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Title:
TEA HARVESTER
Document Type and Number:
WIPO Patent Application WO/2000/028804
Kind Code:
A1
Abstract:
There is disclosed a tea harvester having a support structure (A) intended to be supported on an upper region of a canopy of tea bushes in a tea bush plantation, the support structure (A) including a support frame (1, 4, 5) carrying a front roller (10) and a rear roller (11), drive means (8, 9) to drive at least one of the rollers (10, 11), a tea harvesting cutter assembly mounted from the support structure (A) in front of the front roller (10) and rearwardly of a height adjusting roller (E), and cut tea leaf collection means (D) carried on the support structure (A), the support frame having at least three longitudinally extending beams (1, 5) and at least two longitudinally spaced transverse connecting members (4) connected to each of the longitudinally extending beams (1, 5), each of the beams (1, 5) being constructed of a core (2) of solid expanded polymeric foam material with a skin (3) bonded to said foam material (2), said skin (3) being formed by a light weight metal.

Inventors:
Williames, Geoffrey Allan (Wills Street, Warragul, VIC 3820, AU)
Application Number:
PCT/AU1999/000982
Publication Date:
May 25, 2000
Filing Date:
November 08, 1999
Export Citation:
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Assignee:
WILLIAMES HI-TECH INTERNATIONAL PTY. LTD. (Wills Street, Warragul, VIC 3820, AU)
Williames, Geoffrey Allan (Wills Street, Warragul, VIC 3820, AU)
International Classes:
A01D46/04; (IPC1-7): A01D46/04
Attorney, Agent or Firm:
WATERMARK PATENT AND TRADEMARK ATTORNEYS (2nd floor, 290 Burwood Road Hawthorn, VIC 3820, AU)
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Claims:
THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:
1. A tea harvester including a support means adapted, in use, to be solely supported on an upper region of a canopy of tea bushes in a tea bush plantation, said support means including support frame means carrying front and rear roller means and an endless conveyor spanning said support frame means and extending around said front and rear roller means, drive means to drive at least one of said front or rear roller means, tea harvesting cutter means carried by said support means, and tea leaf collection means carried by said support means to receive tea leaf cut by said cutter means, said tea harvester being characterized in that said support frame means includes at least three transversely spaced longitudinally extending beams and at least two longitudinally spaced transversely extending connecting members connected to each of said longitudinally extending beams, each of said beams being constructed of a core of solid expanded polymeric foam material with a skin bonded to said foam material, said skin being formed by a light weight metal.
2. A tea harvester according to Claim 1, wherein the polymeric foam material is expanded polystyrene foam.
3. A tea harvester according to claim 1 or claim 2 wherein the skin is a high tensile light weight metal.
4. A tea harvester according to Claim 1 or Claim 2, wherein the skin is formed by aluminium or aluminium alloy.
5. A tea harvester according to any one of Claims 1 to 4, wherein each outermost said longitudinally extending beams have formations in upper and lower edges cooperable with formations located along edge regions of the endless conveyor.
6. A tea harvester according to Claim 5, wherein the formations along the edge regions of the endless conveyor are also adapted to engage with drive formations of at least one of the front or rear roller means to thereby drive the endless conveyor.
7. A tea harvester according to any one of Claims 1 to 6, wherein the cutter means is positioned in front of the front roller means with a further adjustment roller being located forward of the cutter means, the further adjustment roller being supported for height adjustment relative to the cutter means.
8. A tea harvester according to claim 7 wherein the further adjustment roller is constructed of a central shaft formed by a tube of light weight metal and a plurality of discs connected to the central shaft and spaced therealong, with a sheet material wrapped around and secured to said discs.
9. A tea harvester according to claim 8 wherein the sheet material is a polyfabric heat shrunk onto said discs.
10. A tea harvester according to claim 8 wherein the sheet material is a light weight metal sheet.
11. A tea harvester according to any one of claims 8 to 10 wherein the discs are formed from a solid expanded polymeric foam material with at the at least the outermost said discs having a skin of light weight metal secured thereto.
12. A tea harvester according to claim 7 wherein each of the front and rear roller means are constructed of a central shaft formed by a tube of light weight metal and a plurality of discs connected to the central shaft and spaced therealong, each said disc having a core of solid expanded polymeric foam material with a skin of light weight metal secured thereto.
13. A tea harvester cutter assembly comprising a transversely extending stationary cutter bar and a sub assembly of a plurality of cutter bars each being movable past said stationary cutter bar in a cutting action to cut tea leaf growth therebetween, said sub assembly of movable cutter bars being rotatable about a rotational axis generally parallel to said stationary cutter bar with a region within said sub assembly of movable cutter bars being substantially open and unobstructed along at least a cutting region of the cutter assembly.
14. A tea harvester cutter assembly according to claim 13 wherein at least three of said movable cutter bars are provided connected to one another at least one intermediate transverse position by a respective brace member.
15. A tea harvester cutter assembly according to claim 13 or claim 14 wherein each said movable cutter bar has a cutting edge formed in at least two sections, each section being angled or inclined radially inwardly from an intermediate point.
16. A tea harvester cutter assembly according to claim 15 wherein a plurality of said intermediate points are provided spaced along the cutting edge.
17. A tea harvester cutter assembly according to any one of claims 14 to 16 wherein a forwardly extending projection is provided on said stationary cutter bar at the or each said brace member, and/or at the or each said intermediate point.
18. A tea harvester including a support means adapted, in use, to be solely supported on an upper region of a canopy of tea bushes in a tea bush plantation, said support means including a drivable endless conveyor for engagement with the tea bush canopy, said support means carrying a tea harvester cutter assembly at a forward end, said cutter assembly being in accordance with any one of claims 13 to 17.
19. A tea harvester according to Claim 18, further including a cut tea leaf delivery means arranged to receive the cut tea leaf from the cutter assembly and deliver same to a collection means carried by the support means at a rearward location, said delivery means including a chute extending upwardly and rearwardly from the stationary cutter bar of the cutter assembly, and a plurality of spaced transversely disposed members arranged to move along said chute and move cut tea leaf towards said collection means located at a rearward end region of the chute.
20. A tea harvester according to Claim 19, wherein drive means to move said transversely disposed members along said chute is also utilised to rotate the movable cutter bar sub assembly.
21. A tea harvester according to claim 20 wherein a said transversely disposed member is arranged immediately behind each said movable cutter bar of the cutter bar assembly as the respective movable cutter bar passes the stationary cutter bar.
22. A tea harvester according to claim 20 or claim 21 wherein said transversely disposed members are carried by a pair of spaced endless chains, at least one of said endless chains also cooperating with and drive the movable cutter bar sub assembly.
23. A tea harvester according to any one of claims 18 to 22 including two said support means located side by side with the drivable endless conveyor of each said support means being independently drivable.
Description:
TEA HARVESTER The present invention relates to improvements to tea harvesting machinery.

