NL2020260B1

NL2020260B1 - Ploughing device and method for ploughing a trench in a field

Info

Publication number: NL2020260B1
Application number: NL2020260A
Authority: NL
Inventors: Ferdinand Walsweer Robertus; Marinus Lensink Gehard; Gerrit Hendrik Sefrien Dimmendaal Jan
Original assignee: Allinq Group B V
Priority date: 2018-01-10
Filing date: 2018-01-10
Publication date: 2019-07-17

Abstract

The invention relates to a ploughing device and a method for ploughing a trench in a field having a surface layer and a soil layer, wherein the ploughing device comprises a. first plough facing jíl a ploughing direction and a second plough that is located behind the first plough with respect to the ploughing direction, wherein the first plough comprises a first share for separating the surface layer from the soil layer and a first mouldboard for directing the separated surface layer ij1 a first lateral direction with respect to the ploughing direction to a first side of the trench, wherein the second plough comprises a second share for separating the soil layer from a lower layer below said soil layer and a second mouldboard for directing the separated soil layer in a second lateral direction opposite to the first lateral direction to a second side of the trench.

Description

Ploughing device and method for ploughing a trench in a field

BACKGROUND

The invention relates to a ploughing device and a method for ploughing a trench in a field, in particular a trench for laying cables, wires, pipes and the like. WO 86/00356 A1 discloses a machine for ploughing trenches and laying cables or wires therein. The machine includes a plough that is connected to a vehicle and a guide means arranged directly behind the plough for feeding a conduit from a rotatably mounted storage reel. Hence, the conduit is immediately laid down at the required depth.

Since WO 86/00356 Al, the complexity of underground cable and piping networks has increased significantly. Nowadays, it is no longer allowed to immediately plough to the intended depth of the cable or pipe. Even with the introduction of official registers to keep track of existing cables and wires, in practice, the actual position of said cables and wires may deviate from the position logged in the register. Therefore, a small excavator is used to dig a shallow trench, which is then carefully explored and excavated further with manual tools to prevent that existing cables and/or pipes are hit accidentally. After the new cable or pipe has been laid, the trench is filled and the surface is sown with grass seeds to repair the surface layer. It may take several months until the trench area is restored to its original condition .

SUMMARY OF THE INVENTION

The above process of (manually) digging, laying filling and sowing can be very time consuming, in particular when laying long lengths of cable or pipe. As a result, a typical crew of five workers can only lay a little over one-hundred meters of cable or pipe per day.

It is an object of the present invention to provide a ploughing device and a method for ploughing a trench in a field, wherein at least one of the aforementioned drawbacks is addressed.

According to a first aspect, the invention provides a ploughing device for ploughing a trench in a field having a surface layer and a soil layer underneath said surface layer, wherein the ploughing device comprises a first plough facing in a ploughing direction and a second plough that is located behind the first plough with respect to the ploughing direction, wherein the first plough comprises a first share that is arranged for separating the surface layer from the soil layer and a first mouldboard for directing the separated surface layer in a first lateral direction with respect to the ploughing direction to a first side of the trench, wherein the second plough comprises a second share that is arranged for separating the soil layer from a lower layer below said soil layer and a second mouldboard for directing the separated soil layer in a second lateral direction opposite to the first lateral direction to a second side of the trench.

The abovementioned ploughing device can plough a trench that can be filled and repaired easily after the cable, wire, pipe or the like has been laid. In particular, the soil layer can be put back into the trench from the second side of the trench and the surface layer can subsequently be put back on top of the soil layer from the first side of the trench. Provided that the surface layer is still substantially in tact, the surface layer can be restored to its original condition immediately, simply by putting it back. In a preferred embodiment, the surface layer is a grass layer, wherein the first share is arranged for separating the grass layer from the soil layer to form sods of grass. The sods of grass can be put back onto the soil layer when closing the trench. Hence, no new grass has to be sown.

