GB2120514A - Harvesting pyrethrum - Google Patents

Description

SPECIFICATION Improvements rotating to pyrethrum harvesting machines This invention relates to pyrethrum harvesting machines.

Pyrethrum is one of the oldest and best known plant insecticides. It has been used for many years for controlling household insects such as flies and for controlling pests on agricultural crops. The fact that it is harmless to man and animal has made it particularly desirable for household use and on food crops.

The range of usefulness of the insecticide has been achieved by the extracting of pyrethrins from the flowers of the pyrethrum plant. These extracts in suitable form are widely used as household sprays and for the control of insects in greenhouse and garden crops.

The pyrethrum flow must be harvested during a relatively short time because the flowers rapidly reach and pass the preferred stage of picking.

Furthermore the plants are not strong being prone to lean or fall to the ground in unfavourabie conditions. These factors have made it difficult to mechanically harvest the pyrethrum flower.

It is an object of the present invention to provide a harvesting machine which will harvest pyrethrum flowers substantially at maturity with little or no damge to the plant and minimal wastage.

There is provided according to the present invention a harvesting machine for pyrethrum flowers comprising a header mounted forward of a chassis for contacting a crop to be harvested the header including a rotatable picking head including picker means mounted relatively to said drum for engaging and picking mature pyrethrum flowers.

Conveniently said picker means is a series of rotatable rods extending along the drum and mounted on an endless chain support means for engaging flower heads forcing them into contact with said drum to remove those heads of mature size for collection, the rotatable rods moving at a speed differential to said drum to provide a picking effect on the flowers.

In a further embodiment of the invention there is provided a harvesting machine for pyrethrum flowers comprising a rotatable header drum with a series of circumferentially disposed combs having radially extending fingers, the spacing of the comb fingers being such that flowers of predetermined maturity are picked. Accordingly selective harvesting of mature flowers is achieved by varying the space between the picking members.

It is characteristic of pyrethrum plant flowers for the base bowl of the flower to grow larger and be firm as the flower matures. According to the invention the header or picking means engages against said bowl to harvest them but for smaller immature flowers to pass through, enabling the buds and smaller flowers to be left on the bush until they mature.

Conveniently the harvester picking head includes a suction vacuum system which can be attached to a high clearance tractor frame to enable the straddling of pyrethrum beds and the conveyance of the picked flowers to a bulk hopper bin suitably designed to discharge into bulk collection bin.

Such a harvesting machine is easily controlled by the operator to harvest selectively picked flowers and provides storage means for the harvested produce.

There is provided according to the present invention a harvesting machine particularly for harvesting pyrethrum flowers comprising a mobile chassis, an adjustable height picking head attachment for accurate positioning relative to the plants, a crop conveying device associated with the picking head attachment for receiving and conveying crop to a storage device, said storage device including a rotatable drum movable between two angular positions one to receive said crop, and the other an emptying position.

The picking head attachment is a rotating drum with retractable fingers (picking combs) ; these fingers are removable so as to allow different diameter fingers to be attached to selectively pick mature flowers. The harvester can also be fitted with various picking heads as herein disclosed.

The conveyor device is a duct subjected to vacuum such that picked crop material is drawn from the picking head attachment by suction along the duct to said storage device.

The storage device includes a bin pivotally mounted for rotation through approximately 180 .

In the loading position the bin forms part of the area subject to vacuum such that crop material ; drawn along the vacuum duct falls under gravity 'into the storage drum.

The periphery of the drum has an open segment which in the loading position is at the top and communicates the drum with the source of vacuum. In the unloading position the open segment of the drum is at the bottom so that crop material can fall from the drum. The machine is constructed to straddle the plants to be harvested and the picking head attachment is pivoted at a point remote from the picking head near the rear of the machine.

According to a further embodiment of the invention there is provided a fluted roller drum mounted horizontally adjacent to a second fluted roller drum and spaced therefrom a predetermined distance to engage mature pyrethrum flowers therebetween for harvesting therefore, selectively harvesting flowers that are mature; the top fluted drum is substantially double the diameter of the lower fluted drum therefore resulting in a speed twice that of the smaller lower drum; the flutes are twice as far apart and engage the flowers pulling them in between the fluted rollers of the larger drum to remove the mature flowers.

