WO2016048166A1

WO2016048166A1 - Title: symmetric, folding machine for levelling.

Info

Publication number: WO2016048166A1
Application number: PCT/NZ2015/050152
Authority: WO
Inventors: Nicolaas Laurisse Sieling
Original assignee: Rotacon Engineering Limited
Priority date: 2014-09-22
Filing date: 2015-09-17
Publication date: 2016-03-31
Also published as: AU2015322197A1; AU2015322197B2

Abstract

A versatile, folding, symmetrical chassis for agriculture simulates a rigid levelling beam as two halves pivotally joined. Attachment beams connect the two-part levelling beam to a drawbar. In a roadworthy transport mode, the two halves are brought forward, lie parallel to each other and are restrained in place. In a working mode, the levelling beam is towed over a soil surface while aligned across a tow direction, and the attachment beams are spread into a symmetrical triangle each side of a third, inextensible median beam or chain which supports the levelling beam at the pivot joint.

Description

TITLE: SYM M ETRIC, FOLDING M ACHINE FOR LEVELLING.

FIELD: Agricultural machinery; levelling or soil-shifting machinery; and in particular, ground levelling machinery including means for self-folding between a working configuration and another. DEFINITIONS

Working configuration: an unfolded form in which the machine has a shape providing in effect a single wide or elongated beam to be pulled over ground in a transverse orientation.

Transport configuration: a narrow folded position; also useful for storage.

CROSS-REFERENCES: The Applicant has concurrent patent applications having a common priority date, locatable by inventor name SIELING, Nicolaas Laurisse. This specification details several mutually interdependent innovations in relation to openers installed in seeders.

BACKGROUND:

Areas of land used for intensive, large-scale mechanised cultivation of crops such as wheat are best made substantially level for efficient farming, and useful for flooding-type irrigation. A level surface is best achieved with very wide-beam graders (around 15-20 metres wide), if possible. Supported GPS navigation or other electronic aids may be of assistance for closely controlling the levelling process.

PROBLEM TO BE SOLVED: Very wide agricultural machines are difficult to move from one field to another on account of obstacles such as farm gates (typically about 3 to 5 metres wide) and legislation about "wide loads" on public roads. Minimal till operations are also possible with a wide machine of this type. The problem can be seen as providing a machine that can be folded, yet has enough structural integrity to be used as a working leveller, and also enough integrity to be transported while intact.

PRIOR ART:

WO 03/080943 "Ground levelling apparatus" and related US 7284261, also by the present inventor and applicant, are hereby imported in their entirety. They describe a non- symmetrical folding system for the frame of the apparatus, in which a single, stiff beam having no medial pivot joint carries the levelling knife and the tractor is coupled to one side of the beam by a triangular drawbar arrangement when the apparatus is being used, in the unfolded position. When the apparatus is being transported (as in Figs 2 and 3) the drawbar arrangement is decoupled and folded to one end of the beam and idler wheels are dropped to the ground, and the apparatus is folded into a minimised-width configuration. OBJECT:

An object of this invention is to provide an agricultural machine such as an effective leveller; particularly a wide leveller, and more particularly one providing an about 18 metres grading width yet capable of being folded into a narrow configuration suitable for negotiating farm gates, for road transport, and storage; or at least to provide the public with a useful choice. SUMMARY OF INVENTION:

In a first broad aspect this application provides a reconfigurable agricultural machine capable of being towed by means of a hitch point (231) capable of being attached to a prime mover such as a tractor the machine having, two configurations and when in a working configuration an elongated levelling beam comprising parts (203a) and (203b) is maintained in an attitude transverse to a direction of towing; wherein the machine has a frame including four pivotally connected beams including an elongated levelling beam comprised of two part beams (203a, 203b) each of which is articulated at a middle part about a central pivoted joint (202) having a vertical axis; the frame also including two drawing or attachment beams (201a, 201b) each connecting one part of the elongated beam to the hitch point (231) by a pivotable attachments located one along each half of the elongated beam; and having one steerable and liftable support wheels (204a, 204b) located one along each half of the elongated beam thereby being capable of supporting the machine; wherein the frame of the machine, when in use, exists in either a first unfolded state or working configuration (Fig lc) in which each half of the elongated beam (203a or 203b) shares a straight line axis with the other half, and maintains said elongated beam in an attitude transverse to a direction of towing using position locking means (240, 241); or is reversibly transformable into a second or folded transport configuration (Fig la), in which the frame is in a folded state and each half of the elongated beam has been pivoted about the central pivoted joint (202) to lie substantially parallel to the other half with the free ends directed toward the hitch point (231); the frame maintaining symmetry about a dividing line passing fore-and-aft through the hitch point (231); wherein the length of the machine in the transport configuration is half of the width of the elongated beam of the machine in the working configuration.

Preferably the wheels are each provided with a resilient tyre, and together the wheels are capable of carrying the weight of the machine when towed in the transport mode.

Preferably each support wheel assembly is provided with powered raising or lowering means, and powered steering means; all powered means preferably comprising bidirectional rams.

