MULTI-DISC MOWING MACHINE

Abstract: A cutter blade (13) for mounting on the periphery (14) of a mower disc of a multi-disc type mowing machine and having a first end (17) for mounting pivotably on a peripheral mounting portion (16) of a mower disc, an opposite second end (18) having a cutting edge (19), and a connecting portion (20) interconnecting the first and second ends (17, 18), in which: (a) the cutter blade (13) is formed from an initially flat metal plate; (b) the first end (17) of the blade (13) is substantially flat and has a mounting hole (21) by which the blade can be pivotally mounted on a pivot (16) provided on the disc periphery (14); (c) the second end (18) of the blade (13) is substantially flat and is located in a plane (18a) which is generally parallel to, but spaced a small distance from the plane (17a) containing the first end (17); and (d) the connecting portion (20) is deformed out of the general plane of the plate from which the blade is formed, and so as to space apart the parallel planes (17a, 18a) containing the flat first and second ends (17, 18)) so as to increase the resistance of the blade to loads applied in service. When the cutter blades (13) are mounted on mower discs (10), 11), the blades (13) move through a clearance gap S between the discs in opposite directions, and each blade projects outwardly from the periphery (14) of the respective disc by a sufficient extent so that the tip (13a) of each blade of one disc can overlap with the periphery (14) of an adjacent disc, as seen in plan, during each revolution of the disc; and the blades (13) of the discs (10, 11) are rotatable in respective planes having different heights relative to the ground so as to prevent the blades striking each other as they move through the clearance gap S.

Description: MULTI-DISC MOWING MACHINE This invention relates to a multi-disc mowing machine which comprises a set of rotary mower discs spaced apart in a direction transverse to the mowing direction, and in which each disc carries a set of cutting knives or blades which are rotatable in a plane generally parallel to the surface of the ground over which the machine is tr duelling . The invention also relates to a novel construction of cutting blade for mounting on the periphery of a mower disc. Rotary mower disc type mowing machines are well known m the art, having a set of mower discs which are mounted at spaced apart locations along a cutter bar (with the cutting blades mounted on the peripheries of the discs to extend outwardly therefrom) , and the entire set of discs is able to exert a cutting action on a standing crop e.g. grass, throughout the length of the cutter bar. The discs are spaced apart from each other so as to define clearance gaps between the disc peripheries of adjacent discs, and with the cutting blades projecting outwardly of each disc periphery, it is important to synchronise the rotation of the discs so that the blades of adjacent discs do not strike each other as they move through the common gaps or spaces between adjacent discs. Bearing m mind that the width of a standing crop which can be cut by each disc is dependent upon the diameter of the circular path of travel of the tips of the cutter blades of each disc, it is desirable to increase the radial projection of each blade from the disc periphery by as large an extent as is possible, and this is done conveniently by increasing the length of each blade. However, increasing the length of each blade gives two technical problems wnich have to be overcome. First of all, since each blade is pivotally mounted on a disc periphery at its inboard end, and usually will extend radially outwardly of its pivotable mounting during rotation of the disc under the action of centrifugal force, the greater the length of the blade, the greater will be the tendency of the - . - blade to bend under load, unless steps are taken to increase the resistance of the blade to bending stresses. Secondly, with greater radial projection of each blade from the disc periphery, the greater will be the projection of the blade into the common space or gap between each pair of adjacent discs, and consequent increased risk of blades of adjacent discs striking each other when the adjacent discs rotate in the same direction i.e. m which the blades move in opposite directions towards each other, as they move through the clearance gap between the discs. The invention therefore seeks, in one aspect, to provide an improved assembly of mower discs, so as to provide blades with greater radial projection from the disc peripheries and yet having increased strength by way of resistance to bending and other loads, and also to minimise the risk of blades of adjacent discs striking each other when adjacent discs rotate in the same direction. According to one aspect of the invention there is provided an assembly of mower discs on a cutter bar, in which each disc has a pair of mower blades pivotally mounted on the periphery of the disc at opposite ends of a diameter passing through the axis of rotation of th» disc, and m which the discs are mounted at spaced apart Locations aJong the length of the cutter bar so as to define clearance gaps between the peripheries of each pair of adjacent discs, and in which: (a) a first disc and an adjacent second disc comprise a co-operating pair of discs which are rotatable in the same direction such that, in use, the blades of the first and second discs move through the clearance gap between the discs in relatively opposite directions; (b) the blades project outwardly from the periphery of each disc by a sufficient extent so that the tips of each blade of one disc can overlap with the periphery of an adjacent disc, as seen m plan, during each revolution of the disc; and, (c) the blades of the first and second discs are rotatable in respective planes having different heights relative to the ground so as to prevent the blades striking each other as they move through the clearance gap between the first and second discs. According to a further aspect of the invention, there is provided a cutter blade for mounting on the periphery of a mower disc of a multi-disc type mowing machine, said cutter blade comprising a first end for mounting pivotably on a peripheral mounting portion of a mower disc, an opposite second end having a cutting edge, and a connecting portion interconnecting said first and second ends, and in which: (a) the