The top flute travelling faster than the bottom flute causes a rolling action on the flower similar to hand picking, inducing a greater strain on one side of the stem attached to the flower. This causes the flower to be picked with a shorter stem than a purely plucking action.

Conveniently the radially extending combs or flutes include retractable fingers mounted for reciprocable movement relative to said exterior of the drum such that flower heads of predetermined size are picked and carried partly around the periphery of the drum and released as said fingers are retracted; the outer surface of the drum is associated with an enveloping shroud connected to a source of vacuum adapted to collect harvested flower heads as they are released by the retracting fingers. When the flower is picked the stem is drawn taut creating a small amount of compression in the flower head when the stem parts of the head; flowers if unrestrained, tend to spring off the picking means and fall away from the head onto the ground. Conveniently the drum is perforated allowing the vacuum sucking fan to pull air through the drum. This causes loose picked flowers to adhere to the surface of the drum preventing dislodgement and falling to the ground.

As the drum rotates and the flowers are transported to the opposite side of the rotating drum and inside the vacuum shroud the reverse action takes place and the flow of air through the perforated drum removes the flowers and accelerates their movement into the air conveyance duct or onto a conveyor belt to receiving chamber.

The invention will now be described in greater detail having reference to the accompanying drawings in which: Fig. 1 is a partial perspective view of a pyrethrum flower harvesting head according to one embodiment ; Fig. 2 is a partial perspective view of a pyrethrum flower harvesting head according to another embodiment; Fig. 3 is a partial end view showing the operation of the harvester head with freely rotating drum and picking bars; Figs. 4 and 5 show further detail of the harvester shown in Fig. 2 ; Fig. 6 is a partial end view of a pyrethrum flower harvester according to the fluted roller embodiment; Figs. 7,8 and 9 are partial sectional views of a further embodiment of a pyrethrum flower harvesting head and machine; Fig. 8 (a) is a detailed view of a modified flower collection device; Figs. 10,11 and 12 show a further embodiment of a modified header and picking method; Figs. 13 (i) and 13 (ii) is a partial view of a harvesting method; Fig. 14 (i) and 14 (ii) shows a header with fingers; Fig. 14 (a) is a modification of Fig. 14; Fig. 15 shows header with a shroud; Figs. 16,17 and 18 show a further embodiment of a picking head with retractable pickingfingers; Figs. 19 and 22 show a further embodiment of a picking head with retractable picking fingers; Figs. 23 to 27 show typical harvesting machine end storage hopper arrangements; Figs. 28 and 29 illustrated specific hopper actuating mechanisms ; Fig. 30 shows an alternative harvesting machine; Figs. 31,32A, 32B, 32C, 32D, 34,34A and 34B show further embodiments of harvesting heads; Figs. 33 (a) and 33 (b) shows a further embodiment of a Fig. 35 is a further general view of an alternative harvesting machine; Fig. 36 shows a basic chassis construction for a harvester machine; Figs. 37 and 37A are schematic views of a chassis construction for a harvester machine ; Figs. 38 and 38 (a) show a bin handling mechanism; and Figs. 39A and 39B show schematically separator devices for harvested material.

In Figs. 1 and 2 a roller 18 freely rotating on a bar 15 is connected to either end to a drive chain 16 and is movable in a generally rotary action B.

The roller 18 engages against drum 12 and causes the bar 15 to be held at a fixed distance from the drum face. This space can be varied by changing to a different roller diameter 18.

The roller drum 12 is comparatively smooth and adapted to freely rotate in the direction of arrow B opposite to the spaced bar roller 15 under the action of the harvested plants. The spaced bars 15 are adapted to be spaced a controlled distance from the drum during its travel adjacent thereto by rollers 18 adapted to engage the drum surface (see Fig. 3). The spacing of the bar is arranged such that only mature flowers of adequate size are gripped and therefore removed from the plant. Detailed illustrations appear at Fig.

