AU5356799A

AU5356799A - Cutting blades

Info

Publication number: AU5356799A
Application number: AU53567/99A
Authority: AU
Inventors: Not Given Name
Original assignee: Ingersoll Argentina SA
Current assignee: Ingersoll Argentina SA
Priority date: 1998-10-08
Filing date: 1999-10-08
Publication date: 2000-04-13

Description

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AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): INGERSOLL ARGENTINA SA

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55 S. Invention Title: CUTTING BLADES The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 Cutting Blades This invention relates to cutting blades for sugar cane harvesters and also relates to an improved sugar cane harvester.

Sugar cane harvesters have a well known problem associated with the quality of cut delivered by the cutting blade. The cutting blades are rectangular in shape and have sharpened edges on the long sides of the blade.

Multiple blades are mounted on turrets on the harvester which rotate about vertical axes. Rotation of the turrets causes the blades to cut through plants while the harvester moves in a forward direction. The problem with typical cutting blades is that the blunt, short ends of the blades reduce the quality of the cut as the blade moves through the plants. A poor cut leaves an uneven stem which causes poor regrowth and makes the plant more susceptible to a variety of diseases. Yet another problem is that the blunt ends have the effect of beating and shaking the plants.

This causes the roots to be loosened which delays shooting for next year's crop and, in extreme situations, can cause the root structure to dry up thus killing the plant. It has also been found that conventional cutting blades on S 25 most sugar cane harvesters wear very quickly and have a short working life requiring regular servicing.

.9 9. It is thus perceived that there is a need for an improved cutting blade and a sugar cane harvester that provides a clean cut to plants and has blades that remain sharp and effective for long periods.

According to one aspect of the present invention there is provided a blade for a sugar cane harvester, the blade being fabricated in toughened steel to be rectangular in plan with bevelled peripheral edges defining two longer and two shorter cutting edges, and means to facilitate \\melbf iles\home$\Monique\Keep\speci\P3 572 7 .doc 08/10/99 3 attachment to a support surface.

In one embodiment the bevelled edge may be provided on one side of the blade and in a further embodiment the bevelled edge may be symmetrically positioned on opposite sides of the blade and in a third embodiment the bevelled edge may be asymmetrically positioned on opposite sides of the blade.

The means to facilitate attachment to a support surface preferably comprises an array of apertures arranged centrally of the blade.

According to a further aspect of the present invention there is provided a sugar cane harvester comprising a forwardly mounted cutting head in the form of at least two turrets each mounted to rotate about a vertical axis with the lower end defining a rotating support surface, a plurality of cutting blades of the kind described above being detachably secured in a spaced array to each support surface to project radially to define cutting edges projecting radially from the support surfaces.

25 Preferably the path of the cutting edges of the blades of one turret cross the path of the cutting blades of the adjacent turret. In a preferred embodiment the turrets are arranged to rotate in opposite directions.

An embodiment of the present invention will know be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a schematic side elevation showing the cutting head of a sugar cane harvester in cutting position against sugar cane, \\melbfiles\hoe$\Moniue\Keep\peci\P3 5 7 2 7 .doc 08/10/99 4 Figure 2 is an underside view of the cutting head, Figure 3 is a plan view of a cutting blade, Figure 4 is a sectional view taken along the lines V-V of Figure 3, Figure 5 is a sectional view taken along the lines IV-IV of Figure 3, and Figures 6, 7 and 8 are fragmentary views illustrating a variety of cutting blade profiles.

As shown in the accompanying drawings a cutting head 10 of a sugar cane harvester comprises a pair of frustoconical turrets 11, 12 that are mounted spaced apart with their axes extending vertical. The underside of each turret 11, 12 supports a circular plate 20 and the turrets 11, 12 are driven to rotate about the vertical axis X-X in either direction. The underside of the plates support a plurality of radial extending cutting blades In the preferred embodiment five cutting blades 30 are positioned equally spaced around the periphery of the underside of the plate 20 to extend radially outwardly so that approximately 30% of the blade projects outside the periphery of the plate. Each blade 30 is secured to the plate by location of one or more bolts that extend through holes 31 in the blade and corresponding holes in the plate.

Suitable locktight nut and bolt assemblies (not shown) will be used to secure the blades 30 to the plate 20. It is also understood that the plate 20 could be designed to provide a rabbet to locate each blade.

As shown in Figure 1 the turrets 11, 12 are positioned so that the cutting blade 30 of each turret 11, \\melb_f iles\home$\Monique\Keep\speci\P 35727 .doc 08/10/99 5 12 extends outwardly to cross the path of the cutting blades of the adjacent turret. In Figure 1 a raised furrow Z supports a clump of sugar cane C having a root structure R. It should be noted that the cutting blade 30 contacts the cane C very close to a position where the cane C extends out of the furrow Z.

The cutting blade 30 is shown in detail with reference to Figures 3 to 8. The blade 30 is constructed of toughened steel, such as boron-type steel, and is of a rectangular shape as shown in Figure 3. The blade defines an upper surface 21 a lower surface 32, longer sides 33, 34 and shorter sides 35, 36.

