NZ337150A - Kumara harvester attachable to tractor three-point linkage via double articulation at front and with tilting and steering at rear of harvester - Google Patents

Abstract

Harvester 1 has drawbar 2 attached via pivot 4 to drawbar 5 which is attachable via lugs 6, 7 to the eyes of lower three point linkage arms. The rear of harvester is attached to steerable wheels via tie rod and actuator (not shown but respectively attached between arms 172 and 182, and arm 172 and frame 21).

Description

1 FORM 5 NEW ZEALAND S.9 Reg.19(4) Fee: $250.00 , t h f PATENTS ACT 1953 Insert number of Provisional Specification(s) (if Number: 337150 any) and date(s) of filing; otherwise leave blank Date: 19 February 1998 COMPLETE SPECIFICATION Insert Title of Invention IMPROVEMENTS IN HARVESTERS Insert full name, full street address and nationality of (each) applicant l/WE MARK SLACK, a New Zealand citizen, of State Highway 12, Naumai, Ruawai, New Zealand Indicate if following page is numbered "1a" .9.96 hereby declare the invention for which l/we pray that a patent may be granted to me/us and the method by which it is to be performed, to be particularly described in and by the following statement:- intellectual property j office of n.z. 1 6 FEB 2001 RECEIVES This invention relates to improvements in harvesters particularly harvesters that are designed to harvest kumara.

Kumara is a difficult crop to harvest because of the non-uniform shape of the tuber. Also the depth that the tubers are found will depend somewhat on the dryness or wetness of the growing season which typically extends for about four months, with harvesting in a period from March to June.

The traditional method of planting kumaras is to arrange rows with crests at thirty inch (750mm) lateral intervals. The tractors which work the crop have wheel tracks set at sixty inches (1 500mm).

Intensive hand labour is used under traditional growing methods. For example, when planting, a sledge is towed along above the formed ridges to enable workers to insert plants by hand, one worker to a ridge. Picking is equally labour intensive with the crop being lifted by a suitable plough or blade passing underneath the crop and workers bending over to sort the dug kumaras into buckets.

It is becoming more difficult to find labourers prepared to undertake such back-breaking work and there is also the disadvantage that harvesting takes so long that the grower is very dependant on good weather conditions lasting for a long enough period of time.

Accordingly over recent years some efforts have been made to mechanise the harvesting process but the machines have generally been cumbersome with a sixty inch (1500mm) wheel base and dual conveyors, for a two row harvester, to convey the dug crop up an incline and along a level portion of the conveyor to enable the sorters standing alongside the machine to sort the crop, perhaps into an overhead conveyor, thus separating good kumaras from defective kumaras and rubbish such as weeds, kumara vines or earth. intellectual property i office of n.z. • ! 1 6 FEB 2001 7 150 3 A refinement is to include a bin tilting device at the rear of the machine which is held in an elevated, forward tilted position to receive the sorted contents of the upper conveyor into the lower-most region of the bin which is progressively lowered and tilted back as filling proceeds. Hydraulic means may be used to control the bin movement. The bin is finally lowered to a position, when the bin is full, where it is horizontal and can be approached by a forklift for removal from the harvester.

Other less sophisticated types of harvesters dispense with the central conveyor and simply have bins on either side of the horizontal portions of the main conveyors into which the sorted crop is tossed by hand. The bins when full are removed from the machine by a forklift.

One of the problems of such harvesters is that they are necessarily quite long in order to accommodate the required number of sorters, who stand side by side on either side of the machine, if maximum harvesting rates are to be achieved. The actual harvesting rates which can be achieved will depend on soil type and conditions. For example a sandy soil will easily separate itself from the tubers and may be relatively easy to plough so that quite fast towing speeds can be achieved. This may require more sorters then a situation where the soil was relatively heavy, or the tractor horse-power was low and thus limits were imposed on the towing speed. Usually the harvesters will need four or five sorters standing alongside the horizontal portion of the main conveyors and perhaps another one or two persons along each side of the inclined conveyor portions whose sole task is to separate the tubers from the earth, weeds and vines which have been ploughed up before they reach the sorters.

The sheer length of the machine poses its own problems when it comes to turning at headlands. Obviously growers want to keep headlands as narrow as possible. intellectual ftor'^ty office of m.'.. 1 6 FEB 2001 RECEIVES 4 33 7 The object of the present invention was to provide a machine which might to some extent improve the harvesting of crops such as kumaras.

The present invention consists in a harvester provided with a first drawbar which is attached at a trailing end at or adjacent the front of the harvester substantially central, by means of a pivot with a vertical axis and which has at or adjacent its leading end a substantially horizontal pivot, pivotally supporting a second drawbar, said second drawbar having means enabling it to be secured to the three point linkage arms of a tractor or the like in use, the construction and arrangement being such that (a) when the linkage arms are raised or lowered from a given position this effects a corresponding raising or lowering of the front of the harvester and (b) the horizontal pivot allows a degree of relative sideways rocking motion between the tractor and the harvester in use such as might occur if a tractor wheel on one side passed over a substantial clod of earth momentarily, and (c) the vertical pivot allows the first drawbar to swing across the front of the harvester, in use, to improve the turning circle of the tractor with attached harvester; the harvester being supported at the rear on a pair of steerable wheels, there being control means operable in use from the tractor to cause the wheels to steer in a desired direction; the harvester blade being pivotally mounted with respect to the transverse axis of the rear wheels and there being actuation means operable from the harvester to control the tilting of the blade with respect to the transverse axis.

