MOWING MACHINE

Abstract: The invention relates to a mowing machine provided with a hollow frame beam (6) and with a plurality of mowing means (9) supported by said frame beam (6). The mowing means (9) are rotatable about axes of rotation (23) extending upwardly and parallel to each other and can be driven by means of a driving belt (29) provided in said frame beam (6) and pulleys (28, 30), located in said frame beam (6), which are coupled to said mowing means (9). The axes of rotation (23) of the mowing means slope upwards during operation, when seen in the intended direction of movement, relative to a vertical plane extending in the direction of movement. Stubs (16) are secured to the bottom plate of the frame beam (6), on each of which stubs (16) there is journalled, by means of bearings (15) a driving mechanism secured to a mowing means.

Description: The invention relates to a mowing machine provided with a frame having a hollow frame beam and with a plurality of mowing means supported by said frame beam, which mowing means are rotatable about axes of rotation extending upwardly and parallel to each other and which can be driven by means of a driving belt provided in said frame beam and pulleys, located in said frame beam, which are coupled to said mowing means. A mowing machine equipped with a belt transmission (EP-A-0206965) for driving the mowing means has several advantages compared with a mowing machine wherein the mowing means are driven by means of a gear transmission located in the frame beam (NL-A-8501817). Thus the driving mechanism is considerably lighter and less expensive and at the same time more silent when a belt transmission is used, and also it is possible for a mowing means to slip with respect to the belt when said mowing means strikes an obstacle, without the other mowing means having to be slowed down. With a gear transmission, however, the whole driving mechanism and all mowing means must be slowed down when one of the mowing means strikes an obstacle, which may lead to heavy loads and even breaking down of the transmission means or the like. A disadvantage of the mowing machine (EP-A-0206965) wherein a belt transmission is used for driving the mowing means is, however, that the adjacent, partially overlapping mowing means must be arranged at different heights in order to prevent that the cutting knives of the mowing means touch each other in case of slip in the belt transmission possible occurring at the location of one of the mowing means. In practice this may lead to an irregular mowing pattern, since the crop in adjacent strips covered by different mowing means may have different heights after mowing. According to the invention the axes of rotation of the mowing means slope upwards during operation, when seen in the intended direction of movement, relative to a vertical plane extending in the direction of movement. It has become apparent that as a result of said sloping arrangement of the axes of rotation said irregular mowing pattern can be pushed back to a considerable degree, and an even cutting of the crop to the desired distance from the ground can be obtained. Thereby there can be obtained a simple and inexpensive support for the mowing means, consisting of only few parts, when stubs are secured to the bottom plate of the frame beam, on each of which stubs there is journalled, by means of bearings, a driving mechanism secured to a mowing means. Further a mowing means arranged near one end of the mowing machine is coupled to an outgoing shaft of a gear box arranged thereabove, and an ingoing shaft of said gear box has been provided with a pulley, which forms part of a belt transmission to be coupled to the rear of a tractor or the like, whilst the outgoing shaft of the gear box is fixed to the mowing means and an arm is secured to the box, which arm is coupled to the frame in two points spaced from each other by some distance, in such a manner that the arm can make a limited tilting movement in two directions with respect to the frame. The connection between the outgoing shaft of the gear box and the mowing means can thereby be made in a very simple manner, whilst the tolerance variations in the parts and the force exerted on the gear box by the belt transmission can be taken up in an efficient manner by the means with which the arm connected with the gear box is connected with the remaining part of the frame. The invention will be further explained hereinafter with reference to an embodiment of the construction according to the invention diagrammatically illustrated in the accompanying figures. Figure 1 shows, partly in elevational view and partly in section, a front elevational view of a machine according to the invention. Figure 2 shows a plan view of Figure 1. Figure 3 shows on a larger scale a bottom part of a mowing means, partly in section and partly in elevational view, as well as the frame beam supporting the mowing means located thereunder. Figure 4 shows on a larger scale a view of a part of the machine illustrated in Figure 2, according to the arrow IV in Figure 2. Figure 5 shows a side elevational view of Figure 4, partly in section. Figure 6 shows a plan view of Figure 5. The mowing machine illustrated in Figures 1 and 2 has an attachment block 1 of a usual construction, by means of which the machine can be coupled to e.g. the three-point hitch of a tractor. Near its centre a frame