AU2004203845A1 - Sugar cane harvester - Google Patents

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "SUGAR CANE HARVESTER" The following statement is a full description of this invention, including the best method of performing it known to me: TITLE: SUGAR CANE HARVESTERS BACKGROUND OF THE INVENTION 1. Field of the Invention THIS INVENTION relates to sugar cane harvesters.

The invention particularly relates, but is not limited to, sugar cane harvesters capable of harvesting all types of sugar cane crops, eg., burnt or unburnt green), erect or lodged, under the varying field conditions found in the sugar cane growing countries of the world.

2. Prior Art Sugar cane harvesters have been produced by which the sugar cane is topped, cut at the base, and chopped into billets for delivery to a sugar mill to extract the sugar juice. The present applicant has been designing/developing sugar cane harvesters for many years and examples are described and illustrated in, inter alia, US 3,673,774 (MIZZI); US 4,194,344 (MIZZI) and AU 200022606 B2 (MIZZI).

A sugar cane harvester which has been widely used in Australia and overseas for many years has been sold under the "AUSTOFT 7000" Trade Marks. ("AUSTOFT" is an Australian Registered Trade Mark of Austoft Industries Limited, Bundaberg, Australia.) Tests have established that up to 25%, and in some extreme cases, up to 35%, by volume, of the harvested product delivered to the sugar mills, is trash cane leaf matter/grass/dirt/ other rubbish material). 10% by volume represents approximately 3% by weight of the harvested product. This trash material reduces the efficiency of the transport system (as more cane trucks are required than if the cane billets were clean), while reducing the quality of the sugar cane juice recovered at the mills (and thereby the quality of the final sugar products).

If the leaf matter, dirt and grass, were returned to the cane fields at harvesting, soil nutrient losses would be minimised and valuable topsoil would not be removed from the cane fields.

Sugar cane production losses further occur to the "crushing" or "squeezing" which the cane stalks undergo as they are cut into billets by the chopping cutters of existing harvesters.

Furthermore, the removal of the leaf matter trash from the billets by the trash extractors on known harvesters has not been optimised. (NB: This problem has been addressed by the invention entitled "TRASH EXTRACTORS FOR SUGAR CANE HARVESTERS" in copending Australian Patent Application 2004203478 (MIZZI).

SUMMARY OF THE PRESENT INVENTION It is an object of the present invention to provide a sugar cane harvester with one or more improved operating sections which will reduce (or minimise) the volume (or weight) of trash unseparated from the harvested cane billets.

It is a preferred object to provide such a harvester which minimises the loss of sugar cane juice from the cane during the harvesting procedure.

It is a further preferred object to provide a harvester suitable for double row operation which is more compact then existing harvesters.

It is a further preferred object to provide a harvester which minimises damage to the remaining stools and to the harvested field.

Other preferred objects will become apparent from the following description.

In one aspect, the present invention resides in a sugar cane harvester, capable of harvesting double rows of cane, of the type having a pair of pickup fronts, where each pickup front has lifting and separating spirals and base cutters; and wherein: a lifting tongue, intermediate the pickup fronts, directs cane stalks to be harvested to respective pickup fronts, the tongue being substantially triangular in plan view and hingedly mounted on at least one support arm or link.

Preferably, the or each support arm or link is hingedly or pivotally mounted on the harvester and is operable to raise or lower the lifting tongue relative to the pickup fronts.

Preferably, the lifting tongue is hingedly mounted on the or each support arm or link forwardly of its centre of gravity to enable a heel, or rearward end, of the lifting tongue to skim or pass over the ground as the harvester advances.

Preferably, a hydraulic ram selectively raises and lowers the or each support arm or link.

Preferably, a substantially vertical cutter saw is mounted in alignment with the longitudinal axis of the lifting tongue to cut any cane stalks and/or trash in its pathway as the cutter saw advances.

In a second aspect, the present invention resides in a wheel-mounted sugar cane harvester of the type having at least one pickup front with base cutters, so arranged that the base cutters are aligned with the front wheels to follow the soil contour therewith as the harvester advances.

In a third aspect, the present invention resides in a sugar cane harvester including: a plurality of transversely extending, longitudinally spaced, lower feed rollers to feed cut (and topped) sugar cane mass to a chopper assembly, the lower feed rollers being optionally square in end view; and a plurality of transversely extending, longitudinally spaced, upper feed rollers, spaced above, but forwardly of, respective lower feed rollers, to lift and agitate the cane mass to assist in the release of trash from the cane mass.

