WO2012047176A1 - Universal cutting head for motor trimmers - Google Patents

Universal cutting head for motor trimmers Download PDF

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Publication number
WO2012047176A1
WO2012047176A1 PCT/SI2011/000055 SI2011000055W WO2012047176A1 WO 2012047176 A1 WO2012047176 A1 WO 2012047176A1 SI 2011000055 W SI2011000055 W SI 2011000055W WO 2012047176 A1 WO2012047176 A1 WO 2012047176A1
Authority
WO
WIPO (PCT)
Prior art keywords
cutting head
head according
universal
cutting
blade
Prior art date
Application number
PCT/SI2011/000055
Other languages
French (fr)
Inventor
Franjo OĈKO
Original Assignee
Ocko Franjo
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
Application filed by Ocko Franjo filed Critical Ocko Franjo
Publication of WO2012047176A1 publication Critical patent/WO2012047176A1/en

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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
    • A01D34/733—Cutting-blade mounting 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
    • A01D34/736—Flail type

Definitions

  • the object of the invention is a universal cutting head for motor trimmers, which is an assembly part of motor trimmers affiliated with agriculture and forestry and is also useful for professional and private use in landscaping.
  • Common string trimmers display problems such as brief life cycle and time- consuming string replacement.
  • the strings break easily during the cutting process if they hit stones or other harder materials, thus representing additional cost for the operator.
  • the torn leftovers also have an unnecessary impact on environment, since the steel or plastic strings are very persistent pollutants.
  • the process of replacing strings is time-consuming, represents additional work and disrupts the work process.
  • common string trimmers are unable to cut high and dry grass, shrubbery, thinner branches or smaller trees, requiring the use of other tools in order to complete the work.
  • the strings usually do not cut the grass but tear or tatter it, making such trimmers inappropriate for use in neat gardens, since they could damage the lawn.
  • Hour-long work with common string trimmers represents strenuous work for the operator, who has to control the height at which the cutting takes place. If the distance from the ground is inadequate, the terrain could be damaged or the already cut surface must be re- cut.
  • the technical problem, solved by the invention is a universal cutting head for motor trimmers, cutting all types of grass as well as shrubbery, thinner branches, smaller trees, etc. Work is conducted much easier and faster with the universal cutting head because of the special form of the head and the blades, enabling a less strenuous trimming on any type of terrain and a maximum cutting effect on all types of vegetation. Cutting itself does not damage the grass, because the cuts are sharp and clean, and the technical problem of grass wrapping itself around the blades has been solved.
  • the universal cutting head for motor trimmers designed to be fastened to the drive shaft of the trimmer, comprises of a clamping fixture 2, at least three cutting units 1 and a sliding safety shield 3.
  • the clamping fixture 2 of the universal cutting head comprises of a base plate 4, fastened to the drive shaft of the trimmer with a custom-built nut 5, which is compatible with most motor trimmers on the market. From the bottom, a bearing 12 is mounted onto the shaft of the nut 5 and fitted into the bearing housing 15. The bearing 12 on the shaft of the nut 5 holds the bottom locking ring 13 in place. To prevent it from falling out of the bearing housing 15, the bearing 12 is also clamped with a top locking ring 11.
  • the sliding safety shield 3 is mounted to the bottom of the bearing housing 15 with a screw 14.
  • the clamping fixture 2 is constructed in a way that enables easy and uncomplicated assembling and ensures that the safety shield 3 does not turn in contact with the ground resulting from the use of bearing 12, which is fitted into the bearing housing 15 and enables independent operation of the upper and lower part of the clamping fixture 2.
  • Each cutting unit 1 comprises of a blade 9 and a custom-built flange 8, attached to an axis 10 and fastened to the base plate 4 with an attachment 6 and a screw 7.
  • the strings in the custom-built cutting units 1 were replaced with blades 9, thus solving the problems of short durability of strings as well as environment pollution.
  • the specific assembly of the cutting unit 1 to the base plate 4 of the universal cutting head ensures a maximum cutting efficiency as well as blade 9 durability.
  • At least three cutting units 1 with blades 9 independently revolving around their own axes are mounted to the rim of the base plate 4.
  • the cutting units 1 are distributed symmetrically to the centre of the base plate 4 on its rim; three cutting units 1 at an angle of 120°, several other cutting units 1 are mounted at relatively smaller angles. Otherwise vibrations occur, hindering the cutting or even making it impossible.
  • the latch openings 17 are shifted lengthwise from the centre of the blades 9.
  • Minimum 1/3 of the blade 9 length exceeds the diameter of the base plate 4.
  • the blade 9 edges are damaged, they can be sharpened and reused for cutting.
  • the damages always occur on the longer part of the blade 9 according to the latch opening 17, the blade edges 9 of the shorter part remain undamaged. Therefore, the shorter part of the blade 9 can be used for cutting, namely by shortening or cutting off the damaged part along the line 16, marked on the blade 9, with a grinder.
  • the distance between the latch opening 17 and the edge of the shortened blade 9 is shorter than the distance to the edge of the undamaged blade 9.
  • the undamaged part of the blade 9 is now in position for cutting.
  • the invention ensures uncomplicated removal of blades 9 for sharpening. First, the screw 7 is unfastened and the attachment 6 removed, then the axis 10 is detached from the base plate 4. The flange 8 and blade 9 are then detached from the axis 10 and replaced.
  • the cutting unit 1 is assembled in reversed order.
  • a custom-built flange 8 is mounted to the axis 10 between the base plate 4 and the blade 9, thus solving the technical problem of grass wrapping around the blades 9.
  • the flange 8 is thinner on the outer rim at an angle, so the grass slides off, preventing it from wrapping itself around the blades 9. Therefore, cutting is easier and faster, since we do not need to remove grass wrapped around the blades 9.
  • the custom-built sliding safety shield 3 at the bottom of the universal cutting head does not revolve, but only glides across the surface, enabling an easier operation on lawns or other terrains. Moreover, cutting is less strenuous, since the operator is not forced to hold the cutting head of the trimmer at a certain distance from the ground as is the case with string trimmers, but glides with it across the surface.
  • the size or rather diameter of the sliding safety shield 3 equals the diameter of the base plate 4 of a cutting unit 1.
  • the curvature radius of the sliding safety shield 3 grows with diameter widening and vice versa. Thus, an even distance of the sliding safety shield 3 from the ground is maintained, irrespective of the cutting head size. If we want to cut grass at a higher distance from the ground, we replace the sliding safety shield 3 with a shield of a larger angle. As a result to this construction of the universal cutting head, the trimmer uses less power and less fuel for cutting.

