GB2144315A - Crop harvesting machine - Google Patents

Abstract

A crop harvesting machine for harvesting bush-borne crops, comprises a frame (10) having rear ground wheels (11) and a processing channel (15) extending longitudinally therethrough, shaker drums (19) at opposite sides of the processing channel and a pair of collection conveyors (22, Figure 3) along the bottom of the processing channel to catch crop dislodged from the bushes by the shaker drums. The conveyors (22) are laterally separated by an adjustable gap (23, Figure 3) along which the stems of the bushes pass, and are positioned close to ground level. A control (32, 33) automatically senses the height of the conveyors above the ground and adjusts the height relative to the wheels (11) in accordance with the height sensed. The conveyors (22) are pivotally connected to a pair of elevator conveyors (38) at their respective rear ends and have ground wheels (42) at their front ends respectively. <IMAGE>

Description

SPECIFICATION Crop Harvesting Machine This invention relates to a machine for harvesting a bush-borne crop, such as blackcurrents.

Existing blackcurrent harvesters typically comprise a self-powered frame which is driven along a row of bushes to be harvested, the frame having a longitudinally-arranged processing channel through which the bushes pass. During their passage through the processing channel, the bushes are shaken to dislodge the fruit, which then falls onto conveyors for collection.

In such existing harvesters, the conveyors are disposed a significant distance (usually a minimum of 8 in) above the ground.

Consequently, any fruit disposed below this level on the bush cannot be harvested. Whereas the production loss due to this missed fruit may fall to an acceptable amount for relatively old bushes which have plenty of fruit-bearing branches above this level, for first-year fruiting bushes the losses are often commercially unacceptable, being typically 40% of the total cropping potential.

Moreover, in existing harvesters it is the practice to drive the collection conveyors accurately at ground speed so that there is no relative movement between the conveyors and the bushes. This however requires the use of a complicated synchronizing control, often utilizing a ground -engaging sensor wheel. The need to provide such a synchronising control, coupled with the fact that each harvester must have its own drive, results in the cost of the harvester being very high. Taking into account the fact that the harvester will usually be used for only two or three weeks in each year, the cost of such existing harvesters can be prohibitive.

It is an object of the present invention to overcome the above-mentioned problems, and in particular to provide a harvesting machine which is relatively inexpensive and which is capable of harvesting even first year crops at low wastage.

Accordingly, the present invention provides a machine for harvesting bush-borne crops which comprises a wheeled frame which is moved along a row of crop-bearing bushes in use and which contains a processing channel through which the bushes pass, shaking means mounted on the frame and operative to shake the bushes as they pass through the processing channel and thereby dislodge said crop therefrom, a pair of collection conveyors disposed so as to catch the crop dislodged from the bushes, the conveyors being laterally separated by a gap along which stems of the bushes pass in use, the collection conveyors being positioned at a level close to the ground, and a control operative to sense the height of the collection conveyors above the ground and to adjust the height of the conveyors relative to the wheels of the frame in accordance with the height thus sensed.

In this way, because the collection conveyors are positioned lower than on existing harvesting machines, the crop can be collected even from those parts of the bush which are close to the ground. The control automatically prevents the conveyors from fouling on the ground by suitably adjusting their height.

In order to avoid the expense of providing a self-contained drive for the machine (although the invention is also applicable to such a construction), the frame is preferably in the form of a trailer for towing behind a vehicle, such as a tractor. In this case, the frame can be provided with a draw bar having a point for attachment to the said vehicle, the draw bar being pivotable relative to the frame between respective positions wherein said attachment point is in line with and laterally offset from the frame. This arrangement enables the vehicle to drive between the rows of bushes while the harvesting machine moves directly along the latter, whilst still permitting the vehicle to tow the machine in a conventional inline manner when travelling along a road, for example.

Desirably, the harvesting machine also comprises lifting means which is operable to lift the collection conveyors relative to the frame, so that the conveyors can be held clear of the ground for road travel. The lifting means may be associated with an override for the height-sensing control, whereby the frame may be lifted relative to the wheels. In a particular construction, the collection conveyors are pivoted at their rear ends and are provided with ground wheels at their front ends, and the lifting means is operable to raise the conveyors about their said pivots, thereby to lift the ground wheels out of engagement with the ground.

As in conventional harvesting machines, a pair of elevator conveyors can be provided to elevate the crop from the collection conveyors to a delivery point. Unlike conventional machines, however, the elevator and collection conveyors can be formed as a unit which can readily be detached from the frame.

