WO2013183996A1

WO2013183996A1 - Device and method for cultivating turf

Info

Publication number: WO2013183996A1
Application number: PCT/NL2013/050398
Authority: WO
Inventors: Johannes Hendricus Wilhelmus Herman DE KORT
Original assignee: IMANTS HOLDING BV
Current assignee: IMANTS HOLDING BV
Priority date: 2012-06-06
Filing date: 2013-06-05
Publication date: 2013-12-12
Anticipated expiration: 2014-12-06
Also published as: NL2008947C2

Description

DEVICE AND METHOD FOR CULTIVATING TURF

Description

The present invention relates to a device for cultivating turf, comprising a mobile frame, a rotor element which can be rotatably driven in a direction of rotation about a horizontal axis relative to the frame, which rotor element is provided with a tubular shaft body, with cultivation means on the outer side of the shaft body, and with connecting means via which the cultivation elements are connected to the shaft body, said device further comprising vertical adjustment means for positioning the central axis of the shaft body at an adjustable height, said cultivation elements each having a cutting edge that extends parallel to the central axis of the shaft body.

Such a device is used, inter alia, in the restoration or renovation/replacement of turf, in particular turf used for sports purposes, or in the harvesting of hot season grasses or for removing felt, moss, weeds and/or any other undesirable vegetation. The specific treatment that is carried out for this purpose can be designated by the term "flat rotary tillage". Usually, the aim is on the one hand to obtain the highest possible quality of the new turf and on the other hand to use as little time as possible for the work. The quality of turf is in part determined by its levelness and also by the types of grass of which the turf is composed.

A device as referred to in the introduction is described in Dutch patent NL 1018565. In said device, right-angled cutter blades are used as the cultivation elements, which blades are provided on vertically oriented, star-shaped supporting plates, which are concentrically connected to the shaft body at regular intervals. Because of the right-angled shape of the cutter blades, said blades not only have an axially oriented cutting edge, but also a radially oriented cutting edge, which cutting edges adjoin. In particular in the area where the two cutting edges adjoin, wear in particular on the radially oriented cutting edge is high. Wear on the cutting edges, and in particular on the radially oriented cutting edge, has a negative effect on the precision with which the rotary tillage of the turf can take place. The strip-shaped part of the cutter blades that adjoins the axially oriented cutting edge is tangentially oriented and, as a result of said orientation, cuts through the turf. Using such a device, the soil in which the grass is rooted is removed to a certain depth, more specifically cut away, or the grass and any layers of moss or felt are removed from a certain height above the soil. The height/depth being used is connected, inter alia, with the question whether the turf is to be renovated or replaced. Within the framework of attempting to achieve the highest possible quality of the new turf it is always important that the cultivation of the turf by the cultivation elements be carried out with the highest possible precision. The object of the invention is in particular to provide an improvement in order to realise this aim. In order to achieve that object, the device according to the present invention is characterised in that the connecting means comprise a support body connected to the shaft body for each cultivation element, which support body has a supporting surface that extends parallel to the central axis of the shaft body, against which the associated cultivation element abuts with an abutment surface thereof. The invention is based on the inventive concept that the manner of support of the cultivation elements can have a major effect on the precision with which the cultivation of the turf can take place. The above characteristic features of the invention make it possible to realise a very stable support and thus a very stable positioning of the cultivation elements during operation of the device, in spite of the considerable forces that can act on the rotor element, more specifically on the cultivation elements and the connecting means thereof. Such forces will to a significantly lower extent lead to deformation of the cultivation means and the connecting means in comparison with the deformation of corresponding parts in the device according to the prior art. The invention also provides a possibility of making use of cultivation elements which are configured differently from the prior art cultivation elements. The range of configuration possibilities of the cultivation elements is wider, so that the configuration of the elements can be more specifically geared to a specific use.

