DEVICE AND METHOD FOR MOVING AND CUTTING AN AGRICULTURAL CROP, SUCH AS HEMP

Abstract: A device and a method for cutting fibrous material, such as the agricultural crop hemp, provided with a rotatable cutting member (1) comprising a blade (11) whose cutting edge lies substantially on a cylindrical surface which extends coaxially with respect to the axis of rotation. Furthermore, a stationary counter blade (13) is provided, whose cutting edge likewise lies substantially on said cylindrical surface. The cutting member (1) is provided with two substantially disc-shaped flanges (7), which extend perpendicularly to the axis of rotation on either side of the blade and which have a diameter which is larger than that of said cylindrical surface.

Description: DEVICE AND METHOD FOR MOWING AND CUTTING AN AGRICULTURAL CROP, SUCH AS HEMP The invention relates to a device for cutting fibrous material, said device being provided with a rotatable cutting member comprising a cutting blade, whose cutting edge lies substantially on a cylindrical surface which extends co-axially with respect to the axis of rotation, and with a stationary counter blade, whose cutting edge likewise lies substantially on said cylindrical surface. A device of this type may be used for cutting an agricultural crop, for example hemp, into pieces of a selected length. Depending on the rate at which the crop is supplied, the rotational speed of the cutting member and the number of blades present on said cutting member, the crop is cut into pieces of a selected length. One or more blades may thereby be mounted on the cutting member in such a manner that said cutting edge or cutting edges extend co-axially and are straight. The cutting edge(s) may also be helical, so that a limited part of the cutting blade will co-operate with the counter blade at all times upon passing said counter blade. The counter blade, which will usually have a straight cutting edge, is mounted co-axially. A device of this type may be incorporated in a mowing machine, so that the agricultural crop is cut into pieces immediately after being mown and subsequently windrowed on the land. Feed rolls may be provided, which feed the crop in the correct manner and the correct position at a selected speed to the cutting member. Especially in those cases where a fibrous crop is to be cut by means of the device, there is a danger that parts of the crop are properly separated from each other during the cutting operation, so that longer fibres may accumulate in the device, which fibres will in particular wrap themselves round the cutting member. In case of excessive wrapping of fibres round the cutting member, in particular round the cutting member shaft, the cutting member will get jammed or be bent in such a manner that the intended cutting operation can no longer be carried out . The longer fibres may also be formed as a result of shorter fibres twisting together, thus forming a longer fibre or an assembly of fibres . The object of the invention is to provide a device for cutting fibrous material, wherein the material is cut in an efficient manner and wherein fibres are prevented from accumulating round the cutting member. In order to accomplish that objective the cutting member is provided with two substantially disc-shaped flanges, which extend perpendicularly to the axis of rotation on either side of the cutting blade and which have a diameter which is larger than the diameter of said cylindrical surface. Due to the presence of said flanges the area within which fibres may accumulate remains limited to the space between said two flanges, so that the fibres are for example prevented from finding their way into the area where the cutting member is journalled. As a result of the use of the invention longer fibres, which are formed as a result of parts of the agricultural crop not being completely separated from each other by the cutting operation, as well as fibres which are formed as a result of shorter fibres twisting together, cannot find their way into the area where the cutting member is journalled or in the area between the rotating cutting member and the stationary walls positioned on either side of the cutting member, in which said cutting member is journalled. Said fibres can only land in an area of the cutting member which is bounded by the two flanges, in which area no parts are present which move at mutually different speeds. When too many fibres accumulate in the cutting member, said fibres will land on or near the cutting blade, after which said fibres will be subjected to a cutting operation, so that they will move away from said cutting member. According to another aspect of the invention the ends of the cutting blade abut the surfaces of the respective flanges, whereby the ends of the cutting blade preferably extend beyond the flange surfaces. The blade thereby extends into recesses in the flanges. As a result of this fibres being wrapped round the cutting member will always extend over the cutting edge of the blade, so that when sufficient fibres are present said fibres will be subjected to a cutting operation. According to another aspect of the invention at least one part of the side of each flange facing the cutting blade, which part is positioned outside said cylindrical surface, has a substantially conical surface. The conical surface of the flange thereby tapers off towards its axis of rotation in the direction of the cutting blade. In this manner both the crop to be cut and any fibres that may be present and that wrap themselves round the cutting member are led in the direction of the cutting