Conveniently, the frame has steerable ground wheels at its rear, these wheels preferably being steerable about respective vertical axes which are disposed forwardly of the wheel rotation axes. In this case, the harvesting machine advantageously also comprises a second control operative to sense the position of the frame relative to the row of bushes and to steer said wheels in accordance with the position thus sensed. As with the firstmentioned control, an override can be provided for the second control to enable the wheels to be steered at will by an operator.

Each collection conveyor may be provided with a flexible apron along a side thereof which confronts the other collection conveyor, the apron being flexed upwardly by engagement with the bushes as the latter pass along the processing channel, so that it guides the crop dislodged from the bushes onto the collection conveyors.

The harvesting machine can also comprise air blast means which directs air through the processing channel, thereby assisting in directing the dislodged crop onto the conveyors from the bushes. In this case, an outlet channel is preferably provided along a side of each collection conveyor remote from the processing channel, whereby the air directed through the processing channel can also be used to separate debris from the crop and to eject such debris from the machine through the outlet channel. The air blast means (like the conveyors) can be formed as a unit which is readily detachable from the frame.

The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a harvesting machine according to the present invention; Figure 2 is a schematic side view of the harvesting machine with parts thereof broken away; and Figure 3 is a schematic transverse section through the harvesting machine.

Figure 4 is a schematic transverse section through a modified form of harvesting machine, and Figure 5 is a schematic fragmentary view from above, of part of the machine of Figure 4.

The illustrated machine is primarily intended for harvesting blackcurrents, and will therefore be described in this context. However, it is to be appreciated that the machine may also be used to harvest other crops, such as raspberries. The machine comprises generally a frame 10 in the form of a trailer having ground wheels 11 at its rear and a draw bar 12 at its front, the trailer being towed in use by a tractor 13 or other similar vehicle. To enable the machine to move along a row of bushes while the tractor drives between adjacent rows, the draw bar 1 2 is offset to one side of the frame 10.However, it can be pivoted about its attachment point to the frame, and a section 1 2a thereof can be extended as indicated in chain dotted lines in Figure 1, so that the tractor can tow the harvesting machine in a conventional in-line manner when travelling along a road, for example. Such pivoting of the draw bar 12 relative to the frame 10 is achieved by an hydraulic ram (not shown) connected between these parts. This ram can also be employed to shift the front end of the harvesting machine laterally of the row of bushes, to achieve initial alignment of the machine with the row.

At the front end of the frame 10 there is mounted a forwardly-extending divider 14 which penetrates each bush in turn, and guide members which guide the branches of the bush into a generally V-shaped processing channel 1 5 which extends longitudinally through the frame 10. The guide member on the right-hand side of the machine (as viewed in the direction of travel) is formed by an angled plate 16, while the guide member on the left-hand side is constituted by a grid-like part 1 7 which is pivotally attached to the rear of one or more guide plates 18 provided along the right-hand side of the tractor 13. These guide plates assist in the channelling of the branches towards the entrance to the harvesting machine, and also help to prevent the bushes from being damaged by the tractor.For the sake of convenience, the guide plates 1 8 have been omitted from Figure 2.

As the bushes pass along the processing channel 15, they encounter shaker drums 19 which shake the branches to dislodge the blackcurrents therefrom. The shaker drums are of conventional construction, and are composed of a series of spoked or tined wheels 20 (see Figure 3) which are freely rotatable, but which at the same time are angularly vibrated. The sides of the processing channel are defined by spaced grid bars 21 extending longitudinally of the frame 10, with the tines of the shaker drums 19 projecting through adjacent ones of these bars. In the illustrated embodiment, only two shaker drums 1 9 are provided, one for each limb of the processing channel: this is because the machine is intended for use on young bushes only.

However, for use on older bushes additional shaker drums can be provided, for example as indicated in chain-dotted lines at 1 9a in Figure 1.

Where only two such drums are used, these are staggered longitudinally of the processing channel so that each may cover the full length of the respective limb of the latter. Where however more than two shaker drums are employed, in order to maintain the longitudinal dimensions of the machine compact, the additional drums 1 9a can be provided laterally opposite the existing drums, being suitably shortened so that they do not interfere with the latter.

Along the bottom of the processing channel 15, there are disposed a pair of relatively shallow collection conveyors 22 which collect the blackcurrents dislodged from the bushes. The conveyors are laterally separated so that a gap 23 is defined therebetween, along which the stems of the bushes pass in use. In order to facilitate collection of the blackcurrents, a collector plate 24 is disposed outboard of the outside bars 21 of each limb of the processing channel 15, which directs the blackcurrents onto the conveyors 22.