Landscapes

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

Abstract

The universal cutting head for motor trimmers, which is an assembly part of motor trimmers, affiliated with agriculture and forestry, solves the problem of mowing all types of low vegetation with the same cutting head. The universal cutting head for motor trimmers consists of a clamping fixture (2), at least three cutting units (1) and a sliding safety shield (3). The clamping fixture (2) comprises of a base plate (4); symmetrically distributed cutting units (1) are mounted to its rim, the strings replaced with blades (9). The latch openings (17) are shifted lengthwise from the centre of the blades (9). Thus, when the blades (9) hit harder materials, they revolve or retract and immediately return into the original position, necessary for effective cutting. The custom-built sliding safety shield (3) does not revolve but only glides across the surface, enabling easier operation, less strenuous cutting, and ensures an adequate distance between the blades (9) and the ground.

Description

UNIVERSAL CUTTING HEAD FOR MOTOR TRIMMERS
The object of the invention is a universal cutting head for motor trimmers, which is an assembly part of motor trimmers affiliated with agriculture and forestry and is also useful for professional and private use in landscaping.
Common string trimmers display problems such as brief life cycle and time- consuming string replacement. The strings break easily during the cutting process if they hit stones or other harder materials, thus representing additional cost for the operator. The torn leftovers also have an unnecessary impact on environment, since the steel or plastic strings are very persistent pollutants. The process of replacing strings is time-consuming, represents additional work and disrupts the work process. Moreover, common string trimmers are unable to cut high and dry grass, shrubbery, thinner branches or smaller trees, requiring the use of other tools in order to complete the work. The strings usually do not cut the grass but tear or tatter it, making such trimmers inappropriate for use in neat gardens, since they could damage the lawn. Hour-long work with common string trimmers represents strenuous work for the operator, who has to control the height at which the cutting takes place. If the distance from the ground is inadequate, the terrain could be damaged or the already cut surface must be re- cut.
The technical problem, solved by the invention, is a universal cutting head for motor trimmers, cutting all types of grass as well as shrubbery, thinner branches, smaller trees, etc. Work is conducted much easier and faster with the universal cutting head because of the special form of the head and the blades, enabling a less strenuous trimming on any type of terrain and a maximum cutting effect on all types of vegetation. Cutting itself does not damage the grass, because the cuts are sharp and clean, and the technical problem of grass wrapping itself around the blades has been solved.
Hereinafter the invention is also depicted in the basic form of the universal cutting head:
Fig. 1 Universal cutting head in cross-section
Fig. 2 Distribution of the cutting units on the base plate in plan view
The universal cutting head for motor trimmers, designed to be fastened to the drive shaft of the trimmer, comprises of a clamping fixture 2, at least three cutting units 1 and a sliding safety shield 3.
The clamping fixture 2 of the universal cutting head comprises of a base plate 4, fastened to the drive shaft of the trimmer with a custom-built nut 5, which is compatible with most motor trimmers on the market. From the bottom, a bearing 12 is mounted onto the shaft of the nut 5 and fitted into the bearing housing 15. The bearing 12 on the shaft of the nut 5 holds the bottom locking ring 13 in place. To prevent it from falling out of the bearing housing 15, the bearing 12 is also clamped with a top locking ring 11. The sliding safety shield 3 is mounted to the bottom of the bearing housing 15 with a screw 14. The clamping fixture 2 is constructed