Preferably each of the two elongated beams (203a, 203b) are sealed at a median end by median plates (216a, 216b) serving also as limits for opening of the pivoted joint (202). Preferably each of the two elongated beams (203a, 203b) are each sealed at a free end by a lateral plates (219a, 219b), one overlapping the other when the leveller is in a transport configuration, serving as restraining means to maintain the elongated beams parallel to each other in the transport configuration. Preferably the plates may be reversibly held together with a locking bracket passing through holes (221a, 221b) . Preferably, means to render an end plate (219a, 219b) attached to a corresponding elongated beam (203a, 203b); each plate bearing a medially directed receiving profile (220) or "mouth" - a concave area having a selected radius of curvature substantially the same as a radius of a component of a corresponding attachment beam (201a, 201b) in alignment with the attachment beam for entry into the folded, transport configuration comprises a lug (223a, 223b) mounted on each levelling beam and aligned along the axis of the elongated beam; the means comprising a tensioning device (207a, 207b) having a first end pivotally connected on to the lug and having a second end pivotally attached to an adjacent end of an attachment beam (201a, 201b); so that, when in use, variation in an applied tension causes a change in relative height of the receiving profile (220) with respect to the adjacent attachment beam. The "mouths" (220) on ends (219) will move over beams (201).

In a related aspect, reversible conversion of the leveller between the working configuration and the transport configuration is powered by forwards or reverse movement of tractor, after the currently active restraining means has been deactivated and after a direction of each wheel has been altered. In another aspect the frame of the machine also includes one pivotally mounted median beam reversibly capable of extension from a shorter fixed length when in the working configuration into a longer length when in the transport configuration; while always being pivotally attached between third pivot at the hitch point (231) and the central pivoted joint (202) shared between the two parts of the elongated beam; said pivotally mounted median beam serving as position locking means (240, 241) to maintain the respective parts (203a, 203b) of the elongated levelling beam at a desired angle.

In one option the pivotally mounted median beam comprises two shafts; one slidably held against the other; the shafts capable of becoming locked together and thereby of maintaining a length when in the working configuration. Preferably shaft (241) comprises a rod or tube and is capable of sliding inside tube (242) in a telescoping manner.

Preferably the median beam includes one or more restraining means capable of ensuring that the leveller remains locked in the working configuration until an operator disables the restraining means and causes the configuration to change. In a preferred alternative, a physical locking means is provided to maintain the median beam in the shorter fixed length, whereby the median beam transfers forces between pivot (202) and the hitch point (231).

Preferably the physical locking means comprises a hook and a compatible latch between the first member and the second member and the two members are slid together during transformation into the working configuration until the hook of the latch overrides the catch member.

A preferred method to cause the releasable locking means to engage is to slide the first member into the second member until the hook of the latch overrides the catch member.

A preferred method to cause the releasable locking means to release is to apply an opening force sideways on to the latch thereby causing the hook to become disengaged from the catch. Optionally the median beam comprises an inextensible, flexible article selected from a range including chain, wire, wire rope, rope and a strop.

Optionally the length during different configurations may be managed using a braked winch.

Alternatively a chain can be held by shackles and reversibly tensioned by a levered tensioning device. Accordingly, conversion of the agricultural machine from the transport configuration to the working configuration may be facilitated by pulling by a winch, causing retraction of the median beam structure. Preferably the width of the machine when in the transport configuration is less than 3 metres. (3 metres relates to the maximum width of an unescorted vehicle on public roads).

125 Preferably the length of the machine when in the transport mode is a function of the extended width; being slightly greater than one half of the extended width.

Preferably activation or deactivation of at least some of the restraining means is effected with the aid of bidirectional hydraulic rams.

Preferably the elongated beam includes a levelling knife or knives attached beneath the wide 130 beam thereby providing a leveller or grader.

Preferably the leveller includes adjustment means capable of adjusting an angle of rotation of the or each levelling beam relative to an orientation of the or each attachment beam.

Preferably that adjustment means comprises adjustment of the relative angles of rotation of each levelling beam across the pivot joint (202), and preferably the adjustment is retained even if the 135 configuration of the leveller is changed.

Preferably an adjustment means (207, 223) capable of aligning each free end of the levelling beam (203) in relation to the attachment beams when entering the folded configuration is provided.

In a second broad aspect, the invention provides an agricultural machine to be drawn over a field 140 or from place to place by a prime mover; the machine having a reconfigurable hinged frame including a wide and stiff carrying beam in two parts pivoted together bearing agricultural equipment in a maintained symmetrical disposition, wherein the chassis includes a first paired set of attachment beams (201a, 210b) sharing maintained pivotal connections at a median joint (209) and a second paired set of carrying beams (203a, 203b) sharing pivotal connections at a 145 median joint (202); each attachment beam (201a, 201b) being pivotally joined to a corresponding carrying beam (203a, 203b) at pivoted joint (210a, 210b); all joints having pivots sharing a common substantially vertical axis of alignment.

PREFERRED EMBODIMENT:

The description of the invention to be provided herein is given purely by way of example and is 150 not to be taken in any way as limiting the scope or extent of the invention. In particular the dimensions shown in one illustration are purely illustrative. The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. In this specification, reference numerals, including reference numerals appearing in the 155 Summary of Invention, are provided for clarification only and are not intended to restrict the scope of the invention to the particular embodiments of the components in conjunction with which the reference numerals are used.