A bevelled edge 40 is furnished around the periphery of the blade and may assume a number of profiles Ssuch as a 450 edge on one side as shown in Figure 6, a split bevelled edge on both sides as shown in Figure 7 and an asymmetric split bevelled edge shown in Figure 8. The bevelled edge 40 is sharpened throughout its periphery so that is can be turned through 1800 so that both ends can be used as a cutting surface. It is for this reason that a array of four equally spaced bolt holes 45, 46, 47, 48 are provided along the centre of the blade Figure 2 shows the positioning and orientation of the blade plates 20 and the associated blades 30 and o *demonstrates how the blades of one plate cross through the path of the blades of the adjacent plate. It should also be noted that the array of blades 30 on each plate 20 are spaced in a manner that they do not foul each other.

The direction of rotation of the respective blade plates is reversed so that the left hand turret 11 as shown in Figure 2 rotates in a clockwise direction whilst the right hand turret 12 rotates in an anti-clockwise direction. The forward direction of the harvester 10 is \\mnebf ieshome\Monrie\Keep\spei \F3$? 27 .oc 09/10/99 6 shown by the arrow F. It can thus be seen that the blades provide a high density of cutting strokes to a particular cane.

The cutting edges of the blades are defined by both the forward, leading edge of the bevelled longer sides 33 and the bevelled edge of the short side 35. In operation a stem directly in the path of the longer, leading side of a blade is cut clean. However, stems out of reach of the leading side of the blade 33 come into contact with the sharp short side 35 as the harvester moves forward. Thus, rather than knocking and damaging the stem the bevelled short side 35 delivers a clear cut.

Together, the longer, leading side and the short side ensure a continuous cutting path which is followed through by the next blade.

Once the blade becomes worn the blade can be simply removed by removing the bolts and then turning the blades through 1800 so that the other end defines a new cutting edge. It is also understood that the blades can be serviced to re-sharpen the edges. It has been found that the edge geometry of the blades described above provides a very efficient and clean cut whilst leaving the blades in S 25 an effective sharpened condition for a long period. Tests have indicated that stem cuts by the blade produce a healthier and faster regrowth of sugar cane. Further, it has been found the cutting edge of the blade is still satisfactory after cutting 35 hectares of cane.

The blades and their operation provide a better quality of cut cane, less damage to the remaining plant and substantially reduces the down time and servicing that operators of such equipment usually encounter. The plants are healthier and are less prone to shaking and becoming loosened in the soil. The overall efficiency and in long term output of a sugar cane crop is thus enhanced by a \\melb_ files\home\Monique\Keep\speci\P3572 7 .doc 08/10/99 7 mechanical harvester incorporating the blades of the blades discussed above.

It will be understood to persons skilled in the art of the invention that many modifications may be made without departing from the spirit and scope of the invention.

For the purposes of this specification it will be clearly understood that the word "comprising" means "including but not limited to", and that the word "comprises" has a corresponding meaning.

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Claims

1. A blade for a sugar cane harvester, the blade being fabricated in toughened steel to be rectangular in plan with bevelled peripheral edges defining two longer and two shorter cutting edges, and means to facilitate attachment to a support surface.

2. The blade claimed in claim 1 wherein the bevelled edges are provided on one side of the blade.

3. The blade claimed in claim 2 wherein the bevelled edges are 450 edges on one side of the blade.

4. The blade claimed in claim 1 wherein the bevelled edges are provided symmetrically on opposite sides of the blade.

5. The blade claimed in claim 1 wherein the bevelled 20 edges are provided asymmetrically on opposite sides of the blade.

6. The blade claimed in any one of the preceding claims wherein the means to facilitate attachment to a 25 support surface comprises an array of apertures arranged centrally of the blade.

7. A sugar cane harvester comprising: a forwardly mounted cutting head in the form of at least two turrets each mounted to rotate about a vertical axis with the lower end defining a rotating support surface; a plurality of cutting blades, the blades being fabricated in toughened steel to be rectangular in plan with bevelled peripheral edges defining two longer and two shorter cutting edges, and means to facilitate attachment to the support surface; 7 2 7 .doc 08/10/99 9 wherein the cutting blades are detachably secured in a spaced array to each support surface to project radially to define cutting edges projecting radially from the support surfaces.

8. The sugar cane harvester claimed in claim 7 wherein the path of the cutting edges of the blades of one turret cross the path of the cutting blades of the adjacent turret.

9. The sugar cane harvester claimed in claim 7 or 8 wherein the turrets are arranged to rotate in opposite directions.

10. The sugar cane harvester claimed in any one of claims 7 to 9 wherein the blades radially project approximately 30% from the support surfaces.

11. A blade for a sugar cane harvester substantially 20 as herein described with reference to and as illustrated by the accompanying drawings.

12. A sugar cane harvester substantially as herein described with reference to and as illustrated by the 25 accompanying drawings. Dated this 8th day of October 1999 INGERSOLL ARGENTINA SA By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia 7 2 7 .doc 08/10/99