International Patent Application No. PCT/AU92/00376 and equivalent National Phase Patents and Patent Applications therefrom discloses a novel tea harvesting machine supported in use solely by the tea bushes being harvested with a counter balanced cutting head having its cutting depth controlled by a forward supporting roller. The subject matter of the aforesaid International Patent Application is incorporated herein by this reference thereto.

The ability of a tea harvesting machine to be solely supported by the tea bush canopy provides a number of significant advantages. Firstly, it eliminates the problem of ground compaction, root disturbances and damage that can be caused by more expensive wheeled and tracked machines and avoids the irregular height cut of hand held machines with the resultant poor quality tea leaf harvested. It also means that the plantation can be allowed to grow over the existing clear rows between the lines of bushes currently being used for vehicle access, which subsequently increases the yield of the plantation by increasing the area harvested by up to 15% in the same area. By increasing the area harvested, by means of a continuous tea bush canopy, weed growth is controlled reducing the need for herbicides. Also the need for large headlands, which are used for turning the wheeled and tracked machines to re-enter the rows, is removed and the tea plantation area can be extended to include these headlands. This again increases yields and productivity from any given tea harvesting plantation. By this means, certain civil works such as culverts, roads and bridges for access to each end of the tea bush rows may also be eliminated.

It is therefore an objective of the present invention to provide an improved tea harvesting machine (or parts thereof) that will enable tea harvesting of very high quality tea with the tea harvesting machine being solely supported by the tea bush canopy.

Accordingly, the present invention provides features and aspects as defined in any one of the claims annexed hereto or any one or more of the features either singly or in any combination as hereinafter described.