The aforesaid advantageous effects of the present invention will be obtained in particular if the supporting surface extends over at least 50%, more preferably over at least 80%, of the working width of the cutting edge of the associated cultivation element, and/or if the supporting surface also extends at least substantially in radial direction. In addition to that, this preferred embodiment provides the advantage that the supporting body can thus contribute better to pushing along material loosened by the rotary tillage, which can thus be discharged more easily and will less easily tend to remain behind on the tilled soil. Any grass loosened by said rotary tillage or seeds therefrom might at a later stage lead to the growth of undesirable grass types. Material remaining behind during rotary tillage may lead to an irregular ground surface with small bumps, which in turn may lead to vertical movement of the cultivation device when driving over such bumps. In addition, the radial orientation of the supporting surface will enhance the sucking effect of loosened material.

According to a very advantageous preferred embodiment, the support body is provided with at least one passage, one end of which terminates in the supporting surface, whilst the connecting means further comprise a screw element that extends through the passage, via which screw element the cultivation element is connected to the support body. Thus, a constructionally very simple but robust connection of the cultivation elements to the support body can be realised. Moreover, such a device also makes it possible to exchange the cultivation elements in a simple manner, for example because of wear or because another type of cultivation elements is needed.

For reasons of constructional simplicity it is furthermore preferable if the support body is at least substantially strip-shaped and the thickness of the strip shape is tangentially oriented.

In order to prevent jerky loading of the device according to the invention it is preferable if the cultivation elements are provided in at least one spiral row.

To prevent the risk of strips not being cultivated it is furthermore preferable if cutting edges of adjacent cultivation elements within a spiral row overlap in axial direction at ends of the cutting edges.

To obtain a stable attachment of the support body to the shaft body, it is preferable if at least one gusset member is provided between the support body and the shaft body on the side of the support body remote from the cultivation element.

The aforesaid stable attachment can be achieved in particular if a gusset member is provided at each of two opposite ends of the support body.

In the case of an overlap of cutting edges of adjacent cultivation elements according to an above-discussed preferred embodiment, it is furthermore preferable if the gusset members are provided in the area of overlap of the cutting edges.

When a spiral row of cultivation elements according to another above- discussed preferred embodiment is used, it is advantageous if gusset members at facing ends of adjacent cultivation elements forming part of a row are in line, wherein it is furthermore preferable for reasons of constructional simplicity if the co-axial gusset members form one integral part. Thus it is very easy upon assembly of the rotor element to position adjacent cultivation elements with the correct pitch.

In order to make it possible to realise an accurate positioning of the cultivation element relative to the shaft body it is advantageous if the gusset member has a circumferential edge on a part of which the associated cultivation element abuts with a side that faces the shaft body.

Preferably, the cultivation elements each comprise a carrier body and at least one cutter blade connected thereto, an edge of which at least partially forms the associated cutting edge. Thus it is possible to make the operative part of the cultivation element, being the cutter blade, from a different material than the remaining part of the cultivation element, being the carrier body. The material properties of the cutter can thus be better geared to its function. This makes it possible to make more efficient use of the device according to the invention, because there will be less wear and inherently less time will be needed for set-up changes for exchanging cultivation elements due to wear.

Within the above framework it is preferable if the cutter blade is made of a hard metal, whilst furthermore preferably the cutter blade is connected to the carrier body by soldering.

In order to be able to effect an accurate positioning of the cutting edge relative to the central axis of the rotor element, it is preferable if the cutter blade is provided in a recess formed in the carrier body by a machining operation.

Each cultivation element can in particular have robust properties if each cultivation element is at least substantially block-shaped, which block shape may for example be the result of using a longer strip divided into shorter lengths. The cutting edges may have a leading, a neutral or a trailing orientation, depending on their use. The surface defined by the length and the width of the block shape is preferably radially or at least substantially radially oriented for the same reason why the supporting surface is preferably radially oriented.

The diameter of the shaft body is preferably large in comparison with shaft bodies that form part of a prior art devices. As a result, the moment acting on the connecting means during operation of the device will remain limited, so that also the tendency of the connecting means to deform will be limited. More specifically it is preferable in that regard if the diameter of the shaft body is at least 250 mm, more preferably at least 300 mm. It is assumed in that connection that the operative diameter of the blades remains the same or at least substantially the same.

