GB2059236A

GB2059236A - Mowing machine

Info

Publication number: GB2059236A
Application number: GB8030644A
Authority: GB
Original assignee: C Van der Lely NV
Current assignee: C Van der Lely NV
Priority date: 1979-09-26
Filing date: 1980-09-23
Publication date: 1981-04-23
Also published as: DE3035961C2; DE3035961A1; NL177375C; GB2059236B; FR2465402B1; NL177375B; FR2465402A1; NL7907139A

Abstract

A mowing machine comprises a cutter bar which can be hitched to a tractor (3). The cutter bar comprises a frame portion (6) carrying cutting units (7). The frame portion (6) is made up of sections (20) which enable simple replacement of damaged cutting units (7). The sections (20) are clamped together by tie members (29, 30, Figure 6 (not shown)), which extend the length of the frame portion (6). The frame portion (6) accommodates drive gear for the cutting members (7), this drive gear including a shaft made up of several lengths, corresponding to the sections (20). <IMAGE>

Description

SPECIFICATION A mowing machine This invention relates to a mowing machine.

According to the present invention there is provided a mowing machine comprising a plurality of rotary cutting units which are drivable about upwardly extending axes, a frame portion being provided beneath the cutting units, the frame portion being made up of a plurality of sections connected to one another side by side to provide a single structure which accommodates drive gear of the machine, each section being provided with at least one ofthe cutting units.

An embodiment of the present invention can be manufactured and assembled in a simple manner.

The sections may be located with respect to one another by locating collars, and bearings may be mounted in the sections to centre the sections with respect to a drive shaft.

A construction in accordance with the present invention provides a light-weight but rigid cutter bar, the parts of which can be simply and readily replaced or supplemented. Further advantages are that matching the cutting units to one another can be simple and that the machine can withstand collisions with obstacles.

Since the cutting units can be driven with high speed, the construction may be additionally light in weight, whilst with the efficient structure of a cover provided on the cutting units the crop can be effectively conducted away. Moreover, the blades of the cutting units can be exchanged in a simple manner.

For a better understanding of the present inven- tion and to show how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure lisa plan view of a mowing machine; Figure 2 is an enlarged plan view of part of the mowing machine of Figure 1; Figure 3 is a partly sectioned view taken on the line Ill-Ill in Figure 2; Figure 4 is a view taken on the line IV-IV in Figure 3; Figure 5 is a partly sectioned view taken on the line V-V in Figure 1, showing a wrench for use in removing parts ofthe machine; Figure 6 is a partly sectioned view taken on the line VI-VI in Figure 1 on the scale of Figure 2; Figure 7 is a view in the direction of the arrow VII in Figure 1 on the scale of Figure 2;; Figure 8 is a partial view in the direction of the arrow VIII in Figure 1 on the scale of Figure 2; Figure 9 is a view in the direction ofthe arrow IX in Figure 8; and Figure 10 is a sectional view corresponding to Figure 6, showing a further component.

The mowing machine shown in the Figures comprises a three-point trestle 1 for hitching the machine on the three-point lifting device 2 of a tractor 3. There is a frame portion 4 fastened to the three-point trestle 1, extending transversely of the normal forward direction of travel ofthetractor, indicated by an arrow A. The portion 4 is connected to a frame portion 6 by an upwardly extending gearbox 5 which is part of the frame portion 6 (see Figure 8). The frame portion 6 carries in this embodiment twelve cutting units 7. The frame portion 6 is pivotable relatively to the frame portion 4 about a horizontal axis 8 extending in the direction A.

The machine may be used in conjunction with any known arrangement for coupling the frame portion 4 to the lifting device 2 of the tractor. It is, however, important that the frame portion 6 should be pivotable about a horizontal axis 8 during operation. An example of a suitable coupling arrangement is given in our Dutch Patent Application 7605371 (British Patent Application No. 21004/77).

A horizontal shaft 9 extends into the gearbox 5 and a bevel pinion 10 (Figure 8) is mounted on the shaft 9 in the gearbox. The shaft 9 is also provided with a pulley 11 located outside the gearbox. A shaft mounted in the frame portion 4 is connectable with the power take-off shaft of the tractor and is provided with a pulley 12. The pulleys 11 and 12 are drivably connected to one another by a belt transmission 13. The bevel pinion 10 in the gearbox 5 meshes with a bevel pinion 14, which is mounted on a shaft 15 extending transversely of the direction A.