In a further embodiment the first share is arranged for separating the surface layer from the soil layer at a first depth, wherein the second share is arranged for separating the soil layer from the lower layer at a second depth that is at least three times the first depth. Preferably, the second depth is at least five times the first depth. Hence, the surface layer is a relatively thin layer compared to the soil layer.

More preferably, the first depth is in a range of three to eight centimetres, preferably in a range of four to seven centimetres. When choosing a first depth within said specified range, the surface layer can be separated effectively from the soil layer. In particular, in the case of the surface layer being a grass layer, the separated surface layer can form sods of grass that remain coherent or substantially coherent when being directed in the first lateral direction.

In a further embodiment, the trench has a trench width, wherein the first share extends over the entire trench width or substantially the entire trench width. Consequently, the first share is able to separate the surface layer from the soil layer across the entire trench width.

Preferably, the second share extends over the entire trench width or substantially the entire trench width. Similarly, the first share is able to separate the soil layer from the lower layer across the entire trench width.

In a further embodiment the first mouldboard is arranged to turn-over the separated surface layer over at least ninety degrees after which the separated surface layer is allowed to free fall onto the side of the trench in the first lateral direction, wherein the ploughing device further comprises an impulse element that is placed in the path of the free falling separated surface layer and is arranged to exert an impulse on said separated surface layer during its free fall from the first mouldboard such that the separated surface layer rotates further. Typically, a ploughed over surface layer lands on the side of the trench in an up-side-down orientation. In the case of a grass layer, the roots of the grass are exposed and can quickly dry out. In the present invention, with the momentum of said surface layer in the first lateral direction, the surface layer tends to lands onto the first side of the trench and falls-over in an orientation that is the same as the orientation in which it was separated from the soil layer. In other words, the surface layer is ultimately rotated over three-hundred-and-sixty degrees. This keeps the grass sods fresh over a longer period of time. Moreover, as the surface layer is already in the correct orientation, they can easily be slid back onto the soil layer when the trench is closed.

Preferably, the impulse element is an impulse wheel which ensures that the separated surface layer, in particular in the event of grass sods, can be deposited consistently onto the side of the trench in the first lateral direction.

In another embodiment the first share extends obliquely with respect to the ploughing direction and the first lateral direction. Hence, the surface layer can be separated from the soil layer progressively across the trench width.

In another embodiment the second share extends parallel or substantially parallel to the second lateral direction. Hence, the soil layer can be separated from the lower layer simultaneously across the trench width.

In another embodiment the ploughing device comprises a wedge for lifting the separated soil layer from the second share to the second mouldboard. By first lifting the separated soil layer prior to directing it onto the second mouldboard, it can be prevented that the separated soil is already directed to the second side of the trench prior to the soil being lifted out of the trench.

In a preferred embodiment thereof the wedge extends at a ploughing angle in the range of twenty to forty degrees to the ground. More preferably, the ploughing angle is in the range of twenty five to thirty-five degrees. This ploughing angle has been found to be optimal for effectively lifting the separated soil out of the trench.

In a further preferred embodiment thereof, the second mouldboard is located in the second lateral direction to the side of said wedge, wherein the ploughing device further comprises a soil conveyor extending from the wedge to the second mouldboard for conveying the separated soil layer from the wedge to the second mouldboard. Preferably, the soil conveyor is a screw conveyor. The soil conveyor can consistently convey a certain amount of soil to the second mouldboard.

In another embodiment the second share is at least partially located vertically below the first mouldboard. Hence, the ploughing device can already separated the soil layer from the lower layer while the surface layer is being separated from the soil layer. Moreover, because of the overlap the ploughing device can be more compact in the ploughing direction.

In a further embodiment, the wedge is at least partially located vertically below the first mouldboard. Similarly, the separated soil can already be lifted towards the surface while the surface layer is being separated from the soil layer.