Throughout this specification unless the text requires otherwise, the word "comprise" and variations such as "comprising" or "comprises" will be understood to imply the inclusion of a

160 stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. Each document, reference, patent application or patent cited in this text is expressly incorporated herein in their entirety by reference. Reference to cited material or information cited in the text should not be understood as a concession that the material or information was part of the common general knowledge or was known in New

165 Zealand or in any other country.

Drawings:

Fig la is an exploded plan view diagram, showing the leveller in a folded configuration.

Fig lb is a sketch during a change of configuration.

Fig lc is a plan view diagram, showing the working configuration.

170 Fig 2: is a diagonal view from the rear of the unfolded configuration, showing hydraulically adjustable parts.

Fig 3: shows details of the shaped plate (219).

Fig 4 illustrates use of a chain as an equivalent to a metal beam as the median beam.

Fig 5 shows the leading end of the leveller in the folded configuration including the ram used to 175 open or close the link between plates (219a) and (219b) located at the outer ends of the levelling beams.

Fig 6. shows details of the joint (202a).

Related to appreciation of the above Figures and text is a Youtube video which shows the leveller in use; in both the working (unfolded) configuration and in the folded (transport) 180 configurations and in changing from one to the other. See https://www.voutube.com/watch?v=xZu2VKEi5wo which was downloaded on 12:09:2015.

INTRODUCTION: The present application provides an improved and symmetric folding mechanism for a leveller; an agricultural machine to be towed by a tractor when in use. In one example, its operating

185 configuration is 18.2 metres (60 feet) wide. This width can be reduced for transport. A prototype of the machine is only 1.8 metres (6 feet) wide in the transport configuration. The leveller can be folded by use of on-board hydraulic actuators to rotate the support wheels and then tractor pushing and pulling in a symmetrical way, ready for transport. The machine's folding mechanism has similarities with devices in other patents as referred to under "Cross-references"

190 The present application provides locking apparatus for the folded and for the working configurations.

Use of large diameter pipe for levelling beams (203a, 203b) is preferred by the inventor because of the rigidity that is obtained for a given weight. Also, welds around a larger structure are subjected to less stress for the same function.

195 EXAMPLE 1 :

The principle of the folding mechanism will be described. Fig 1 shows the shape changes, in principle. Fig la; which is an exploded plan view diagram showing the symmetrical folded configuration. Pivot apertures to be overlaid in actuality are placed along dashed lines A— A and B— B. The separations shown in the drawings along the dashed lines will then disappear.

200 Note that use of the exploded view in Fig la, does not demonstrate the reduction in width to in the example - 1.6 metres - for transport (or storage) that results from adoption of the folded configuration. The tractor which is coupled to hitch (231) at the leading end (at the top of the page) is not shown here. Fig lc is a plan view diagram showing the working configuration.

The two attachment beams (201a, 201b) meet at pivot point (209) and are placed on top of each 205 other at the shared pivot point (209) where they connect to a three-point hitch (231) behind the tractor. In a variation this could be replaced by a universal joint linked to a hitch fixed between the lower plough arms of the tractor, eliminating the need for the three point hitch.

The levelling beam (203) is split into two parts (203a, 203b) always held together at pivot joint (202). Each part is 9.1 metres (30 feet) in length and made of large diameter steel pipe. Each part 21 0 is terminated at a flat plate (216 a, 216b) that includes a side bar having a pivot aperture for joint (202) which allows the machine to fold into the transport configuration of Fig la. Conveniently the flat place closes the end of the tube. One of the improvements in this machine (when in first unfolded state or working configuration (Fig lc)) provides the elongated levelling beam with useful stability in the direction of towing, across the pivotable joints (202) which would

215 otherwise require support.

In a preferred option, support to the two halves of the levelling beam (203a, 203b) at the pivot joint (202) is provided using an inextensible median beam (240, 241) which maintains pivot (202) in place in relation to the hitch point (209). Excessive forces could otherwise arise at joint (202) if a soil levelling action was unevenly applied along the grading beam. If the inextensible 220 median beam (240, 241) was replaced with a rope or chain, and a braking winch, the rope or chain is put under sufficient tension to maintain the joint at pivot (202) in a stable position. Tension will pull pivot (202) closer to pivot (209) and bring plates (216a, 216b) firmly together.

All pivots include pins secured in place by spring clips. All pins for the frame have substantially vertical axes.

225 Two identical length attachment beams 201a, 201b each of which preferably has a two-part frame construction as shown in part in Fig 2 are attached to each other at a common leading-end pivot 209 (shown in Fig la as (209, 209' and 209"); to be overlaid) which is also attached to, or is part of a hitch (231) that can be connected to the tractor typically on to a three point linkage. Each attachment beam is pivotally attached at a trailing end to the levelling beam at (210a,

230 210b), at about one third of the distance along each levelling beam from pivot joint (202).

A central, rigid, telescoping or median beam provides the elongated beam with useful stability in the direction of towing, to reduce stability requirements imposed on the pivot joint (202) between the two parts (203a, 203b) of the grading beam. The example beam is required to have a fixed length during use of the agricultural machine in the working configuration. But that beam

235 has to lengthen when the machine changes into the transport configuration. The beam in this example is comprised of outer component (240) and inner component (241). One beam slides inside the other beam, for the purpose of transforming the leveller from one mode to the other, and provides a rigid beam having either of two different lengths. In the transport configuration, about one metre of the inner beam (241) remains inside the outer beam (240), and when in the

240 working configuration, most of the inner beam is inside. A mechanical latch is preferred for holding the telescoping structure in a shortened form. It will be appreciated that functional equivalents to inextensible telescoping round or square tubes can be used (see "Variations").

