WO2022098287A1

WO2022098287A1 - Tip, holder and tool for working soil and method and tool for assembly and disassembly of tip

Info

Publication number: WO2022098287A1
Application number: PCT/SE2021/051104
Authority: WO
Inventors: Crister Stark; Morgan Collin
Original assignee: Väderstad Holding Ab
Priority date: 2020-11-09
Filing date: 2021-11-04
Publication date: 2022-05-12
Also published as: SE544787C2; SE2051298A1; EP4240132A1

Abstract

A tip (120) of a soil-working tool for agricultural implements (1 ), comprising a tip body having a front portion (1201 ) facing forward in a direction of working (Da) and an attachment portion (1202) facing rearward, wherein the attachment portion (1202) has a rear edge and a gap which extends through the rear edge and forward to the front portion (1201 ). The attachment portion (1202) has at least one locking element (12022a, 12022b) located at the rear edge, which has a forward-facing locking surface (12023a, 12023b). The document also relates to a tip holder and tool for soil working and to a method and tool for assembly and disassembly of a tip.

Description

Tip, holder and tool for working soil and method and tool for assembly and disassembly of tip

Technical Field

This document relates to an agricultural implement and more specifically an implement for soil working, harrowing, breaking up plant residues and/or weed control in the form of so-called “row cultivating”. The document more specifically relates to a tip, holder and tool for soil working and to a method and tool for assembly and disassembly of a tip.

Background

One problem for various soil-working agricultural implements is that the tool, which engages with the soil, becomes worn and thus needs to be changed. It is known to only change a tip of the tool as this is the part exposed to the highest level of wear.

It is normal that such tips are attached to a holder tine using a screw joint.

So-called “row cultivating” or “row weeding” is a technique which has been known for some time in agriculture. It is based on controlling weeds by cutting off their roots using a “cutting blade”, which is pulled underneath the surface of the soil.

In recent years, the interest for row cultivating has increased as it is an alternative or a complement to using pesticides.

During row cultivating, it is often desirable not to loosen up, or in any other way disturb the soil, apart from controlling the weeds. Therefore it is desirable that the cutting blade has a design which allows it to pass through the soil with a relatively low resistance, without raising the soil more than is necessary.

In order to work well, the cutting blade therefore needs to have a low profile, i.e. it needs to be thin and have a sharp front edge.

However, the cutting blade is exposed to substantial wear as it is pulled underneath the surface of the ground, wherein it is continuously subject to wear through abrasion and it collides with obstacles, such as stones or similar.

There are also different types of cutting blades and it can be desirable to change between these depending on the desired effect.

Consequently, it is desirable to be able to change the cutting blade in a simple way.

Another factor to bear in mind is the cost of each cutting blade, as a cost which is too high makes row cultivating less attractive.

Consequently, it is desirable to be able to manufacture the cutting blade at a low cost.

Known row cultivators are shown in DE423299A, DE467905A and US5941318A.

There is a need for an improved agricultural implement for row cultivating, which enables secure fastening of the cutting blade in combination with simple interchangeability and a low cost of manufacture.

Summary

One object is thus to provide an improved concept for an agricultural implement for soil working, and in particular a concept which allows robust assembly of the tip in combination with simple assembly and disassembly of the tip, as well as a low cost of manufacturing.

The invention is defined in the independent claims. Embodiments are set forth in the dependent claims, in the description that follows and in the accompanying drawings.

According to a first aspect, a tip of a soil-working tool for agricultural implements is provided, comprising a tip body having a front portion facing forward in a direction of working and an attachment portion facing rearward, wherein the attachment portion has a rear edge and a gap, which extends through the rear edge and forward to the front portion. The attachment portion has at least one locking element, located at the rear edge, which has a forward-facing locking surface. The tip body can be formed to be arranged substantially horizontally, where “horizontally” means the orientation of the blade body during normal work, or when it is placed on a plane, horizontal surface.

“Direction of working” means the direction in which the cutting blade is designed to work. Since all tips for the agricultural implement have a portion which is clearly intended to be oriented forward in a direction of working, the direction of working can always be determined from the tip itself.

The tip body can be formed in one piece, preferably starting from a plane blank.

By providing a locking element with a forward-facing locking surface, stable assembly of the tip is enabled.

The tip can be a cutting blade for a row cultivator, a so-called “duckfoot” or a tip for a harrow tine or a cultivator tine.

The locking element can extend inward into the gap.

The locking element can have a ramp surface, which faces rearward and inward into the gap.

The attachment portion can be curved along the gap, so that it has a radius of curvature viewed in a vertical plane containing the direction of working.

The attachment portion can be curved along at least 50% of the length of the gap, preferably at least 60%, at least 70%, at least 80%, or substantially along the entire length of the gap.

By providing the attachment portion with a first radius of curvature and a tip holder with a second, different radius of curvature, it is possible to provide an attachment of the tip in the tip holder without any play.

The gap can divide the attachment portion into a pair of elongated material tongues wherein the locking element is arranged on one of the material tongues.

By way of forming a pair of elongated material tongues, assembly and disassembly of the tip is facilitated by making it easier for the locking element to be bent out of an engagement position.

The material tongues can be tapered rearward in relation to the direction of working. At least one of the material tongues can have a tapered waist at a connection to the front portion.

At the locking surface, the material tongues can have a width corresponding to 50-150% of the width of the gap.

The gap can be tapered forward in the direction of working.

The tip can have a pair of side portions extending across the direction of working.

Preferably, there are recesses laterally between each material tongue and side portion, so that the material tongue can move freely relative to the side portion.

A front edge of the side portions can have a cutting blade edge.

The cutting blade edge can be U-shaped or V-shaped, viewed in a horizontal plane.

The tip can be a cutting blade for a row cultivator.

The tip can be a tip for a harrow tine or a cultivator tine.

The attachment portion can extend rearward and upward relative to the front portion.

The attachment portion can extend less than 30 degrees upward to a horizontal plane, viewed in a vertical plane containing the direction of working.

The front portion and the side portions can be located in the same plane.

The rear portions of the side portions can be curved or angled upward relative to the front portion.

A front portion of the attachment portion can be located in front of the rear portions of the side portions.

The front portion can have a protrusion facing upward, or a ridge, which is aligned with the gap.

