A MOWING MACHINE

Abstract: A mowing machine comprising at least three mower members (4) which are arranged rotatably about substantially vertical axes on a supporting beam (1) containing drive means. Said drive means include a rotating torsion shaft (30) which is driven at both ends thereof and which carries gears for driving said mower members (4).

Description: The invention relates to a mowing machine comprising at least three mower members which are arranged rotatably about substantially vertical axes on a supporting beam having accommodated therein drive means for driving the said mower members, which supporting beam, during operation, extends substantially transversely to the direction of operative travel above the soil, the said drive means being driven near the two ends of the supporting beam by means of mechanically intercoupled drive shafts. A mowing machine of this type is disclosed in the Netherlands Patent Specification 171,955, which describes a disc mower comprising mowing discs provided above a supporting beam, the two outermost mowing discs including a drum-shaped crop guide. Above and parallel to the supporting beam there is disposed a main drive shaft which is connected via gear wheels to two drive shafts. Each drive shaft is accommodated in one of the drum-shaped crop guides and is connected to an outermost mowing disc. Hereby, the two outermost mowing discs on the supporting beam are driven. A series of meshing gear wheels is arranged in the supporting beam in such a manner that each one of the other mowing discs is driven from one of the drive shafts. Preferably, the mowing disc, which relative to the hauling vehicle is the outermost disc, is driven via the one drive shaft and the remaining mowing discs are driven via the other drive shaft. The reason for this is that the mowing disc most remote from the hauling vehicle is loaded to the highest extent due to the presence of the crop guide in the thick of the crop. The invention has for its object to provide a mowing machine wherein the power supplied to the mower members is distributed optimally over the two drive shafts. To this end, according to the invention, the drive means include a torsion shaft which extends through the entire supporting beam and carries gear wheels driving the mower members, while the torsion shaft is driven at both ends by the drive shafts. Due to the use of a torsion shaft which extends in the longitudinal direction of the supporting beam and comprises gear wheels for the drive of each mower member, all the mower members are flexibly interconnected. A section of the torsion shaft functioning as a torsion spring is provided between each pair of interconnected, adjacent mower members. This flexible interconnection renders it on the one hand possible for all the mower members to be intercoupled, while on the other hand said drive means at the two ends of the supporting beam can be driven by means of drive shafts which are intercoupled mechanically, i.e. non-flexibly. Since the entire row of mower members is flexibly intercoupled, the extent to which each mower member is driven from either the one or the other drive shaft will depend on the load to which the further mower members are submitted. Thus, an optimum force distribution is obtained automatically. It will be obvious that, when gear wheels are used for intercoupling the mower members, as described in the said Netherlands Patent Specification 171,955, a non-flexible connection between the mower members is obtained, as a result of which it is not possible to drive a mower member via both drive shafts. A drive system comprising a torsion shaft extending through the entire supporting beam and carrying gear wheels driving the mower members is known per se from EP-A-0 065 809. However, in this publication the torsion shaft is driven by vertically arranged gear wheels at one side of the machine, which construction does not result in the desired power distribution as indicated above. According to a further feature of the invention, the torsion shaft may have an out-of-round cross-section and the gear wheels which are fitted slidably on said torsion shaft are provided with a correspondingly shaped recess. This renders it possible to slide the torsion shaft axially relative to the gear wheels and relative to the supporting beam and, acting thus, to remove same from the supporting beam. For example, the torsion shaft may be of a square cross-section. The torsion shaft can then be chosen to have such a thickness that on the one hand sufficient power can be transferred, while on the other a sufficient flexibility is provided. In accordance with a further feature of the invention, the supporting beam may be located just above the soil during operation and the mower members may be provided with discs arranged above the supporting beam. For example, said discs may be of a circular or oval shape and may have a somewhat upwardly directed convex form. One or a plurality of cutters may be mounted on the periphery of the discs. In addition, according to the invention, the drive of the torsion shaft may be effected via the two outermost mower members arranged on the supporting beam. The power supplied is then passed to the torsion shaft via each of said two mower members and via the gear wheels by means of which said mower members are connected to said torsion shaft, so that it need not be engaged separately in order to be driven. In accordance with a further feature of the invention, the outermost mower members may be provided with upwarly extending drums accommodating the drive shafts for driving the said torsion shaft. In this connection, a "drum" should be understood