blade. According to another aspect of the invention the cutting member is rotatable within a space which is bounded near each flange by a stationary wall provided perpendicularly to the axis of rotation, whereby said wall is provided with an annular member, which extends substantially round the respective flange. Said annular member may thereby have a conical surface, just like the flange, which tapers off in the same direction as the conical surface of said flange. In addition to that said ring may butt closely against the flange, so that both the agricultural crop being supplied and any accumulating fibres will move along the stationary wall and the stationary ring provided thereon towards the rotating conical flange, after which they will be led to the cutting blade. In this manner it is impossible both for the crop and for any loose fibres to land between the rotating flange and the stationary wall, so that the cutting member is prevented from getting jammed. As already said before, the blade of the cutting member may abut the surface of each of the flanges. This is not possible for the stationary counter blade, however, so that some space will be present between the end of the stationary counter blade and the rotating flanges at all times. This implies that part of the agricultural crop and/or of the fibres lying over the cutting edge of the blade cannot be cut, so that there is a risk of said crop or said fibres being wrapped round the cutting member. With the device according to the invention the amount of agricultural crop and/or fibres being wrapped round the cutting member will remain limited, because said crop and/or said fibres will be moved in the direction of the place where the counter blade co-operates with the cutting blade if there should be any further accumulation, so that said crop and/or said fibres will be cut. The invention furthermore relates to a method for cutting fibrous material, for example an agricultural crop such as hemp, whereby said material is cut by means of a rotatable cutting member comprising a blade whose cutting edge lies substantially on a cylindrical surface which extends co¬ axially with respect to the axis of rotation, which blade co-operates with a stationary counter blade, whose cutting edge likewise lies substantially on said cylindrical surface, wherein said cutting member is according to the invention provided with two substantially disc-shaped flanges, which extend perpendicularly to the axis of rotation on either side of the blade and which have a diameter which is larger than that of said cylindrical surface. Further aspects of the invention, which may be used both separately and in combination with each other, will be described in more detail with reference to the Figures and be defined in the claims. Hereafter an embodiment of a device for cutting an agricultural crop, in particular hemp, will be described by way of illustration, whereby reference will be made to the drawing. Figure 1 is a view of a cutting member; Figure 2 is a sectional view along line II-II of Figure 1; Figure 3 shows part of Figure 2; and Figure 4 is a sectional view along line IV-IV of Figure 3. The Figures merely show a diagrammatic embodiment, with only the relevant parts being shown. Figure 1 shows a rotatable cutting member 1, whose shaft 3 is rotatably journalled, by means of bearings 2, in a housing whose side walls 4 are illustrated in sectional view. Cutting member 1 can be rotated because shaft 3 is rotated, by driving means not shown, in the direction indicated by arrow 5. Cutting member 1 is provided with three discs 6 which are radially provided on shaft 3, for example by being welded thereto. Furthermore two flanges 7 are welded to shaft 3, which flanges 7 have a larger diameter than discs 6. The side walls 4 are each provided with a ring 8 attached thereto, which rings are provided round flanges 7 and which butt closely against the circumferential edge of flanges 7. The facing sides 9 of rings 8 are tapered, and that to an angle which corresponds with a surface 10 of flanges 7, which is likewise tapered. Cutting member 1 is provided with a blade 11, which is attached to the discs 6 by means of bolts 12. The length of blade 11 has been selected such that the ends thereof extend to within recesses 31 of flanges 7. The device according to Figure 1 is furthermore provided with a stationary counter blade 13, which is attached to a part 15 of the frame of the device by means of bolts 14. Figure 2 is a sectional view along line II-II of Figure 1. Figure 2 shows the manner in which blade 11 is mounted on a flat part of the circumference of disc 6 by means of bolt 12, and that in such a manner that the cutting edge 21 of blade 11 may co-operate with the cutting edge 22 of counter blade 13 upon rotation of the cutting member 1 in the direction indicated by arrow 20. Figure 2 also shows two feed rolls 23, which rotate in the direction indicated by arrows 24. Feed rolls 23 are provided with catch means 25, by means of which an agricultural crop can be moved in the direction of cutting member 1. The agricultural crop is furthermore guided by guide surface 26 provided on frame 15, and by the conical shape of surface 9 of stationary ring 8 and surface 10 of flanges 7, so that all the crop is led to a space through which the cutting edge 21 of blade 11 passes. With each rotation of the cutting member a piece of the crop will be cut off, for example in lengths of 25 cm. In the present embodiment blade 11 has a straight cutting edge 21, it is also possible, however, to design the blade 11 such that cutting edge 21 lies