Preferably, the upper feed rollers are "floating".

Preferably, at least one reversing roller is provided between, but below the level of, at least one pair of lower feed rollers, and rotated in the opposite direction thereto, the or each reversing roller having flexible blades operable to strip trash from the cane mass, preferably due to a pinching action between the or each reversing roller and its associated pair of lower feed rollers.

Preferably, at least one stripping roller is provided between adjacent pairs of the top feed rollers, the or each stripping roller having a plurality of flexible bars, with a greater overall diameter, and rotated at a higher rotational speed, than the adjacent lower feed rollers, to strip trash from the cane mass.

In a fourth aspect, the present invention resides in a chopper assembly for a sugar cane harvester including: an upper chopper having a plurality of chopper blades operable to cut the cane stalks into billets, the or each chopper blade cooperating with ledger bars, on a lower chopper, to cut the stalks with a minimal "pinching" or "squashing" action.

Preferably, the upper chopper rotates at half the rotational speed of the lower chopper, and the tip speed of the chopper blades is identical to the peripheral speed of the ledger bars.

Preferably, the chopper blades do not come into physical contact with the ledger bars, for longer blade life and more efficient cutting of the cane stalks.

In a fifth aspect, the present invention resides in a sugar cane harvester including a plurality of transversely extending, carry rollers, operable to advance the chopper cane billets, and any trash, from the chopper assembly towards a primary trash extractor, the carry rollers preferably having overlapping toothed rings to agitate the cane billets to release trash therefrom, the carry rollers preferably being driven at higher rotational speeds in the advancing direction to separate the cane billets to assist trash removal.

Preferably, an impinging roller is provided above the carry rollers, preferably above the rearmost thereof, and upstream of the primary trash extractor.

Preferably, the impinging roller is of mesh-type construction to allow air being drawn into the primary trash extractor to hold trash onto the impinging rollers until the trash enters the primary trash extractor.

Preferably, the impinging roller also directs cane billets towards a separation chamber of the primary trash extractor.

Preferably, the primary trash extractor has air inlets forwardly of and/or above the ends of, the carry rollers.

In a sixth aspect, the present invention resides in an impinging roller, as hereinbefore described, for a sugar cane harvester.

In a seventh aspect, the present invention resides in a sugar cane harvester incorporating one or more of the first to sixth aspects.

BRIEF DESCRIPTION OF THE DRAWINGS To enable the invention to be fully understood, a preferred embodiment will now be described with reference to the accompanying drawings, in which: FIG. 1 is a schematic sectional side view of the harvester in accordance with the present invention; FIG. 2 is a schematic top plan view of the topper assembly; FIG. 3 is a side view thereof; FIG. 4 is a schematic top plan view of a two-row pickup front; FIG. 5 is a sectional view on line 5-5 on FIG. 4; FIG. 6 is a sectional side view of the rollers/chopper on a than in FIG. 1; FIG. 7 is a schematic sectional end view of the chopper larger scale assembly; and FIG.8 is a schematic top plan view of a single-row pickup front.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The cane harvester 10 is of the self-propelled type, but may be provided on a chassis towed by a suitable prime mover, eg, a tractor.

The chassis 11 is mounted on a pair of steerable front wheels 12 and a pair of rear wheels 13. The front and/or rear wheels may be driven by hydrostatic hub motors (not shown) selectively driven from a hydraulic pump 14 powered by a diesel) motor 15. NB: It will be readily apparent to the skilled addressee that the wheels 12, 13 may be replaced by continuous tracks.

Preferably, at least the front of the chassis 11 can be raised and lowered relative to the wheels 12 (and the ground level GL) via suspension units of the type disclosed in AU 200026602B2.

The operation of the harvester 10 is controlled from an operator's cabin 16, which is preferably air conditioned.

At the rear of the harvester 10, a primary trash extractor is mounted above the rearmost rollers (as to be hereinafter described) and a secondary trash extractor 30 is provided at the discharge end of a cane billet elevator 31. Preferably, both trash extractors 20, 30 are arranged in accordance with the trash extractors disclosed in Australian Patent Application 2004203478.