Within this framework it is furthermore preferable if the radius of the shaft body is at least 60%, more preferably at least 70%, of the distance between the central axis of the shaft body and a cutting edge.

A very advantageous preferred embodiment is obtained if a guard is provided on the outer side of the path described by the cutting edges during rotation of the rotor element, which guard is at least partially arcuate in shape, wherein the spacing between said path and the arcuate part of the guard is at most 20 mm, more preferably at most 15 mm. As a result of the limited clearance between the cutting edges and the arcuate part of the guard in the present preferred embodiment, in particular in combination with the use of supporting surfaces for the cultivation elements that extend parallel to the central axis, a suction effect is obtained on account of the rotation of the rotor element, as a result of which material being loosened, including undesirable grass types or seeds thereof that are released during cultivation of the turf, are sucked up and can be discharged rather than remain behind on the cultivated ground. Such material may have an adverse effect on the levelness of the cultivated turf and start to grow again, which will likewise adversely affect the quality of the new turf.

The present invention also comprises a rotor element for use in a device according to the invention as described in the foregoing, the rotor element comprising a tubular shaft body, cultivation elements on the outer side of the shaft body, and connecting means via which the cultivation elements are connected to the shaft body, said cultivation elements each having a cutting edge with a working width, which cutting edge extends parallel to the central axis of the shaft body, a characteristic feature of the invention being the fact that the connecting means comprise a first support body connected to the shaft body for each cultivation element, said support body having a supporting surface that extends parallel to the central axis of the shaft body, against which the associated cultivation element abuts with an abutment surface thereof. The advantages that may be connected with the use of such a rotor element have already been explained in the foregoing in the explanation of the device according to the present invention. It is conceivable to exchange the rotor element of prior art cultivation devices for a rotor element according to the invention.

The invention also provides a cultivation element for use in a device according to the invention as described in the foregoing, whether or not in preferred embodiments thereof.

The invention further provides a method for cultivating turf, characterised by using a device according to the invention as explained in the foregoing.

The invention will now be explained in more detail by means of a description of a preferred embodiment of the device according to the invention with reference to the following figures:

Figure 1 is a side view of a preferred embodiment of a cultivation device according to the invention;

Figure 2 is an isometric and partially exploded view of a part of a rotor element forming part of the cultivation device according to figure 1 ;

Figures 3a-3c are schematic side views of alternative embodiments of cultivation elements as can be used in a cultivation device according to the invention;

Figures 4a and 4b are schematic front views of two alternative embodiments of cultivation elements as can be used in a cultivation device according to the invention.

The cultivation device 1 comprises a frame 2 which can be coupled to a tractive vehicle (not shown), such as a tractor, at its front side 3. Alternatively, the frame could also form part of a self-propelling vehicle or be coupled to a pushing vehicle at its rear side, opposite the front side 3.

The cultivation device 1 further comprises two rollers 4 at two opposite ends, by means of which the cultivation device 1 can be moved in the direction of movement over turf upon tractive action of the aforesaid tractive vehicle. The vertical position of the frame 2 relative to the rollers 4 can be adjusted by operating an adjusting wheel 6, to which a screw adjusting mechanism is connected. The frame 2 can thus be set at a desired vertical position relative to the ground on which the rollers 4 are supported.

The cultivation device 1 also comprises a rotor element 1 1 , which is connected to the frame 2 in such a manner as to be rotatable in a direction of rotation 12 about a horizontal axis of rotation 13 which coincides with the central axis of the rotor element 1 1 and which extends horizontally, perpendicularly to the direction of movement 5. The rotation of the rotor element 1 1 can be effected by drive means which may be present on the tractive vehicle for that purpose and which are coupled to the rotor element 1 1 via the so-called power takeoff (PTO). Alternatively it is in principle also possible for the drive means to form part of the cultivation device 1 itself.