on a cylindrical surface and is helical. Furthermore it is possible for the cutting member to have more than one blade 11. Figure 2 furthermore shows a guard plate 27, which on the one hand abuts blade 11 and which is on the other hand welded to two discs 6 and to shaft 3. Figure 1 shows four such guard plates 27, two between discs 6 and two between disc 6 and flange 7. Guard plates 27 prevent the agricultural crop from passing over shaft 3 instead of under shaft 3. Figure 2 shows that flange 7 is provided with a detachable part 29, which is illustrated separately in Figure 3. Said detachable part 29 may be attached to flange 7 by means of bolts 30. Detachable part 29 is provided with a recess 31, into which blade 11 can extend. Mounting or detaching of blade 11 is possible in the detached position of detachable part 29, and part 29 supports blade 11 in the mounted position of said detachable part 29 in the cutting member. Figure 4 is a sectional view along line IV-IV of Figure 3, albeit on a larger scale. Figure 4 shows that holes 32 are formed in such a manner that the head of bolt 30 does not project from the surface of flange 7. By designing the device in the manner shown in the embodiment, fibres and/or parts of the crop to be cut are prevented from wrapping themselves round the cutting member 1 in such manner as to cause the cutting member to jam. As a result of the presence of stationary rings 9 and the conical surface 10 of flanges 7 material wrapping itself round cutting member 1 will automatically be led to blade 11. Since counter blade 13 does not completely abut flanges 7, there is a possibility of material landing between counter blade 13 and the flanges 7, reaching as far as shaft 3, but this material will always pass the cutting edge 21 of blade 11. When said material accumulates, it will pass the counter blade and be cut, therefore. The illustrated embodiment of the invention is to be considered as a mere example, also other embodiments may fall within the scope of the invention.

Claims: CLAIMS 1. A device for cutting fibrous material, said device being provided with a rotatable cutting member (1) comprising a cutting blade (11) , whose cutting edge (21) lies substantially on a cylindrical surface which extends co-axially with respect to the axis of rotation, and with a stationary counter blade (13), whose cutting edge (22) likewise lies substantially on said cylindrical surface, whereby the cutting member (1) is provided with two substantially disc¬ shaped flanges (7), which extend perpendicularly to the axis of rotation on either side of the cutting blade (11) and which have a diameter which is larger than the diameter of said cylindrical surface. 2. A device according to claim 1, characterized in that the ends of the cutting blade (11) abut the the surfaces of the respective flanges (7) . 3. A device according to any one of the preceding claims, characterized in that at least one part of the side of each flange facing the cutting blade (11), which part is positioned outside said cylindrical surface, has a substantially conical surface (10) . 4. A device according to any one of the preceding claims, characterized in that said cutting member (1) is rotatable within a space which is bounded near each flange (7) by a stationary wall (4) provided perpendicularly to the axis of rotation, whereby said wall (4) is provided with an annular member (8) , which extends substantially round the respective flange (7) . 5. A device according to claim 4, characterized in that said annular member (8) has a conical surface (9), which extends from the outside to the inside, in a direction away from said wall (4) . 6. A device according to any one of the preceding claims, characterized in that said cutting member (1) is provided with a central, axially extending shaft (3), and that one or more guard plates (27) are provided between said shaft (3) and said blade (11) . 7. A machine for mowing and processing an agricultural crop comprising means for mowing said crop and means for guiding the crop being mown to a cutting device, said machine being provided with a device according to any one of the preceding claims . 8. A method for cutting fibrous material, whereby said material is cut by means of a rotatable cutting member (1) comprising a cutting blade (11) whose cutting edge (21) lies substantially on a cylindrical surface which extends co-axially with respect to the axis of rotation, which blade (11) co-operates with a stationary counter blade (13), whose cutting edge (22) likewise lies substantially on said cylindrical surface, wherein said cutting member (1) is provided with two substantially disc-shaped flanges (7), which extend perpendicularly to the axis of rotation on either side of the blade (11) and which have a diameter which is larger than that of said cylindrical surface. 9. A method according to claim 8, characterized in that the ends of said blade (11) abut the surfaces of the respective flanges (7) . 10. A method according to claim 8 or 9, characterized in that at least part of the side of each flange (7) facing the cutting blade (11), which part is positioned outside said cylindrical surface, has a substantially conical surface (10) . 11. A method for mowing and processing an agricultural crop, whereby said crop is mown and then passed to a cutting device, in which said crop is subjected to an operation according to the method of any one of the claims 8 - 10.

Inventors: EVENHUIS NANNO, EVENHUIS, NANNO
Applicants: EVENHUIS NANNO, EVENHUIS, NANNO
Application year: 1996
Main classification: A01D75
IPC codes: A01D75, A01F29