In the embodiment illustrated, the cane harvester 10 is designed to harvest double rows of cane (and as hereinafter described with reference to FIG. 4, this is possible even though the overall width of the harvester rearward of the pickup front is narrower than for existing double-row harvesting, and is approximately intermediate the widths of known single- and double-row harvesters).

The topper assembly 40 is mounted on two pairs of parallel arms 41, 42 (via a parallelogram mounting arrangement 43) and can be selectively raised and lowered by at least one hydraulic ram (not shown).

A pair of topper drums 44, 45, with peripheral cutting teeth 46, are rotatable about axles 47, 48 received and journalled in top and bottom topper plates 49, 50. The drums 44, 45 are driven by hydrostatic motors (not shown). A directional arm 51 is provided between the drums 44, 45 to co-operate with the base cutters 80 (to be hereinafter described) for positive directional feed of the upper ends of the cane stalks to the topper assembly 40 for removal of the cane tops.

Referring to FIGS. 4 and 5, the pickup fronts 60, 61 are designed to harvest double rows of cane. It will, however, be readily apparent to the skilled addressee that the pickup fronts 60, 61 can be designed for single row operation (see FIG. As the pickup fronts 61 are mirror-images, each are fitted with respective lifting and separating spirals 62, 63. The pickup fronts 60, 61 can be raised and lowered relative to the chassis 11 (and ground level GL) via links 64 and at least one hydraulic ram (not shown).

A lifting tongue 65 is mounted intermediate the pickup fronts 60, 61 and is substantially triangular in plan view see FIG. 4.

The lifting tongue 65 is mounted on a pair of links 66 pivotally mounted on a support member 67, the links 66 being selectively raised and lowered by a hydraulic ram 68. The mounting of the lifting tongue 65 on the links 66 is forward of its centre of gravity (C of G) so that the heel or trailing edge can engage the ground and the lifting tongue can "float" relative to the ground level. A vertical cutter saw 69 can cut tangled cane to allow it to pass through pickup fronts 60, 61.

As shown in more detail in FIG. 6, upper and lower knock down rollers 70, 71 in the pickup fronts 60, 61 tend to knock down the upper ends of the (topped) sugar cane stalks. The location of the two knock-down rollers 70, 71 is selected to direct erect or lodged cane to the throat of the harvester 10, while complementing the previous operation of the spirals 62, 63 and the following operation of the base cutters 80, to be hereinafter described, without breaking or pushing down erect cane prior to the base cutting operation.

The pairs of base cutters 80 are arranged substantially in alignment with the front axles for front wheels 12. This relative positioning of the base cutters 80 is sufficiently forward in the harvester to sever the cane at the base prior to any possibility of breaking or pushing down erect cane, thereby minimising/eliminating stool damage.

(Stool damage affects ratooning capacity.) The alignment of the base cutters 80 with the front wheels 12 greatly assists in maintaining the desired level of base cutting as the base cutters 80 and front wheels 12 closely follow the same level. This minimises any "scalping" or "crewcutting" of the remaining stools. "Scalping" can seriously affect the quality of the harvested cane (by increasing the volume of extraneous matter) and further ratooning of a particular field.

There are five lower feed rollers 90-94 provided at spaced intervals and on an upwardly directed path. The lower feed rollers 90-94 are substantially square in end view see FIG. 1 to agitate the cane mass as it is being fed to the chopper assembly 110 (to be hereinafter described). The agitation tends to shake out loose dirt and other rubbish, which can fall between the lower feed rollers 90-94.

There are three upper feed rollers 95-97. The upper feed rollers 95-97 can "float", and are spaced above, but just forwardly of the first, third and fifth lower feed rollers 90, 92, 94, respectively. Being slightly ahead of the respective lower feed rollers 90, 92, 94, the upper feed rollers 95-97 apply a desired lifting action to the cane mass.

A pair of reversing rollers 98 and 99 are provided between the third and fourth lower feed rollers 92, 93 and the fourth and fifth lower feed rollers 93, 94, respectively. They rotate in the reverse direction to the lower feed rollers 92-94 and are set at a lower level so as to not impede the feeding of the cane to the chopper. The reversing rollers 98, 99 are fitted with four flexible blades or bars, eg., made from industrial belting. The flexible bars can be of varying depths to reduce the overall diameter of the reversing rollers 98, 99; and some or all can be removed to suit the particular conditions. The bulk of the extraneous material is removed by the pinching action of the lower feed rollers 92-94 and the reversing rollers 98, 99.