to mean a crop guide which may have a variety of shapes and in particular may be provided with means arranged on its circumferential surface area for exerting a force on the crop during rotation. The drums may be of a substantially cylindrical shape, although other shapes are possible as well. Consequently, the word "drum" should be interpreted in a wide sense. In addition, in accordance with the invention, the supporting beam may be connected to the further frame of the mowing machine by means of the two drive shafts, which also drive the torsion shaft. Due to the presence of two drive shafts, it is possible, at least when said shafts are adequately bearing-supported, to connect the supporting beam to the further frame of the mowing machine without the use of additional attaching means. In accordance with a further feature of the invention, the drive may be effected via a main drive shaft which extends substantially parallel to the supporting beam and drives the two drive shafts positioned substantially perpendicularly to the main drive shaft. In accordance with a further feature of the invention, the drive shafts may include a flexible coupling, such as a universal joint and/or a joint provided with flexible material and/or a joint having portions which are axially slidable relative to each other. Such a flexible connection may be of importance in order to give the supporting beam moving over the soil some freedom of movement during operation or to allow of a less accurate positioning of the supporting beam with respect to further frame portions. According to the invention, the main drive shaft may be driven via gear wheels in a place located between the connections to the drive shafts, which main drive shaft may consist of two sections which are substantially in alignment and are located on both sides of the place where the main drive shaft is engaged via gear wheels. It is alternatively possible to drive the main drive shaft in a position near its end. In accordance with a further feature of the invention, the machine may be provided, in addition to a mowing implement, with a crop processing implement, e.g. a conditioner. Such an implement can exercise a beating action on the crop, thereby crushing same, which is advantageous for the drying thereof. In accordance with a further feature, drum-shaped crop guides may be mounted on the outermost mower members and, taken in the lateral direction of the machine, the crop processing implement may be shorter than the length of the supporting beam. By means of the crop guides, the crop is directed slightly inwardly, as a result of which the crop processing implement may be of a somewhat shorter length than that of the supporting beam. By means of further crop guiding members, such as swath boards, the mown and optionally processed crop can ultimately be deposited on the soil in a narrow strip (swath). In addition, in accordance with the invention, a frame portion may be provided with wheels, in which frame portion the supporting beam is suspended capable of movement, the mowing machine including means for hitching same to a tractor. In such a special support for the mowing machine, a mowing implement of a considerable length is usually employed, in which connection a supporting beam that is driven from two ends can be particularly useful. In accordance with a further feature of the invention, the supporting beam is assembled from sections which are arranged against each other in the longitudinal direction of the supporting beam, of which sections at least a number include drive units for the mower members. A particularly advantageous construction of a mowing implement assembled from such units is obtained when, in accordance with a further feature of the invention, the sections are kept together by means of a tensile rod extending through all of said sections. For relatively large mowing machines, to which the present invention relates in particular, it is of the utmost importance that such an implement need not or hardly be made inoperative for repair purposes during its period of operation. Due to the construction using modules which can be replaced as units, it is possible to carry out a repair rapidly by replacement, for which purpose, in accordance with a feature of the invention, the tensile rod and the torsion shaft extending parallel thereto, which both extend through the sections of the supporting beam, are removable, so that the sections of the supporting beam are detachable and hence replaceable individually. For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings illustrating some embodiments of a mowing machine according to the invention, in which drawings: Figure 1 shows a first embodiment of a mowing machine according to the invention; Figure 2 is a cross-sectional view taken on the line II - II in Figure 1; Figure 3 is a cross-sectional view taken on the line III - III in Figure 2; Figure 4 illustrates a second embodiment of an implement according to the invention, and Figure 5 is a cross-sectional view taken on the line V - V in Figure 4. In the drawings, which give only a schematic rendering of the embodiments, corresponding component parts have been given the same reference numerals. The mowing machine of Figure 1 includes a supporting beam 1 which is assembled from a plurality of adjoining sections 2, 3. Each of the sections 2 is fitted at its upper side with a mower member 4 capable of rotation about a substantially upwardly directed shaft. The mower member 4 includes a disc-shaped portion having at its outer periphery one or more knives 5. In addition, each of said sections 2 of the supporting beam 1 is provided with a slide