Additionally, each conveyor has a flexible apron 25 on a side thereof which confronts the other conveyor: these aprons are flexed upwardly by the stems of the bushes, and also direct the dislodged blackcurrents onto the conveyors 22.

Along the longitudinal centre line of the frame 10, there is positioned an air chamber 26 into which air is impelled by a fan 27 or the like. Along its bottom, the air chamber 26 communicates with an air box 26a which opens into both limbs of the processing channel 1 5 by way of slots 28, so that an air blast is directed laterally through the processing channel in the manner indicated by arrows in Figure 3. This air blast not only slows the blackcurrents falling from the bottom end of each collector plate 24 onto the respective conveyor, but also carries debris (such as leaves and broken-off branches) through outlet channels 29 defined between the collector plates 24 and further plates 30 disposed outboard thereof, thereby ejecting such debris sideways from the machine.

In order to catch as much of the crop as possible, the collection conveyors 22 are positioned relatively closely together and only a . very small distance above the ground (indicated at 31 in Figures 2 and 3). In order to avoid fouling of the conveyors on the ground, a control is provided which automatically adjusts the height of each conveyor to maintain a desired ground clearance. The control includes a sensor 32 (Figure 2) which senses the height of each conveyor above the ground, and an hydraulic ram 33 which adjusts the height of the frame 10 (and thus the conveyors 22) relative to each wheel 11 in accordance with the height thus sensed. The ram 33 is in fact connected between a lever arm 34 which carries the respective wheel 11 and a steering arm 35 which is pivotally connected to the frame 10 by a vertical king post 36.The steering arms 35 of the two wheels 11 are interconnected by a tracking rod 37 which extends across the rear of the frame 10.

A second control is provided to steer the wheels 11 and thereby maintain the harvesting machine in proper alignment with the row of bushes. The second control includes sensor bars or the like (not shown) which sense the position of the machine relative to the row of bushes, and an hydraulic ram (also not shown) connected between the frame 10 and the tracking rod 37 which steers the wheels 11 in accordance with the position thus sensed. It will be seen that the king posts 36 are positioned forwardly of the rotation axes of the wheels 11, so that the wheels trail behind their steering pivots. Accordingly, when the second control turns the wheels 11, a reaction is set up in the frame 10 which causes the latter to move in the appropriate direction.

Thus, the response of the machine to misalignment is substantially immediate, which is an important factor considering the very slow speed (1 mph or less) at which the machine moves along the row of bushes.

The blackcurrents collected on the conveyors 22 are transported rearwardly of the machine to a pair of elevator conveyors 38 which elevate the blackcurrents onto a cross-conveyor 39 for discharge at an end 40 of the latter, where they are placed in trays or the like in a conventional manner. A subsidiary air blast from the chamber 26 may be directed either through the conveyors 38 or through the conveyor 39 at the discharge end thereof, to remove any debris not previously extracted. Each elevator conveyor 38 preferably forms an extension of the respective collector conveyor 22, so that only a single endless conveying element is needed for both conveyors.

In order that the harvesting machine may be adapted to different sizes of bush, the conveyors are mounted on the frame 10 in such a manner that their lateral separation can be adjusted. For the same purpose, the width of each limb of the processing channel 15 can also be adjusted, either by altering the spacing between the inboard and outboard grid bars 21, or by adjusting the whole centre section of the frame 10 (including the air chamber 26 and the shaker drums 19) in a vertical direction.

As can be seen to advantage in Figure 2, each of the collection conveyors 22 is pivotable relative to the associated elevator conveyor 38 about a horizontal axis 41 at the rear end thereof, and is supported at the front end thereof by a ground wheel 42. This enables the collector conveyors 22 to "float" relative to the elevator conveyors 38 as the machine moves along the row of bushes. For road travel it is desirable that the conveyors 22 should not be disposed so close to the ground, and to this end a lifting device (not shown) is provided whereby the conveyors 22 can be pivoted upwardly about the axes 41 so as to disengage the wheels 42 from the ground.For the same purpose, the ground clearance control is provided with an override, operable by a driver of the tractor 13, whereby the whole frame 10 can be jacked up relative to the wheels 11 by suitable operation of the hydraulic rams 33. The steering control is similarly provided with an override, so that the tractor driver may obtain greater steering control during road travel or, for example, when turning in the headland at the end of the row of bushes, in preparation for harvesting another row.