In the working embodiment, a telescoping arrangement is used. A 100 mm diameter steel tube (240) slightly shorter than the distance between pivot (202) and pivot (the shared 209) in the 245 working configuration comprises the outer beam (240), which has a pivotable attachment at one end. A second tube (or a rod) (241) which can slide into the tube (240) is used as the second part; and has a pivotable attachment (the shared 202) at the external end. The order of the assembly (240 and 241) could be reversed if convenient.

When in the working configuration the inner portion of the median beam will be physically

250 locked to the outer portion, in order to provide a stable length and hence rigidity between the drawbar pivot joint and the grading beam pivot joint. That rigidity avoids occurrence of excessive bending moments at the pivot joint (202).

Note that relative thicknesses of parts in the drawings are diagrammatic. Attachments between the beams and pivot pins are best created by welding flat sheet portions to each beam, with holes 255 to accommodate the pins, as is common practice.

The leveller is raised off the ground and carried during transport on wheels (204a, 204b each of which is placed about half way along each part of the grading beam. Both wheels are preferably both liftable and steerable by reversible hydraulic actuators - see Fig 2.

Changing the Configuration from Transport to Working.

260 The person driving the tractor can cause the leveller to become converted from the transport to the working configuration by backing the tractor against the leveller, without having to dismount, by having an ability to steer the steerable support wheels (204) using actuators.

A number of catch means had been employed during the transport configuration to maintain integrity, in case of mechanical shock or loss of hydraulic power, for instance. Other catch 265 means are used to maintain the integrity of the working configuration. The steps are as follows:

1) A locking bracket (not shown) passing through holes (221) between aligned plates (219a) and (219b), is manually removed.

2) Lever (212) is pulled forward using ram (213) which lifts a rod (214) out of the notch (215) in the shaped plates (219a, 219b) forward end (219) of beams (203).

270 3) The wheels (204) are steered outwards, slightly at first, using rams (206) so that as the tractor is backed a short distance until the angle between attachment beams (201a, 201b) at pivot (209) opens up to approximately 20 degrees. (The two pivot points (210) move apart). The wheels (204) are steered outwards (in the forward direction) and the tractor is driven forward until the two rear faces (216) of beams (203a, 203b) meet flush with each other - at which

275 time the two beams are in a straight line. 4) The wheels (204) are then steered back using rams (206) so that they are at right angles to beams (203), and in line with the intended direction of travel.

5) Assuming that the leveller has arrived at a site to be levelled, the wheels are then raised by retracting rams (205) until the beams (203a, 203b) are resting on the ground.

280 6) At this point, if the median beam comprises a pair of telescoping tubes, the latch that held the median beam in its short-length mode will become latched so that the median beam is held in a short configuration.

7) (If a chain or rope, perhaps managed with a winch is used as the median beam; the chain or rope is pulled into tension which contributes to an effect that the plates (216a, 216b) at pivot

285 (202) are pressed together, thus holding the beams (203a, 203b) in a straight line).

8) Ball valves may be fitted into the individual hydraulic lines leading to the wheel height rams (205) and the wheel steering rams (206). These can be closed when the wheels (204) have been lowered to the transport mode to "lock" the wheels down and straight and the machine can be towed by a vehicle without hydraulics (say a small truck) for delivery or other

290 purpose. In another form they could be locked in the "down and straight" position using appropriately placed brackets and pins.

9) The steering rams (206) share the same hydraulic line from the tractor. The line is branched to reach the ram beside each wheel and an identical restrictor is placed in the individual lines to the rams (206). This ensures that the wheels are steered slowly and evenly (with respect to

295 each other) without the need for the more expensive solution of using phased rams. The steering rams (206) are only used away from their fully retracted (road travel) or fully extended (working) positions during folding and unfolding and then for only very short durations so that any "drift" caused by oil running through the restrictors will not be significant.

300 10) The inventor has noted that individual tractor drivers have developed different styles of backing the tractor, steering the tractor, and managing the wheels on the leveller in order to change configurations. The Youtube video referred to above shows one style.

Maintaining the Working Configuration:

Median Beam assembly (240/241) Locking. The outer tube (240) pipe has a hook (242) at the 305 trailing end, pinned between two vertical lugs with holes in them welded on top of the aft end.

As the machine is unfolded out to the working position by backing the tractor, the hook (242) slides along the top surface of the inner tube (241) until the leveller attains the working configuration, at a point where the hook (242) drops over the end of the inner tube (241) which is now almost full inserted into the outer tube (240). As a result, the centre (pivot point (202)) of the folded out machine is held at a fixed distance from the drawbar pivot point (209) regardless of the load exerted by the earth building up in front of it during a levelling procedure. The hook (242) conveniently has a rope tied to it, leading to the tractor seat or to the front ram (213).