In another embodiment, the ploughing device comprises a first coulter and a second coulter which are located in front of the first plough in the ploughing direction for cutting vertically into the ground at the first side and the second side of the trench, respectively. Preferably, the first coulter and the second coulter are disc coulters. Said coulters can prepare the boundaries and/or side walls of the trench in the first lateral direction and the second lateral direction, respectively, such that the surface layer and the soil layer can be separated accurately from the sides of the trench.

In a preferred embodiment thereof, the first coulter and the second coulter are spaced apart in the first lateral direction over a distance in the range of twenty to forty centimetres. This spacing can define the trench width.

In a further embodiment the ploughing device further comprises a third plough that is located behind the second plough in the ploughing direction, wherein the third plough is arranged for digging a guiding channel in the lower layer. The guiding channels can be used to accurately lay down the wires, cables, pipes or the like. In particular in the field of fibre optic cables, it can be very important that said cables are laid down along a line that is as straight as possible, to easily blown in the optic fibres.

According to a second aspect, the invention provides a method for ploughing a trench in a field with the use of the ploughing device according to any one of the aforementioned embodiments, wherein the field has a surface layer and a soil layer underneath said surface layer, wherein the method comprises the steps of: - separating the surface layer from the soil layer with the first share; directing the separated surface layer with the first mouldboard in the first lateral direction to the first side of the trench; - separating the soil layer from a lower layer below said soil layer with the second share; and directing the separated soil layer with the second mouldboard in the second lateral direction to the second side of the trench.

The method relates to the practical implementation of the ploughing device according to any one of the aforementioned embodiments and thus has the same technical advantages which will not be repeated hereafter.

In a preferred embodiment of the method the surface layer is a grass layer, wherein the first share separates the grass layer from the soil layer to form sods of grass.

In a further embodiment of the method the first share separates the surface layer from the soil layer at a first depth, wherein the second share separates the soil layer from the lower layer at a second depth that is at least twice the first depth. Preferably, the second depth is at least three times the first depth.

In a further embodiment of the method the first depth is in a range of five to fifteen centimetres, preferably in a range of eight to twelve centimetres.

In a further embodiment of the method the surface layer is turned-over by the first mouldboard over more than two-hundred-and-seventy degrees.

In a further embodiment of the method the ploughing device comprises a first coulter and a second coulter which are located in front of the first plough in the ploughing direction, wherein the method further comprises the step of cutting vertically into the ground with the first coulter and the second coulter at the first side and the second side of the trench, respectively.

In a further embodiment of the method the ploughing device further comprises a third plough that is located behind the second plough in the ploughing direction, wherein the method further comprises the step of digging a guiding channel in the lower layer with the third plough .

In a further embodiment the method comprises the steps of closing the trench by first putting back the separated soil layer from the side of the trench in the second lateral direction and by subsequently putting the separated surface layer back onto the returned soil from the side of the trench in the first lateral direction. The trench can thus be closed in the reverse order with respect to the order in which it was ploughed. More in particular, the separated surface layer can easily be put back on top of the separated soil to repair the trench.

In an alternative embodiment the method comprises the steps of closing the trench by first putting back the separated surface layer from the side of the trench in the first lateral direction and by subsequently putting the separated soil layer back onto the returned soil from the side of the trench in the second lateral direction. This has the advantage that the grass sods are at the bottom of the trench and the soil of the ridge can form a clean and suitable surface for sowing new grass seeds.

In a further embodiment of the method the trench is ploughed next to a road, wherein the road is at the side of the trench in the second lateral direction, wherein the method comprises the step of forming the ridge between the road and the trench. Hence, the location of the trench is easily accessible. More in particular, this allows for the tractor to close the trench mechanically, e.g. with the use of an alternative soil conveyor (not shown), while the tractor can stay on the road.

The various aspects and features described and shown in the specification can be applied, individually, wherever possible. These individual aspects, in particular the aspects and features described in the attached dependent claims, can be made subject of divisional patent applications .