In one preferred embodiment, the basic configuration of this machine is a single cut lightweight hand held unit, which is self-propelled. In another preferred embodiment, a second configuration is the joining of two of these machines together, side by side, using a single, central rear drive engine and transmission with chain drive to both the rear drive axles. The transmission on the twin machine enables it to be steered by rotating one drive belt in reverse and the other drive belt in the forward direction for counter rotation or any differential in speeds and for gentle changes in direction. The machine can be radio controlled for remote operation or this double machine is stable and strong enough to support an operator using a unique construction allowing support of 115 times its own weight. Each machine has its own cutter bar with a tea diverting means between the two machines to divert the uncut tea into the separate cutter bars, conveying means and leaf collection means. It is again only supported by the tea bush canopy. In one embodiment the combining together of the two machines doubles the productivity per hectare harvested with only one operator.

The invention will now be described with reference to the accompanying drawings which show various preferred embodiments and preferred features.

In the drawings, Figure 1A is a schematic side elevation view of tea harvester apparatus according to one preferred embodiment of this invention; Figure 1 B is a schematic plan view of apparatus of the type shown in Fig.

1A; Figure 2A is a perspective view of a support frame forming part of the apparatus of Fig. 1A; Figures 2C and 2B are detailed cross-sectional views of parts of the support frame shown in Fig. 2A; Figure 3 is an exploded view showing a method of construction for the beams utilized in the support frame of Fig. 2A; Figure 4 is a schematic perspective view partially exploded showing a sub assembly including the support frame of Fig. 2A together with front and rear roller members;

Figure 5 is a perspective view of a drive sprocket wheel intended as part of the front and rear roller members shown in Fig. 4; Figures 6 and 6A are a schematic perspective view and a part detail view of an endless conveyor belt cooperable with the sub assembly shown in Fig. 4.

Figures 7A, 7B and 7C are further detailed views of part of the endless belt shown in Fig. 6.

Figure 8 illustrates one preferred form of drive motor; Figure 9 shows in perspective form one preferred form of a cutter assembly; Figures 9A and 9B illustrate sequentially a cutting process of the cutter assembly shown in Fig. 9; Figures 9C and 9D illustrate alternative preferred forms of cutter assemblies; Figure 10 illustrates schematically in side view features of the cutter assembly and lower regions of a cut tea leaf delivery chute; Figure 11 illustrates schematically features of the cut tea leaf delivery chute; Figure 12 illustrates one preferred form of cut tea leaf collection means; Figure 13 shows a construction method for a forward height of cut adjusting roller; Figures 14A to 14D show various configurations and features of a tea harvester including two independently driven endless belt support arrangements; and Figure 15 shows a schematic plan view of the arrangement shown in Figs. 14A and 14B.

In a preferred embodiment illustrated in Figure 1A, the machine includes five sections, a main frame (A), including drive mechanism and drive belt, a cutter bar assembly (B), a leaf conveying means (C), a leaf collection means (D), and an outrigger roller (E), attached to the conveyor to maintain exact picking height regardless of undulations and in relationship to the previously harvested surface. Figure 1 B shows the position of a cutter/conveyor engine transmission (F), a propulsion engine transmission (G) and operator handles

(H). As the tea bush canopy supports the machine, and there is no ground contact at all, minimum weight is of the utmost importance. To achieve the lowest weight possible, a novel type of construction has been employed.

The main frame (Figures 2A, 2B and 2C) includes a plurality of longitudinal lightweight beams (1) comprising of expanded polystyrene (EPS) sections (2) (Figure 3) totally enclosed with thin sheets of high tensile aluminium (3) which is attached to the EPS with a specialised adhesive. When tested this construction was able to support 115 times its own weight without failure ensuring a very strong yet extremely light construction. Joining these longitudinal members (1) (Figure 2A, 2B and 2C) are a number of laterally placed high tensile aluminium, fibreglass or carbon fibre tubes (4) on which the longitudinal beams (1) are positioned at specified locations. The joints of the longitudinal beams (1) and lateral tubes (4), in one preferred embodiment, are glued using a structural grade adhesive combined with a pressed steel collar (4b) (Figure 2C) on either side of the longitudinal beams (1).

On the two outside beams (5), on both the top and bottom surface running full length of the beam, are prefabricated slots (6) fabricated from, preferably, stainless steel which form an inverted"V", (Figure 2B). These slots (6) are provided to accommodate the drive and alignment wedges (22) attached to the drive belt (20) (see Figures 6A and 6B). At the front of the main frame assembly, on either side, are adjusters (Figure 4) (7) to tension the drive belt.

In one preferred embodiment, at the rear on one side of the main frame is a bearing assembly to accommodate the rear axle and on the opposite side a right angle drive reduction box (8) is used as an integral part of the main frame which uses the bearings in the reduction box to accommodate the opposite end of the rear axle. Mounted on top of the reduction box is a lightweight fuel- efficient small four-stroke engine (9), which drives the drive belt (20).