There are two fixed stripping rollers 100, 101 above the second and fourth lower feed rollers 91, 93, respectively. Their purpose is to strip and loosen the upper layer of trash during feeding. They are each fitted with six flexible bars, with a much greater diameter than the corresponding lower feed rollers 91, 93, but are driven at the same rotational speed. The greater tip speed of the stripping rollers 100, 101, relative to the feeding speed, has a stripping action and further prepares the cane mass for cleaning after the chopper.

The chopper assembly 110 see FIG. 7 has an upper chopper 111 with a plurality of radially-directed chopper blades 112 and is of twice the diameter than the lower chopper 113, which carries the ledger bars 114.

Each chopper blade 112 is received in a slot 115 defined by a pair of adjacent ledger bars 114. The tip speed of the chopper blades 112 exactly matches the peripheral speed of the slots 115, as the lower chopper 113 rotates at twice the rotational speed of the upper chopper 111. The chopper blades 112 are adjustably mounted on the upper chopper 111 via offset adjustment blocks 116 which support the cutter blades 112 radially to the upper chopper 111. The chopper blades 112 never come into physical contact with the ledger bars 114, to both increase blade life and provide efficient cutting of the cane stalks into billets.

The operating relationship between the chopper blades 112 and the ledger bars 114 is set so that the chopper assembly 110 has a clean chopping action, with little "squashing" of the cane and thereby minimal subsequent loss of cane juice. The cylindrical lower chopper 113 also eliminates billet loss through recirculation.

Five carry rollers 120-124 are provided directly behind the chopper assembly 110 and are driven at progressively higher rotational speeds (from roller 120 to roller 124), to thin out the chopped cane mass and maintain an even cane flow for better separation. Extraneous dirt and mud can fall between carry rollers 120-124 and they also assist in billet/trash separation.

In addition, the carry rollers 120-124 also assist in the operation of the primary trash extractor 20, which begins to act on the chopped cane mass immediately it leaves the chopper assembly 110. The primary trash extractor 20 has a forward air intake 21 and side air intakes 22, and the incoming airflow over the chopped cane mass begins the trash separation from the billets. The carry rollers 120-124 are preferably provided with overlapping toothed rings to eliminate the buildup of trash about the carry rollers.

A cylindrical impinging roller 130, of mesh-type construction, and having a variable speed drive, is mounted above the last carry roller 124 and is designed to have air drawn through it by the primary trash extractor 20. Any trash drawn onto the impinging roller 130 will travel a short distance and then be lifted off the impinging roller 130 by the air flow into the primary trash extractor 20. The impinging roller 130 also directs the billets into the lower separating chamber 24 of the primary trash extractor 20. This action improves cane/trash separation, maximising trash extraction and minimising cane loss through the primary trash extractor.

The elevator 31 has a variable speed drive which can be adjusted to suit a particular crop.

With particular reference to FIG. 4, it will be noted that the "profile" of the double row harvester is tapered in top plan view. The cane cut from the two rows follows a converging path rearwardly of the base cutters 80 so that the lower and top feed rollers 91-94, top feed rollers 95-97 and subsequent sections of the harvester are narrower than for existing double row harvesters. Despite the more compact nature, the overall arrangement of the harvester results in improved trash extraction, and thereby a high quality harvested product. In addition to the lower trash content with the harvested billets, the higher quality handling/chopping of the cane (with less squashing) results in minimised sugar juice losses, further improving the value of the harvested cane.

FIG. 8 shows a schematic top plan view of a single-row harvester, in accordance with the present invention, where the reference numerals of equivalent components are increased by 200, c.f. FIG. 4.

For example, the spirals are identified by reference numerals 262, 263; and the base cutters by reference numeral 280. Preferably, the pickup front 260 will be 1.2m wide, where pickup fronts 60, 61 will be each 0.9m wide.

Various changes and modifications may be made to the embodiments described and illustrated without departing from the scope of the present invention defined in the appended claims.

DATED this twelfth day of August 2004.

JOSEPH MICHAEL MIZZI By his Patent Attorneys FISHER ADAMS KELLY

Claims (19)

1. A sugar cane harvester, capable of harvesting double rows of cane, of the type having a pair of pickup fronts, where each pickup front has lifting and separating spirals and base cutters; and wherein: a lifting tongue, intermediate the pickup fronts, directs cane stalks to be harvested to respective pickup fronts, the tongue being substantially triangular in plan view and hingedly mounted on at least one support arm or link.