13 (i) and (ii) showing the manner of bending of the flower stem during the picking operation.

The harvested flowers are carried back on the surface of the drum into the collecting bin 20. See Fig. 1.

Referring to Figs. 2,4 and 5 a drum 30 is provided with a series of combs 31 evenly distributed about the periphery of the drum. The combs have teeth 32 with predetermined spacing to engage and harvest flower of mature size as the drum is rotated in the direction of arrow B. To ensure cleaning of the combs of flowers a brush 33 is provided to sweep flowers into the receptacle 34 in the direction of arrow C. The combs 31 are mounted on bracket 35 for adjustable rake movement of the combs relative to the horizontal axis of the picking head to achieve optimum picking efficiency.

It has been discovered that if the flutes or comb fingers are raked; the fingers when contacting the flower stem lend to bend or distort the stem. This simulates a hand picking action as shown in Fig.

10. Further detail is shown in Fig. 14 (i) and 14 (ii).

As is better shown with reference to Fig. 34 the effect of the picking head moving across a field of pyrethrum is to cause it to deflect away from the drum and slide beneath the drum approximately in the 7-8 o'clock position on the surface of the drum. By angling the comb teeth the flowers are still effectively picked. The through flow vacuum holes through the drum hold the flowers against the drum until it rotates up into the main vacuum flow. See e. g. Fig. 8.

In Figs. 6 and 11 there is shown a further embodiment of a harvesting head 40 having radially extending flutes 41 around its circumference and over its entire length. Adjacent thereto and therebeneath is a second rotatable fluted picking head 43 with radial flutes 44. The disposition of the two drums as illustrated is adjustable so that the spacing 42 between the flutes can be adjusted to pick flowers of mature size. Small immature flowers escape being picked.

The two fluted drums are housed in a shroud 45 which is connected to a fan thereby creating a draft of air and vacuum rearwardly of the rollers to carry harvested flowers to a container. In another configuration the fluted picking head is comprised of end plates and flutes only to allow through passage of air in a vacuum system.

Referring to Figs. 7,8,9 and 9 (a) a modified picking head 50 is illustrated.

The head inclues a reciprocating support mechanism 51 for a series of circumferentially spaced combs 52 mounted on a comb support bar 53. The combs 52 include a series of predetermined spaced fingers 54 which are reciprocable relative to the drum surface 50 depending upon the circumferential portion as is best shown in Fig. 7.

The combs 54 are arranged such that they are angled or raked upwardly see arrow A relative to the surface of the drum 50 to achieve efficient picking as described above.

In operation the drum rotates in the direction of arrow A and the comb fingers 54 are fully projected from the drum surface at the point of contact with a plant to be harvested : The spacing of the comb fingers ensures that only flowers of mature size are harvested. A scraper 56 within shroud 55 may be provided to ensure flowers are dislodged from the drum.

Figs. 7,9 and 11 show in greater detail the construction and operation of the retractable finger mechanism. The comb bar 53 is mounted on a cam follower 57 which follows a cam track 58 fixedly mounted on the harvester frame 60.

The cam track 58 follows an off-centre profile whereby the fingers 54 project from the drum surface at the leading edge to harvest the flowers and retract at the trailing edge to release harvested flowers. The spacing of the fingers may be adjustable and also the length of the fingers may vary as best shown in Fig. 14a.

The angled teeth pass through slots in the drum wall and both the comb assembly and outer drum are kept in alignment by a 1: 1 ratio drive to both of them from a common drive shaft.

With reference to Fig. 21 (a) the timing of the comb fingers can be altered so that they are made to exit on an angle to the drum face and to engage on the brushed over pyrethrum stems at the 7-8 o clock position as viewed from the drum end.

Referring to Figs. 8,17 and 18 for example the drum is surrounded by a shroud or vacuum chute to enable a high velocity air draft to be generated to collect harvested flower heads as they drop off the roller when the picking fingers retract into the drum.

A further feature is that the air draft created tends to draw the flower and associated stem into the correct attitude relative to the picking fingers.