During operation of the cultivation device 1 , said device is moved in the direction of movement 5 and the rotor element 1 1 rotates in the direction of rotation 12, as a result of which the part of a field of turf consisting of grass and a layer of soil in which the grass is rooted that lies in the path of the rotating rotor element 1 1 will be loosened and at least partially carried along over about half a revolution of the rotor element and deposited on the discharge conveyor 7. The discharge conveyor deposits the loosened material in a container that moves parallel to the cultivation device 1 in the direction of movement 5.

The aforesaid part may consist only of grass, of grass including the associated growing points, or of grass including the associated growing points and a layer of soil in which the grass is rooted.

Figure 2 shows a part of the rotor element 1 1 in more detail. The rotor element 1 1 comprises a tubular shaft body 21 having a closed end 22, where shaft pins 23 are concentrically provided for bearing and coupling purposes. The diameter of the shaft body 21 is about 325 mm. Three spiral rows of cultivation elements 24 are circumferentially provided on the shaft body 21 . Each cultivation element 24 is connected to the shaft body 21 via a strip-shaped support body 25, whose length extends parallel to the axial direction, whose width extends in radial direction and whose thickness is oriented in tangential direction. On the side facing an associated cultivation element 24, the strip-shaped support body 25 has a radially oriented supporting surface 26, which adjoins the circumference of the tubular shaft body 21 . The associated cultivation element 24 is provided at the front side of the support body 25, seen in the direction of rotation 12, and abuts against the supporting surface 26 of the support body 25 with an abutment surface 27 (see figures 3a-3c). Each cultivation element 24 comprises a steel carrier body 28 and a number of side- by-side hard metal cutter blades 29. Instead of using a number of side-by-side cutter blades 29, it is also possible to use a single cutter blade having a greater length. The cutter blades 29 are connected to the carrier body 28 by soldering and jointly define a cutting edge 30 with a working width b of 10.6 cm. The working width is generally at least 4 cm. The cutting edge 30 extends parallel to the central axis of the rotor element 1 1 . As is also shown in figures 3a-3c, each carrier body 28 is provided with a rectangular (in this case) recess formed therein by means of a machining operation for positioning the cutter blades 29 with a high degree of precision. More specifically, said recess is very precisely positioned relative to the lower edge 39 of the carrier body 28.

Two bores 31 are provided in each of the support bodies 25, and two internally threaded bores 32 are provided at corresponding positions in each of the carrier bodies 28. Each of the cultivation elements 24 is bolted to the support body 25 by means of two bolts 33.

In the present example, the working width b corresponds to the length (dimension in axial direction) of the associated cultivation element 24. The length of the support body 25 also corresponds to the working width b, taking into consideration the fact that each support body 25 has projecting part 34 at axially opposite ends thereof, which parts fall into correspondingly shaped recesses provided in gusset plates 35 that are oriented transversely to the support body 25. The gusset plates 35 are plates which have been shaped by means of laser beams. On the side facing the shaft body 21 , each gusset plate 35 has an arcuate part whose radius corresponds to the (nominal) radius of the shaft body 21. The gusset plates 35 extend in particular on the side of the support body 25 remote from the cultivation element 24, or, in other words, at the rear side of the support body 25, for supporting the support body 25 during operation of the cultivation device 1. The gusset plates 35 also have a bearing part 36 extending at the front side of the associated support body 25, which bearing part has a bearing edge 37 at the radial outer side, on which the cultivation elements 24 abuts with the lower edge 39. As a result of the precise positioning of the cutter blades 29, and thus of the associated cutting edge 30, relative to the lower edge 39 and as a result of the precise dimensioning of the gusset plates 35 obtained by laser cutting, the radial dimensioning of the cutting edges 30 is very precise, so that also the rotary tillage carried out by means of the cultivation device 1 takes place with a high degree of precision. The gusset plates 35, like the support bodies 25, are welded to the shaft body 21.