According to a second aspect, a tip holder for a row cultivator is provided, comprising an attachment portion, comprising a pair of grooves, which extend substantially along a direction of working and which are laterally open, wherein the grooves are curved so that they have a radius of curvature viewed in a vertical plane containing the direction of working. The grooves are curved along at least 50% of the length of the groove, preferably at least 60%, at least 70%, at least 80%, or substantially along the entire length of the groove.

The grooves can have a respective groove bottom, and a distance between the groove bottoms can decline forward in the direction of working.

A lower portion of the tip holder can have an edge that is tapered forward in the direction of working.

A lower portion of the tip holder can have a pivotal attachment, for pivotal engagement with a tool for assembly and/or disassembly.

According to a third aspect, a material set for forming a soil-working tool for agricultural implements is provided, comprising a tip having a substantially horizontal tip body, which has a front portion facing forward in a direction of working, as well as an attachment portion facing rearward, wherein the attachment portion has a rear edge and a gap, which extends through the rear edge and forward to the front portion, and wherein the attachment portion has at least one locking element, located at the rear edge, which forms a forward-facing locking surface; and a tip holder having an attachment portion with a pair of grooves, which extend substantially along a direction of working and which are laterally open, wherein the grooves have a length which is shorter than a length of the gap, and wherein the edges of the gap are insertable into the groove so that the locking surface is engageable with the rearward-facing surface of the attachment portion.

The tip in the material set can be formed according to the description for the tip above. In the same way, the tip holder can be formed according to the description for the tip holder above.

The attachment portion of the tip can be curved along the gap, so that it has a first radius of curvature viewed in a vertical plane containing the direction of working, wherein the grooves are curved so that they have a second radius of curvature in the vertical plane, wherein a length of the first radius of curvature differs from a length of the second radius of curvature.

According to a fourth aspect, a soil-working tool for agricultural implements is provided, formed of a material set as described above, wherein the edges of the gap are inserted into the groove so that the locking surface is in engagement with the rearward-facing surface of the attachment portion of the tip holder.

According to a fifth aspect, an agricultural implement for soil working is provided, such as for row cultivating, cultivating, or harrowing, comprising a number of a soil-working tools as described above.

In the agricultural implement, a number of soil-working units can be moveably attached to a frame of the agricultural implement, wherein each soil-working unit has a unit frame on which at least two soil-working tools, as described above, are mounted.

According to a sixth aspect, a method for assembly of a tip for a soilworking tool on a tip holder is provided, wherein the tip has a substantially horizontal tip body, which has a front portion facing forward in a direction of working as well as an attachment portion facing rearward, wherein the attachment portion has a rear edge, and a gap which extends through the rear edge and forward to the front portion, wherein the tip holder has an attachment portion with a pair of grooves, which extend substantially along a direction of working and which are laterally open, and wherein the grooves have a length which is shorter than a length of the gap. The method comprises bringing the delimited edges of the gap into engagement with the grooves, leading said edges along the grooves until a locking element, with a forward-facing locking surface, located at the rear edge of the attachment portion of the tip, engages with a rearward-facing surface of the attachment portion of the tip holder.

The method can further comprise providing an assembly tool, comprising a first lever arm and a second lever arm, which is shorter than the first lever arm, wherein proximal portions of the lever arms meet at a pivotal attachment located at a pivot axis, wherein a pulling hook is pivotally attached to a distal portion of the second lever arm, bringing the pivotal attachment of the assembly tool into engagement with a pivotal attachment arranged on the tip holder, so that the assembly tool is in pivotal engagement with the tip holder, and bringing a gripping claw located at the distal end of the pulling hook into engagement with the front portion of the tip. The step of leading the edges of the gap along the grooves is provided by pivoting the first lever arm about the pivot axis so that the pulling hook exerts a force on the tip.

According to a seventh aspect, a method for disassembly of a tip for a soil-working tool from a tip holder is provided, wherein the tip has a substantially horizontal tip body, which has a front portion facing forward in a direction of working as well as an attachment portion facing rearward, wherein the attachment portion has a rear edge, and a gap which extends through the rear edge and forward to the front portion, wherein the tip holder has an attachment portion with a pair of grooves, which extend substantially along a direction of working and which are laterally open, wherein the grooves have a length which is shorter than a length of the gap, and wherein a locking element, with a forward-facing locking surface, located at the rear edge of the attachment portion of the tip is in engagement with a rearward-facing surface of the attachment portion of the tip holder. The method comprises applying force to the rear edge of the attachment portion of the tip, so that the gap is widened until the engagement of the forward-facing locking surfaces with the rearward-facing surface ceases, and leading the tip forward along the grooves.

The method can further comprise providing a disassembly tool, comprising a first lever arm and a second lever arm, which is shorter than the first lever arm, wherein proximal portions of the lever arms meet at a pivotal attachment located at a pivot axis, wherein a disassembly lug is pivotally attached to the second lever arm, bringing the pivotal attachment of the disassembly tool into engagement with a pivotal attachment arranged on the tip holder, so that the disassembly tool is in pivotal engagement with the tip holder, and bringing a distal end of the disassembly lug into engagement with the locking elements, wherein the step of applying force to the rear edge of the attachment portion of the tip is provided by pivoting the first lever arm about the pivot axis so that the force is provided by the engagement of the disassembly lug with the locking elements.

According to an eighth aspect, a tool for assembly of a tip of a soilworking tool on a tip holder is provided, comprising a first lever arm and a second lever arm, which is shorter than the first lever arm, wherein proximal portions of the lever arms meet at a pivotal attachment located at a pivot axis, a pulling hook, which is pivotally attached to a distal portion of the second lever arm, and a gripping claw located at a distal portion of the pulling hook, which has a gripping surface facing a proximal portion of the pulling hook.

The tool can further comprise a disassembly lug, which is pivotally attached to the second lever arm, preferably closer to the pivot axis than the pulling hook, wherein the disassembly lug has a stop surface located at a distal portion thereof.

At its distal portion, the disassembly lug can have a bevelling against the stop surface.