As the high velocity air in the vicinity of the picking drum travels further towards a collection bin the air loses its velocity and consequently the flowers fall out of the air stream.

With reference to Figures 16 to 18 there is shown a picking head 1 inside harvester drum 2.

This picking head 1 is made up of 2 end plates 3 and joined by bar lengths 4 with picking fingers attached (see Fig. 17). Various diameter fingers can be fitted to the bar to alter finger aperture and selectively pick mature flowers.

This picking head is offset (Fig. 16) as illustrated. To allow fingers 5 to be fully retracted when outside drum is being cleaned and fully extended when in the picking position. The outside drum is driven by combs attached to picking head engaging through the outer drum. Rollers 6 are located around the circumference of drum 2 to keep drum in a central position.

As seen in Fig. 18 combs are retracted when passing over foliage so as to ensure no entanglement in, or pick up of, foliage. Extended when picking and retracted when cleaning. Again the drum 2 is perforated and a vacuum system is used, allowing high velocity air to pass through drum sucking flowers onto drum or picking side and pulling flowers off drum and cleaning side.

Total picking head is enclosed in a vacuum chute which leads to a collection bin.

With reference to Figs. 18 to 20, picking head using a pianetary gear arrangement as illustrated.

Drum 1, gears (2) and drive gear (3) are intermeshed and timed to effectively control and maintain the position of the square bar to which picking fingers are attached. As drive gear (3) rotates in a clockwise direction gears 2 are driven anti-clockwise movement. Fig. 20 shows the various movements of the geared system. Drum revolution speed is 1/2 that of drive gear to ensure that picking fingers are always in correct relation and position to drum. This embodiment again ensures that picking fingers are extended in the picking position only and retracted when cleaning and travelling over foliage to stop entanglement and consequent pick up of foliage.

Again drum is slotted to allow picking fingers to extend and retract and a vacuum system is used in association with perforations 55 in the drum. High velocity air can be used in association with this drum to sucl < picked flowers onto the drum in picking position and to pull them off in cleaning position. The head is enclosed in a vacuum chute 73 which leads to a collection bin 71 as per Figs.

8 and 8A.

Figs. 23 to 27 and 30 to 35 show various methods of collecting harvested flowers using either a vacuum or conveyor transport or combination of both.

Referring to Fig. 24, the tractor frame is mounted on wheels 20 with the operator's cabin 21 disposed above and adjacent the picking head attachment 22. The tractor is adapted to straddle the plants to be harvested. This form of harvesting is particularly suitable for pyrethrum flower picking. The picking head attachment is a rotating drum with retractable picking fingers with removable fingers so that larger fingers can be fitted to selectively pick mature flowers. Or the harvester can be fitted with another of the beforementioned embodiments, the picking head being driven hydraulically.

The picking head attachment 22 is mounted on a pivotal boom 24 for up and down movement under the control of power cylinder 25. The boom is preferably pivoted near the rear of the machine at point 26. The boom 24 forms part of the mounting frame 24 for the storage bin 27 and suction equipment 28. The construction is such that the picking head attachment 22, the storage bin 27 and suction equipment 28 and associated ducting 29 all move in unison about pivot 26 upon operation of the power cylinder 25.

The ducting 29 connects between the picking head 22 and the suction equipment 28 via the storage bin 27. The ducting acts to carry harvested material to the storage bin 27, the trajectory of the ducting is such that the material in the air current enters the bin near the top in a horizontal direction. As the air and material enters the bin the increase in area results in a loss of velocity and impetus so that the harvested material falls under the influence of gravity into the bottom of the bin. The bin 27 thus forms a part of the air suction path and in its closed position effectively seals the vacuum path formed between the picking head attachment 22 and the suction equipment 28. The suction equipment 28 inclues an interna combustion or hydraulic motor driven blower fan of conventional construction. A similar arrangement is illustrated in Fig. 23.

The operation of the storage bin will now be described with reference to Figs. 25,26 and 27 and Figs. 28 and 29.