Pulling enables the hook to be lifted to allow inner tube (241) to slide out again during reconfiguration of the machine in a folded form for transport. A plurality of catches could be included along the median beam assembly to provide for leveller beam attitudes other than straight line. A similar telescopic arrangement latched by a hook mechanism) was used in the original leveller Patent Number US 7284621 B2 and is shown in figure 7 of that patent.

If a chain (242) is used (as shown in Fig 4), the chain may be held across the space between the hitch point (231) and the pivot (202) in tension using known means, such as by connecting the chain to shackles or carabiner-like quick-release shackles, and placed in tension with a tool.

In Fig lc, the working configuration, the levelling beam comprised of parts (203a, 203b) which trails behind the tractor, lies at right angles to the direction of motion. Note that in Fig lc, wheel (204a) is shown as lifted up and above the soil surface, while wheel (204b) is shown as not lifted. This difference is shown to illustrate wheel liftability. When in the working configuration the attachment beams (201a, 201b) form sloping sides of two drawing triangles that terminate on pivots (210a, 210b) attached to the levelling beams. Both triangles share a common beam which is the now fixed-length telescoping beam (240) with (241). Both triangles are formed of rigid beams. In this version, a strong bracket around pivot (202) linking the two faces (216a) and (216b) is not required. When in the working

configuration, about two thirds of each levelling beam( 203a, 203b) is located beyond pivot points (210a) and (210b).

When in the transport configuration, or if being moved about without actually scraping on the soil the levelling machine is lifted off the ground and supported by two wheels (204a, 204b). One wheel is on each side, mounted on a hydraulically steered caster support (steered by rams (206a or b) that is mounted about half way along each beam (203a, 203b). Note that the pivot points (210a or b), at the trailing ends of beams (201) are located about one third of the length of each levelling beam (203 a, 203b) from the midpoint (pivot 202) and the tractor hitch at the front. Each wheel is supported from a horizontally aligned suspension pivot so that wheel height rams (205a, 205b) may be used in order to control the wheel height. Details of the wheel support are shown in Fig 2, taken from a photograph.

Entering and Maintaining the Transport Configuration: When in the folded configuration - hereinafter called the "transport configuration" as shown schematically in Fig la the attachment beams (201a, 201b) and levelling beams (203a, 203b) form two parallel and almost touching straight lines, like a collapsed quadrilateral. The (209) ends of the attachment beams might be bent sideways toward the centre line and into an offset shape to achieve the most compact shape about the hitch point. During transport, the leading part - about two thirds in a preferred design - of each of levelling beams (203 a, 203b) on the leading side of the corresponding pivot point (210a) or (210b) is maintained parallel to and close to the outer edge of attachment beams (201a, 201b) by latches or catches (see later). Wheels (204a) and (204b) are in Fig la shown in line with the direction of travel since they are actively lowered by hydraulic actuators to carry the weight of the levelling machine during transport. The hydraulic actuators or rams (205a, 205b) (see Fig 2) connected on to the exterior of each levelling beam exert sufficient pressure on the wheel supports to push the wheels down on to the road or soil surface against the weight of the agricultural machine.

The process of folding for transport is the reverse of the unfolding process, with some further requirements. Note that the outside ends of beams (203) have a plate (219) fixed to them with a special profile as seen in Figure 3. There is an upper "mouth" (220) in the form of a semi-circle and a lower notch - referred to above as notch (215. A hole (221) is located near the top.

The folding process is:

1) The latch that holds the median beam in its short-length mode is unlatched so that the median beam may increase in length. (If a chain or rope is used; the chain or rope is released, and may be taken away, or if a powered winch including a takeup drum is used, more chain or rope will be let out during the conversion).

2) The wheels (204) are lowered by extending rams (205) forcing the levelling beams (203a, 203b) up and clear of the ground.

3) The wheels (204) are then steered using rams (206) so that they are almost in line with beams (203).

4) The wheels (204) are steered inwards in the reverse direction and the tractor still connected to the drawbar is driven backward until the angle between beams (201) at pivot point (209) reduces to approximately 20 degrees.

5) Wheels (204) are steered inwards (in the forward direction) as the tractor is driven forward.

The attachment beams (201a, 201b) will move together to become parallel and close to one another (similarly the levelling beams (203a, 203b) will move together to become parallel and close to one another), so that the machine adopts the narrow, folded configuration. 375 6) As the machine nears the end of the folding process, the outside ends of levelling beams (203a, 203b) carrying plates (219a, 219b) move forward to be close to the hitch point. The "mouths" (220) on ends (219) will move over beams (201). The notches (215) in each end (219) will overlap each other to form a single notch.

7) The wheels (204) are steered so that they are now in line with the intended direction of travel.

380 8) Lever (212) is then released by extending ram (213) and rod (214) moves into the combined notch (215).

A removable locking bracket comprising a strip of steel having a pin extended laterally near each end is inserted into the plates (219a, 219b) near pivot (210). It forms a bridge across a space occupied by the two attachment beams (201a, 201b), and joins a hole (221a) through shaped 385 plate (219a) welded on to levelling beam (203a) with a hole (221b) through a mirror-image shaped plate (219b) on levelling beam (203b). For road transport, the locking bracket is manually restored in place passing through holes (221) in ends (219) and secured properly using the pins, held in place with linch pins.

