Mobile planter

Abstract: A planter for placement of plants in spaced parallel rows in the soil has a plant dispenser (30) fed manually or automatically from a plant supply and delivering to a furrow-opening coulter (50) assembly and press wheels (46). The plant dispenser (30) comprises a drum having an internal impellor defining plant-receiving chutes through which the plants (34) pass, and thence downwards and outwards through an opening in the drum. The coulter assembly has reciprocated coulter side plates (48) which receive and support each plant in a receiving zone between them, and by forward movement relative to the plant and relative to a fixed placement member (84) located in front of the plant, allow soil to flow back to cover the plant's root ball. The press wheels (46) are mounted with a variable castor angle to vary their soil-­ gathering effect. A hitch has twin parallel toolbars whereby the row units are freely laterally position-­ adjustable even across the tractor hitch.

Description: This invention relates to mobile planters for placing plant material in the ground, and to a plant material placement mechanism. In agriculture and horticulture there is a requirement for high speed transplanting of plants. Such plants are grown from seed to a size at which they can be handled by manual or automatic manipulation of the vegetative part. They are transported to the field of work in moulded plastic trays. Each tray has a large number of individual recesses each containing a quantity of plant growing medium in which a seedling has been growing, and from which the seedling and its root ball incorporating the plant growing medium (the assembly being known as a module) can be removed by pulling. There is a requirement for planting, for example, approximately 100,000 plants per working day with a planting machine drawn by a tractor and having several operatives handling the plants for the individual rows being planted by the machine. The invention concerns the need for improvements in the mechanism for placement of plants in furrows in the soil. Previous proposals provide for each plant to be deposited between the side plates of the coulter assembly, which temporarily support the plant, whereupon it is pushed out rearwards by a reciprocated ejector plate to its final resting place, to make room for the next plant. This arrangement suffers from various shortcomings including the fact that soil fills back into the furrow behind the counter before the plant reaches its destined location. As a result the plant is effectively pushed out into a furrow which has already been at least partially refilled with soil. In consequence, it not infrequently happens that the plant ends up with its roots on top of the soil, and since it is in any case laterally unsupported at this stage, the plant in such a case will usually be at an attitude other than the desired upright one. The phenomenon will perhaps be more readily understood if consideration is given to the inherent dynamics of the movement of the reciprocated ejector or placement plate. Even at a planter ground speed of only 1.6 km/h (1 mile/h) if the plant spacing in the row is only a few centimetres, the ejector plate will have to move at a speed so as to make a full reciprocative movement in the time taken for the planter to move a few inches. As a result, the ejector needs to move significantly faster than the planter ground speed and it therefore imparts significant momentum to each plant, which likewise is not favourable to achieving a stable and predetermined placement of the plant. Also, the mechanism is unduly influenced by the varying effect of gravity on undulating terrain. Moreover, the ejector plate is inclined to become jammed with soil and/or plant material, particularly when the next plant drops before the plate has returned to its starting position. There is disclosed in AU-B-560 051 a mobile planter as defined in the pre-characterising portion of claim 1 hereof. In DE-A-2 424 011 there is disclosed a mobile planter in which a digging member mounted at the end of a driveable pendulum arm is angularly rotated so as to move in a direction opposite to the direction V of forward movement of the machine. A prong pushes a plant out of a tray in the digging member and into the furrow created. An object of the present invention is to provide a mobile planter for placing plant material in the ground, offering improvements in relation to the predetermined placement of plant material. According to this aspect of the invention there is provided a mobile planter for placing plant material as defined in the accompanying claims. In a preferred embodiment of the invention, the new approach to the placement of plants provided by the invention has the effect that instead of ejecting plants from the coulter by means of an ejector or placement member, the latter remains relatively static with respect to the planter chassis. To place the plant in its growing position, the plant is received in the previously proposed way, by dropping into the coulter and being located thereby in an upright attitude, but placement in the furrow is effected by the coulter moving forward relative to the placement member until the latter is