beam 2 is pivotable with respect to the headstock 1 about a horizontal pivot pin extending perpendicularly to the longitudinal axis of the frame beam 2, by means of a hinge construction 3 engaging one end of the frame beam 12. The other end of the frame beam 12 is secured to an upwardly extending frame part 4 of the mowing device. Said frame part 4 of the mowing device is furthermore coupled, by means of a rod mechanism 5, to the upper end of the hinge construction 3. The frame part 4, with the further parts secured thereto to be described in more detail hereafter, can be pivoted rearwards with respect to the headstock 1 for moving the mowing machine from an operating position into a transport position. To the lower end of the frame part 4 there is secured a hollow frame beam 6, which is provided with a profiled bottom plate 7 and with an upper plate 8. During normal operation said hollow frame beam extends in a usual manner transversely to the intended direction of movement according to arrow A (Figure 2). Said frame beam 6 is used to support a plurality of mowing means 9 arranged side by side in a usual manner. As is apparent in particular from Figure 3 each mowing means is provided with a dish-shaped plate 9', to the outer circumferenence of which there are coupled cutting knives 11 by means of hinge pins 10. Said cutting knives 11 are usually made of a strip-shaped material, whilst the parts of the knives projecting beyond the outer circumference of the dish 9' during normal operation are twisted about their longitudinal axis in a usual manner, so that the knives have a certain lifting effect on the cut-off crop. The dish-shaped means 9' is clamped on the hub 13 of a pulley 14 by means of bolts 12. Said pulley 14 is journalled, by means of bearings 15 accommodated in a bore of said hub 13, on a stub 16. Said stub 16 is at its lower side provided with a flange 16' being integral therewith, which flange 16' is welded on the bottom plate 7 of the frame beam 6. The bearings 15 are secured against displacement relative to the hub 13 by means of a projecting collar 17 provided at the lower side of the hub and being integral therewith, and by means of a spring washer 18 located above the two bearings which is placed in a groove provided in the hub. Furthermore the inner rings of the ball bearings 15 are confined between a shoulder of the stepped lower end of the stub 16 and a retaining ring 19 located on top of the inner ring of the upper bearing 15, said retaining ring 19 being secured to the stub 16 by means of a bolt 20. As furthermore appears from Figure 3 the upper part of the pulley 14 projects beyond the frame beam 6. For this purpose a hole 21 is provided in the upper plate 8, the diameter of said hole 21 being only slightly larger than the external diameter of the upper part of the pulley 14. As is furthermore diagrammatically indicated in Figure 2 the pulleys 14 of the mowing means 9 located side by side are coupled together by means of a belt 22, which is passed over the various pulleys in a manner known per se, such that mowing means located side by side can rotate in opposite directions in a usual manner. As is furthermore diagrammatically indicated by means of dotted lines in Figure 3 a drum-shaped means 9'' may furthermore be secured to one or more of the mowing means. As is furthermore indicated in Figure 3 the central axes of the stubs 16, and therewith also the axes of rotation 23 of the mowing means 9, are arranged in such a manner that said axes of rotation slope upward and forward during normal operation, usually at an angle of ± 5° with respect to the vertical. With the usual mowing devices the axes of rotation 23 of the mowing means are thereby located in vertical planes which extend perpendicularly to the longitudinal direction of the frame beam 6 supporting the mowing means or, put differently, parallel to the intended direction of movement according to arrow A, so that the parts of the mowing means illustrated in section in Figure 1 are arranged horizontally. As is illustrated in Figure 1, however, the axes of rotation 23 of the mowing means also include an angle with a plane extending vertically and parallel to the direction of movement, whereby all axes of rotation extend obliquely upwards and parallel to each other, when seen in the direction of movement. In general said angle will be between 2° and 4°, and in order to give an idea it may be noted that for example with a centre distance between the discs of 39 cm the angle will preferably be 3°. With a larger centre distance said angle will become smaller and with a smaller centre distance said angle will become larger, in order to achieve that the crop is cut as optimally as possible. As is furthermore illustrated in the Figures 4 - 6 the end of a shaft 25 projecting from the gear box is secured to the mowing means located furthest to the right, seen in Figures 1 and 2, by means of a bush 24 fixed to the dish 9 of said mowing means. Said outgoing shaft 25 is connected, by means of a right-angled gear transmission located in the gear box 26, with an ingoing shaft 27 of the gear box. Said ingoing shaft 27 carries a pulley 28, which is coupled, by means of one or more belts 29 diagrammatically indicated in Figure 1, to a pulley 30, which is secured to a shaft 31 supported by the beam 2. Said shaft 31 can for example be coupled in a usual manner to the power