cutter, blade is formed from an initially flat metal plate; (b) the first end of the blade JS substantially flat and has a mounting hole by which the blade can be pivotably mounted on a pivot provided on the disc periphery; (c) the second end of the blade is substantially flat, and is located in a plane which is generally parallel to, but spaced a small distance from the plane containing the first end; and, (d) the connecting portion is deformed out of the general plane of the plate from which the blade is formed, and so as to space apart the parallel planes containing the flat first and second ends, and so as to increase the resistance of the blade to loads applied in service. In use of a mower disc, the cutter blades (which are pivotably mounted on the disc periphery) rotate in a plane which is generally parallel to the surface of the ground over which the mowing machine s travelling, and such plane is located at a height above the ground orrespondmg to the required level at which a standing crop e.g. grass is to be cut . The blade is subject to transverse loads as it cuts through the standing crop, but also will tend to oscillate up and down relative to its pivotal mounting. However, by forming the blade from an initially flat plate i.e. the blade is a unitary part, and by deforming the connecting portion from the general plane of the plate, a strong construction of blade is obtained which is better able to withstand applied loads in service . The second end (which is flat may merge gradually with the deformed part of the connecting portion e.g. by way of one or more sloping portions, and the cutting edge of the blade may extend along one side of the blade end and preferably also along at least part of one or more of the sloping portions. A preferred embodiment of the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, m which: Figures la to lh are schematic plan of a number of different arrangement? of multi-dis<~ mowing machines, to which the invention may be applied; Figure 2 is a detail and enlarged view showing the cooperation between an adjacent pair of mower discs in an embodiment of multi-disc mowing machine according to the invention; Figure 3 is an enlarged view, generally corresponding to Figure 2, and showing in more detail the co-operation between the cutting blades of the adjacent discs; and, Figures 4a to 4e are views of a preferred form of cutting blade or knife according to a further embodiment of the invention, for mounting on a mower disc of a multi-disc mowing machine. Referring first to Figure 1 of the drawings, by way of background to the invention, this shows schematically a number of different arrangements of multi-disc mowing machine, to which the invention may be applied. The construction and operation of multi-disc mowing machines will be well known to those of ordinary skill in the art, and need not be described in detail herein. The forward mowing direction is shown by the arrow X in Figure 1, and as per standard practice, the discs or cylinders at the outer end of each row of discs are caused to rotate inwardly, with respect to direction X, so as to cut a portion of standing crop in front of it, and to direct the cut crop in a direction inwardly of usual side plates (not shown) of the mowing machine, located one at each end of a usual cutter bar (also not shown) . Figure 1 shows different arrangements of disc, and the respective directions of rotation, for, running from the top down to the bottom, a five disc mower set shown in Figure la down to a nine disc mower set shown in Figure In. It will be noted from Figure 1 that the discs at the end of each row are caused to rotate in an inward direction, as shown by the arrows. However, the discs in each set, located between the two outer end discs, can be caused to rotate in different directions, according to the total number of discs in the set, and the required number of streams of cut grass which are to be formed behind the cutter bar. In the case of a conditioner / mower, the streams of grass issuing from the mower discs can be caused to pass through a conditioner device, to undergo some form of "conditioning", prior to deposit in one or more swathes behind the mower. In some of the arrangements, e . < . as shown in Figures lb, c and f, the discs are caused to rotate, consecutively, in relatively opposite directions i.e. as in Figure lb, looking from the right hand end, anti-clockwise, clockwise, anticlockwise, clockwise, anti-clockwise and clockwise. In such an arrangement, the blades mounted on the outer peripheries of the discs move together in a direction opposite to the mowing direction X through the clearance gap between each co-operating pair of discs, and therefore, with appropriate mounting of the blades on the peripheries of the discs, it can be arranged that there is substantially no risk of the blades striking each other as they move together through the clearance gap. However, in the examples shewn in Figures la, d and e, the left hand pair of mower discs rotate in the same direction. namely clockwise, and this means that the blades on the two discs move in relatively opposite directions through the clearance gap or space defined between the peripheries of the two discs. In addition, in the example shown in Figure lg, the right hand pair of discs also rotate ?n the same direction as each other, although in this case it is anti-clockwise direction. In one aspect of the invention, and as will be described with reference to a preferred embodiment, it is an objective to minimise the risk of the blades of the adjacent pair of discs from striking each other, during movement in relatively opposite directions through the clearance gap, which applies when the discs of each co-operating pair rotate in the same direction. Referring now to Figures ? and 3 ot the drawings, this shows a co-operating pair of first and second mower discs 10 and 11, and by way of example only, it will be assumed that discs 10 and 11 comprise one of the left hand pair of cooperating discs shown in Figures la, d, e, g and h, in which discs 10 and 11 are caused to rotate in a clockwise direction. The discs 10 and 11 are mounted on suitable mounting positions spaced apart along the length of a cutter bar, shown generally by reference 12, and with a suitable drive train being provided (not shown) to apply driving torque to rotate the discs 10 and 11. Each of the discs 10 and 11 has a pair of cutting blades or knives 13 mounted on its outer periphery, and evidently, with clockwise rotation of the discs 10 and 11, the blades will move in relatively opposite directions as they move through a clearance gap or space (.