in a way that enables easy and uncomplicated assembling and ensures that the safety shield 3 does not turn in contact with the ground resulting from the use of bearing 12, which is fitted into the bearing housing 15 and enables independent operation of the upper and lower part of the clamping fixture 2. Each cutting unit 1 comprises of a blade 9 and a custom-built flange 8, attached to an axis 10 and fastened to the base plate 4 with an attachment 6 and a screw 7. The strings in the custom-built cutting units 1 were replaced with blades 9, thus solving the problems of short durability of strings as well as environment pollution. The specific assembly of the cutting unit 1 to the base plate 4 of the universal cutting head ensures a maximum cutting efficiency as well as blade 9 durability. At least three cutting units 1 with blades 9 independently revolving around their own axes are mounted to the rim of the base plate 4. The cutting units 1 are distributed symmetrically to the centre of the base plate 4 on its rim; three cutting units 1 at an angle of 120°, several other cutting units 1 are mounted at relatively smaller angles. Otherwise vibrations occur, hindering the cutting or even making it impossible. Through latch openings 17 on the blades 9, these are attached to an axis 10, around which they revolve independently. The latch openings 17 are shifted lengthwise from the centre of the blades 9. Thus, the blades 9 are always in cutting position. Minimum 1/3 of the blade 9 length exceeds the diameter of the base plate 4. When the blades 9 hit stones or other hard materials, they revolve or retract and - because of the off-centre drilled latch openings 17 - return to the original position necessary for effective cutting.
If the blade 9 edges are damaged, they can be sharpened and reused for cutting. The damages always occur on the longer part of the blade 9 according to the latch opening 17, the blade edges 9 of the shorter part remain undamaged. Therefore, the shorter part of the blade 9 can be used for cutting, namely by shortening or cutting off the damaged part along the line 16, marked on the blade 9, with a grinder. Hence, the distance between the latch opening 17 and the edge of the shortened blade 9 is shorter than the distance to the edge of the undamaged blade 9. Hereby, the undamaged part of the blade 9 is now in position for cutting. The invention ensures uncomplicated removal of blades 9 for sharpening. First, the screw 7 is unfastened and the attachment 6 removed, then the axis 10 is detached from the base plate 4. The flange 8 and blade 9 are then detached from the axis 10 and replaced. The cutting unit 1 is assembled in reversed order.
A custom-built flange 8 is mounted to the axis 10 between the base plate 4 and the blade 9, thus solving the technical problem of grass wrapping around the blades 9. The flange 8 is thinner on the outer rim at an angle, so the grass slides off, preventing it from wrapping itself around the blades 9. Therefore, cutting is easier and faster, since we do not need to remove grass wrapped around the blades 9.
The custom-built sliding safety shield 3 at the bottom of the universal cutting head does not revolve, but only glides across the surface, enabling an easier operation on lawns or other terrains. Moreover, cutting is less strenuous, since the operator is not forced to hold the cutting head of the trimmer at a certain distance from the ground as is the case with string trimmers, but glides with it across the surface. The size or rather diameter of the sliding safety shield 3 equals the diameter of the base plate 4 of a cutting unit 1. The curvature radius of the sliding safety shield 3 grows with diameter widening and vice versa. Thus, an even distance of the sliding safety shield 3 from the ground is maintained, irrespective of the cutting head size. If we want to cut grass at a higher distance from the ground, we replace the sliding safety shield 3 with a shield of a larger angle. As a result to this construction of the universal cutting head, the trimmer uses less power and less fuel for cutting.