Reference numeral 43 in Figure 1 designates a shaft carried by the draw bar 12 which is coupled to the power take off of the tractor 1 3. This shaft 43 provides a mechanical drive by means of which the conveyors 22, 38 and the fan 27 are driven. The mechanical drive is in turn coupled to an hydraulic pump, so that an hydraulic drive is provided for powering the shaker drums 19, the cross-conveyor 39 and (when provided) a fan for the subsidiary air blast at the discharge end of the conveyor 39.The hydraulic drive, which controls the factors governing the rate at which the blackcurrents are removed from the bushes and are discharged for collection, is arranged to be operable from a position adjacent to the discharge end 40 of the conveyor 39, so that an operator supervising the collection of the blackcurrents can readily adjust the discharge rate in accordance with prevailing circumstances. On the other hand, the various hydraulic rams controlling the angle of the draw bar 12 and the height and steering of the wheels 11 are all powered by the tractor hydraulics so that these functions may readily be controlled by the tractor driver.

The above-described machine has the following significant advantages over conventional harvesters: (1) Because the collection conveyors 22 are spaced relatively close together, are positioned close to the ground and are relatively shallow, blackcurrents on even the lowermost parts of the bushes can be harvested, so that the percentage yield (particularly for first-year fruiting bushes) is considerably increased.

(2) Because the machine is trailed rather than being self-propelled, there is no need to provide a separate drive unit on the machine and therefore its cost can be dramatically reduced.

(3) Because there is an articulated connection between the tractor and the machine, and since the rear wheels of the machine can themselves be steered, the machine is considerably more maneouverable than existing harvesters. In particular, with conventional harvesting machines it has been necessary to leave at least 21 feet of headland at the ends of the rows of bushes to enable the machine to turn around, and even then it may not be possible for the harvester to return to the row next or next-but-one to the row which has just been harvested. Using the abovedescribed machine, a return can be made at least to the next-but-one row in an equivalent amount of headland.

In addition, by designing the centre section of the frame (including the air chamber 26 and the shaker drums 19) on the one hand, and the conveyors 22, 28 and 39 on the other hand as units which can readily be detached from the frame 10, the machine can be adapted to other uses (such as pruning) by replacing these units with others having a different purpose. In this regard, the conveyor unit may be designed so that it hooks over a cross-member 44 at the rear of the frame 10: the conveyor unit may then be detached from the frame simply by undoing a few securement bolts and then jacking the frame 10 up relative to the wheels 11 by operating the hydraulic rams 33, thereby leaving the conveyor unit resting on the ground and allowing the frame 10 to be towed away therefrom.

Figures 4 and 5 show a modified harvesting machine which differs only in two respects from the machine of Figures 1 to 3.

As with the machine of the first embodiment, the present machine has a pair of relatively shallow crop collection conveyors 100 which are laterally separated so that a gap 110 is defined therebetween, along which the stems of the bushes bearing the crop can pass. This lateral separation is adjustable as indicated by an alternative position of one of the conveyors at 1 O0a. Above the conveyors are provided two shaker drums 120 arranged in a generally Vformation. These drums have spoked or tined wheels 130 and as with the earlier machine these tines project through grid bars 140 defining the sides of the processing channel.

Also as with the earlier version of the machine, there is an air chamber 150 forming a longitudinally extending central divider disposed substantially above the gap between the conveyors and extending laterally thereof. It is believed that crop collection is considerably improved if there are associated with a shaker one or more crop collection surfaces formed on one or more respective shelves. Figure 4 thus shows this first difference over the other embodiment, namely the provision of a lowermost shelf 160 at the bottom of a shaker 100, the shelf being connected to the chamber 1 50 and directed downwardly at an angle towards the conveyor below the shaken As can be seen, the shelf extends up to the inner grid bars.Above the shelf 1 60 are formed shelves 1 70 and 180 also extending to the inner grid bars.

These shelves terminate inwardly of the side of the conveyor below the shaker so that crop is delivered from the shelves to the conveyor.

To accommodate the shaker, the air chamber is recessed as shown in Figure 5 at 1 90. This provision of shelves increases crop collection amounts by preventing or substantially preventing any of the crop passing out of the gap between the conveyors and also by guiding crop from the collection surface provided by the shelf to the conveyor. Even when the gap between the conveyors is at its maximum, the shelves extend to cover it.

Air blown through the chamber 150 will tend to throw the crop sidewardly and thus down onto the conveyor. However it is considered that the air blast will be important in clearing debris, such as leaves and broken-off branches, sideways from the machine.

If required, the shakers can be slid out sidewardly from the recessed parts of the air chamber for removal, once the grid bars have been removed.