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis of an exemplary embodiment shown in the attached schematic drawings, in which: figure 1 shows a tractor and a ploughing device coupled to said tractor for ploughing a trench in a field, wherein a surface layer, a soil layer and a lower layer of said field have been shown in cross section; figure 2 shows a rear view of the tractor and the ploughing device of figure 1; figure 3 shows a top view of the tractor and the ploughing device of figure 1 and the trench being ploughed by said ploughing device; figure 4 shows a perspective view from behind of the tractor and the ploughing device of figure 1 and the trench being ploughed by said ploughing device; figure 5 shows a perspective view of the ploughing device of figure 1 viewed from a first side of the trench; figure 6 shows a perspective view of the ploughing device of figure 1 viewed from a second side of the trench; figure 7 shows a side view of the rear of the ploughing device of figure 1 viewed from the second side of the trench; figure 8 is a schematic representation of the ploughing device of figure 1 in side view as viewed from the second side of the trench; figures 9A-9F are schematic representations of the stages that a grass sod goes through during the ploughing at several cross sections of a mouldboard; and figures 10A and 10B show two different methods of closing or filling the trench.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a ploughing device 1 according to an exemplary embodiment of the invention for ploughing a trench 90 in a field 9. The field 9 comprises a surface layer 91, in this example in the form of a grass layer. The field further comprises a soil layer 92 below said surface layer 91 and a lower layer 93 below said soil layer 93.

As best seen in figures 1, 2 and 3, the ploughing device 1 is arranged to be coupled to a tractor 8 or another suitable pulling device. The tractor 8 is arranged for pulling the ploughing device 1 in a ploughing direction P. As best seen in figure 3, the trench 90 has a first side in a first lateral direction Ll perpendicular to the ploughing direction P and a second side opposite to the first side in a second lateral direction L2 perpendicular to the ploughing direction P. The tractor 8 may be provided with an auxiliary drive (not shown) to drive parts of the ploughing device 1 in a manner that will be described in more detail later in this description.

As shown in figures 1, 2 and 3, the ploughing device 1 comprises a frame 2, in this example formed by one or more metal beams. The frame 2 is arranged to be coupled to the tractor 8 and supports and/or carries the parts of the ploughing device 1 in a trailing position behind the tractor 8. As shown in figures 1 and 3, the ploughing device 1 further comprises a first coulter 31, a second coulter 32, a first plough 4 that is located behind the coulters 31, 32 in the ploughing direction P and a second plough 5 that is located at least partially behind the first plough 4 in the ploughing direction P. As, shown in figure 1, the ploughing device 1 may optionally comprises a depth wheel 6 to set the depth at which the ploughing device 1 operates. In use, said depth wheel 6 is located to the side of trench 90 in one of the lateral directions Ll, L2 to run over the field and, as such, support the ploughing device 1 at a certain height with respect to the field 9. Alternatively, different ways of setting the depth of the ploughing device 1 may be used.

The coulters 31, 32 are located in front of the first plough 4 in the ploughing direction P for cutting vertically into the ground. As such, the coulters 31, 32 prepare the ground prior to the actual ploughing, such that the trench 90 can be ploughed more accurately with respect to the side walls of said trench 90. In this exemplary embodiment, the coulter 31, 32 are disc coulters. The first coulter 31 and the second coulter 32 are spaced apart in the first lateral direction Ll over a distance in the range of twenty to forty centimetres. This distance defines the width of the trench that is ultimately ploughed. In this exemplary embodiment, the trench width W (and thus the distance between the coulters 31, 32) is approximately thirty centimetres.

As seen in detail in figure 5, the first plough 4 comprises a first share 41 and a first mouldboard 42. As schematically shown in figure 8, the first share 41 is arranged for separating the surface layer 91 from the soil layer 92. The first share 41 effectively forms a cutting edge of the first plough 4. Said first share 41 extends at an oblique angle to the ploughing direction P and/or the first lateral direction Ll for progressively separating the surface layer 91 from the soil layer 92 across the trench width W. The first share 51 preferably extends over the entire trench width W or substantially the entire trench width W. The first share 41 is preferably arranged for separating the surface layer 91 from the soil layer 92 at a first depth of approximately five centimetres.