Figs. 25,26 and 27 show the various unloading positions of the bin 27 which is pivotally mounted on axle 30. The periphery of the bin 27 has a cut out segment 31 which is normally closed by the vacuum chamber flange 33 in the closed bin loading position shown in Figure 23. As the bin turns through 180 the bin is completely emptied assisted by the provision of a flat bottom part 34 which is vertical when the bin is completely turned.

The bin is turned by a power cylinder mechanism shown in Figs. 28 and 29. A sprocket 40 is fixed to the pivotal bin 27, the sprocket 40 interconnects with a chain or belt 41 connected at each end to power cylinders 42,43 adapted to operate in opposite directions in unison. Thus a cylinder 42 retracts cylinder 43 extends so that the bin is turned to an unloading position.

In addition to abovementioned harvester, another harvester having rubber tracks as shown in Fig. 30 is provided. Also included in this harvester is the vacuum suction system described above the addition of air blowers mounted on top tip of front chute. See Fig. 31. In this embodiment high velocity air via vacuum system is not used, but a conveyor belt is used to convey picked flowers which are blown via the air blower mounted on the front chute onto the conveyor and thence, to the storage receptacle.

With reference to Figs. 28,29 and 33, the bulk bin 1 is pivoted at point 2 and supported on frame 24. Power cylinders 42 Fig. 28 connected to pulley 40 rotate frame 24 to swing the bin out and hang until the frame is fully rotated to rest the bin on the ground. Thus the bin can be lowered and swung out away from the frame of the machine to place the bin on the ground, to detach it and allow for bulk handling of the contents. The bin can be re-engaged by following the reverse procedure.

With reference to Figs. 38 and 38 (a) the bin has pegs 60 engageable with hook members 61. Thus the frame can lower or raise a bin from or onto the harvester. The bin is engaged against the frame of the machine for stability.

In the embodiment shown in Figs. 30 and 31 the various pyrethrum picking heads can be attached forward of a conveyor 50, angle air jets blow the picked flower onto conveyor 50 which transports them to a storage bin 51 or container which can be lowered from the machine for bulk handling. Figs. 38 and 38a show the bin handling in greater detail.

The bar 51 is supported on central pivot point 80 by pivotal arm 81 which is controlled by power cylinder 82 supported on the rear of the tractor frame shown in Fig. 30. The pivotal arm 81 is adapted to lower the bin onto the ground in response to extension of the power cylinder 82 as shown in Fig. 38a.

Figs. 32A and 32B show another embodiment using chains 90 and sprocket bars 91, the chains having picking combs 93 thereon which runs a triangula path 94. The chains 90 are guided between support frame members 95 to protrude at the leading edge (see Fig. 32A) and retract at the trailing edge.

The picking head is preferably used in association with a vacuum shroud 73 and scraper 56 as previously described. The open frame construction 95 allows free flow of an air draft therethrough and into the conveyor tube.

The fingers protrude through the steel frame (5) in the picking position and retract out of. the way in the cleaning position as shown in Fig. 32A.

This embodiment used with vacuum system and collection bin allows the air to flow through the steel frame and sucks flowers against frame and puis them off on the cleaning side.

To overcome the problem of fallen plants and flowers rotating combs or pick up bars schematically shown in Fig. 32C are provided for mounting in front of the pick up head for contact with the header. In Fig. 32D angle type bars are provided contact side flowers. Thus side flowers which are outside the track of the harvester are picked up using the angle arrangement as shown.

With reference to Fig. 35 the picking head may be placed ahead of the harvester so that a wide path can be harvested ahead of any wheel damage inflicted on the stems and flowers to avoid the necessity of growing pyrethrum in beds (which is the traditional method) and allows broad acre field planting with increased density per acre.

It has been found that one of the problems in harvesting pyrethrum is the necessity to hold the picking head at a set distance from the ground to avoid the picking comb reaching down into the pyrethrum plant thus contacting and harvesting unwanted stem and foliage material. In one embodiment shown in Fig. 36 this problem can be overcome by the use of a pair of large diameter equal size tractor tread type types 100, driven and mounted on a box angle assembly 101 that can be extended by power cylinder 102 to widen the track once off road and in field to give a wider area of support to the wide picking head or heads. The large diameter tyres prevent minor ground surface irregularities entering the head heights.