According to a ninth aspect, a tool for disassembly of a tip for row cultivating from a tip holder is provided, comprising a first lever arm and a second lever arm, which is shorter than the first lever arm, wherein proximal portions of the lever arms meet at a pivotal attachment located at a pivot axis, a disassembly lug, which is pivotally attached to the second lever arm, wherein the disassembly lug has a stop surface located at a distal portion thereof.

Brief description of the drawings

Fig. 1 is a schematic top view of an agricultural implement 1 coupled to a tractor vehicle 2.

Figs 2a-2c show schematic views of the agricultural implement 1 .

Figs 3a-3d show schematic views of a row cultivating tool 100.

Figs 4a-4b show schematic illustrations of the attachment mechanism of the row cultivating tool.

Figs 5a-5b show schematic perspective views of a cutting blade of the row cultivating tool.

Figs 6a-6b show schematic perspective views of a holder of the row cultivating tool.

Figs 7a-7d show schematic views of a sequence of assembly of the cutting blade in the holder using a tool. Figs 8a-8e show schematic views that illustrate disassembly of the cutting blade from the holder.

Figs 9a-9b show schematic views of alternative methods of disassembly of the cutting blade from the holder or assembly of the cutting blade on the holder, respectively.

Fig. 10 shows a schematic perspective view of a harrow tool.

Detailed description

The concept will be described with reference to row cultivating below, wherein the tip will be in the form of a cutting blade for a row cultivator.

However, it will be appreciated that the concept described herein can be used for other types of interchangeable tips, such as so-called “duckfeet”, harrow tips and cultivator tips.

Fig. 1 shows an agricultural implement 1 for row cultivating, which is coupled to a tractor vehicle 2, such as a tractor. In different embodiments, the agricultural implement can be fully or partly carried by the tractor vehicle.

In other embodiments, the agricultural implement can be towed by the tractor vehicle 2.

In the example shown in Fig. 1 , the agricultural implement is coupled to the tractor vehicle via a coupling 102 to an implement hoist.

The agricultural implement 1 can, besides row cultivating tools, comprise one or more distribution devices for seed, fertilizer and/or pesticides.

The agricultural implement can comprise an entire frame portion, which carries all tools, a number of frame portions 10a, 10b, which can be foldable in relation to each other, for example, in order to be able to convert the agricultural implement between a working mode and a transport mode.

A direction of working Da is defined as a horizontal direction in which the agricultural implement 1 is designed to be driven during row cultivating.

In the example shown in Fig. 1 , the agricultural implement 1 has a main frame portion 101 and a pair of side frame portions 10a, 10b, which can be folded upward relative to the main frame portion 101 . Figs 2a-2c show more detailed views of an agricultural implement 1 for row cultivating.

The agricultural implement 1 shown in Figs 2a-2c comprises a main frame portion 101 , which has a coupling 102 which is adapted to be connected to an implement hoist of a tractor.

Fig. 2a shows a top view of an agricultural implement 1 for row cultivating.

The agricultural implement has a left-hand side frame portion 10a and a right-hand side frame portion 10b, which can be foldable relative to the main frame portion 101 .

Each side frame portion 10a, 10b comprises a longitudinal beam 100, on which a number of row cultivating units 11 a-11 u are mounted. The row cultivating units 11 a-11u can be, but do not have to be, mutually identical.

As illustrated in Fig. 2a, each row cultivating unit 11 a-11 u is arranged to work in a space S between two adjacent rows of plants R1 , R2.

It will be appreciated, and is illustrated in Fig. 2a, that the row cultivating units 11 a-11u can be arranged at regular spacings from each other, depending on how closely the rows of plants R1 , R2 are arranged. It will also be appreciated that the number of row cultivating units 11 a-11 u can be varied by means of disassembling or assembling as many row cultivating units 11 a-11 u as needed for the longitudinal beam 100 with reference to the row spacing between the rows of plants R1 , R2.

Fig. 2a illustrates how the row cultivating units 11 a-11 u are positioned more closely on the left-hand side frame section 10a than on the right-hand side frame section 10b.

The agricultural implement 1 can have one or more support wheels 12a-12d, arranged to relieve the frame 10a, 10b. The number of support wheels 12a-12d can be selected based on what is deemed suitable.

Fig. 2b shows a side view of the agricultural implement 1 in Fig. 2a, and in particular a row cultivating unit 11a.

The row cultivating unit 11a comprises a unit frame 111 , which extends rearward from the longitudinal beam 100. The unit frame 111 is connected to the longitudinal beam 100 via a coupling device 112, which can be adjustable and which is illustrated here as a parallel linkage.

The coupling device 112 can be designed to pre-tension the unit frame downward, in order to contribute to providing ground pressure from the row cultivating unit 11a.

The row cultivating unit 11a can further comprise one or more depthregulating wheels 113, whose position can be adjustable relative to the unit frame 111.

A number of transverse cross frame portions 115a, 115b, 115c can extend from the unit frame 111. These cross frame portions 115a, 115b, 115c can be fixed relative to the unit frame 111 , such as fixed to this.

Alternatively, the cross frame portions 115a, 115b, 115c can be moveably, such as displaceably, attached relative to the unit frame 111.

Row cultivating tools 117a, 117b, 117c are attached via resilient attachments 116a, 116b, 116c to the transverse cross frame portions 115a, 115b, 115c. One or more row cultivating tools 117a, 117b, 117c can be attached to each cross frame portion 115a, 115b, 115c.

In the event of the cross frame portions 115a, 115b, 115c being fixed relative to the unit frame 111 , the row cultivating tools 117a, 117b, 117c can be moveably mounted relative to each cross frame portion 115a, 115b, 115c.

In the event of the cross frame portions 115a, 115b, 115c being moveably arranged relative to the unit frame 111 , the row cultivating tools 117a, 117b, 117c can be fixedly or moveably mounted relative to each cross frame portion 115a, 115b, 115c.

In the example shown, the resilient attachments 116a, 116b, 116c can be formed as curved leaf springs.

Alternatively, the row cultivating tools 117a, 117b, 117c can be pivotally attached to each cross frame portion 115a, 115b, 115c and pretensioned using a torsion spring (not shown), which can be formed as a helical spring mounted in pivotal mode, or alternatively as a spring of the type shown in, for example, EP1541003B1 , SE534357C2 or W02014051507A1 . Alternatively, a linear spring, such as a helical spring or a gas spring, can act upon a row cultivating tool 117a, 117b, 117c connected to or integrated with the lever arm.