The other change from the construction of machine described with reference to Figures 1 to 3 is the replacement of the grid-like part denoted by the reference numeral 17 by a vertical axis roller-blind. This enables improved manoeuvrability of a tractor towing the machine to be obtained, at extreme angles of the tractor relative to the machine.

Claims (18)

1. A machine for harvesting bush-borne crops comprising a wheeled frame which is moved along a row of crop-bearing bushes in use and which contains a processing channel through which the bushes pass, shaking means mounted on the frame and operative to shake the bushes as they pass through the processing channel and thereby dislodge said crop therefrom, a pair of collection conveyors disposed so as to catch the crop dislodged from the bushes, the conveyors being laterally separated by a gap along which stems of the bushes pass in use, the collection conveyors being positioned at a level close to the ground, and a control operative to sense the height of the collection conveyors above the ground and to adjust the height of the conveyors relative to the wheels of the frame in accordance with the height thus sensed.

2. A machine as claimed in Claim 1, wherein the frame is in the form of a trailer for towing behind a vehicle, such as a tractor.

3. A machine as claimed in Claim 2, wherein the frame is provided with a draw bar having a point for attachment to the said vehicle, the draw bar being pivotable relative to the frame between respective positions wherein said attachment point is in line with and laterally offset from the frame.

4. A machine as claimed in any one of the preceding claims, wherein there is provided lifting means, which is operable to lift the collection conveyors relative to the frame, so that the conveyors can be held clear of the ground for road travel.

5. A machine as claimed in Claim 4, wherein the lifting means is associated with an override for the height-sensing control, whereby the frame may be lifted relative to the wheels.

6. A machine as claimed in Claim 5, wherein the collection conveyors are pivoted at their rear ends and are provided with ground wheels at their front ends, and the lifting means is operable to raise the conveyors about their said pivots, thereby to lift the ground wheels out of engagement with the ground.

7. A machine as claimed in any one of Claims 1 to 6, wherein a pair of elevator conveyors are provided to elevate the crop from the collection conveyors to a delivery point.

8. A machine as claimed in Claim 7, wherein the elevator and collection conveyors are pivotally connected together as a unit which can readily be detached from the frame.

9. A machine as claimed in any one of the preceding claims, wherein the frame has steerable ground wheels at its rear, these wheels being steerable about respective vertical axes which are disposed forwardly of the wheel rotation axes.

10. A machine as claimed in Claim 9, wherein there is provided a second control operative to sense the position of the frame relative to the row of bushes and to steer said wheels in accordance with the position thus sensed.

11. A machine as claimed in Claim 10, wherein an override is provided for the second control to enable the wheels to be steered at will by an operator.

12. A machine as claimed in any one of the preceding claims, wherein each collection conveyor is provided with a flexible apron along a side thereof which confronts the other collection conveyor, the apron being flexed upwardly by engagement with the bushes as the latter pass along the processing channel, so that it guides the crop dislodged from the bushes onto the collection conveyors.

13. A machine as claimed in any one of the preceding claims, comprising air blast means which directs air through the processing channel, thereby assisting in directing the dislodged crop onto the conveyors from the bushes.

14. A machine as claimed in Claim 13, wherein an outlet channel is provided along a side of each collection conveyor remote from the processing channel, whereby the air directed through the processing channel can also be used to separate debris from the crop and to eject such debris from the machine through the outlet channel.

1 5. A machine as claimed in Claim 13 or Claim 14, wherein the air blast means is formed as a unit which is readily detachable from the frame.

16. A crop harvesting machine comprising a wheeled frame which is moved along a row of crop-bearing bushes in use and which contains a processing channel through which the bushes pass, shaking means mounted on the frame and operative to shake the bushes as they pass through the processing channel and thereby dislodge said crop therefrom, a pair of collection conveyors disposed so as to catch the crop dislodged from the bushes, the conveyors being laterally separated by a gap along which stems of the bushes pass in use, the collection conveyors being positioned at a level close to the ground, and central divider means extending longitudinally of the frame and above said gap between the conveyors, said divider means providing at least one crop reception surface at the bottom of said shaking means to guide dislodged crop to a collection conveyor.

1 7. A machine as claimed in claim 16, wherein said crop reception surface is a shelf below a shaking means and directed to direct crop to a collection conveyor therebelow.

18. A machine as claimed in Claim 17, wherein a plurality of shelves are provided one above the other at each shaking means.

1 9. A machine for harvesting bush-borne crops substantially as hereinbefore described with reference to and as shown in the accompanying drawings.