Lug (222a or b) and the corresponding adjustable link (208a or b), and lug (223a or b) and its 390 corresponding adjustable link (207a or b) both have a secondary function. (See later for the primary function). In the working configuration lug (223) with link (207) holds the corresponding attachment beam (201) upright. While the machine is being folded, the levelling beam (203a, 203b) rotates around pivot point (210) (as previously described), and lug (223) moves from being at right angles to beam (201) to more and more in line with it. At the same 395 time lug (222) moves from being in line with beam (201) to more and more at right angles to it.

As a result, while the folding operation is carried out the task of holding beam (201) passes gradually from lug (223) to lug (222) until in the fully folded configuration lug (222) is holding up beam (201) on its own.

Once step 8 of the folding operation described above is completed the beams (201) are secured 400 in the mouths (220) of the shaped sheet of Fig 3, and all four beams: attachment beams (201a, 201b) and levelling beams (203a, 203b) are locked together as a single unit. The machine can be driven be driven from field to field over rough surfaces without further strain on adjuster (208) and pivot point (224).

Lever (212) has a locking function. It rests in a downwardly directed deep notch (215a) through 405 shaped plate (219a), and also in a downwardly directed notch (215b) through the mirror image (219b) having a special profile as shown in Fig 3. The positions of the shaped plates (219) are indicated on Fig lc, where they are optimised to serve as retaining means for the folded levelling beams (203a, 203b). Lever (212) is pivotally mounted on beam (201b) and is extended toward the rear as the retaining rod (214). For operator convenience, because this lever is used each time the leveller is configured into the folded version in order to pass through a gate (for example), the lever is operated by bidirectional ram (213) which lifts rod (214) out of the notch or replaces the rod..

EXAMPLE 2: WORKING Configuration ADJUSTMENT

For applying the levelling process to a soil surface, the underneath of both beams (203a, 203b) carries a rubbing surface adjacent knife edges (218a, 218b) (see Fig 6) for scraping the soil, according to the amount by which the beams (203) are rotated along their long axis. The extent to which the knife protrudes (the "bite" of the knife) may be varied by rotation of the draw- beam. A small rotation only is sufficient. The knife, which is conveniently comprised of a number of segments in line, is already described in the inventor's previous patents as cited above as "knife 12a".

The frame pivot structures described in this section are designed with sufficient play in the pivot linkages at (202), (210a) and (210b) to allow the levelling beams (203a, 203b) to rotate.

See Fig 2, which shows the "b" side levelling beam - (203b). Each levelling beam has one large lug or arm (222a, 222b) fixed to it near pivot point (210). The lug or arm is fixed at right angles to the length of the beam and has an adjustable length link (208b) (preferably a turnbuckle) attached by one end. The other end of the link (208b) is attached to a pivot point (224) (obscured in fig 2) placed on the upper, trailing part of the attachment beams (201a, 201b). Point (224) is preferably placed directly above and in line with pivot point (210a or b) which is on the lower part of attachment beam (201a or 201b), to minimise any torque. Once the levelling beams (203a, 203b) are lowered to the ground the length of the link (208) has the effect of rotating the or each beam (203a, 203b) along its long axis to adjust the depth of the knife (218a, 218b) (see fig 6) relative to the bottom rubbing surface of either beam (203) by slightly rotating that beam (203). Once set, the link (208) does not need to be changed until there is sufficient wear on blade (218) to require an adjustment. The pivot (202) between beams (203a and 203b) has "play" designed into it to allow independent adjustment of the blades to the extent that will be required in the field. See Fig 6 which shows details of the pivot joint between the two halves of the levelling beam, in the "transport" configuration for clarity. The bottom pivot (202a) is a simple plate on plate with a pin through overlaid holes. The top pivot (202b) is again a plate on plate pivot but in this case the hole in the plates is made oversize (by around 10mm) so that one beam can be twisted by a sufficient amount in relation to the other beam allowing the "bite" of the knife along the levelling beams to be adjusted yet the joint retains integrity. The backward force of the soil being moved in front of the blades (218a, 218b) on levelling beams (203a, 203b) as the machine is pulled through the paddock, together with tension applied through the median beam (240 with 241, or chain 242) 445 tends to force the faces (216) hard together holding the two levelling beams (203a, 203b) straight.

The second lug (223a or 223b) also shown in Fig 2 is used to manage alignment of the mouths of plates (219) with the top part of beam (201) and of the notches (215) with each other toward the end of the folding operation. Each lug (223) is fixed in line with beam (203) and also has an

450 adjustable length link (207) such as a turnbuckle attached to it. The other end of link (207) is attached to pivot point (224) also on the end of attachment beam (201b). Tension in this link is varied in order to set the height of the "mouth" (220) on either or both of the profiled sheets (219) welded on to beams (203) and used as a latch during the folding process (see later), so that as the leveller reaches the final part of the folding operation the height of the mouth (220)

455 matches the height of the beam (201) or at least one of the two rods comprising that beam, thereby locating beam (201) with beam (203).

The packing plates (230) described below to meet flush with the opposite face (216) may be adjusted for total thickness, originally at the time of manufacture as also described below.

The rear face (216) of the "port" beam (203a) has two packing plates (230a , 230b) ((Fig 6) made 460 up of a number of shims) attached to the top outside and bottom outside corners respectively.