-J) defined between the circular periphery 14 of each of the discs 10 and 11. The clearance gap has a minimum, as shown by spacing S shown in Figure 2, and evidently there will be a risk of the blades 13 striking each other as they approach and move through this region. Each pair of blades 13 is mounted on the opposite end of a diameter passing through the axis of rotation 15 of each disc, and it will be apparent that each blade 13 projects by a substantial distance outwardly of its pivotal mounting 16 on the periphery 14 of each disc, so as to overlap the periphery 14 of the adjacent disc during each revolution. This will be apparent from Figure 2 in particular, where it can be seen quite clearly that the length of each blade 13 is substantially greater than the minimum spacing S between the peripheries 14 of the discs 10 and 11. Figure 3 is a generally similar view to Figure 2, but shows in enlarged view, the co-operation between the discs 10 and 11, and the blades 13 mounted the eon. In order to avoid the blades 13 striking each other, as they move in opposite directions through the clearance gap, it is arranged so that the blades of the discs 10 and 11 are rotatable in respective planes having different heights relative to the ground. This can be achieved by mounting the discs on their cutter bar mountings at different levels e.g. by use of spacers. Alternatively, or in addition, the different heights of the planes of rotation of the blades 13 can be achieved by use of spacers to vary the height of the mounting of each blade relative to the disc on which it is mounted. As can be seen in particular in Figure 3, the blades 13 of disc 10 and 11 are slightly off-r,r.t n height (one blade tip 13a overlaps the other), so that there is no risk of them striking each other as they move through the clearance gap between adjacent discs. This arrangement is particularly effective in use of multi-disc type mowing machines, in which an adjacent pair of first and second co-operating discs rotate in the same direction such that, in use, the blades of the first and second discs move through the clearance gap between the discs in opposite directions. The preferred embodiment shown in Figures 2 and 3 is further advanced technically, by use of an improved design of cutter blade or knife, which will now be described in more detail with reference to Figures 4a to 4e. It should be understood that the embodiment of cutter blade shown in Figures 4a to 4e also has independent inventive significance by itself i.e. that the invention further includes a novel and non- obvious design of cutter blade per se, for mounting on a periphery of a disc of a multi-disc mowing machine. Referring now to Figures 4a to 4e, this shov/s an improved new design of cutter blade, and which is designated generally by reference 13. The blade 13 is intended to be mounted pivotably on the periphery 14 of a mower disc (10, 11) of a multi-disc type mowing machine, and in which the cutter blade 13 comprises a first end 17 by which it can be mounted pivotably on a peripheral mounting portion (16) of a mower disc. The blade 13 also has an opposite second end 18 having one or more cutting edge 19. A connecting portion 20 interconnects the first and second ends 17, 18. The cutter blade 13 is formed from an initially flat metal plate, and the first end 17 of the blade remains substantially flat, and has a mounting hole 21 by which the blade can be pivotally mounted on a pivot 16 provided on the disc periphery 14. The second end 18 of the blade also is substantially flat, but is located in a plane 18a (see Figure 4e) which is slightly spaced from the general plane 17a which contains the first end 17. The connecting portion 20 is deformed out of the initial plane of the flat metal plate, so as to interconnect the flat portions 17 and 18 i.e. to allow the shape of the plate to merge from first flat end portion 17 to second flat end portion 18 (located in a plane parallel to, but slightly spaced from the plane containing first flat end portion 17) , and by reason of this deformation imparted to the metal plate so as to form the connecting portion 20, the resistance to applied bending loads of the blade is increased, as compared with an entirely flat blade. During the formation of the blade 13 from initially flat metal plate, the planes 17a, 18a c o ntaining the first and second flat end portions 17 and 18 are separated from each other through a small distance, and at the same time the connecting portion 20 is deformed so that it has a narrow crown portion 24 which is located in the same plane as the flat end portion 17 and forms a prolongation thereof, and which has sloping side shoulders 22 and 23 which extend downwardly to lower edges which are generally on a level with the second flat end portion 18. The crown portion 24 also merges into the flat end portion 18 via a sloping shoulder 25. In use of a mower disc, the cutter blades are pivotally mounted on the disc periphery and rotate in a plane which is generally parallel to the surface c l _ι:e ground over which the mowing machine is travelling, and such a plane is located at a height above the ground corresponding to the required level at which a standing crop e.g. grass is to be cut. Each blade is subjected to transverse loads, as it cuts through the standing crop, but also will tend to oscillate up and down relative to its pivotal mounting. However, by forming the blade from a plate i.e. a unitary part, and by deforming the connecting portion 20 from the general plane of the plate so as to interconnect the flat first and second end portions 17 and 18, and also to impart small spacing between the planes 17a and 18a of these end portions, a strong construction of blade is obtained which is better able tc .-Lhstand applied loads in service . Figure 4a is a plan view of the blade, and Figures 4c and 4d are respective opposite end views, showing the cross sectional profile of the blade. Figure 4b is a side view of the blade, and Figure 4e is a further side view showing the resilient deformabi lity of the blade under severe load, and also showing the small spacing apart " of the parallel planes 17a and 18a containing the flat end portions 17 and 18.