As best seen in figure 3, the first mouldboard 42 is arranged for directing the separated surface layer 91 in the first lateral direction Ll to the first side of the trench 90. In particular, the first mouldboard 42 is arranged for depositing and/or placing the separated surface layer 91 on the field at the first side of the trench 90. In the case of the surface layer 91 being a grass layer, the separated surface 91 forms sods of grass 95 on the first side of the trench 90. As best seen in figure 4, the sods of grass 95 are preferably kept as coherent as possible, e.g. as continuous as possible, to ensure that they can be put back more easily.

Returning to the detail view of figure 5, it is shown that the first mouldboard 42 has a curved, concave or double-arcuate surface to not only direct the surface layer 91 upwards and to rotate said surface layer 91 at least partially. Preferably, the first mouldboard 42 has a curvature to turn-over the surface layer 91 over more ninety degrees, and preferably more than one-hundred-and-thirty-five degrees. The turning-over of the separated surface layer 91, in this example a grass sod 95, is shown schematically at different cross sections of the first mouldboard 42 in figures 9A-9D. As shown in figure 9E, the separated surface layer 91 is then allowed to free fall from the first mouldboard 42 onto the side of the trench 90 in the first lateral direction Ll. Optionally, as shown in figure 9F, the ploughing device 1 is provided with a freely rotatable impulse element 43, in this example in the form of an impulse wheel, that is arranged in the path of the free falling separated surface layer 91 to exert an impulse on said separated surface layer 91 during its free fall such that the separated surface layer 91 rotates turns-over further, preferably to a total of at least two-hundred-and-seventy degrees and more preferably at least three-hundred-and-sixty degrees with respect to the starting orientation at the trench 90. As a result, the overturned surface layer 91 is rotated over at least two-hundred-and-seventy degrees and - when it lands - tends to fall over in an orientation that is substantially equal to the orientation prior to the separation, as shown in figures 3 and 4.

The impulse wheel 43 rotates in the ploughing direction P and thus ensures that the grass sods 95 can be led consistently onto the side of the trench 90. Alternatively however, a stationary impulse element 43 may be used, e.g. a suitably shaped block (not shown) . In a further alternative embodiment, the first mouldboard 41 may be extended to turn-over the separated surface layer 91 over two-hundred-and-seventy degrees (not shown).

During tests, it has been found that a continuous grass sod 95 can be formed because the cohesion in the continuous grass sod 95 is sufficiently strong to keep the grass sods 95 together. This has the additional advantage that once a leading part of the continuous grass sod 95 has been rotated over three-hundred-and-sixty degrees, the rest of the continuous grass sod 95 will be pulled automatically into the same orientation by the previously overturned part of the continuous grass sod 95.

As seen in figure 1, the second plough 5 comprises a second share 51, a second moulboard 52 and a wedge 57. As schematically shown in figure 8, the second share 51 is arranged for separating the soil layer 92 from the lower layer 93. The second share 51 effectively forms a cutting edge of the second plough 5. The second share 51 extends parallel or substantially parallel to the second lateral direction L2 or perpendicular to the ploughing direction P. The second share 51 extends over the entire trench width W or substantially the entire trench width W. The second share 51 is preferably arranged for separating the soil layer 92 from the lower layer 93 a second depth D2 that is at least three times the first depth DI, and preferably at least five times the first depth DI. In this exemplary embodiment, the second depth D2 is approximately thirty centimeters.

