WO2023200343A1 - Seedling lifting and root trimming machine - Google Patents

Abstract

In one aspect the invention provides a seedling lifting and root trimming machine which includes a lifting module configured to clamp and lift a plurality of seedlings from a growing medium. The machine also includes a trimming module configured to cut the roots of seedlings lifted by the lifting module, and a packing module configured to deliver seedlings to a packaging container after the trimming module has cut the roots of the seedlings. A chassis engages with the lifting module and the packing module. A translation module is provided which is configured to move the lifting module towards and away from the packing module, or to move the packing module towards and away from the lifting module.

Description

SEEDLING LIFTING AND ROOT TRIMMING MACHINE

Field of the Invention

This invention relates to a seedling lifting and root trimming machine. In preferred embodiments this machine may be used to lift and trim the roots of forestry seedlings.

Background of the Invention

The forestry industry needs to be supplied with large numbers of tree seedlings to complete planting operations. The number of seedlings consumed in these operations far exceeds plant numbers utilised in residential landscaping operations and focuses on delivering large volumes of high quality seedlings at low-cost.

Nursey sites for forestry seedlings plant long rows of seedlings arranged in several parallel lines. This approach uses land efficiently and usually results in an array of eight (or more) parallel lines of seedlings extending along the length of the row.

It is common for forestry seedlings to be provided as bare rooted trees. In this form a seedling is removed from the soil at a nursery site and its side roots are trimmed to present a main taproot extending parallel to the stem. In this form the seedling therefore has its stem extending along the same axis its main taproot. Bare rooted trees have the bulk of the soil removed from their roots, but still have some retained to act as a source of the symbiotic fungi arbuscular mycorrhiza to colonise a later planting site. These bare rooted trees can therefore be packed into a container in large numbers. Although it is known for forestry seedlings to be packaged individually within a planter bag in combination with a growing medium, bare rooted trees reduce cartage costs, packaging overheads and seedling processing times.

The processing of a bare rooted tree from soil through to packaging in a container is currently a time consuming and laborious process. Prior art techniques rely on seedlings being removed from the ground in bunches by hand, then having their roots manually trimmed and cleared of soil. The bare rooted seedlings are then placed in a bulk transportation container such as a bag of box, commonly in lots of approximately 100 seedlings.

Various prior art machines have also been developed to assist in the lifting or removal of plants from a growing site. For example, US patent US3643354 describes a representative form of ground working device designed to dig out and cut the roots of an individual plant. However this machine is of limited use with forestry seedlings as it would operate at the same speed or slower than the current manual processing of seedlings referenced above. This type of machine is also not suitable for use with the row based layout of seedling plantings at forestry nursey sites.

It would therefore be of advantage to have improvements in the field of seedling lifting, trimming and packaging which addressed or at least mitigated the above issues, or which provided an alternative over the current state of the art. In particular, it would be of advantage to have improvements over the prior art which allowed for at least the semiautomated lifting of relatively large numbers of seedling trees in a single or continuous operation. It would also be of advantage to have improvements over the prior art which automated or mechanised the presentation and trimming of the roots of seedlings.

Disclosure of the Invention

According to one aspect of the present invention there is provided a seedling lifting and root trimming machine which includes a lifting module configured to clamp and lift a plurality of seedlings from a growing medium, and a trimming module configured to cut the roots of seedlings lifted by the lifting module, and a packing module configured to deliver seedlings to a packaging container after the trimming module has cut the roots of the seedlings, a chassis engaged with the lifting module and the packing module, and a translation module configured to move the lifting module towards and away from the packing module, or to move the packing module towards and away from the lifting module. According to another aspect of the present invention there is provided a seedling lifting and root trimming machine substantially as described above wherein the lifting module incorporates a plurality of clamp arms arranged into a plurality of jaws, each jaw being configured to clamp a plurality of seedlings, and a clamp drive assembly arranged to open and close the plurality of jaws defined by the clamp arms.

According to a further aspect of the present invention there is provided a seedling lifting and root trimming machine substantially as described above wherein the trimming module incorporates a plurality of root combs, each arranged to be located adjacent to a jaw defined by a pair of clamp arms, a comb drive assembly arranged to move each of the plurality of root combs into engagement with seedlings clamped by the adjacent jaw, a plurality of trimming blades, each located adjacent to a root comb, and a trimming blade drive assembly arranged to move each trimming blade across an adjacent root comb to sever seedling roots projecting from the root comb.

According to another aspect of the invention there is provided a method of seedling lifting and root trimming which includes the steps of: i. moving a lifting module into contact with a plurality of seedlings and clamping the seedlings using a plurality of clamp arms arranged into a plurality of jaws, ii. using a translation module to raise the lifting module upwards to pull the clamped seedlings from a growing medium, iii. moving a trimming module underneath and into alignment with the lifting module to engage the roots of the clamped seedlings with the teeth of a plurality of root combs, iv. raising the lifting module upwards to draw a section of the roots of the clamped seedlings through the teeth of the root combs, v. moving at least one trimming blade laterally across the root combs to trim the roots of the clamped seedlings, vi. using the translation module to move the lifting module into alignment with a packaging module to deliver seedlings to a packaging container. The present invention provides a seedling lifting and root trimming machine. This machine lifts seedlings from a growing medium and trims the roots of these seedlings to ready them for packaging and transportation. In preferred embodiments the invention can be used to lift and trim forestry seedlings grown in long rows composed of parallel planting lines. In such embodiments the invention can lift and trim large numbers of seedlings quickly and efficiently with a minimum of manual labour input.