Fig. 2c shows the row cultivating unit 11a in detail viewed from above, wherein it can be seen more clearly how the transverse frame portions 115a, 115b, 115c extend laterally from the unit frame 111.

The row cultivating unit 11 u shown in Fig. 2c, which is located furthest out laterally on the longitudinal beam 10b, can have a set of row cultivating tools 117a, 117b, 117c, which work across a smaller width than the other intermediate row cultivating units 111, which can be explained by the fact that the intermediate row cultivating unit 11t always works across an entire width between two rows of plants, while the outermost row unit 11 u can pass through a width between two rows of plants twice, once in each direction.

As can be seen from the left-hand part in Fig. 2a, the intermediate row cultivating unit 111 can have more row cultivating tools 117a, 117b, 117c than the outer row cultivating unit 11 u. In the example shown, the intermediate row cultivating units 11t have five row cultivating tools 117a, 117b, 117c, while the outer row cultivating unit 11 u has three row cultivating tools 117a, 117b, 117c.lt can also be seen in Fig. 2c that three of the row cultivating tools 117a, 117b, 117c are arranged on the row cultivating unit 11 a.

The row cultivating tools 117a, 117b, 117c are displaced laterally in relation to each other. How far the row cultivating tools 117a, 117b, 117c are displaced in relation to each other can be determined by each row cultivating tool 117a, 117b, 117c being positioned freely along one of the transverse frame portions 115a, 115b, 115c.

The row cultivating tools 117a, 117b, 117c are also displaced in the direction of working in relation to each other. How far the row cultivating tools 117a, 117b, 117c are displaced in relation to each other is determined by the distance in the direction of working between the transverse frame portions 115a, 115b, 115c.

It will be appreciated that it is possible to position one or more row cultivating tools 117a, 117b, 117c on each transverse frame portion 115a, 115b, 115c. It will be appreciated that each row cultivating unit can support one or more row cultivating tools 117a, 117b, 117c, preferably 1 , 2, 3, 4 or 5 row cultivating tools.

Figs 3a-3d show an embodiment of a row cultivating tool 117, which comprises a cutting blade holder 118 and a cutting blade 120.

With reference to Figs 2a-2c, an upper portion of the cutting blade holder 118 can be connected to the spring 116a, 116b, 116c, wherein the cutting blade 120 is connected to the lower portion of the cutting blade holder 118.

The lower portion of the cutting blade holder 118 comprises an attachment portion 1181 , for detachable attachment of the cutting blade 120. The attachment portion 1181 has a pair of grooves that are open laterally and in opposite directions and whose depth is tapered in a rearward direction in relation to the direction of working Da, so that a material portion 1184 between the groove bottoms 11821a, 11821 b (Fig. 4b) is tapered in a forward direction, viewed in the direction of working Da.

The lower and partly upward facing portion 1181 of the cutting blade holder can furthermore be bevelled, so that it tapers in a forward direction in the direction of working Da. This bevelled portion 1185 can extend across a height which corresponds to a maximum work depth for the row cultivating tool 117a, 117b, 117c. Typically, the bevelled portion 1185 can be doublesided, so that an edge is formed right at the front of the cutting blade holder. The bevelled portion 1185 can extend 3-20 cm upward from the lower front edge of the cutting blade holder 118.

The cutting blade 120 has a front portion 1201 , viewed in the direction of working Da, an attachment portion 1202, a pair of side portions 1203a, 1203b, which extend outward laterally, relative to the direction of working Da and whose front portions each have a cutting blade edge 1204a, 1204b, which can be bevelled.

In the example shown, the front portion 1201 and the side portions 1203a, 1203b are located in the same plane, which, during working, is horizontal, i.e. it contains the direction of working Da. Depending on the desired extent of tillage or loosening up of the soil, the rear portions of the side portions 1203a, 1203b can be directed somewhat upward.

The cutting blade 120 can have an upwardly extending soil flow indicator 1206, which can be located at the lateral centre of the cutting blade and between the front portion 1201 and the attachment portion 1202, viewed in the direction of working Da.

The soil flow indicator 1206 can extend along the direction of working Da a distance which corresponds to 20-80%, preferably 30-60%, of a distance between the front portion and a proximal portion of the attachment portion 1202.

The soil flow indicator 1206 can extend across the direction of working Da a distance which corresponds to at least a width of the lower portion of the holder 118, preferably 100-350% of the width of the lower portion 1181 of the holder.

The soil flow indicator 1206 can have a front ramp surface. The bulge 1206 can possibly have a rear ramp surface, which can be steeper than the front ramp surface.

The soil flow indicator 1206 can be formed as an upward bulge. Such a bulge can be formed by pressing a disc-shaped blank from which the cutting blade 120 is formed. The disc-shaped blank can be a metal plate, which can be 3-15 mm thick, preferably 5-10 mm.

As an alternative to a soil flow indicator, it is also possible to give the front portion 1201 a somewhat upward vaulted design, in order to control the soil flow past and above the front edge 1181 f of the cutting blade holder.

The cutting blade edges 1204a, 1204b of the side portions 1203a, 1203b can be, but do not have to be, substantially straight and can form a first angle with each other, viewed in a horizontal plane. This can be advantageous if the cutting blade edges meet at a tip at the front portion 1201 of the cutting blade, which reduces the risk of plant residues getting stuck to the cutting blade and having an adverse effect on the row cultivating. The cutting blade edges 1204a, 1204b can have an angle relative to the direction of working Da, which can be less than 50 degrees, preferably approximately 35-45 degrees.

The rear edges of the side portions can also be substantially straight and form a second angle with each other, viewed in the horizontal plane, which can be greater than the first angle. Consequently, the side portions can be outwardly laterally tapered, viewed in the horizontal plane.

The attachment portion 1202 can comprise a pair of material tongues 1202a, 1202b, which extend rearward relative to the direction of working Da and between which a gap is formed.

The gap can be tapered forward in the direction of working Da.

The material tongues 1202a, 1202b can be tapered in a rearward direction relative to the direction of working.