The wedge 57 is arranged for lifting the separated soil layer 92 from the second share 51 to the second mouldboard 52 . The wedge 57 extends at or forms a ploughing angle H to the ground in the range of twenty to forty degrees, and preferably in the range of twenty five to thirty-five degrees. The wedge 57 is arranged for lifting the separated soil from the second share 51 out of the trench 90 and/or towards the surface. As best seen in figure 3, the ploughing device 1 further comprises a side board 58 at the side of the wedge 57 in the first lateral direction Ll to prevent the separated soil from leaving the wedge 57 to the first side of the trench 90.

As best seen in figure 3, the second mouldboard is located in the ploughing direction P to the back and in the second lateral direction L2 to the side of the wedge 57. As seen in detail in figure 6, the ploughing device 1 further comprises a soil conveyor 53 extending from the wedge 57 to the second mouldboard 52 to help convey the separated soil layer 92 from the wedge 57 to the second mouldboard 52. In this exemplary embodiment, the soil conveyor 53 is a screw conveyor. Said screw conveyor is mounted to a shaft 54 that is arranged to be driven by a transmission 55, as shown in figure 3. In this exemplary embodiment, the transmission 55 is coupled to an auxiliary drive at the tractor 8 via a drive shaft 56.

As seen in detail in figure 7, the second mouldboard 52 is curved, concave or double-arcuate to direct and turn-over the separated soil layer 92 in the direction of the second path B to the second side of the trench 9. As shown in figure 4, the separated soil layer 92 is directed to the second side of the trench 90 in the second lateral direction L2 opposite to the separated surface layer 91 which is directed to the first side of the trench 90 in the first lateral direction Ll. As such, the separated soil of the soil layer 92 forms a ridge 96 of soil in the field at the second side of the trench 90.

As best seen in figures 3 and 5, in this exemplary embodiment of the invention, the second share 51 is at least partially located vertically below the first mouldboard 42. Additionally, the wedge 57 is at least partially located vertically below the first mouldboard 42. Hence, the first plough 4 and the second plough 5 at least partially overlap and - as s result - the ploughing device 1 can be more compact in the ploughing direction P.

As shown in figure 7, the ploughing device 1 may further a third plough 7 that is located behind the second plough 5 in the ploughing direction P. The third plough 7 is arranged for digging a guiding channel 94 in the lower layer 93. Said guiding channel 94 may be used to accurately lay a cable, in particular a fibre-optic cable, in a straight line in the trench 90. A method for ploughing a trench 90 in a field 9 using the aforementioned ploughing device 1 will now be elucidated with reference to figures 1-8.

Figures 1 and 8 show the situation in which the coulters 31, 32 are used to cut vertically into the ground at the first side and the second side of the trench 90 respectively. The sides of the trench 90 have now been prepared. As shown schematically shown in figure 8, the first share 41 of the first plough 4 subsequently separates the surface layer 91 from the soil layer 92. The separated surface layer 91 is directed by the first mouldboard 42 of the first plough 4 along the first path A, as shown in, amongst others, figures 1, 5 and 8. As shown in figures 3 and 4, the surface layer 91 is directed in the first lateral direction Ll to the first side of the trench 90.

Preferably, as discussed before, the combination of the shape of the first mouldboard 42 and the impulse element 43 causes the separated surface layer 91 to rotate over at least two-hundred-and-seventy degrees before landing on the field at the first side of the trench 90 in the first lateral direction Ll, as for example shown in figure 4. Because of the momentum of said separated surface layer 91, the separated surface layer 91 tends to fall-over into an orientation in which the separated surface layer 91 has been rotated over three-hundred-and-sixty degrees. As a result, the separated surface layer 91 is in the same or substantially the same orientation as the surface layer 91 prior to the separation.

Simultaneously with or shortly after separating the surface layer 91 from the soil layer 92, the second share 52 separates the soil layer 92 from the lower layer 93, as schematically shown in figure 8. The separated soil layer 92 is then lifted by the wedge 57 to the level of the second mouldboard 52, as for example shown with arrow B in figures 1 and 6. The soil conveyor 53 conveys the lifted soil layer 92 to the second mouldboard 52. The second mouldboard 52 is subsequently arranged for directing the separated soil layer 92 in the second lateral direction L2 to the second side of the trench 90, as for example shown in figures 3 and 4.