Seen in front view, adjacent cultivation elements 24 within a row overlap over a length of about 6 mm at the ends thereof. In said area of overlap, the gusset plates 35 are also provided. The centre-to-centre distance between adjacent cultivation elements is 100 mm. Gusset plates 35 located on facing sides of adjacent support bodies 25 of a row are in line with each other and may even be formed by a single integral part, as is the case in the present example.

The rotor element 1 1 largely extends within a housing 14 that comprises a guard 15 which is partially arcuate in shape. The radius of the arcuate part of the guard 15 is about 280 mm. More specifically, the arcuate part extends from half past seven to twelve o'clock in figure 1. The spacing between the path of the cutting edges 30 and the arcuate part of the guard 15 is about 10 mm. As a result of said small spacing and also as a result of the radial orientation of the cultivation elements 24 and the support bodies 25, a suction effect occurs during rotation of the rotor element 1 1 in the direction of rotation 12. As a result of said suction, loosened material is sucked into the space between the shaft body 21 and the guard 15 and deposited on the discharge conveyor 7. In practice such loose material will consist of grass types or seeds thereof. If said material were to remain behind on the cultivated ground, this might lead to the growth of undesirable grass types after cultivation by the cultivation device 1 .

Due to the support of each cultivation element 24 over a significant part of its length, in this case even over its entire length, by the support body 25 and to the robust nature of the cultivation elements 24 themselves on account of their block-shaped configuration, no variations will occur in the radial position of the cutting edge 30, or at least only to a comparatively negligible extent, as a result of which material can be removed from the turf with a high degree of precision and a very level ground surface can be created. The invention also makes it possible to effect an easy changeover to a different type of cultivation element 24, so that the type of cultivation element can be optimally geared to the desired operation. In figures 3a-4d various variants of cultivation elements 24 for rotary tillage of a turf surface are shown. In figures 3a, 3b and 3c a leading, a neutral and a trailing orientation, respectively, of the cutter blades 29, 29', 29" is shown, whilst also the shape of the carrier bodies 28, 28', 28" is adapted to the aforesaid orientations of the cutter blades. Figures 4a and 4b show in front view various possible shapes of the cutting edge 30. Thus, a straight cutting edge 30 or a merlon-shaped cutting edge 30' may be used. With regard to the merlon-shaped cutting edge 30' shown in figure 4b it is noted that the cutting edge of a cultivation element in an adjacent spiral row located at the same axial position may be oriented in mirror image thereof, so that cultivation can nevertheless take place over the entire width of the cultivation element 24 in question.

The cultivation device according to the invention also makes it possible to exchange all or some cultivation elements of the rotary tillage type as discussed in the foregoing for cultivation elements of a different type, for example of the aerating type. After such an exchange, such cultivation elements may be formed by the cultivation elements of a single spiral row, of a number of rows or even of all spiral rows.

The invention is not limited to the preferred embodiment discussed in detail in the foregoing, but it is defined by the appended claims.

Claims

1. A device for cultivating turf, comprising a mobile frame, a rotor element which can be rotatably driven in a direction of rotation about a horizontal axis relative to the frame, which rotor element is provided with a tubular shaft body, with cultivation means on the outer side of the shaft body, and with connecting means via which the cultivation elements are connected to the shaft body, the device further comprising vertical adjustment means for positioning the central axis of the shaft body at an adjustable height, said cultivation elements each having at least one cutting edge with a working width, which cutting edge extends parallel to the central axis of the shaft body, characterised in that the connecting means comprise a support body connected to the shaft body for each cultivation element, which support body has a supporting surface that extends parallel to the central axis of the shaft body, against which the associated cultivation element abuts with an abutment surface thereof.

2. A device according to claim 1 , characterised in that the supporting surface extends over at least 50%, more preferably over at least 80%, of the working width of the cutting edge of the associated cultivation element.

3. A device according to claim 1 or 2, characterised in that the supporting surface also extends at least substantially in radial direction.