The front roller assembly (10) and rear roller assembly (11) are made from high tensile aluminium tube and positioned across these tubes are a number of EPS discs (12) with a skin of thin high tensile aluminium sheet (13) glued to both sides of the EPS discs. Around the circumference of these discs there is a section of aluminium sheet (14), again glued to the outer circumference of the EPS discs. On either side of these tubes, or axles, are

located the combination guides and drive sprockets (15) which engage in the wedges (22) attached to the drive belt (Figure 7A and 7B). The two rear sprockets are the drive sprockets, and the front two are idlers. These sprockets (Figure 5) are so designed that any tea debris or material trapped between the belt and the sprocket is squeezed out through the openings (16) between the sprocket teeth (17) and down the sloping outside face (18) of the sprocket by the belt wedges (22). This eliminates any build up on the sprockets and subsequent stretching, riding off and consequent breakage of the belt. The drive sprocket assembly combines the multiple functions of driving, alignment and belt tensioning.

To stop any flexing or bending of these axles when the belt is tensioned, four lengths of small diameter rods of stainless steel or high tensile material, (Figure 4) (18) are provided at ninety degrees apart running the full length of the axles, passing through the intermediate discs (12) and outside sprockets (15).

Where these rods pass through the outside sprockets (15) the rod is threaded with a nut (19) either side of the sprocket. This enables the tensioning of these rods to straighten and stiffen the axle assembly. In an alternative form of construction for the front and rear roller assemblies 10,11, a simple length of aluminum pipe may be utilized having the same diameter as and connected to the drive sprockets (15) (as shown in Fig. 4). This provides a simpler construction avoiding the need for the discs 12, cross tubes or axles and the stainless steel rods (18).

Figures 6A and 6B illustrate the drive belt which includes a full width, lightweight single ply endless belt (20). Running full length around both outside edges of the belt are four strips of belt reinforcing (21), two per side, one attached to the top of the belt and one attached to the underside of the belt.

These add extra strength to the belt on the outside edges to eliminate stretch.

They also act as reinforcing for the attachment of the drive and alignment wedges (22), which are fastened to the underside of the belt (20) at the correct pitch which matches the pitch of the sprockets (Figures 7A, 7B and 7C). These wedges are manufactured from nylon or equivalent material. Running laterally across the belt at a set distance apart are stiffener bars (23) (Figures 6A and 6B, also Figures 7A, 7B and 7C) made from a composite or lightweight material

for lightness and strength. These bars are attached to the belt (20) either by mechanism fasteners (23A and 23B) or bonded pockets (23C) to the belt.

These lateral bars assist in traction of the drive belt and they also stop the belt from turning over on itself when the machine is turned by giving a stiffness to the belt. The upper and lower U-shaped tracks (6) (Figure 2) also assist in guiding and holding the belt taught and in the correct location with the stiffener bars of fibreglass, high tensile aluminium or carbon fibre being attached to the belt and the side V blocks.

The drive (Figure 8), in one preferred embodiment, is composed of a small fuel efficient four stroke engine (9) running through a V-belt drive (24) to the input shaft of the right angle drive box (8). The drive is engaged by an over centre roller assembly (25) the roller of which runs on the outside of the V-belt (26) between the pulleys (27), and when pressure is applied to the V-belt via the roller it pulls tight on the pulleys and the drive is engaged. A guard (28) surrounds the V-belt drive and also stops the belt from coming off the pulleys when the drive is disengaged and in the relaxed position when in neutral, holds the belt clear of the driven pulley to act as a clutch for engaging and disengaging the drive to the belt.

The cutter bar shown (Figure 9) includes three lateral crossbars (29) which run full width across the harvester, onto which the cutter blades (30) are bolted. These lateral bars (29), in one preferred embodiment, are placed at 120 degrees to each other and are connected to each end hub (31) via connecting bars (32). The cutter bar rotor assembly (33) is hollow in the centre (that is, no central shaft) to allow the entrance of the tea to the cutter bar assembly. In (Figure 9A) the drawing shows the direction of travel and the tea foliage enclosed within the cutter rotor assembly (33) and the cutter bars rotating around the outside of the foliage in the direction of the arrow, and in (Figure 9B) it shows the cutter bar (33) cutting edge intersecting with the cutter bar anvil (40) and tea foliage stem, consequently cutting the tea foliage. To ensure torsional integrity triangular braces (34) are welded to the cross bars (29) in one or more positions. In one embodiment one central triangular brace (34) is used with a corresponding horizontal forward facing projection in a V shape (64) which is attached to, or is part of, the lower cutter bar anvil (40) protruding