Figs. 37 and 37a show schematically a further embodiment applicable to the chassis shown in Fig. 36 wherein multiple picking heads 105 are mounted forward of the front bar axle 101, the picking heads 105 (a) and (c) are pivotal as shown in Fig. 37a for transport.

With reference to Fig. 8A, a turbine 70 creates vacuum in a chamber 71 causing the pyrethrum flowers to be transferred from the picking heads to ducts 73 the revolving screen 74 prevents flowers passing through machine, and the drop in air velocity in the chamber allows flowers to settle onto slatted mobile floor 76 which then conveys the flowers while maintaining air locks at 77 and 78. A brush 79 may be provided to maintain the screen 74 clear of debris.

With reference to Figs. 39A and 39B the removal of unwanted leaf and stem is achieved by a secondary mobile screen type floor separating flowers from loose stems which latter are ejected.

This can be carried out in two forms by using a screen conveyor 110 or a rotating mesh drum 111 mounted over a hopper 112. The harvested flowers are placed on the conveyor or in the drum through which flowers fall into hopper with unwanted foliage going to waste.

Claims (10)

1. A harvesting machine for pyrethrum flowers comprising a mobile frame, a header mounted forwardly of the frame for contacting a crop to be harvested the header including a rotatabie drum including picker means mounted relatively to said drum for engaging and picking mature pyrethrum flowers.

2. A harvesting machine as claimed in claim 1, said picker means is a series of rotatable rods extending along the drum and mounted on an endless chain support means for engaging flower heads forcing them into contact with said drum to remove those heads of mature size for collection, the rotatable rods moving at a speed differential to said drum to provide a picking effect on the flowers.

3. A harvesting machine for pyrethrum flowers comprising a mobile frame, a rotatable header drum with a series of circumferentially disposed combs having radially extending fingers, the spacing of the comb fingers being such that the flowers of predetermined maturity are picked.

4. A picker head for a pyrethrum harvesting machine as claimed in claim 3 comprising a drum or series of picking fingers mounted on the drum and movable relative to the drum to project on the leading edge of the drum and retract at the trailing edge of the drum.

5. A pyrethrum harvesting machine as claimed in claim 2,3 or 4 including a picker head mounted in conjunction with vacuum means adapted to draw harvested material away from the head into a storage area.

6. A pyrethrum harvesting machine particularly for harvesting pyrethrum flowers comprising a mobile chassis, an adjustable height picking head attachment for accurate positioning relative to the plants, a crop conveying device associated with the picking head attachment for receiving and conveying crop to a storage device, said storage device including a rotatable drum movable between two angular positions one to receive said crop, and the other an emptying position.

7. A pyrethrum harvesting machine as claimed in claim 6 wherein the picking head attachment is a rotating drum with retractable fingers (picking combs); these fingers are removable so as to allow different diameter fingers to be attached to selectively pick mature flowers.

8. A pyrethrum harvesting machine as claimed in claim 6 wherein the conveyor device is a duct subjected to vacuum such that picked crop material is drawn from the picking head attachment by suction along the duct to said storage device.

9. A pyrethrum harvesting machine including a fluted roller drum mounted horizontally adjacent to a second fluted roller drum and spaced therefrom a predetermined distance to engage mature pyrethrum flowers therebetween for harvesting, therefore selectively harvesting flowers that are mature; the top fluted drum is substantially double the diameter of the lower fluted drum therefore resulting in a speed twice that of the smaller lower drum, the flutes are twice as far apart and engage the flowers pulling them . in between the fluted rollers of the larger drum to remove the mature flowers.

10. A pyrethrum harvesting machine as claimed in claim 9, wherein the radially extending combs or flutes include retractable fingers mounted for reciprocable movement relative to said exterior of the drum such that flower heads of predetermined size are picked and carried partly around the periphery of the drum and released as said fingers are retracted; the outer surface of the drum is associated with an enveloping shroud connected to a source of vacuum adapted to collect harvested flower heads as they are released by the retracting fingers.