2. A harvester as claimed in Claim 1 wherein: the or each support arm or link is hingedly or pivotally mounted on the harvester and is operable to raise or lower the lifting tongue relative to the pickup fronts; and the lifting tongue is hingedly mounted on the or each support arm or link forwardly of its centre of gravity to enable a heel, or rearward end, of the lifting tongue to skim or pass over the ground as the harvester advances.

3. A harvester as claimed in Claim 2 wherein: a hydraulic ram selectively raises and lowers the or each support arm or link.

4. A harvester as claimed in any one of Claims 1 to 3 wherein: a substantially vertical cutter saw is mounted in alignment with the longitudinal axis of the lifting tongue to cut any cane stalks and/or trash in its pathway as the cutter saw advances.

A wheel-mounted sugar cane harvester of the type having at least one pickup front with base cutters, so arranged that the base cutters are aligned with the front wheels to follow the soil contour therewith as the harvester advances.

6. A sugar cane harvester including: a plurality of transversely extending, longitudinally spaced, lower feed rollers to feed cut (and topped) sugar cane mass to a chopper assembly, the lower feed rollers being optionally square in end view; and a plurality of transversely extending, longitudinally spaced, upper feed rollers, spaced above, but forwardly of, respective lower feed rollers, to lift and agitate the cane mass to assist in the release of trash from the cane mass.

7. A harvester as claimed in Claim 6 wherein: the upper feed rollers are "floating".

8. A harvester as claimed in Claim 6 wherein: at least one reversing roller is provided between, but below the level of, at least one pair of lower feed rollers, and rotated in the opposite direction thereto, the or each reversing roller having flexible blades operable to strip trash from the cane mass, preferably due to a pinching action between the or each reversing roller and its associated pair of lower feed rollers.

9. A harvester as claimed in any one of Claims 6 to 8 wherein: at least one stripping roller is provided between adjacent pairs of the top feed rollers, the or each stripping roller having a plurality of flexible bars, with a greater overall diameter, and rotated at a higher rotational speed, than the adjacent lower feed rollers, to strip trash from the cane mass.

A chopper assembly for a sugar cane harvester including: an upper chopper having a plurality of chopper blades operable to cut the cane stalks into billets, the or each chopper blade co- operating with ledger bars, on a lower chopper, to cut the stalks with a minimal "pinching" or "squashing" action.

11. An assembly as claimed in Claim 10 wherein: the upper chopper rotates at half the rotational speed of the lower chopper, and the tip speed of the chopper blades is identical to the peripheral speed of the ledger bars; and the chopper blades do not come into physical contact with the ledger bars, for longer blade life and more efficient cutting of the cane stalks.

12. A sugar cane harvester including a plurality of transversely extending, carry rollers, operable to advance the chopper cane billets, and any trash, from the chopper assembly towards a primary trash extractor, the carry rollers preferably having overlapping toothed rings to agitate the cane billets to release trash therefrom, the carry rollers preferably being driven at higher rotational speeds in the advancing direction to separate the cane billets to assist trash removal.

13. A harvester as claimed in Claim 12 wherein: an impinging roller is provided above the carry rollers, preferably above the rearmost thereof, and upstream of the primary trash extractor.

14. A harvester as claimed in Claim 13 wherein: the impinging roller is of mesh-type construction to allow air being drawn into the primary trash extractor to hold trash onto the impinging rollers until the trash enters the primary trash extractor.

A harvester as claimed in Claim 13 or Claim 14, wherein: the impinging roller also directs cane billets towards a separation chamber of the primary trash extractor.

16. A harvester as claimed in any one of Claims 12 to wherein: the primary trash extractor has air inlets forwardly of and/or above the ends of, the carry rollers.

17. An impinging roller, as claimed in Claim 13 or Claim 14, for a sugar cane harvester.

18. A sugar cane harvester substantially as hereinbefore described with reference to FIGS. 1 to 7; or FIGS. 1 to 8; of the accompanying drawings.

19. A chopper assembly for a sugar harvester substantially as hereinbefore described with reference to FIGS. 1 to 7 of the accompanying drawings.