forward of the cutter separating the foliage from the triangular brace (34). If desired a plurality of spaced brace members (34) may be provided each having an associated V-shaped projection (64) on the stationary cutter bar (40). The novel feature of the hollow cutter bar rotor in lieu of a central through shaft is that a central shaft pushes the tea over in a forward direction causing it to remain outside the cutting members, missing long stems of tea, which eliminates a clean cut of the full length of tea foliage. In another preferred embodiment (Figure 9C shown in the drawing, for aid of clarity, without sprockets or centre supports), the cutter bar cross bars (29) are angled out toward the direction of cut to a central peak (65) this produces a scissor type action as the rotor blades (30) sweep past the anvil blade (40). In the centre of the anvil blade (40), matching the peak of the rotor bars (65) is a cutter bar guide (66) or forward facing V, as described above, which protects the blades (30) on the rotor from engaging against the front face of the anvil blade and it also acts as a guide to direct the tea into the path of the rotary blades at the joint point of the diverging angular blades at (65). The increased section of the cross bars (29) at the centre section reduces deflection at the central highest point of loading. In another embodiment, (Figure 9D which shows a section of the top bar only) there are a number of peaks (65) on the cross bars (29) of the rotary cutter at specified distances apart, and on the anvil blade are guides (66) placed at the same distance as the peaks to guide the blades and direct the tea into the path of the blades. This allows for a multiple of scissor type actions across the full width of the cutter bar. The blades (30) are shaped to allow for the radius of the cutter assembly, so that the blades engage against an anvil cutter blade (40) and cut precisely and cleanly over the full width.

On each end of the cutter bar is a sprocket (35) which carry the chain (36) on which the conveyor cleats (37) are attached. The cleats which run full width of the cutter bar rotor assembly (33), are spaced and timed to fit neatly behind each of the cutter bar cross bars (29) (Figure 10), one cleat behind each cross bar. As the tea is cut, the cutter bar assembly (33) sweeps the cut tea onto the conveyor frame (38) and rotates out of the way. But as the conveyor cleat (37) (figure 10) is immediately behind the cross bar (29) this cleat comes into contact with the cut leaf (39) and elevates the cut leaf up the conveyor

frame (38). In another embodiment the leading edge of the elevator cleat closest to the cutter bar cross bars is radiused to fit very closely behind the cross bar (29), the radius being equal to the passage of the elevator cleat as the conveyor chain leaves the cutter/conveyor and proceeds up the conveyor. The combination of the hollow rotary cutter assembly (33) and the conveyor with full width elevator cleats (37) which run around and within the outer circumference of the cutter bar assembly (33) is novel and unique. It allows for a lightweight and gentle method of cutting and conveying high quality tea leaf as a combined process. Attached to the bottom edge of the conveyor frame is the cutter anvil (40), on which the ajustable anvil cutter blade (41) is bolted. It is so positioned that the tea foliage comes against this fixed blade and as the rotating cutter bar assembly (33) rotates, each bar (29) with its cutter blade (30) sweeps past the anvil blade (41) and subsequently cuts any foliage trapped therein. On one side of the cutter bar assembly and in one preferred embodiment, is a drive mechanism (42), which is identical in function to the arrangement for the main frame final drive.

The leaf conveying means shown in Figure 11 includes an external framework (38), the cleated conveyor chain (37) and the fixed cutter bar anvil (40). The framework is manufactured using the same method as the longitudinal beams of the main frame, that is, sheets of EPS with lightweight thin high tensile aluminium sheet glued to either side with an upper and lower channel cap bonded to the EPS and fastened to the high tensile aluminium side sheets. Attached to the floor of the conveyor frame are two strips of high- density polyethylene (43), or equivalent material on which the conveyor cleats (35) slide on their way up the conveyor frame. Mounted near the top of the conveyor frame vertical sides (44), one per side, are two more sections of polyethylene (45), which act as chain guides for the return chain.