The laterally outermost rear portion of the side portions 1203a, 1203b, viewed in the direction of working, can be located further rearward than proximal portions of the material tongues 1202a, 1202b. Preferably the outermost and rear portion of the side portions 1203a, 1203b can be located at a distance behind the proximal portion of the material tongues, which corresponds to at least 20% of the length of the material tongues, preferably 30-90% or 40-70%.

Thus a recess can exist between each material tongue 1202a, 1202b and corresponding side portion 1203a, 1203b.

At least one of the material tongues 1202a, 1202b, preferably both, are, at a distal portion thereof, provided with a locking element 12022a, 12022b, which extends inward into the gap between the material tongues 1202a, 1202b.

Fig. 4a shows an outline diagram of the attachment between the cutting blade 120 and the cutting blade holder 118.

The grooves in the cutting blade holder 118 are also open laterally and curved, viewed in a vertical plane which contains the direction of working Da, i.e. a plane which is perpendicular to a horizontal plane in which the cutting blade 120 is intended to work. In the embodiment shown, the grooves 1282a, 1282b can be curved so that they are downwardly concave. The grooves 1282a, 1282b can be curved over at least 50% of their length, preferably at least 75%, at least 90%, at least 95%, or over substantially their entire effective length.

Correspondingly, the attachment portion 1202 and its material tongues 1202a, 1202b can be curved so that they are downwardly concave. The material tongues can be curved over at least 50% of their length, preferably at least 75%, at least 90%, at least 95%, or over substantially their entire effective length.

The material tongues 1202a, 1202b can have a greater length than the grooves 1282a, 1282b. For example, the length of the material tongues can be 5-25% longer than the length of the grooves.

The grooves 1282a, 1282b can be curved with a radius of curvature Rs.

The material tongues 1202a, 1202b can be curved with a radius of curvature Rk.

The radius of curvature Rk, Rs can differ from each other, preferably in so far as the greater of the radii of curvature is 5-15% greater than the smaller one.

By the grooves 1282a, 1282b and the material tongues 1202a, 1202b having different radii of curvature, it is possible to provide a pre-tension in the attachment. In principle, the contact between the grooves and the material tongues can be concentrated to three points P1 , P2, P3.

In the example shown, the radius of curvature Rk of the material tongues is greater than the radius of curvature Rs of the grooves, which results in contact points P1 , P3 at the front portions 1182f and the rear portions 1182r of the upper flanges 11823a, 11823b of the grooves 1282a, 1282b, and contact points P2 approximately at the longitudinal centre point of the grooves at the lower flanges 11824a, 11824b of the grooves.

Alternatively, the radius of curvature Rk of the material tongues can be smaller than the radius of curvature Rs of the grooves, which would result in contact points at the front portions 1182f and the rear portions 1182r of the lower flanges 11824a, 11824b of the grooves 1282a, 1282b, and contact points approximately at the longitudinal centre point of the grooves at the upper flanges 11823a, 11823b of the grooves.

Fig. 4b shows a detail view of the design of the material tongues 1202a, 1202b and the material portion 1184.

The material portion 1184 is tapered forward in the direction of working Da. In the example shown, the material portion 1184 is tapered across its entire length.

The rear part 1182r of the material portion has a locking surface 11822 for interacting with locking surfaces 12023a, 12023b which are formed on the locking elements 12022a, 12022b of the material tongues 1202a, 1202b. The locking surfaces 12023a, 12023b mainly face forward to the direction of working Da. The locking elements 12022a, 12022b extend inward into the gap between the material tongues 1202a, 1202b at the distal portion of the material tongues.

At a distal portion of the locking elements 12022a, 12022b, ramp surfaces 12024a, 12024b are formed and face rearward relative to the direction of working Da and inward to the gap between the material tongues 1202a, 1202b.

The grooves 1182a, 1182b can run parallel to each other and on the same vertical level. In Fig. 4b the groove bottom 11821a of the left-hand groove 1182a and the groove bottom 11821 b of the right-hand groove 1182b are marked. In the same way, the surface 12021a of the left-hand material tongue 1202a facing the gap and the surface 12021b of the right-hand material tongue 1202b facing the gap are marked.

At the proximal portion of the material tongues 1202a, 1202b, their width may decrease somewhat, so that the width of the gap increases, wherein an inner gap space 12025 can be formed. By providing the inner gap space with a rounded shape, the risk of ruptures is reduced, and the ability of the material tongues 1202a, 1202b to spring laterally outward is improved. As a consequence, the smallest width of the gap can be located at a distance in the direction of working Da from the foremost edge of the gap. This distance can be 1-15% of the total length of the gap.

Figs 5a and 5b show perspective views of the cutting blade 120. Fig. 5a shows the cutting blade 120 obliquely rearward and from above.

Fig. 5b shows the cutting blade 120 obliquely rearward and from below.

Figs 6a-6b show the cutting blade holder 118 without the cutting blade mounted.

In Fig. 6a the grooves 1182a, 1182b, the upper groove flanges 11823a, 11823b, the lower groove flanges 11824a, 11824b, and a pivotal attachment 1183 in the form of a through-hole are indicated.

The pivotal attachment 1183 can be formed as a through-hole or as a blind hole. Alternatively, a blind hole can exist on either side of the cutting blade holder 118. The function of the pivotal attachment 1183 will be explained later in the description.

In Fig. 6b the front portion 1182f of the groove and the rear portion 1182r of the groove are marked.

Figs 7a-7d show a sequence of assembly of the cutting blade 120 in the cutting blade holder 118 using an assembly tool 3. Fig. 7e shows an enlarged detail view of one part of Fig. 7c.

The assembly tool 3 comprises a first lever arm portion 31 , which, at a proximal end thereof, connects to a second lever arm portion 32, which is integrated with the first lever arm portion 31 . A pivotal coupling 33 is arranged at the coincident proximal portions of the lever arm portions 31 , 32. In the example shown, the pivotal coupling 33 has the form of a cylindrical protrusion, which extends perpendicular to the lever arm portions 31 , 32 and is formed to fit in the pivotal attachment 1183. Alternatively, the pivotal coupling 33 can be formed as a blind hole or as a through-hole, wherein the pivotal attachment can be formed as a cylindrical protrusion from the cutting blade holder 118.

The lever arms 31 , 32 can be formed in one piece of sheet.