They are bolted to end plate (216a) with countersunk bolts. The thickness of the packing plates is adjusted individually (at the time of manufacture) to ensure that when in the working configuration the levelling beams (203a, 203b) are straight and level. As approximately two thirds of each levelling beam (203a, 203b) is outside pivot point (210), the soil pushing back 465 against the blade (218), (and therefore beam (203), will tend to ensure that packing plates (230) are pressed hard against the other face (216)

The outermost shim on each of the packing plates (230), is hard-faced welded (with a chromium rod). Places where they meet the other face (216) in the operating configuration are also hard- faced welded.

470 In extremely uneven ground it may happen that the backwards force between the pivot points (210) could exceed the backward force on the outside two thirds of levelling beam (203a), or (203b). The median beam provides a suitable amount of support when levelling uneven ground. After considerable service time, the packing plates (230) may need to be re-shimmed. They are bolted to end plate (216) with countersunk bolts.

475 A practical embodiment of the leveller also includes a number of locking brackets and other refinements on top of the overall changeable and symmetric configuration which will be described below.

VARIATIONS

The telescoping tubes (240, 241) of the median beam may be replaced by a chain or equivalent 480 (rope, strop, or other inextensible cord) having a length that is at least sufficient to reach between pivot (202) and 209) when the leveller is in the working configuration. See Fig 4, which replicates the central part of Fig lc and includes a chain (242) serving as an inextensible median beam.

The simplest chain attachment means is to run the chain between a shackle placed at each end. 485 One or both shackles might include a spring-loaded side (like a carabiner) to allow quick manual retrieval or insertion of the chain. A tensioning lever and catch system (not shown) is used to raise the chain tension and put joint 202 into a straight orientation after being manually placed.

In an automated leveller the chain (or rope) would be managed by using a braking winch (not shown) to release or take up chain during changes between working and transport configurations. 490 A winch of that type is provided with an effective brake in order that tension in the chain is maintained despite forces arising from use.

Configuration Remote-Control Ram (213) as seen in Fig 5 enables the operator to open and close the machine (without the locking bracket in place), to manoeuvre from one field to another, without getting out of the cab. He or she can retract ram (213) to pull lever (212) to "unlock" rod 495 (214) from notch (215) to start opening the machine. Or the operator can extend ram (213) to allow rod (214) to move back into notch (215) to complete closing the machine. Usefully, ram (213) has a secondary function. It is identical to the four wheel control rams and can serve as a spare.

Optionally the operator is provided with a rope out of the cab to pull lever (212) to open the 500 machine to the working configuration. On closing it, another pull on this rope as soon as the notches (215) come together and then releasing the rope allows rod (214) to "fall" into the combined notch (215).

In variants of this invention apart from levelling, the beams (203a, 203b) could be kept off the ground (on a number of similar wheels), and used as a very wide and stiff attachment beam on to which a variety of agricultural machines may be attached. Such machines as discs, harrows (to provide a fine and even seed bed), or seeders that could be towed through a field may be used. A mechanism could be provided to raise or tilt attached machines above the beams (203a, 203b) when folded, to help minimise the transport width. The leveller could be used in "minimum till" and broad acre farming, to break and shatter dry grasses ready for re-seeding, for rubbing in grass seeds and clover seeds, or for rubbing down stubble to initiate decomposition. Pugging damage in annual pastures can be flattened without cultivation.

Finally it will be understood that the scope of this invention as described and/or illustrated herein is not limited to the specified embodiments. Those of skill will appreciate that various modifications, additions, known equivalents, and substitutions are possible without departing from the scope and spirit of the invention as set forth in the following claims.

Claims

AIM:

A reconfigurable agricultural machine capable of being towed by means of a hitch point (231) for attachment to a prime mover such as a tractor; the machine having two configurations; characterised in that a. the machine has a frame including two pivotally connected attachment beams (201a, 201b) each of which pivotally (209) connects the hitch point (231) to one of two pivotally connected (202) levelling beams (203a) and (203b) each connected to an attachment beam at a pivotal connection (210a, 210b) disposed at about one third of a distance from the pivoted joint (202) of the elongated beams to a free end; b. the two articulated beams (203a) and (203b) are articulated at the pivot joint (202) which has a vertical axis and allows the beams to rotate, respective to each other, between a parallel orientation and a straight in-line orientation thereby comprising an elongated levelling beam; c. when the machine is in a first or working configuration the frame has a triangular shape in which the sides of the triangle are comprised of the attachment beams pivotally connected at shared pivot (209); the elongated levelling beam forms the base and is maintained in a straight line having an axis transverse to a direction of towing; and when the machine is in a second or transport configuration the frame assumes a collapsed quadrilateral shape and the elongated levelling beam becomes folded about the central pivoted joint (202); each part (203a) and (203b) being in paralleled orientation in line with the direction of towing, and maintained in place; and d. the frame of the machine maintains a symmetrical position with respect to a median line passing fore-and-aft through pivots (209) and (202); e. the machine includes at least two steerable and liftable support wheel assemblies (204a, 204b) disposed at or about a midpoint of a corresponding beam (203a, 203b) and together capable of raising the machine off a soil surface below, and f. the machine is reversibly reconfigurable between the working and the transport configurations wherein, when in use in the transport configuration, the width of the machine is substantially less than the width of the machine when in use in the working configuration and the length of the machine in the transport configuration is about half of the width of the elongated beam of the machine in 550 the working configuration.