Hence, a trench 90 is created to manually dig deeper or to directly lay cables, wires, pipes or the like. Optionally, the third plough 7 as shown in figure 7 can be used to dig the previously discussed guiding channel 94 into the lower layer 93.

When closing the trench 90, as shown in figure 10A, one can easily put the soil in the ridge 96 on the second side of the trench 90 back into the trench. Once all of the soil has been put back in, the trench can be closed even more easily by simply putting back the separated surface layer 91 from the first side of the trench 90. This is particularly easy if the separated surface layer 91 has indeed been flipped over three-hundred-and-sixty degrees so that said separated surface layer 91 is already in the correct orientation. In the case of grass sods 95, as shown in figures 3 and 4, the grass will still be fresh because of its upright orientation and will be likely to restore relatively quickly once in place on the soil in the trench 90.

Alternatively, the grass sods 95 may be put back into the trench 90 first, as shown in figure 10B, after which the trench 90 is closed by putting the soil in the ridge 96 back into the trench 90. This has the advantage that the grass sods 96 are at the bottom of the trench 90 and the soil of the ridge 96 can form a clean and suitable surface for sowing new grass seeds.

As shown in figures 3 and 4, the trench 90 is preferably ploughed next to a road 99. Hence, the location of the trench 90 is easily accessible. More in particular, the trench 90 is created with the road 99 at the side of the trench 90 in the second lateral direction L2, such that the ridge 96 can be formed between the road 99 and the trench 90. This allows for the tractor 8 to close the trench 90 mechanically, e.g. with the use of an alternative soil conveyor (not shown) , while the tractor 8 can stay on the road 99.

It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the scope of the present invention.

Claims

Plowing device for plowing a trench in a field having a surface layer and a base layer below the surface layer, the plowing device comprising a first plow directed in a plowing direction and a second plow located behind the first plow relative to the plow direction, wherein the first plow comprises a first shear arranged by separating the surface layer from the base layer and a first ratchet for directing the separated surface layer in a first lateral direction relative to the plow direction to a first side of the plow direction ditch, wherein the second plow comprises a second shear adapted to separate the base layer from a bottom layer below the base layer and a second ratchet for directing the separated base layer in a second lateral direction opposite to the first lateral direction to a second side of the ditch.

A plowing device according to claim 1, wherein the surface layer is a grass layer, the first scissors being adapted to separate the grass layer from the ground layer to form turfs.

3. Plowing device as claimed in claim 1 or 2, wherein the first scissors is arranged for separating the surface layer from the base layer at a first depth, wherein the second scissors is arranged for separating the base layer from the bottom layer at a second depth which is at least at least three times the first depth.

The plowing device of claim 3, wherein the second depth is at least five times the first depth.

Plowing device according to claim 3 or 4, wherein the first depth is in a range of three to eight centimeters, preferably in a range of four to seven centimeters.

Plowing device as claimed in any of the foregoing claims, wherein the trench has a trench width, the first scissors extending over the entire trench width or substantially the entire trench width.

Plowing device as claimed in claim 6, wherein the second scissors extends over the entire ditch width or substantially the entire ditch width.

A plowing device according to any one of the preceding claims, wherein the first rister is adapted to invert the separated surface layer by at least ninety degrees, after which the separated surface layer is allowed to fall free on the side of the trench in the first lateral direction, wherein the The plowing apparatus further comprises an impulse element placed in the path of the free-falling separated surface layer and adapted to exert a pulse on the separated surface layer during its free fall from the first ridge such that the separated surface layer rotates further.

The plowing device of claim 8, wherein the pulse element is a pulse wheel.

Plowing device according to any one of the preceding claims, wherein the first scissors extends obliquely with respect to the plowing direction and the first lateral direction.