Claims: CLAIMS 1. An assembly of mower discs (10, 11) on a cutter bar (12), in which each disc (10, 11) has a pair of blades (13) pivotally mounted on the periphery (14) of the disc at opposite ends of a diameter passing through the axis of rotation (15) of the disc, and in which the discs (10, 11) are mounted at spaced apart locations along the length of the cutter bar (12) so as to define clearance gaps S between t^ peripheries (14) of each pair of adjacent discs (10, 11) and in which: (a) a first disc (10) and an adjacent second disc (11) comprise a co-operating pair of discs which are rotatable in the same direction such that, in use, the blades (13) of the first and second discs (10, 11) move through the clearance gap S between the discs in opposite directions; (b) the blades (13) project outwardly from the periphery (14) of each disc (10, 11) by a sufficient extent so that the tip (13a) of each blade (13) of one disc can overlap with the periphery ι!4) of an adjacent disc, as seen in plan, during each revolution of the disc; and, (c) the blaαes (13) of the ύrst and second discs (10, 11) are rotatable in respective planes having different heights relative to the ground so as to prevent the blades striking each other as they move through the clearance gap S. 2. An assembly according to Claim 1, in which the discs (10, 11) comprise a pair of discs provided at one end of a multi-disc type of cutter bar assembly (Figures la, d, e, g, h) . 3. An assembly according to Claim 1 or 2, in which the different heights of the planes of movement of the blades (13) of adjacent discs is achieved by mounting the respective discs (10, 11) at different heights on the cutter bar (12). 4. An assembly according to iai 1 or 2, in which the different heights of the planes of movement of the blades (13) is achieved by mounting the blades ,13) on one of the discs at a different height relative to its mounting (16), as compared with the mounting of the blades on the other disc. 5. A cutter blade (13) for mounting on the periphery (14) of a mower disc of a multi-dis.- type mowing machine, said cutter blade comprising a first end (17) for mounting pivotably on a peripheral mounting portion (16) of a mower disc, an opposite second end (18) having a cutting edge (19), and a connecting portion (20) interconnecting said first and second ends (17, 18) and in which: (a) the cutter blade (13) is formed from an initially flat metal plate; (b) the first end (17) of the blade (13) is substantially flat and has a mounting hole (21) by which the blade can be pivotally mounted on a pivot (16) provided on the disc periphery (14) ; (c) the second end (18) f the blade (13) is substantially flat and is located in a plane (18a) which is generally parallel to, but spaced a small distance from the plane (17a) containing the first end (17); and, (d) the connecting portion (20) is deformed out of the general plane of the plate from which the blade is formed, and so as to space apart the parallel planes (17a, 18a) containing the flat first and second ends (17, 18), and so as to increase the resistance of the blade to loads applied in service. 6. A cutter blade according to claim 5, in which the flat second end (18) merges gradually into the flat first end (17) by way of at least one sloping portion (22, 23), and in which the cutting edge (19) of the .- iat second blade end (18) also extends along at least part of at least one of the sloping portions (22, 23) .

Inventors: LAURITZEN GEORG, LAURITZEN, GEORG
Applicants: KVERNELAND TAARUP AS, KVERNELAND UK LIMITED, LAURITZEN GEORG, KVERNELAND (UK) LIMITED, LAURITZEN, GEORG
Application year: 1998
Main classification: A01D34
IPC codes: A01D34