in line with the rear end of the coulter. With the plant still in contact with the placement member and at the bottom of the furrow the soil then returns to the furrow covering the plant root ball, the latter being static on the base of the furrow. Also, because there is no displacement momentum applied to the plant, the slope of a field during use does not affect it. Moreover, the press wheels are located closer to the rear end of the coulter so as to press and gather the soil around the plant at the rear end of the coulter. This would not be possible with previously proposed planters as this would accentuate the tendency of the soil to fill the furrow before the plant is in position. In the embodiment, the coulter is generally V-shaped in vertical section, to receive the plant modules, and to produce a V-section furrow. Drive to the mechanism for reciprocating the coulter is from a land wheel via a gear box and a torque limiter to a cross-shaft connected to the row units. The coulters are mounted on parallelogram linkages. The coulter has a self-cleaning action due to its acceleration and the presence of the placement plate. A cam drive may provide positive drive to the coulter only in the forward direction of movement of the coulter, with return thereof being produced by soil forces. Alternatively, a cam return drive mechanism may be provided in any case or for low soil load conditions. Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which : Fig 1 shows, in purely diagrammatic form, a side elevation view of a planting machine drawn by a tractor; Figs 2 and 3 show, also in side elevation view, a single row unit of the planter of Fig 1, illustrating the reciprocating movement of a coulter assembly thereof; Fig 3A shows, on a larger scale, a perspective view of a dispensing drum of the apparatus of Fig 2, the direction of viewing being indicated by arrow IIIA in Fig 2; Figs 4 and 4P show, purely diagrammatically, plan views of a coulter assembly of the invention and of a prior proposal respectively, the direction of viewing being indicated by arrow IV in Fig 3; Figs 5 and 6 show front elevation and side elevation views respectively of hitch means of the planter of Fig 1; Fig 7 shows, some what diagrammatically, a perspective view from above and the rear, of the press wheel assembly of the planter of Figs 1, 2 and 3; and Fig 8 shows an isometric view of a modification for use in the embodiment of Fig 1, providing hexagonal magazines of plant trays. As shown in Fig 1, a planter 10 is drawn by a tractor 12. The planter has three or more row units 14 each capable of placing plants from a supply 16 in a furrow in the ground, at regular intervals, the plants being manually transferred from supply 16 to row unit 14 by an operative 18, one such operative being provided for each row unit. Planter 10 has at least one ground wheel 20 connected by chain and/or other drives 22, 24 to the mechanisms of the individual row units. The planter is connected to the tractor links 26 by a hitch 28 mounted on the planter. Alternatively, the planter may be semi-mounted or trailed from the tractor. As shown in Figs 2 and 3, each row unit 14 comprises dispensing apparatus 30 comprising a dispensing drum 32 into which operative 18 places plants 34 from supply 16. The plants are discharged through an opening 36 by an impellor 38 (see Fig 3A), and then pass via a feed chute 40 to a delivery zone 42 where they are placed in a furrow in the soil 44 and press wheels 46 gather and/or press soil around the plant roots. The furrow in the soil is opened by a coulter 48 having a leading knife edge 50. The coulter is mounted on parallelogram links 52, 54 from a structural member 56 on the planter chassis. A cam 58, rotated by drive 22 acts on an operating lever 60 connected to links 52 to effect reciprocating angular movement thereof, and thus corresponding back-and-forth movement of coulter 48. The return movement of the coulter maybe effected by soil forces arising from forward movement of the planter in direction F through the soil 44. Preferably the cam is arranged itself to provide positive return drive in a similar manner. Turning now to a more detailed consideration of the structure and operation of the dispensing drum 32, it will be seen in Fig 3A that the drum comprises a cylindrical open-ended drum member 62, in which the rectangular discharge opening 36 is formed. The opening 36 extends throughout a substantial portion of the height of drum member 62, as shown in Fig 3A, and its circumferential extent is about 35 degrees of arc, and may be from 25 to 45 degrees of arc. Opening 36 is located with respect to forward travel direction F at 6 o'clock if 12 o′clock represents the most forward point of the periphery of drum 62 with respect to direction F, or elsewhere according to choice. Mounted within drum 32 is impellor 38 which comprises a shaft 64 rotatable about its axis 65 and carrying three pairs of impellor plates. Each such pair comprises a radial plate 66 and an inclined plate 68 cooperating with its radial plate. Thus, the radially inner edges of the plates are joined on shaft 64, their radially outer edges 70, 72 respectively are a sliding and cooperating fit within the inner