For example, the lever arms can be formed in one sheet with a thickness of 6-10 mm, preferably 8-10 mm and the first lever arm can have a length of 40-50 cm. At the distal end of the first lever arm portion 31 , a handle 312 can be arranged.

The first lever arm 31 can have an effective length which is 5-15 times longer than the effective length of the second lever arm.

At the distal end of the second lever arm 32, a pulling hook 34 can be pivotally attached.

The pulling hook 34 can have a pivotal attachment 341 at its proximal end and, at its distal end, a claw or a hook portion 342, with a gripping surface 3421 facing the pivotal attachment. The gripping surface 3421 can be undercut, in order to ensure engagement with the tip of the cutting blade 120.

The pulling hook 34 can have a length which corresponds to 80-120% of a sum of the length of the groove 1182a, 1182b and the length of the cutting blade 120 (including the attachment portion 1202).

The assembly tool 3 can further comprise a disassembly lug 35, which can be pivotally attached to the second lever arm portion 32, preferably between the pivotal attachment 33 and the pivotal attachment 341 of the pulling hook 34.

The disassembly lug 35 can have a pivotal attachment 351 at its proximal end and, at its distal end, a tapered portion 352 and a stop surface 353. The disassembly lug 35 can be formed of one body, which has a thickness corresponding to 95-105% of the maximum width of the material portion located between the groove bottoms of the cutting blade holder, which corresponds to the width of the locking surface 11822.

The tapered portion 352 can be tapered so that the disassembly lug 35 at the stop surface 353 has a width which corresponds to a minimum distance between the locking elements 12022a, 12022b of the material tongues 1202a, 1202b.

The disassembly lug can have an effective length which corresponds to 10-30% of the effective length of the pulling hook 34.

Fig. 7a shows the cutting blade 120 and the cutting blade holder 118 in a fully dismantled state.

Fig. 7b shows the cutting blade 120 and the cutting blade holder 118 in an initial engagement state, wherein the material tongues 1202a, 1202b have been inserted into the respective grooves 1182a, 1182b so far so that the ramp surfaces 12024a, 12024b of the locking elements 12022a, 12022b engage with the front portion 1182f of the groove and obstructs or prevents any additional manual insertion of the material tongues into the grooves.

Fig. 7c shows how a tool 3 is arranged with the pivotal attachment 33 in engagement with the pivotal attachment 1183 of the cutting blade holder 118, which in the example shown has the form of a through-hole.

The second lever arm 32 extends downward past the groove 1182a, 1182b.

The pulling hook 34 extends forward, with its claw or hook portion 342 in engagement with the front portion 1201 of the cutting blade 120.

Later, when the first lever arm 31 is turned, preferably by hand, clockwise in Fig. 7c, and thus the second lever arm 32 is turned clockwise, the pivotal attachment point 341 of the pulling hook is moved to the left in Fig. 7c and as a result, using the pulling hook 43, the material tongues 1202a, 1202b of the cutting blade 120 are pressed to the groove, so that the material tongues spring laterally outward and are fully inserted into the grooves 1182a, 1182b until the locking elements 12022a, 12022b pass the rear portion 1182r of the groove and the locking surfaces 12023a, 12023b engage with the locking surface 11822 of the attachment portion 1181 , as shown in Fig. 7d.

In the position shown in Fig. 7d, the engagement of the locking surfaces 12023a, 12023b with the locking surface 11822 of the attachment portion 1181 prevents the cutting blade 120 from being displaced forward.

In addition, the difference, described with reference to Fig. 4a, between the radii of curvature Rk, Rs results in the cutting blade 120 being retained in the grooves 1182a, 1182b without play.

Figs 8a-8e show a method of disassembly, which uses the same tool as described above.

Figs 8a-8c show different views of an initial position, at which the disassembly begins. In this position, the cutting blade 120 is fully engaged with the attachment portion 1181 and the locking surfaces 12023a, 12023b are in engagement with the locking surface 11822 of the attachment portion 1181. The tool is mounted on the cutting blade holder 118 by bringing the pivotal attachment 33 into engagement with the pivotal attachment 1183 of the cutting blade holder 118. The distal portion of the disassembly lug 35 is brought into contact with the ramp surfaces 12024a, 12024b of the locking elements 12022a, 12022b.

Figs 8d and 8e show views corresponding to Figs 8b and 8c, but where the first lever arm 31 is turned counter-clockwise viewed in Fig. 8e, so that the disassembly lug 35 is pressed in between the locking elements 12022a, 12022b, wherein the material tongues are pressed apart and forward, so that the locking surfaces 12023a, 12023b are brought out of their engagement with the locking surface 11822 of the attachment portion 1181 and displaced somewhat forward. From this position, the cutting blade 120 can be removed manually or by using a pair of pliers or a mallet.

Fig. 9a shows an alternative way of applying the tool 3 during disassembly of the cutting blade 120 from the cutting blade holder 118. By applying the tool so that the first lever arm 31 extends rearward from the cutting blade holder 118 instead of forward from the cutting blade holder 118 (as shown in Figs 7a-7d and 8a-8d), access for disassembly is facilitated.

Fig. 9b shows an alternative way of applying the tool 3 during assembly of the cutting blade 120 on the cutting blade holder 118. By applying the tool so that the first lever arm 31 extends rearward from the cutting blade holder 118 instead of forward from the cutting blade holder 118 (as shown in Figs 7a-7d and 8a-8d), access for assembly is facilitated.

In the variants of the methods described in Figs 9a-9b, the first lever arm of the tool is turned in the same direction and to the same extent as described with reference to Figs 7a-7e and 8a-8e.

The cutting blade 120 can be made based on a plane disc-shaped metal blank, which can be punched or cut with laser to the desired form, and then press-formed for providing the radius of curvature Rk of the material tongues and an optional soil flow indicator 1206.

The cutting blade edges 1204a, 1204b can be provided by lasercutting, milling and/or grinding. Details, such as locking surfaces 12023a, 12023b and ramp surfaces 12024a, 12024b, can also be provided by laser-cutting, milling and/or grinding.

Fig. 10 shows a tip 220 for a harrow tine, which has a tip body with a front portion 2201 and an attachment portion, extending rearward from the front portion, which comprises a pair of material tongues 1202a, 1202b according to the description above.