Claims

PATENT CLAIMS
1. A universal cutting head for motor trimmers, mounted to the drive shaft of the trimmer,
characterized in that
it comprises of a clamping fixture (2), a sliding safety shield (3) and at least three cutting units (1).
2. A universal cutting head according to claim 1,
characterized in that
the clamping fixture (2) comprises of a base plate (4), mounted onto the drive shaft of the trimmer with a custom-built nut (5). From the bottom a bearing (12) is mounted to the shaft of the nut (5) and fitted into the bearing housing (15).
3. A universal cutting head according to claim 2,
characterized in that
the bearing (12) on the shaft of the nut (5) retains the bottom locking ring (13) in the bearing housing (15). To prevent it from falling out, it is also fitted with a top locking ring (11).
4. A universal cutting head according to claim 1,
characterized in that
the bearing (12) is fitted into the bearing housing (15); the sliding safety shield (3) is fastened to it with a screw (14), preventing it from rotating in contact with the ground.
5. A universal cutting head according to claim 2,
characterized in that
at least three cutting units (1) are mounted to the base plate (4), distributed symmetrically on its rim, three cutting units (1) are at an angle of 120°, several other cutting units (1) are distributed at relatively smaller angles.
6. A universal cutting head according to claim 5,
characterized in that
the axis (10) of each cutting unit (1) is mounted to the base plate (4) with a screw (7) and an attachment (6), also retaining the blade (9) and the custom-built flange (8).
7. A universal cutting head according to claims 5 and 6,
characterized in that
the blades (9) in the cutting units (1) revolve independently around their axes, whereas the latch openings (17), through which the blades (9) are attached to the axis (10), are shifted lengthwise from the centre of the blades (9).
8. A universal cutting head according to claim 7,
characterized in that
minimum 1/3 of the blade (9) length exceeds the diameter of the base plate (4).
9. A universal cutting head according to claims 7 and 8,
characterized in that
from the longer part of the blade (9) - according to the latch opening (17) on the blade (9) - the damaged part of the blade (9) is cut off with a grinder along the line (16) marked on the blade (9).
10. A universal cutting head according to claims 5, 6 and 7,
characterized in that
a custom-built flange (8), thinner on the outer rim at an angle, is fitted on the axis (10) between the blade (9) and the base plate (4).
11. A universal cutting head according to several preceding claims,
characterized in that
the diameter of the sliding safety shield (3) equals the diameter of the base plate (4) of a cutting unit 1, whereas the curvature radius of the sliding safety shield (3) grows with diameter widening and vice versa.
PCT/SI2011/000055 2010-10-06 2011-10-03 Universal cutting head for motor trimmers WO2012047176A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SI201000309A SI23490A (en) 2010-10-06 2010-10-06 Universal mowers cutting head
SIP201000309 2010-10-06

Publications (1)

Publication Number Publication Date
WO2012047176A1 true WO2012047176A1 (en) 2012-04-12

Family

ID=45094759

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SI2011/000055 WO2012047176A1 (en) 2010-10-06 2011-10-03 Universal cutting head for motor trimmers

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WO (1) WO2012047176A1 (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2382840A1 (en) * 1977-03-11 1978-10-06 Francescon Sas Portable rotary grass cutter - has double edged interchangeable and reversible blades bolted to disc sandwiched between two splined collars on shaft
WO1981000337A1 (en) * 1979-08-13 1981-02-19 R Feldman Trimming head for vegetation
EP0328988A1 (en) * 1988-02-18 1989-08-23 Wolf-Geräte GmbH Cutter bar for lawn mowers
WO1997002115A1 (en) * 1995-06-30 1997-01-23 Grossi Edward J A trail blazing stumpcutter
WO1999030552A1 (en) * 1997-12-16 1999-06-24 Conceptual Marketing & Development, Inc. Improved weed and grass trimmer attachment head
FR2853491A1 (en) * 2003-04-11 2004-10-15 Gyrax Plants cutting machine e.g. chopper-cutter, has fixing parts presenting bending in lower portion near its one end, where bending is turned towards base to protect protruding lower part of bolts forming related articulation axis
WO2006135952A1 (en) * 2005-04-29 2006-12-28 Raymond Eric Abernethy A cutting blade assembly for a mower

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2382840A1 (en) * 1977-03-11 1978-10-06 Francescon Sas Portable rotary grass cutter - has double edged interchangeable and reversible blades bolted to disc sandwiched between two splined collars on shaft
WO1981000337A1 (en) * 1979-08-13 1981-02-19 R Feldman Trimming head for vegetation
EP0328988A1 (en) * 1988-02-18 1989-08-23 Wolf-Geräte GmbH Cutter bar for lawn mowers
WO1997002115A1 (en) * 1995-06-30 1997-01-23 Grossi Edward J A trail blazing stumpcutter
WO1999030552A1 (en) * 1997-12-16 1999-06-24 Conceptual Marketing & Development, Inc. Improved weed and grass trimmer attachment head
FR2853491A1 (en) * 2003-04-11 2004-10-15 Gyrax Plants cutting machine e.g. chopper-cutter, has fixing parts presenting bending in lower portion near its one end, where bending is turned towards base to protect protruding lower part of bolts forming related articulation axis
WO2006135952A1 (en) * 2005-04-29 2006-12-28 Raymond Eric Abernethy A cutting blade assembly for a mower

Also Published As

Publication number Publication date
SI23490A (en) 2012-04-30

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