Preferably the steering mechanism includes an hydraulic motor and ram arrangement, the hydraulic motor perhaps being part of the tractor hydraulic system in a case where the tractor has sufficient hydraulic capacity.

Preferably the length of the first drawbar is slightly greater than half the width of the front end of the harvester.

Preferably the longitudinal axis of such tilting is substantially at or adjacent the horizontal axis of the wheels. ,■ intellectual property office of n.z. 1 6 FEB 2001 RECEfVES Preferably the tilt of the wheel axis in relation to the harvester is controlled by a hydraulic ram controlled in use via actuation means provided on the harvester. One preferred form of the present invention will now be described with reference to the accompany drawings in which: Figure 1 shows a side perspective view of a drawbar attached to the forward end of a harvester, Figure 2 shows a perspective view from the rear of the wheel and axle assembly of a harvester with the wheels omitted, Figure 3 shows a plan view of the rear wheel and axle assembly, and Figure 4 shows a side view of part of a harvester.

The harvesters shown are not necessarily identical in the various figures.

A kumara harvester, the front end of which is broadly designated by (1), is provided with a first drawbar (2) which is attached at its trailing end at or adjacent the front of the harvester (1) in a substantially central position by means of a vertical pivot (3). The distance between the pivot (3) are the leading edge of the blade may be, say 400mm. The first drawbar (2) has at or adjacent its leading end a substantially horizontal pivot (4) pivotally supporting a second drawbar (5) having means (6) and (7) enabling it to be secured to the three point linkage arms of a tractor (not shown) or the like, in use.

The construction and arrangement is such that when the linkage arms are raised or lowered from a given position this effects a corresponding raising or lowering of the front of the harvester (1) because essentially the pivots (3) and (4) do not allow any end to end articulation of the harvester with respect to the tractor under such conditions. However the horizontal pivot (4) allows a degree of relative sideways rocking motion between the tractor and the harvester in use such as intellectual property office of n.z. 1 6 FEB 2001 R E S EIV S IB 6 33 71 K A might occur if a tractor wheel on one side passed over a substantial clod of earth momentarily or momentarily dipped into a hollow.

The vertical pivot (3) allows the first drawbar to swing across the front of the harvester in use, possibly to a position substantially at ninety degrees to the length of the harvester, while yet keeping the drawbar (5) and the rear wheels and the other componentry at the back of the tractor clear of the harvester. This considerable improves the turning circle of the tractor with attached harvester by effectively reducing the track length of the combination. The effect is similar to that which can be obtained with articulated orchard tractors or articulated loaders. As can be seen the first drawbar (2), which needs to have a high degree of stiffness in a vertical plane, may be fabricated from square section RHS tube.

There are large loads at the pivot points and so the bearing areas need to be correspondingly large. An optimum length for the whole assembly between the axis of the lower linkage eyes and the vertical pivot (3) is about 1200 mm. This length has been found to give adequate clearance for most working tractors used in cropping work when the vertical pivot is displaced 400 mm in front of the cutting edge of the harvester blade (not shown) and where the blade length is 1380 mm.

It is important that the cross member (8) be located a sufficient height above the blade to ensure that even when the blade is deep digging there is no build up of earth in front of the crossmember which will give rise to a bulldozing effect where the earth is swept in front of the harvester. Also, as can be seen, loops such as (9) are provided through which hydraulic hoses can be threaded.

As can be seen from Figure 4 and Figure 3 the harvester is provided with rear wheels (10) and (11) each of which is vertically pivoted to an axle (12) by pivots (13) and (14) respectively and the axle (12) is itself pivoted by a longitudinal horizontal pivot (15) to part of the frame work (16) of the body of the harvester. intellectual property office of n.z 1 6 FEB 2001 P3 /^\ n=J n n - — _ The outer assemblies (17) and (18) which include the hubs also have forwardly projecting arms 172 and 182 which are coupled together by a tie rod (19) and there is provision for a hydraulic ram mounted horizontally to impart a turning effect to the wheels just as is the case with normal car power steering, There will thus be an hydraulic motor, which may be the tractor hydraulic motor in a case where the tractor has sufficient hydraulic capacity to perform the harvesting tasks required of it, and steering is effected by a separate control lever or wheel which is able to be operated by the tractor driver. It is not felt suitable to place steering in the hands of the personnel who are carried on the harvester itself during harvesting.