take-off shaft of a tractor or the like. To the gear box 26 located above the mowing means located furthest to the right, seen in Figure 1, there is furthermore secured a rearwardly extending arm 32 by means of bolts 33. To the frame part 4 there is secured an arm 34 exending parallel to the arm 32 and being located under the arm 32. To the arm 34 there are secured a pair of upwardly extending pins 35 and 36, which are accommodated with some play in holes provided in the arm 32 for that purpose. As is apparent from Figure 5 said pin 36 is thereby located near the centre of the pulley 28, when seen in a direction perpendicular to the axis of rotation of the ingoing shaft 27 of the gear box 26, whilst said pin 35 is located near the frame beam 4, at the side of the pin 36 remote from the gear box. By using this construction the outgoing shaft 25 of the gear box can be connected to the mowing means located furthest to the right, seen in Figures 1 and 2. The gear box 26 is thereby supported via the bearings of the mowing means in question located under the gear box. Said mowing means will be journalled in the frame beam 6 by means of a so-called suspension bearing 38, which allows a certain pivoting of the mowing means relative to the frame beam 6. Forces exerted by the belt transmission 28, 29, 30 on the ingoing shaft, and therewith on the gear box 26, are taken up by means of the arm 32 secured to the gear box and by the ends of the pins 35 and 36 inserted into said arm and transmitted to the frame part 4. The arm 32 can thereby make a limited tilting movement in two directions relative to the frame part 4, viz. in the plane of the drawing of Figure 5 and in the plane of the drawing of Figure 6, about a pivot point near the pin 36.

Claims: Mowing machine provided with a frame having a hollow frame beam (6) and with a plurality of mowing means (9) supported by said frame beam (6), which mowing means (9) are rotatable about axes of rotation (23) extending upwardly and parallel to each other and which can be driven by means of a driving belt (22) provided in said frame beam (6) and pulleys (14), located in said frame beam (6), which are coupled to said mowing means (9), characterized in that the axes of rotation (23) of the mowing means (9) slope upwards during operation, when seen in the intended direction of movement (A), relative to a vertical plane extending in the direction of movement (A). Mowing machine according to claim 1, characterized in that the axes of rotation (23) include an angle between 2° and 4° with a vertical plane extending in the direction of movement (A). Mowing machine according to claim 1 or 2, characterized in that the angle which an axis of rotation (23) of a mowing means (9) includes with a vertical plane extending in the direction of movement (A) is ± 3°. Mowing machine according any preceding claim, characterized in that stubs (16) are secured to a bottom plate (7) of the frame beam (6), on each of which stubs (16) there is journalled, by means of bearings (15), a pulley (14) secured to a mowing means (9). Mowing machine according to any preceding claim, characterized in that the upper end of a pulley (14) projects through a hole (21) provided in an upper plate (8) of the frame beam (6), the diameter of said hole (21) being slightly larger than the external diameter of the upper part of the pulley (14). Mowing machine according to any preceding claim, characterized in that a pulley (14) has been provided with a hub (13), at the upper side of which there is secured a dish-shaped means (9') to the outer circumference of which there are secured cutting knives (11). Mowing machine according to any preceding claim, characterized in that a mowing means (9) arranged near one end of the mowing machine is coupled to an outgoing shaft (25) of a gear box (26) arranged thereabove, and an ingoing shaft (27) of said gear box has been provided with a pulley (28), which forms part of a belt transmission to be coupled to the power take off shaft of a tractor or the like, whereby the outgoing shaft (25) of the gear box (26) is fixed to the mowing means (9) and an arm (32) is secured to the gear box (26), which arm (32) is coupled to the frame in two points (35, 36) spaced from each by some distance, in such a manner that the arm (32) can make a limited tilting movement in two directions with respect to the frame. Mowing machine according to claim 7, characterized in that a second arm (34), extending under and parallel to the arm (32) secured to the gear box (26), is secured to the frame, said second arm (34) being provided with pins (35, 36) extending perpendicularly to the longitudinal direction of said arms (32, 34) and being spaced from each other, the upper ends of said pins (35, 36) being accommodated with some play in holes which are provided in the arm (32) that is secured to the gear box (26). Mowing machine according to claim 8, characterized in that one of said pins (36) is located near the centre of the pulley (28) secured to the ingoing shaft (27) of the gear box (26), when seen in a direction perpendicularly to the longitudinal axis of the ingoing shaft (27) of the gear box (26), whilst the other pin (35) is arranged at the side of the former pin (36) remote from the gear box (26).

Inventors: QUATAERT, PETRUS MARIA
Applicants: GREENLAND GELDROP B.V.
Application year: 1990
Main classification: A01D34
IPC codes: A01D34