07-07 Warren; Richard C. Rotary lawn mower
EP0894427A1 (fr) * 1997-07-29 1999-02-03 JAVERLHAC, Jean-Charles Lame de gyro-broyeur
US6301868B1 (en) 1999-08-26 2001-10-16 James D. Siplinger Vortex reducing mower blade
EP2636296A1 (fr) * 2012-03-07 2013-09-11 SABO-Maschinenfabrik GmbH Barre porte-lames

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI695673B (zh) * 2019-09-25 2020-06-11 何炳梓 刀片及包括該刀片之割草機

Also Published As

Publication number Publication date
AU2017332128A1 (en) 2019-05-16
AU2021200853A1 (en) 2021-03-04
CN109952020A (zh) 2019-06-28
CA3041627A1 (fr) 2018-03-29

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