surface of drum member 62. Inclined plate 68 slopes downwardly towards radial plate 66, thereby defining a downwardly tapering chute 74 into which plants can be placed by operatives 18. Thus, the chute 74 has a wide mouth at its upper end, but has comparatively small dimensions at its lower end. At that lower end, the end edges 76, 78 respectively of plates 66, 68 are in sliding edge-to-face relationship with a generally horseshoe shaped ledge member 80 mounted in drum member 62 and extending arround its inner periphery between ends 82, 84 located close to the upwardly extending side edges of discharge opening 36. Ledge 80 serves to limit downward movement of plant modules 34 in each of the chutes 74. In use, operatives 18 place (arrow P) plant modules 34 from supply 16 into chutes 74. The modules can be placed in the chutes at any location from about 3 o'clock to about 9 o'clock as the impellor 38 rotates anti-clockwise (arrow R in Fig 3A). The modules are discharged through opening 36 at about 6 o'clock and enter chute 40 and thus pass to coulter 48 for placement in the soil 44. The modules thus follow a generally helical path and are discharged both sideways and downwards, as indicated in Fig 3A. This simple system of guidance, the downwardly-tapering form of the chutes 74, and the absence of any structures tending to catch in the foilage of the modules, all promotes efficient dispending with a minimal likelihood of the module or its foilage catching on structures of the dispensing mechanism. The downward and outward movement permitted by the drum opening, coupled with the centrifugal forces acting on the modules greatly aid the smooth dispensing action. Turning now to the plant module placement, it can be seen in Figs 2 and 3 that the modules 34 are received in delivery zone 42 from chute 40. A placement or delivery plate 86 is located between the side plates 88, 90 (see Fig 4) of coulter 48. Fig 4 also indicates the reciprocating movement of the coulter itself and thus of its side plates 88, 90 under the action of the drive provided by cam 58 and lever 60. The rear-most position of the side plates is shown in dotted lines in Fig 4. This corresponds to the Fig 2 position, and the full line position in Fig 4 corresponds to the Fig 3 position of the coulter. Thus, a plant module placed in delivery zone 42 in the Fig 2 position of the coulter is initially supported against lateral toppling by the coulter side plates, and then as these plates are withdrawn forwards, placement or delivery plate 86 effectively delivers the modules from the coulter assembly and press wheels 46 gather soil around it and consolidate the soil to complete the operation. This simple and effective process is to be contrasted with that of the prior proposal shown in Fig 4P in which the coulter side plates 88P and 90P are effectively fixed and the ejector plate 86P reciprocates between the positions shown, traversing the delivery zone 42P and ejecting plants from the coulter. In this way, plants tend to ride up on to the already partly or fully closed furrow, as described previously. Moreover, plant and soil material tends to become jammed under and against the reciprocating ejector plate 86P, and indeed plants dropped early are crushed by that plate as it returns to its dotted line position. It is to be understood that Figs 4 and 4P are purely diagrammatic and not representative of dimensions and relative sizes and thicknesses of the components concerned. Figs 5 and 6 show details of the hitching arrangement for planter 10. It has a conventional A-frame 87 having two lower connectors 91 and an upper connection (not shown) to receive the tractor links 26. The A-frame is connected to toolbar 92 by bridge plates 94 which engage and are fixed to the outer side faces 96 of the toolbar, thus leaving the top and bottom faces 98 and 100 respectively free for other purposes. The tool bar itself comprises twin box beams 102, 104 fixed in spaced parallel relationship and defining between them a channel in which are received bolts 106 having associated nuts 108, plates 110 and (112), whereby the row units 14 are freely laterally position-adjustable lengthwise of toolbar 92 in the direction indicated by arrow A in Fig 5. Fig 7 shows details of the mounting arrangement for press wheels 46. The twin press wheels are journalled on angled stub shafts 114, 116 projecting from an upright shaft 118. The latter is adjustably received in a sleeve 120 having its own shaft 122 adjustably received in a sleeve 124 projecting from an arm 126 carrying the entire press wheel assembly. Adjustability is thus provided by means of an adjuster bolt 128 to vary the castor angle subtended by shaft 118, by means of angular adjustment (arc 130) about axis 132. In this way, the soil gathering and consolidating effect of the press wheel assembly can considerably varied according to conditions and crop requirements. It will be appreciated that the assembly also provides for position adjustment axially along axis 132. Also, adjustment can be provided with respect to shaft 118 both axially, lengthwise thereof, and angularly about its longitudinal axis. Referring now to Fig 8, this shows, somewhat diagrammatically, an alternative means