Plowing device as claimed in any of the foregoing claims, wherein the second scissors extends parallel or substantially parallel to the second lateral direction.

12. Plowing device as claimed in any of the foregoing claims, wherein the plowing device comprises a wedge for lifting the separated base layer from the second scissors to the second rister.

The plowing device of claim 12, wherein the wedge extends at a plow angle in the range of twenty to forty degrees with the ground.

The plowing device of claim 13, wherein the plow angle is in the range of twenty-five to thirty-five degrees.

A plowing device according to any one of claims 12-14, wherein the second set is in the second lateral direction on the side of the wedge, the plowing device further comprising a ground conveyor extending from the wedge to the second set for transporting the separated base layer from the wedge to the second row.

16. Plowing device according to claim 15, wherein the bottom conveyor is a screw conveyor.

17. Plowing device as claimed in any of the foregoing claims, wherein the second scissors lies at least partially vertically below the first rister.

A plowing device according to any one of claims 12-16, wherein the wedge lies at least partially vertically below the first rister.

A plowing device according to any one of the preceding claims, wherein the plowing device comprises a first coulter and a second coulter lying in front of the first plow in the plow direction for vertically cutting into the ground on the first side and the second side of the trench respectively.

The plowing device of claim 19, wherein the first coulter and the second coulter are disc coulters.

A plowing device according to claim 19 or 20, wherein the first coulter and the second coulter are spaced apart in the first lateral direction at a distance in the range of twenty to forty centimeters.

Plowing device as claimed in any of the foregoing claims, wherein the plowing device further comprises a third plow which lies behind the second plow in the plow direction, wherein the third plow is arranged for digging a guide channel in the bottom layer.

A method for plowing a ditch in a field with the use of a plowing device according to any one of the preceding claims, wherein the field has a surface layer and a base layer below the surface layer, the method comprising the steps of: - separating the surface layer of the base layer with the first scissors; directing the separated surface layer with the first web in the first lateral direction to the first side of the trench; - separating the base layer from a bottom layer below the base layer with the second scissors; and - directing the separated base layer with the second web in the second lateral direction to the second side of the trench.

The method of claim 23, wherein the surface layer is a grass layer, the first scissors separating the grass layer from the base layer to form turfs.

A method according to claim 23 or 24, wherein the first scissors separates the surface layer from the base layer at a first depth, the second scissors separates the base layer from the bottom layer at a second depth that is at least twice the first depth.

The method of claim 25, wherein the second depth is at least three times the first depth.

A method according to claim 25 or 26, wherein the first depth is in the range of five to fifteen centimeters, preferably in the range of eight to twelve centimeters.

The method of any one of claims 23-27, wherein the surface layer is inverted by the first set by more than two hundred and seventy degrees.

A method according to any of claims 23-28, wherein the plowing device comprises a first coulter and a second coulter positioned in front of the first plow in the plow direction, the method further comprising the step of vertically cutting into the ground with the first coulter and the second coulter on the first side and the second side of the ditch respectively.

A method according to any of claims 23-29, wherein the plow device further comprises a third plow located behind the second plow in the plow direction, the method further comprising the step of digging a guide channel in the bottom layer with the third plow .

A method according to any one of claims 23-30, wherein the method comprises the steps of closing the trench by first stopping the separated soil layer from the side of the trench in the second lateral direction and then returning the separated surface layer to lay the returned soil from the side of the ditch in the first lateral direction.

A method according to any of claims 23-30, wherein the method comprises the steps of closing the trench by first stopping the separated surface layer from the side of the trench in the first lateral direction and then returning the separated base layer stop on top of the returned soil from the side of the ditch in the second lateral direction.

A method according to any of claims 23-32, wherein the trench is plowed alongside a road, the road on the side of the trench lying in the second lateral direction, the method comprising the step of forming the ledge between the road and the ditch. -o-o-o-o-o-o-o-