The shaft 15 carries a pinion 16, which meshes with a pinion 17. The pinion 17, in turn, engages a further pinion 18 located beneath it. The pinion 18 is mounted on a drive shaft 19 supported in the frame portion 6. The frame portion 6 is made up of six cast iron sections 20. Figure 2 shows one of the sections 20 on an larger scale. In this embodiment each section 20 carries two cutting units 7, which are driven in opposite senses as is indicated by arrows B. The section 20 has three hollow spaces extending transversely of the direction A. The middle hollow space 21 accommodates drive gear for the cutting units 7.

The front hollow space comprises a bore 22, and the rear hollow space 23 has partitions with bores. The sections 20 meet one another in the region of the middle hollow space 21.

At the front, with respect to the direction A, the section 20 has two arcuate portions 24. These arcuate portions each subtend an angle of about 140 (see Figures 2 and 4).

There are two openings 25 in the top of the section 20, through which extend drive shafts ofthe cutting units 7, as will be described later in this description.

In this embodiment, as shown in Figure 7, the centre line l-l of each opening 25 is at an angle of 80" in the horizontal. The arcuate portions 24 are each supported from beneath by a forwardly protruding part 26 of the section 20 (Figure 6), through which the bore 22 extends. At the rear, each section 20 has three bosses 27 in which there are tapped holes 28. If desired, these bosses may be used for fixing skids, as will be described later in this description.

Two of the bosses are at the ends of each section 20, the third being in the middle of each section. The sections 20 are held together side by side by two tie members 29 and 30 which extend transversely of the direction A. The tie member 29 is a rod, and passes through the bores 22, while the tie member 30 is a tube, and passes through the hollow spaces 23 of all of the sections. The two tie members have screwt hreads at their ends for receiving nuts such as nuts 31 and 32 (see Figures 7 and 9). By tightening the nuts 31 and 32, the sections can be clamped to one another to make the frame portion 6. It will be obvious that this enables cutter beams of different lengths to be constructed without difficulty by fixing together the desired number of sections 20. It also makes the repair of a cutter beam a simple operation, performed by replacing the or each damaged or defective section.

The tube 30 preferably has a considerably larger diameter than the rod 29 so that the tube 30, which is located at the rear, can absorb a significantly greater proportion of the stress of the frame portion 6. In this embodiment the diameter of the tube 30 is about 2.5-times that of the rod 29.

The tie members 29 and 30 are preferably the same height as each other above the ground. The tube 30 is further from the centre line I-I than the rod 29. In the embodiment illustrated, the tube is about twice as far from the centre line I-I as the rod 29.

Like the frame portion 6, the drive shaft 19 is made up of several sections (Figure 3). Thus the drive shaft 19 comprises a plurality of lengths 33 located in the sections 20. Each length 33 is provided at its end regions with splined portions 34, smooth cylindrical portions 35 of slightly smaller diameter than the portions 34, and portions 36 having further splines 36.

Bevel pinions 37 are fitted on the splined portions 34.

The lengths 33 are supported by oil-sealed bearings 38, which are located between the portions 35 and the inner wall of the hollow space 21. The lengths 33 are interconnected by tubular sleeves 39, which have internallysplined end portions receiving the portions 36 of the lengths 33.

Locating collars 40 are fitted in the space 21 at the interfaces between adjacent sections 20. These collars 40 and the bearings 38 in the sections 20 serve to centre the sections to each other. All of the spaces 21 together constitute a closed chamber for containing lubricant. The end most sections of the frame each have, at their outer ends, a wall through which the drive shaft 19 passes.

An upwardly projecting, cylindrical spigot 41 surrounds each opening 25 of each section 20. Each spigot accommodates two ball bearings 42 supporting drive shaft 43. The lower end of each shaft 43 is provided with a bevel pinion 44, which meshes with a respective one of the bevel pinions 37 on the shaft 19. Towards the top end of each shaft 43 there are splines 45 for receiving a body 46 of the respective cutting unit 7.

The body 46 comprises a flange 47 which is parallel to the top surface of the section 20. The periphery of the flange comprises two arcuate portions interconnected by two straight sides. These arcuate portions have rims 48 projecting downwardly towards the section 20. These arcuate rims 48 extend in to a circular groove 49 in the top surface ofthe section 20. The body 46 comprises a second flange 50, which is parallel to the flange 47 and which has a similarly shaped periphery. The flange 50 is connected to a cylindrical part 51 of the body 46. The flanges 47 and 50 have aligned openings 52 and 53 respectively. At the top, the cylindrical part 51 has an opening 54 with internal splines engaging those of the shaft 43 to transmit drive to the body 46 from the shaft 43. On the top side, around the opening 54, the body 46 is provided with an upwardly extending rim 55.A cover 56 is mounted over the top of the body 46. The cover 56 has an opening 57 for receiving the rim 55 and has a downwardly directed wall 58 surrounding the periphery of the flange 50 with a small clearance to inhibit the entry of foreign matter. The cover 56 has furthermore an annular channel 59 so that the cover can be considered to be approximately M-shaped (see Figure 5). A nut 60 secures the cover and the body 46 to the shaft 43.