As has already been mentioned, the drawbar makes provision for rocking motion between the tractor and the harvester. As well there is provision for rocking motion of the harvester body and blade itself in relation to the transverse axis of the rear axle (12) so that the harvester blade can be kept at the desired inclination, which is usually level, along its length. This tilting is effected by means of an hydraulic ram (not shown) which has one end coupled to pivot points (20) and its upper end pivotally coupled to a crossmember (21) forming part of the body of the harvester. Thus the body of the harvester, which of course includes the blade is able to be tilted with respect to the transverse axis of the rear axle. The ram is operated via actuation means (42) accessed by one of the persons carried on the harvester during the harvesting operation.

Figure 1 shows the left hand side front cheek (22) and right cheek 22b of the harvester and, although not shown, at the forward apex of the cheeks there is a transverse abrasion resistant steel blade perhaps 200 mm wide by 12 mm spanning between the cheeks with a leading beveled cutting edge and with its rear edge inclined upwardly so that as the blade passes under the crop to be harvested it imparts an upward motion to it. That motion feeds the crop onto a main conveyor (not shown). The sorters place the sorted crop onto an upper central conveyor (28) which is substantially horizontal and is located lengthwise above the intellectual property" office of n.z.

"I 1 8 FEB 2001 I 8 main conveyor. It is the rear sorter who has responsibility for maintaining the blade horizontal as lifting of the crop proceeds. That person will also usually offload bins when full of crop.

As mentioned the relative rocking which is able to be imparted between the harvester body and thus the blade and the transverse axis of the rear wheels is such that the pivot axis and the transverse wheel axis are either intersecting or very close together. For example if the pivot (1 5) (Figure 2) were placed higher up in relation to the wheel axis there would be some sideways movement of the body with respect to the wheel tracks when tilting away from the mid-position was performed. This is undesirable, leading to steering difficulty.

The harvester so described has a number of aspects to it that can be used individually or in a combination as illustrated and described above. Individual concepts are described and claimed in my New Zealand Patent Specification Numbers 335717 - 335722 and 337152 - 337154.

Such a two row harvester would have a width between the cheeks of 1 380mm and would be capable of being drawn by a tractor of about 70 horse-power, preferably a four wheel drive. The blade is also preferably lower than the narrow shoes provided at the bottom of each cheek by about 20mm to assist digging. There would be adequate spacing between the underside of the main conveyor (23) and any framework to prevent a build up of any vine or weeds or earth. A suitable spacing is perhaps of the order of 200mm. Also there would be a shroud over the rear axle to prevent vines, weeds etc. falling onto the steering and tilting mechanism. The return loop of the main conveyor would preferably have a significant gravity loop to provide tension.

The present invention provides a improved harvester, especially when its many aspects are combined, which is a expected to be able to harvest in excess of one hectare of kumaras, for example, per day which is considerable improvement over intellectual property i office of n.z. 16 FEB 2001 337150 manual methods. Thus there is a considerable economic benefit to growers using such a harvester. The harvester may also be suited for other crops than kumaras.

' INTELLECTUAL PROPERTY office of n.z. 1 6 FEB 2001 BESEJ¥EB I

Claims (6)

WHAT I CLAIM IS:
1. A harvester provided with a first drawbar which is attached at a trailing end at or adjacent the front of the harvester substantially central, by means of a pivot with a vertical axis and which has at or adjacent its leading end a substantially horizontal pivot, pivotally supporting a second drawbar, said second drawbar having means enabling it to be secured to the three point linkage arms of a tractor or the like in use, the construction and arrangement being such that (a) when the linkage arms are raised or lowered from a given position this effects a corresponding raising or lowering of the front of the harvester and (b) the horizontal pivot allows a degree of relative sideways rocking motion between the tractor and the harvester in use such as might occur if a tractor wheel on one side passed over a substantial clod of earth momentarily, and (c) the vertical pivot allows the first drawbar to swing across the front of the harvester, in use, to improve the turning circle of the tractor with attached harvester; the harvester being supported at the rear on a pair of steerable wheels, there being control means operable in use from the tractor to cause the wheels to steer in a desired direction; the harvester blade being pivotally mounted with respect to the transverse axis of the rear wheels and there being actuation means operable from the harvester to control the tilting of the blade with respect to the transverse axis.
2. 2. A harvester as claimed in claim 1 wherein a steering mechanism for the steerable wheels includes an hydraulic motor and ram arrangement.
3. 3. A harvester as claimed in claim 1 or claim 2 wherein the length of the first drawbar is slightly greater than half the width of the front end of the harvester. INTELLECiUAL property OFFICE OF N.Z. 1 6 FEB 2001 R u 3 s i v e a
4. 4. A harvester as claimed in any one of the proceeding claims wherein the longitudinal axis of such tilting is substantially at or adjacent the horizontal axis of the wheels.
5. 5. A harvester as claimed in any one of the proceeding claims wherein the tilt of the wheel axis in relation to the harvester is controlled by a hydraulic ram controlled in use via actuation means provided on the harvester.
6. 6. A harvester substantially as herein described with reference to the accompanying drawings. MARK SLACK By his authorised agents J.D. HARDIE & CO. intellectual property i OFFICE OF N.Z. 1 6 FEB 2001 lr^ u w L (J \j [D)