2. An agricultural machine as claimed in claim 1, characterised in that when the machine is in the working configuration, the elongated levelling beams together forming the base of the triangle are extended over a distance beyond the perimeter of the triangular shape.

3. An agricultural machine as claimed in claim 1, characterised in that each support wheel 555 assembly is provided with powered raising or lowering means, and is provided with powered steering means; all powered means comprising bidirectional rams.

4. An agricultural machine as claimed in claim 1, characterised in that the frame includes a third extendable median attachment beam (240/241) having a length alterable between a shorter yet inextensible length when the machine is in the working configuration, and a

560 longer length when the machine is in the transport configuration; the median beam being pivotally attached to the common pivot joint (209) at a first end and to the central pivot joint (202) at a second end.

5. An agricultural machine as claimed in claim 4, characterised in that the extendable median beam comprises a pair of beams; one slidably held against the other and capable

565 of becoming locked together by a reversible locking means and thereby of maintaining a length when in the working configuration.

6. An agricultural machine as claimed in claim 5, characterised in that the median beam comprises a pair of tubular beams; one capable of sliding inside the other unless locked together by the reversible locking means.

570 7. An agricultural machine as claimed in claim 5, characterised in that the reversible locking means between the first member and the second member comprises a hook and a compatible latch, and the two members are slid together during transformation into the working configuration until the hook of the latch overrides the catch member.

8. An agricultural machine as claimed in claim 4, characterised in that the median beam 575 comprises an inextensible, flexible article selected from a range including chain, wire, wire rope, rope and a strop; maintained in tension when the machine is in the working configuration.

9. An agricultural machine as claimed in claim 8, characterised in that the length of inextensible, flexible article is managed using a winch when the machine is within either

580 configuration or when changing between configurations.

10. An agricultural machine as claimed in claim 9, characterised in that the winch is a braking winch, capable when braked of maintaining a tension in the flexible article.

11. An agricultural machine as claimed in claim 1, characterised in that the agricultural machine includes one or more restraining means capable of ensuring that the machine

585 remains locked in a selected configuration; until an operator disables the restraining means and causes the configuration to change.

12. An agricultural machine as claimed in claim 1, characterised in that the two elongated beams (203a, 203b) are each sealed at an end by a lateral plate (219a, 219b) when the leveller is in a transport configuration, the plates capable of being locked to each other

590 using a bridging bracket provided with projecting pins passed through holes (221a,

221b), thereby maintaining the elongated beams parallel to each other in the transport configuration.

13. An agricultural machine as claimed in claim 12, characterised in that means are provided capable when in use of rendering an end plate (219a, 219b) attached to a corresponding

595 elongated beam (203a, 203b) - each plate bearing a medially directed receiving profile

(220) or "mouth" - in alignment with an adjacent attachment beam during entry into the folded, transport configuration; said means comprises a lug (223a, 223b) mounted on each levelling beam and aligned along the axis of the elongated beam; the means comprising a tensioning device (207a, 207b) having a first end pivotally connected on to

600 the lug and having a second end pivotally attached to an adjacent end of an attachment beam (201a, 201b); so that, when in use, variation in an applied tension causes a change in relative height of the receiving profile (220) with respect to the adjacent attachment beam.

14. An agricultural machine as claimed in claim 1, characterised in that each elongated beam 605 (203a, 203b) includes at least one elongated levelling knife attached along the length of the beam and in a dependent attitude; said knives serving as scrapers of the soil surface when the machine is dragged over the surface while the elongated beams (203a, 203b) ride over the surface, wherein each elongated beam (203a and 203b) is provided with independent tilting means capable of rotating said elongated beam about an axis; said 61 0 tilting means comprising (a) an extendible though rigid coupling (208a, 208b) pivotally mounted at a first end from an adjacent attachment beam (210a, 210b) near pivot (210a, 210b) and pivotally mounted at a second end on to a fin (222a, 222b) extended laterally from the adjacent elongated beam and (b) provision of sufficient play at joints (210a, 210b and 202), to allow limited axial rotation of the elongated beam; on extension or withdrawal of the coupling.

15. An agricultural machine as claimed in claim 1, characterised in that the joint surfaces (216a, 216b) at the pivotal connection (202) between beams (203a, 203b) carry added shims in order to maintain the axes of the beams (203a, 203b) in a straight line.

16. An agricultural machine to be drawn over a field or from place to place by a prime mover; the machine having a reconfigurable hinged frame including a wide and stiff carrying beam in two parts pivoted together (202) bearing agricultural equipment in a maintained symmetrical disposition, characterized in that the chassis includes a first paired set of attachment beams (201a, 210b) sharing maintained pivotal connections at a median joint (209) and a second paired set of carrying beams (203a, 203b) sharing pivotal connections at a median joint (202); each attachment beam (201a, 201b) being pivotally joined to a corresponding carrying beam (203a, 203b) at pivoted joint (210a, 210b); all joints having pivots sharing a common substantially vertical axis of alignment.