for providing a supply of plants for the row units. Instead of simply providing trays of modules, the trays can be mounted on hexagonal magazines or drums 134, 136, 138. Each magazine can carry a tray of modules on each of its rectangular faces 140. The magazines are mounted to be rotatable about a common axis 142, whereby the operative has a six-fold increase in the availability of plant material from the supply. The trays are inserted into retaining slots (not shown) on the magazines. The individual modules show no tendency to be come detached from their trays until positively removed by the operative, feeding them in direction P (see Figs 3 and 3a) into the dispensing drum. Amongst modifications envisaged for the above embodiments are the following : 1 The provision of a somewhat conical dispenser drum 62, having a profile as indicated by reference numeral 150 in Fig 3A, with corresponding changes in the impellor to cooperate therewith. In Fig 3A, the conical profile is shown at one side only, for simplicity. 2 The placement member or plate 86 may be mounted for floating lateral and fore/aft movement as indicated by arrows 152 and 154 in Fig 4. Any suitable mounting may be provided for this purpose. It does not affect the relative movement between the coulter and the placement member as such, but simply facilitates smooth operation and cleaning. 3 An actuator 156 (see Fig 3A) may be provided for angular adjustment of dispensing drum 62 about its longitudinal axis to improve the dispensing action. 4 Modifications may likewise be made to the shape of the discharge opening 36. It may also be provided with adjustable shutters to enable the opening to be varied during use, or for different plants or conditions. 5 The driveline 22, 24 may be provided with adjustment means to permit adjustment of the timing between the dispensing drums and the coulters. This permits adjustment to take account of the differences in time taken for plants of different sizes and different kinds to reach the furrow. 6 A membrane may be provided to inhibit soil from entering the coulter assembly behind the displacement member, and lodging in the coulter. 7 The dispenser drum may itself be mounted for position adjustment relative to its driving shaft to enable timing modifications to be made. 8 Provision may be made for application of liquids and chemicals during planting. The drives to the row units may be arranged to trigger water or fertilizer or granule application as required. 9 A rotary slit cutting blade may be mounted ahead of the coulter to facilitate the latter's passage through the soil. 10 The coulter or a forward portion of it may be fixed and plant support plates or a rear portion of the coulter may be reciprocated. 11 Modification of the coulter/plant support plate movement parameters to suit particular requirements. In the above embodiment the amplitude of the coulter movement is about 60 millimetres for a module root block width of about 20 to 25 millimetres. This could be varied to take account of different module sizes, subject to the limitations imposed by the rate of planting required (say, 80 to 120 plants per minute at spacings of 15, 20, 25 centimetres or more between plants in each row). 12 The coulter may have a bolt-on detachable lower portion permitting replacement after wear and to permit alteration of furrow profile.

Claims: A mobile planter (10) for placing plant material in the ground comprising plant material delivery means (40) to deliver plant material in sequence to a delivery zone (42) located between a pair of side plates (88, 90) which in use are located in a furrow opened in soil (44), and a drivable displacement member (86) being provided to displace delivered plant material in sequence from between said side plates to its growing location in the furrow, and a drive (22, 58, 60) to effect movement of the displacement member relative to the side plates to deliver the plant material; characterised in that said drive is arranged to move said side plates (88, 90) lengthwise of the furrow in use, relative to said displacement member (86), in the forward travel direction (F) to effect said displacement of the delivered plant material (34). A planter according to claim 1 characterised in that said drive is arranged to reciprocate the side plates (88, 90) relative to the displacement member (86). A planter according to claim 1 or claim 2 characterised by the side plates (88, 90) being provided by a coulter (48) for opening a furrow in the soil, and the drive therefor comprising a rotatable cam (58). A planter according to claim 3 characterised by said coulter being mounted on a parallelogram linkage (52, 54). A planter according to any one of claims 1 to 4 characterised by said drive comprising synchronization means (24) operative to synchronize the movement of said side plates (88, 90) with respect to the delivery of plant material to said delivery zone (42), whereby plant material is delivered to the zone when the side plates are in the rearmost quarter of their locus of movement.

Inventors: BEBEST ROGER SYDNEY, BEBEST, ROGER SYDNEY
Applicants: BENEST ENG LTD, BENEST ENGINEERING LIMITED
Application year: 1988
Main classification: A01C11
IPC codes: A01C11