shoe 6, which slides over the soil during operation. In addition, the mowing machine is provided with a frame 7 which is connected to the two ends of the supporting beam 1 and extends rearwardly and thereafter upwardly from said connecting points, a hollow tube 8 constituting part of the said frame. The hollow tube 8 has both its ends connected to gear boxes 9, 10, which are mounted rigidly in said frame 7. A main drive shaft 11, which at both ends is provided with a bevel gear wheel 12, 13, each of which is accommodated in one of the gear boxes 9, 10, is located inside the said hollow frame tube 8. The said bevel gear wheels 12, 13 mesh with respective bevel gear wheels 14, 15 mounted on respective drive shafts 16 and 17. Said drive shafts 16, 17, whose other ends are connected to the two outermost mower members 4, are each divided into three sections by means of universal joints 18, 19, 20 and 21. As is apparent from Figure 2, the universal joints 18, 19 are single ones in this embodiment. A crop guide member 22, in the shape of a substantially cylindrical drum, is connected to the middle section of the drive shaft 16, 17. The said drum-shaped crop guide member 22 rotates along with the drive shaft 16 and hence with the mower member 4, which is provided with an edge 23 that is contiguous to the drum-shaped crop guide member 22. At its upper side, the drum-shaped crop guide member 22 is contiguous to a screening hood 24 fitted to the frame 7. A bevel gear wheel 25, by means of which the main drive shaft can be driven, is mounted on the main drive shaft 11. To that end, the bevel gear wheel 25 meshes with a gear wheel 26 which is connected, for example, via the necessary intermediate shafts to the power take-off shaft of a tractor. Furthermore, to the hollow tube 8 of the frame 7 there is attached a trestle 27, by means of which the mowing machine can be hitched to a tractor. As has been described in the foregoing, the two outermost mower members 4 of the supporting beam 1 are driven via the main drive shaft 11 and the two drive shafts 16 and 17. The supporting beam 1 accommodates a torsion shaft 30 (Figure 2) having a substantially square cross-section, which torsion shaft 30 extends substantially through the entire supporting beam. In each of the sections 2 of the supporting beam 1, the torsion shaft 30 is provided with a gear wheel, which gear wheel has a square recess corresponding to the cross-section of the torsion shaft 30, so that each gear wheel is mounted thereon slidably in the longitudinal direction but rigidly against rotation. The said gear wheel in each of the sections 2 of the supporting beam 1 drives the mower member 4 on the relevant section 2. Consequently, all the mower members 4 are interconnected by means of torsion shaft 30 in a flexible manner, i.e. the torsion shaft 30 functions as a torsion spring between every two adjacent mower members. The use of this flexible connection allows of a direct drive of the two outermost mower members, thereby driving each of the further mowing members via the outermost mower members in dependence on the load distribution of the mowing machine. The component sections 2, 3 of the supporting beam are kept together by a tensile rod 31 (Figure 2) which extends through recesses in each of said sections 2, 3 and is provided at its ends with thread, so that by tightening nuts provided thereon the component sections 2, 3 are drawn up against each other and hence constitute one integral whole. In addition, the tensile rod 31 can extend through sections of the frame 7, so that by means thereof also the supporting beam 1 is fitted in the frame 7. Although in Figure 1 there is shown a trestle 27 for coupling the mowing machine to e.g. the rear or the front of a tractor, the mowing machine may alternatively be provided with wheels and be drawn by a hauling vehicle or it may be mounted in an implement in which there are, for example, also provided means for processing the mown crop. In this connection, the main drive shaft 11 may alternatively be driven, for example, near one of its ends. The embodiment shown in the Figures 4 and 5 differs from the one described in the foregoing by the absence of universal joints in the drive shafts 16, 17. In addition, there are lacking frame portions to couple the supporting beam 1 to the superjacent portion of the frame, i.e. the hollow tube 8. The supporting beam 1 is mounted only by means of drive shafts 16, 17 which are bearing-supported in the superjacent frame portion, said bearing being denoted in Figure 5 by reference numeral 32. The drive shafts 16, 17 have their other end rigidly connected to the outermost mower members 4 on the supporting beam. Such a construction has the considerable advantage that it prevents the so-called "piling" of the crop, i.e. the accumulation thereof against stationary frame portions. Also the embodiment shown in Figures 4 and 5 can be connected by means of a trestle 7 to a vehicle or be accommodated in a mowing machine which is drawn by a vehicle and wherein optionally also additional crop processing members, such as a crusher, are incorporated. It will be obvious that the use of the above-described drive of the mower members, whereby the two outermost mowing members are driven directly and all the interposed mower members are interconnected in a flexible manner, allows of an advantageous distribution of the forces when, for example, one of the central mower members is all of a sudden loaded heavily, which extra load need only be taken in part by either of the drive shafts 16, 17. Therefore, an improved distribution of the drive forces is the result of the construction as described.