The leaf collection means shown in Figure 12 includes an external framework (46) attached to the main frame, which supports a number of full harvesting width mesh bags (47). These mesh bags are supported by high tensile aluminium tubes (48) which fit into runners (49) down each side of the bag to form a stretcher type arrangement for carrying the full bags. The empty bags are stored on the harvester in a closed position on a bag cassette type of

arrangement (50), then stretched by moving the adjacent aluminium tubes out and apart when ready to be filled. A further advantage of this bag storage method is that it lends itself to the ongoing tea transport and processing from the harvester to the transport trailers to tea factory and used as withering troughs and after withering can be used as a means of transporting, emptying and conveying withered leaf directly into the tea processing machinery in the tea rooms.

The outrigger roller is shown in Figure 13 and includes a central high tensile aluminium tube axle (51) with intermediate EPS discs (52) glued onto this axle at a predetermined distance apart. The two outside roller disc assemblies (53) are enclosed in thin high tensile sheets of aluminium (54) and are mechanically attached to the inner tube to form the roller assembly. In one preferred embodiment, polyfabric (55) is wrapped around and bonded to all of the discs full length along the roller assembly (56). This fabric is heat shrunk to form an extremely lightweight and smooth outer skin and subsequently covered with a protective coating. In another embodiment thin wall high tensile aluminium sheet can be wrapped around the discs and mechanically fastened to make a lightweight roller assembly. The function of this roller is to both adjust the height of the cutter bar assembly mounted on the pivoted conveyor frame and maintain an even, exact picking height regardless of tea canopy undulations. A top linkage (57) (Figure 1) is adjustable and able to be lengthened or shortened by means of a turnbuckle type arrangement, therefore either raising or lowering the picking head.

On a twin machine (Figure 14) the only difference is the design and location of the drive mechanism (57) and operators platform (58). A single drive engine (59) is located between and above the two drive belts (60). The engine drives through a simple transmission (61) and a chain drive (62) is used to each rear drive axle (63). Figure 14B shows a rear elevation. This transmission arrangement is described in detail in the previous International Patent Application No. PCT/AU92/00376 and subsequent separate country applications but is further described hereinafter with reference to Figures 14C and 14D hereof.

A drive transmission 24 shown in Figures 14C and 14D includes an independent motor 31 provided to drive the rear rollers 13 and thereby the belts 11,12. The transmission further includes a V-belt 32 driven by the motor 31 and via cone V-belt pulleys 33 (so that speed ratios can be changed) driving a primary shaft 34. On the outer ends of the primary shaft 34 are V-belt pulley wheels 35,36 adapted to receive V-belts 37,38. Adjacent to but inwardly of the pulley wheels 35,36 are rollers 39,40 each having a compressible material on the rim (such as polyurethane, rubber or friction material). From the primary shaft 34, the V-belts 37,38 are arranged to drive pulley wheels 41,42 on respective intermediate shafts 43,44. The right-hand intermediate shaft 44 drives the right-hand belt 12 via roller 13 and the left-hand intermediate shaft 43 drives the left-hand belt 11 via its associated roller 13. On the inner ends of the intermediate shafts 43,44 are respectively sprockets 45,46 which drive sprockets 47,48 connected to the shafts 49,50 of the rollers 13 via chains 51, 52. Finally, on the intermediate shafts 43,44 there are provided steel run rollers 53,54 aligned with the rollers 39,40 on the primary shaft 34. Connected to the roller 54 is a brake (not shown) which may be used as a parking brake.

The function of the drive transmission 24 is as follows. The transmission is operated by two levers 55 (see Figure 14A) each with a linkage 56 to the primary shaft 34. If both levers 55 are pushed forward (as in Figure 14A) the linkages 56 raises the primary shaft 34 which drivingly engages the V-belts 37,38 and causes forward movements of both belts 11,12. This position is maintained via spring tension applied by springs 57,58. If the two levers 55 are pulled back to a vertical position, the V-belts 37,38 are disengaged from driving their respective pulleys and the machine is placed in neutral disengaging both belts 11,12 from the drive motor 31. If both levers 55 are pulled back towards the operator, this engages the two rollers 39/53 and 40/54 causing reverse motion to be applied to both belts 11,12. For turning left or right, one lever 55 is kept forward keeping its associated belt 11,12 moving in a forward direction and the other lever is pulled back to enable the other of the belts 11,12 to either stop or move in a reverse direction depending on the tightness of the turn required.

The combination of two variable support units can be used with a centrally mounted single tea harvesting unit as described in Figure 1 which reduces he pressure on the tea bush to 50% that in the form described in Figure 1 which is required for less mature tea that has not fully established a broad frame and full width canopy.

Figure 15 shows a plan elevation of this machine with the single cutter and conveyor (64), twin drive belts (60) central engine/transmission (59) and operators platform (58).