4. A device according to claim 1 , 2 or 3, characterised in that the support body is provided with at least one passage, one end of which terminates in the supporting surface, and wherein the connecting means further comprise a screw element that extends through the passage, via which screw element the cultivation element is connected to the support body.

5. A device according to any one of the preceding claims, characterised in that the support body is at least substantially strip-shaped and in that the thickness of the strip shape is tangentially oriented.

6. A device according to any one of the preceding claims, characterised in that the cultivation elements are provided in at least one spiral row.

7. A device according to claim 6, characterised in that cutting edges of adjacent cultivation elements within a spiral row overlap in axial direction at ends of the cutting edges.

8. A device according to any one of the preceding claims, characterised in that at least one gusset member is provided between the support body and the shaft body on the side of the support body remote from the cultivation element.

9. A device according to claim 8, characterised in that a gusset member is provided at each of two opposite ends of the support body.

10. A device according to claim 7 and according to claim 9, characterised in that the gusset members are provided in the area of overlap of the cutting edges.

1 1. A device according to claim 6 or a claim dependent thereon and according to claim 8 or a claim dependent thereon, characterised in that gusset members at facing ends of adjacent cultivation elements forming part of a row are in line.

12. A device according to claim 1 1 , characterised in that the co-axial gusset members form one integral part.

13. A device according to claim 8 or a claim dependent thereon, characterised in that the gusset member has a circumferential edge on a part of which the associated cultivation element abuts with a side that faces the shaft body.

14. A device according to any one of the preceding claims, characterised in that the cultivation elements each comprise a carrier body and at least one cutter blade connected thereto, an edge of which at least partially forms the associated cutting edge.

15. A device according to claim 14, characterised in that the cutter blade is made of a hard metal.

16. A device according to claim 14 or 15, characterised in that the cutter blade is connected to the carrier body by soldering.

17. A device according to claim 14, 15 or 16, characterised in that the cutter blade is provided in a recess formed in the carrier body by a machining operation.

18. A device according to any one of the preceding claims, characterised in that each cultivation element is at least substantially block-shaped.

19. A device according to any one of the preceding claims, characterised in that the diameter of the shaft body is at least 250 mm, more preferably at least 300 mm.

20. A device according to any one of the preceding claims, characterised in that the radius of the shaft body is at least 60%, more preferably at least 70%, of the distance between the central axis of the shaft body and a cutting edge.

21. A device according to any one of the preceding claims, characterised in that a guard is provided on the outer side of the path described by the cutting edges during rotation of the rotor element, which guard is at least partially arcuate in shape, wherein the spacing between said path and the arcuate part of the guard is at most 20 mm, more preferably at most 15 mm.

22. A rotor element for use in a device according to any one of the preceding claims, said rotor element comprising a tubular shaft body, cultivation elements on the outer side of the shaft body, and connecting means via which the cultivation elements are connected to the shaft body, said cultivation elements each having a cutting edge with a working width, which cutting edge extends parallel to the central axis of the shaft body, characterised in that the connecting means comprise a first support body connected to the shaft body for each cultivation element, said support body having a supporting surface that extends parallel to the central axis of the shaft body, against which the associated cultivation element abuts with an abutment surface thereof.

23. A cultivation element for use in a device according to any one of claims 1 - 21 .

24. A cultivation element according to claim 23, comprising a carrier body and at least one cutter blade connected thereto, an edge of which at least partially forms the associated cutting edge.

25. A cultivation element according to claim 24, characterised in that the cutter blade is made of a hard metal.

26. A cultivation element according to claim 24 or 25, characterised in that the cutter blade is connected to the carrier body by soldering.

27. A cultivation element according to claim 24, 25 or 26, characterised in that the cutter blade is provided in a recess formed in the carrier body by a machining operation.

28. A cultivation element according to any one of claims 24 - 27, characterised in that it is at least substantially block-shaped.

29. A method for cultivating turf, characterised by using a device according to any one of claims 1 - 21 for removing at least part of the turf.