Claims: A mowing machine comprising at least three mower members (4) which are arranged rotatably about substantially vertical axes on a supporting beam (1) having accommodated therein drive means for driving the said mower members (4), which supporting beam (1), during operation, extends substantially transversely to the direction of operative travel above the soil, the said drive means being driven near the two ends of the supporting beam (1) by means of mechanically intercoupled drive shafts (16, 17), characterized in that the drive means include a torsion shaft (30) which extends through the entire supporting beam (1) and carries gear wheels driving the mower members, while the torsion shaft (30) is driven at both ends by the drive shafts (16, 17). A mowing machine as claimed in claim 1, characterized in that the torsion shaft (30) has an out-of-round cross-section, and that the gear wheels which are fitted slidably on said torsion shaft are provided with a correspondingly shaped recess. A mowing machine as claimed in claim 1 or 2, characterized in that, during operation, the supporting beam (1) is located just above the soil, and that the mower members (4) are provided with discs arranged above the supporting beam (1). A mowing machine as claimed in claim 3, characterized in that the drive of the torsion shaft (30) is effected via the two outermost mower members (14) arranged on the supporting beam (1). A mowing machine as claimed in any one of the preceding claims, characterized in that the outermost mower members (4) are provided with upwardly extending drums (22) accommodating the drive shafts (16, 17) for driving the said torsion shaft (30). A mowing machine as claimed in any one of the preceding claims, characterized in that the supporting beam (1) is connected to the further frame (8) of the mowing machine by means of the two drive shafts (16, 17). A mowing machine as claimed in any one of the preceding claims, characterized in that the torsion shaft (30) is driven via a main drive shaft (11) which extends substantially parallel to the supporting beam (1) and drives the two drive shafts (16, 17) positioned substantially perpendicularly to the main drive shaft (11). A mowing machine as claimed in any one of the preceding claims, characterized in that the drive shafts (16, 17) include a flexible coupling (18, 19, 20, 21), such as a universal joint and/or a joint provided with flexible material and/or a joint having portions which are axially slidable relative to each other. A mowing machine as claimed in any one of claims 4 to 8, characterized in that the main drive shaft (11) is driven via gear wheels (25, 26) in a place located between the connections to the drive shafts (16, 17). A mowing machine as claimed in claim 9, characterized in that the main drive shaft (11) consists of two sections which are substantially in alignment and are located on both sides of the place where the main drive shaft (11) is driven via the gear wheels (25, 26). A mowing machine as claimed in any one of claims 4 to 8, characterized in that the main drive shaft (11) is driven in a position near its end. A mowing machine as claimed in any one of the preceding claims, characterized in that the machine is provided with a crop processing implement. A mowing machine as claimed in claim 12, characterized in that drum-shaped crop guides (22) are mounted on the outermost mower members (4), and that the crop processing implement, taken in the lateral direction of the machine, is shorter than the length of the supporting beam (1). A mowing machine as claimed in any one of the preceding claims, characterized in that a frame portion is provided with wheels, in which frame portion the supporting beam (11) is suspended capable of limited movement, the mowing machine including means for hitching same to a tractor. A mowing machine as claimed in any one of the preceding claims, characterized in that the supporting beam (1) is assembled from sections (2, 3) which are arranged against each other in the longitudinal direction of the supporting beam (1), of which sections (2, 3) at least a number include drive units for the mower members (4). A mowing machine as claimed in claim 15, characterized in that the sections (2, 3) are kept together by means of a tensile rod (31) extending through all of said sections (2, 3). A mowing machine as claimed in claim 16, characterized in that the tensile rod (31) and the torsion shaft (30) extending parallel thereto, which both extend through the sections (2, 3) of the supporting beam (1), are removable, so that the sections (2, 3) of the supporting beam (1) are detachable and hence replaceable individually.

Inventors: KOORN, MAARTEN
Applicants: C. VAN DER LELY N.V.
Application year: 1987
Main classification: A01D34
IPC codes: A01D34