The tip body can have an elongate form in the direction of working Da, whose width can be up to approximately 150-350% of the width of the tip holder 218.

Furthermore, the front portion 2201 of the tip body can have a more rounded form, such as a U-shape, viewed in the horizontal plane. The tip 220 can have, but does not have to have, a cutting blade edge.

Side edges 2203a, 2203b can extend substantially along the direction of working Da, such as parallel with the direction of working Da +/- 15 degrees, preferably +/- 10 degrees or +/- 5 degrees.

Apart from the form of the tip body, the tip for a harrow tine 220, and in particular its attachment portion, can be formed in the same way as the cutting blade for a row cultivator described above.

Claims

23 PATENT CLAIMS

1 . Tip (120, 220) of a soil-working tool for agricultural implements (1), comprising: a tip body having a front portion (1201 ) facing forward in a direction of working (Da) and an attachment portion (1202) facing rearward, wherein the attachment portion (1202) has a rear edge and a gap which extends through the rear edge and forward to the front portion (1201 ), characterized in that the attachment portion (1202) has at least one locking element (12022a, 12022b) located at the rear edge, which has a forward-facing locking surface (12023a, 12023b).

2. Tip according to Claim 1 , wherein the locking element (12022a, 12022b) extends inward into the gap.

3. Tip according to either Claim 1 or 2, wherein the locking element (12022a, 12022b) has a ramp surface (12024a, 12024b), which faces rearward and inward into the gap.

4. Tip according to any one of the preceding claims, wherein the attachment portion (1202) is curved along the gap, so that it has a radius of curvature (Rs) viewed in a vertical plane containing the direction of working (Da).

5. Tip according to any one of the preceding claims, wherein the gap divides the attachment portion (1202) into a pair of elongated material tongues (1202a, 1022b) and wherein the locking element (12022a, 12022b) is arranged on one of the material tongues (1202a, 1202b).

6. Tip according to Claim 5, wherein the material tongues (1202a, 1202b) are tapered rearwardly relative to the direction of working (Da).

7. Tip according to either Claim 5 or 6, wherein at least one of the material tongues (1202a, 1202b) has a tapered waist at a connection to the front portion (1201 ).

8. Tip according to any one of Claims 5-7, wherein at the locking surface (12023a, 12023b), the material tongues (1202a, 1202b) have a width corresponding to 50-150% of the width of the gap.

9. Tip according to any one of the preceding claims, wherein the gap is tapered forward in the direction of working (Da).

10. Tip according to any one of the preceding claims, wherein the tip has a pair of side portions (1203a, 1203b) extending across the direction of working (Da).

11. Tip according to Claim 10, wherein a front edge of the side portions (1203a, 1203b) has a cutting blade edge (1204a, 1204b).

12. Tip according to Claim 11 , wherein the cutting blade edge is U- shaped or V-shaped, viewed in a horizontal plane.

13. Tip according to any one of Claims 10-12, wherein the front portion and the side portions (1203a, 1203b) are located in the same plane.

14. Tip according to any one of Claims 10-13, wherein the rear portions of the side portions (1203a, 1203b) are curved or angled upward relative to the front portion (1201 ).

15. Tip according to any one of Claims 10-14, wherein a front portion of the attachment portion is located in front of the rear portions of the side portions (1203a, 1203b).

16. Tip according to any one of the preceding claims, wherein the tip (120) is a cutting blade for a row cultivator.

17. Tip according to any one of Claims 1 -9, wherein the tip is a tip (220) for a harrow tine or a cultivator tine.

18. Tip according to any one of the preceding claims, wherein the attachment portion (1202) extends rearward and upward relative to the front portion (1201 ).

19. Tip according to Claim 18, wherein the attachment portion (1202) extends less than 30 degrees upward to a horizontal plane, viewed in a vertical plane containing the direction of working (Da).

20. Tip according to any one of the preceding claims, wherein the front portion (1201 ) has a protrusion (1206) facing upward, or a ridge, which is aligned with the gap.

21 . Tip holder (118, 218) for a soil-working tool, comprising: an attachment portion (1181 ), comprising a pair of grooves (1182a, 1182b), which extend substantially along a direction of working (Da), and which are laterally open, wherein the grooves (1182a, 1182b) are curved so that they have a radius of curvature (Rs) viewed in a vertical plane containing the direction of working (Da), characterized in that the grooves (1182a, 1182b) are curved along at least 50% of their length, preferably at least 60%, at least 70%, at least 80%, or substantially along the entire length of the grooves (1182a, 1182b).

22. Tip holder according to Claim 21 , wherein the grooves (1182a, 1182b) have a respective groove bottom, and wherein a distance between the groove bottoms declines forward in the direction of working (Da). 26

23. Tip holder according to either Claim 21 or 22, wherein a lower portion (1181 ) of the tip holder has an edge that is tapered forward in the direction of working (Da).

24. Tip holder according to any one of Claims 21-23, wherein a lower portion of the tip holder has a pivotal attachment (1183), for pivotal engagement with a tool for assembly and/or disassembly (3).

25. Material set for forming a soil-working tool (117) for agricultural implements, comprising: a tip (120, 220) having a substantially horizontal tip body, which has a front portion facing forward in a direction of working, as well as an attachment portion (1202) facing rearward, wherein the attachment portion (1202) has a rear edge and a gap, which extends through the rear edge and forward to the front portion, and wherein the attachment portion (1202) has at least one locking element (12022a, 12022b) located at the rear edge, which forms a forward-facing locking surface (12023a, 12023b); and a tip holder (118, 218) which has an attachment portion with a pair of grooves (1182a, 1182b), which extend substantially along a direction of working (Da), and which are laterally open, wherein the grooves (1182a, 1182b) have a length which is shorter than a length of the gap, and wherein the edges of the gap are insertable into the groove (1182a, 1182b) so that the locking surface (12023a, 12023b) is engageable with the rearward-facing surface (11822) of the attachment portion.

26. Material set according to Claim 25, wherein the attachment portion of the tip is curved along the gap, so that it has a first radius of curvature (Rk) viewed in a vertical plane containing the direction of working (Da), wherein the grooves (1182a, 1182b) are curved so that they have a second radius of curvature (Rs) viewed in the vertical plane, wherein a length 27 of the first radius of curvature differs from a length of the second radius of curvature.