A ring 61 having a flange 62 bearing on the flange 50 is positioned around the cylindrical part 51 of the body 46. The openings 52 and 53 of the flanges 47 and 50 receive pins 63 having a peripheral groove 64 at the top end. The flange 62 has two arcuate recesses 65, the dimensions of which are such that the edge of a recess just fits in a groove of a pin 63. A spring 66 arranged between the flange 62 and the top wall of the annular channel 59 of the cover pres seethe ring 61 againstthe flange 50.

The cutting unit 7 comprises blades 67 each having an aperture 68 through which passes the pin 63.

The outer ends of the blades 67 project freely, in this case, radially outwardly during operation, the inner ends 69 being located in a groove 70 in the body. The blades are freely pivotable about the pins 63 and have cutting edges 71. In this embodiment the length of each blade is substantially the same as the distance between the pins 63 and the cutting circle of the two diametrically opposite knives is smaller than 26 cms, preferably 22 cms: The distance between the two pins 63 of each cutting unit 7 is in this embodiment 9 cms and the rotational speed ofthe cutting unit is higher than 6000 RPM and in this embodiment it is 8000 RPM. The blades 67 cut with a scything action, without requiring any cooperating member to provide a shearing action.

From Figure 2 it can be seen that the cover 56 has a periphery formed by two straight sides 72 and two arcuate portions 73 subtending in this embodiment, an angle of 1000 at the axis of the shaft 43. The same applies to the periphery of the flange 50. The length of the blades and the dimensions of the body 46 are such that the blades extend to a position close to the flat sides 72 of the cover of the adjacent cutting unit.

As illustrated in Figure 2 the blades of adjacent cutting units 7 are arranged with a phase difference of 90".

The flange 50 has two small apertures 74 which are located respectively to the side of the openings 53 and which are covered at least partly by the flange 62 of the ring 61. These apertures can be used for replacing the blades as will be described more fully later in this description.

At the end nearer the tractor, the frame portion 6 has a skid 75, which is fastened to the gearbox 5 by a bolt 7qSand a pin 77. The gearbox 5 has two supports 78 and 79 extending upwards and rearwards respectively (see also Figures 1 and 6). If desired, the mowing machine may be provided with more skids, as will be described with reference to Figure 10.

At the end away from the tractor, the mowing machine has a swath board 80. Above the machine there is a protective cover 81 which is fastened to a carrier 82 extending horizontally above the cutter bar (Figure 1). The carrier 82 is secured by a support 83 to the gearbox 5 and extends horizontally above the frame portion 6. It is supported only by the support 83. The screen is substantially rectangular on plan and provides protection for the user and any other people in the vicinity, for example from stones which may be thrown up by the cutting units.

An accessory ofthe mowing machine is a wrench 84 as shown in Figure 5. The wrench 84 has a handle 85 to which is welded, via an intermediate piece 87, a curved finger 86. The wrench also has a hooked part 88, which is pivotally connected to the handle 85 by a pin 89. The hooked part 88 is shaped such that its end 90 fits in the groove 70 and a portion 91 can then bear on the cover 56, with the finger 86 inserted into one of the openings 74 of the flange 50 (Figure 5).

When the handle 85 is pressed down, the pin 86 will push the ring 61 upwards against the pressure of the spring 66 so that the pin 63 located neartheaperture 74 is drawn upwardly. The pin is thus released from the opening 68 in the respective blade 67, which can then be replaced by a new one, if desired. Figure 5, which does not show the blade 67, shows the operation for replacing the blade on the right-hand side of the cutting unit. If the other blade is to be replaced, the finger 86 has, of course, to be passed through the other aperture 74 of the flange 50.

The mowing machine described above has the advantage of simple manufacture and, even if the front of the machine collides with an obstancle, the rugged construction prevents damage of the cutter bar.

A further advantage is that the tube 30 located in a closed space does not come into contact with impurities, and so it need not be made from a special steel. The uninterrupted rod 29 is primarily exposed to a tensile force and contributes to the firm fastening of the sections 20 to one another. The cover 43 is shaped so that the crop can be rapidly conducted away from it. If desired, the shape of the cover may further approach the elliptical form.