27. Soil-working tool (117) for agricultural implements, formed of a material set according to any one of Claims 25-26, wherein the edges of the gap are inserted into the groove (1182a, 1182b) so that the locking surface (12023a, 12023b) is in engagement with the rearward-facing surface (11822) of the attachment portion of the tip holder.

28. Agricultural implement (1 ) for soil working, such as row cultivating, cultivating, or harrowing, comprising a number of soil-working tools (117) according to Claim 27.

29. Agricultural implement according to Claim 28, wherein a number of soil-working units (11 a-11 u) are moveably attached to a frame (10a, 10b) of the agricultural implement (1 ), wherein each soil-working unit (11a, 11 u) has a unit frame (111 , 115a-115b), on which said at least two soil-working tools (117) are mounted.

30. Method for assembly of a tip (120) of a soil-working tool (117) in a tip holder (118), wherein the tip (120) has a substantially horizontal tip body, which has a front portion (1201 ) facing forward in a direction of working, as well as an attachment portion (1202) facing rearward, wherein the attachment portion (1202) has a rear edge and a gap which extends through the rear edge and forward to the front portion (1201 ), wherein the tip holder (118) has an attachment portion with a pair of grooves (1182a, 1182b), which extend substantially along a direction of working (Da), and which are laterally open, wherein the grooves (1182a, 1182b) have a length which is shorter than a length of the gap, wherein the method comprises: 28 bringing the delimited edges of the gap into engagement with the grooves (1182a, 1182b), leading said edges along the grooves (1182a, 1182b) until a locking element (12022a, 12022b), with a forward-facing locking surface (12023a, 12023b), located at the rear edge of the attachment portion of the tip, engages with a rearward-facing surface (11822) of the attachment portion of the tip holder.

31 . Method according to Claim 30, further comprising providing an assembly tool (3), comprising a first lever arm (31 ) and a second lever arm (32), which is shorter than the first lever arm, wherein proximal portions of the lever arms meet at a pivotal attachment (33) located at a pivot axis, wherein a pulling hook (34) is pivotally attached to a distal portion of the second lever arm (32), bringing the pivotal attachment (33) of the assembly tool into engagement with a pivotal attachment (1183) arranged on the tip holder, so that the assembly tool (3) is in pivotal engagement with the tip holder (118), and bringing a gripping claw (342) at the distal end of the pulling hook (34) into engagement with the front portion (1201 ) of the tip (120), wherein the step of leading the edges of the gap along the grooves (1182a, 1182b) is provided by pivoting the first lever arm (31 ) about the pivot axis so that the pulling hook (34) exerts a force on the tip (120).

32. Method for disassembly of a tip (120) of a soil-working tool from a tip holder (118), wherein the tip (120) has a substantially horizontal tip body, which has a front portion (1201 ) facing forward in a direction of working (Da), as well as an attachment portion (1202) facing rearward, wherein the attachment portion (1202) has a rear edge, and a gap which extends through the rear edge and forward to the front portion, 29 wherein the tip holder (118) has an attachment portion (1202) with a pair of grooves (1182a, 1182b), which extend substantially along a direction of working (Da), and which are laterally open, wherein the grooves (1182a, 1182b) have a length which is shorter than a length of the gap, wherein a locking element (12022a, 12022b), with a forward-facing locking surface (12023a, 12023b), located at the rear edge of the attachment portion of the tip (120) is in engagement with a rearward-facing surface (11822) of the attachment portion of the tip holder, wherein the method comprises: applying force to the rear edge of the attachment portion (1202) of the tip, so that the gap is widened until the engagement of the forward-facing locking surfaces (12023a, 12023b) with the rearward-facing surface (11822) ceases, and leading the tip (120) forward along the grooves (1182a, 1182b).

33. Method according to Claim 32, further comprising providing a disassembly tool, comprising a first lever arm (31 ) and a second lever arm (32), which is shorter than the first lever arm, wherein proximal portions of the lever arms meet at a pivotal attachment (33) located at a pivot axis, wherein a disassembly lug (35, 35') is pivotally attached to the second lever arm (32), bringing the pivotal attachment (33) of the disassembly tool into engagement with a pivotal attachment (1183) arranged on the tip holder, so that the disassembly tool (3) is in pivotal engagement with the tip holder (118), and bringing a distal end of the disassembly lug (35, 35') into engagement with the locking elements (12022a, 12022b), wherein the step of applying force to the rear edge of the attachment portion (12022) of the tip is provided by pivoting the first lever arm (31) about the pivot axis so that the force is provided by the engagement of the disassembly lug (35, 35') with the locking elements (12022a, 12022b). 30

34. Method for assembly of a tip (120) of a soil-working tool on a tip holder (118), comprising: a first lever arm (31) and a second lever arm (32), which is shorter than the first lever arm, wherein proximal portions of the lever arms meet at a pivotal attachment (33) located at a pivot axis, a pulling hook (34), which is pivotally attached to a distal portion of the second lever arm (32), and a gripping claw (342) located at a distal portion of the pulling hook (34), which has a gripping surface (3421) facing a proximal portion of the pulling hook.

35. Tool according to Claim 34, further comprising a disassembly lug (35a, 35b), which is pivotally attached to the second lever arm (32), preferably closer to the pivot axis than the pulling hook (34), wherein the disassembly lug (35a, 35') has a stop surface (353) located at a distal portion thereof.

36. Tool according to Claim 35, wherein the disassembly lug (35, 35') has, at the distal portion, a bevelling (352) against the stop surface (353).

37. Tool for disassembly of a tip (120) of a soil-working tool from a tip holder (118), comprising: a first lever arm (31) and a second lever arm (32), which is shorter than the first lever arm, wherein proximal portions of the lever arms meet at a pivotal attachment (33) located at a pivot axis, a disassembly lug (35, 35'), which is pivotally attached to the second lever arm (32), wherein the disassembly lug (35, 35') has a stop surface (353) located at a distal portion thereof.

38. Tool according to Claim 37, wherein the disassembly lug (35, 35') has, at the distal portion, a bevelling (352) against the stop surface (353).