As shown in Figure 10, one or more skids 92, in addition to the skid 75, may be provided. The skid 92 is made from sheet metal and is mounted at the front on a portion of the rod 29 extending between two adjacent projecting portions 26. At the rear, the skid 92 is secured to the section 20 by a bolt screwed into the tapped hole in one of the bosses 27. The skids 92 are simply and inexpensively replaced if they become worn or damaged, and provide protection against wear for the more expensive sections 20.

Whilst various features of the mowing machine that have been described, and that are illustrated in the drawings, will be set forth in the following claims as inventive freatures, it is to be noted that the invention is not necessarily limited to these features and that is encompasses all of the features that have been described both individually and in various combinations.

Claims

1. A mowing machine comprising a plurality of rotary cutting units which are drivable about upwardly extending axes, a frame portion being provided beneath the cutting units, the frame portion being made up of a plurality of sections connected to one another side by side to provide a single structure which accommodates drive gear of the machine, each section being provided with at least one of the cutting units.

2. A mowing machine as claimed in claim 1, in which the sections are fastened to one another by at least one tie member extending lengthwise of the frame portion.

3. A mowing machine as claimed in claim 2, in which the sections are fastened to one another by two tie members extending lengthwise of the frame portion.

4. A mowing machine as claimed in claim 3, in which one of the tie members is disposed near the front and the other near of the frame portion, with respect to the intended direction of operative travel ofthe machine.

5. A mowing machine as clamed in claim 4, in which there is a space in the frame portion for the drive gear of the cutting units, this space being disposed between the two tie members.

6. A mowing machine as claimed in claim 5, in which the trailing tie member is further from the space accommodating the drive gear than the leading tie member.

7. A mowing machine as claimed in any one of claims 4 to 6, in which the trailing tie member has a larger diameter than the leading tie member.

8. A mowing machine as claimed in any one of claims 3 to 7, in which the tie members comprise rod or tube.

9. A mowing machine as claimed in claim 8 when appendantto claim 4, in which the leading tie member comprises a rod and the trailing member a tube.

10. A mowing machine as claimed in any one of claims 2 to 9, in which the or each tie member is provided with at least one nut at the outer end of the frame portion for clamping the sections to one another

11. A mowing machine as claimed in any one of the preceding claims, in which the end most sections of the frame portion each have a space for the drive gear, this space being closed at one end of the respective section.

12. A mowing machine as claimed in any one of the preceding claims, in which the sections are each provided with two upwardly extending shafts of contra-rotating cutting units.

13. A mowing machine as claimed in any one of the preceding claims, in which the drive gear comprises a drive shaft made up of a plurality of lengths, each length being lightly shorter than that ofthe respective section.

14. A mowing machine as claimed in claim 13, in which the lengths are interconnected by tubular sleeves.

15. A mowing machine as claimed in claim 13 or 14, in which each length is supported adjacent its ends in bearings mounted in the respective section.

16. A mowing machine as claimed in any one of the preceding claims in which the leading edge of each section, with respect to the intended direction of operative travel of the machine, comprises two arcuate portions.

17. A mowing machine as claimed in any one of the preceding claims, in which the upper surface of each section has a substantially flat part disposed beneath each cutting unit.

18. A mowing machine as claimed in claim 17, in which each flat part has a circular groove which is centred on the rotary axis of the respective cutting unit.

19. A mowing machine as claimed in any one of the preceding claims, in which the sections are located one with another by locating collars.

20. A mowing machine as claimed in any one of the preceding claims, in which each cutting unit is provided with a protective cover in the upper region of the cutting unit.

21. A mowing machine as claimed in any one of the preceding claims, in which each cutting unit comprises a shaft on which is arranged a body which comprises two flanges and which is provided with at least one blade.

22. A mowing machine as claimed in claim 21, in which the blade is disposed between the flanges and is connected to the body by a pin which passes through aligned openings in the flanges.

23. A mowing machine as claimed in claim 22, when appendant to claim 20, in which the upper end region of each pin has a groove receiving a ring located on the flange, the ring being pressed against the flange by a spring arranged between the cover and the ring.

24. A mowing machine as claimed in claim 22 or 23, in which the upper flange has an aperture located beneath the ring near each opening for a pin.

25. A mowing machine as claimed in claim 24, in which a wrench is provided for use in removing the blades.

26. A mowing machine as claimed in claim 25, in which the wrench comprises a hook adapted to fit over the cover, and a pin adapted to fit in one of the apertures, with part of the wrench bearing on the cover.

27. A mowing machine substantially as described herein with reference to and as shown in the accompanying drawings.

28. A wrench intended for use with a mowing machine in accordance with any one of the preceding claims, claimed by the invention.