Reference in general throughout this specification will be made to the present invention being used to lift and trim the roots of forestry seedlings. However those skilled in the art will appreciate that the invention may be used in other applications with other types of seedlings, and reference to the above should in no way be seen as limiting.

The machine provided incorporates a lifting module, a trimming module, and a packing module. The lifting model clamps and lifts a plurality of seedlings from a growing medium while the trimming module is used to cut the roots of the lifted seedlings. The packing module receives the plurality of lifted seedlings and preferably manoeuvers them for delivery to a packaging container.

The invention includes a chassis used as a mounting frame for other parts of the invention. In a range of embodiments the various modules of the invention may be directly connected to this chassis, or may be mounted to the chassis by connection to a further intermediate module. For example, in some embodiments the trimming module may be indirectly engaged with the chassis by being connected to the lifting or packing modules which are in turn directly connected to the chassis. In yet other embodiments either the lifting or packing modules may be connected to the translation module which is in turn directly connected to the chassis. In yet other embodiments the trimming module may be formed as a standalone component which is directly engaged with the chassis and able to move independently relative to the chassis, lifting and/or packing modules.

A chassis used with the invention preferably mounts at least one axle deploying a pair of wheels at its ends. This arrangement allows the chassis to slowly and continuously traverse a row of seedlings while the lifting and trimming modules process the seedlings.

In a preferred embodiment the chassis may incorporate or define a towing linkage to allow the machine to be drawn behind a tractor or similar vehicle. In further preferred embodiments the chassis may also engage with power delivery systems which may - for example - receive pressurised hydraulic fluid from a towing vehicle or engage with a power take-off linkage.

However in alternative embodiments the chassis may instead mount a motor transmission and associated drive systems to implement the invention in the form of independent self-powered vehicle.

Reference throughout this specification will however be made to the chassis being towed behind a vehicle such as a tractor. Those skilled in the art will appreciate that other configurations and arrangements of the invention are also envisioned and within its scope.

The invention also incorporates a translation module which is used to move the packing and lifting modules adjacent to each other, allowing seedlings clamped by the lifting module to be released and delivered to the packing module, thereby freeing the lifting module to lift a new batch of seedlings. The translation module can then be used to move the modules apart to free the lifting module to operate and lift a new batch of seedlings.

In some alternative embodiments the translation module may be arranged to move the packing module towards and away from a stationary lifting module. However those skilled in the art will also appreciate that a reversed configuration may preferably be used with the lifting module being moved towards and away from a packing module if desired.

Therefore in some embodiments the lifting module may have a stationary form and the packing module may be translated. Again those skilled in the art will appreciate that alternative arrangements are also within the scope of the invention. In some alternative embodiments a mobile packing module may be mounted on a carriage assembly which engages with a guide defined by the chassis. This guide can form a path which is traversed by the packing module carriage and may preferably extend along the longitudinal axis of the chassis. In such embodiments a translation module may preferably be formed by a set of motor driven wheels or gears engaged with a carriage associated with the packing module. This form of translation module can readily move the packing module into and out of alignment with the lifting module as required by the operation of the invention.

However in preferred embodiments other configurations or arrangements of the translation module are also envisioned. For example in a preferred embodiment the translation module may be connected to the lifting module and operate to both lift, lower and/or rotate the lifting module about an axis perpendicular to the longitudinal axis of the chassis. The motion undertaken by the lifting module can lower it to a fixed or potentially adjustable height above ground to clamp a collection of seedlings, and then lift these seedlings to pull them from a growing medium. The translation module may also raise the lifting module to allow for the alignment and operation of the trimming module as discussed further below. The ability to apply a pivoting or rotational motion to the lifting module can be used to align it with the packing module to allow seedlings to be released and transferred to the packing module, with the lifting module then moving through the reverse arc of motion to return to clamp a new collection of seedlings exposed by the forward motion of the chassis. In such embodiments the translation module may be adapted to rotate the lifting module towards and adjacent to the packing module. This movement of the lifting module will align it with the packing module to allow seedlings clamped by the lifting module to be supplied to the packing module. In such embodiments after the seedling have been delivered, the translation module may then operate to move the lifting module out of alignment with the packing module by rotating the lifting module away from the packing module and back to a position where it is ready to lift a new batch of seedlings.

In preferred forms of such embodiments the translation module may include a pivot axle which can be raised or lowered under the action of at least one vertical drive ram, where the pivot axle suspends or otherwise mounts the lifting module to the chassis. This form of translation module may also include at least one pivot drive ram arranged to apply a rotational force to the lifting module about the pivot axle to pivot the lifting module towards and into alignment with the packing module. Similarly the action of this pivot drive ram can be reversed to move the lifting module out of alignment with the packing module after seedlings have been delivered to it.

In preferred embodiments the lifting module incorporates a plurality of clamp arms arranged into a plurality of jaws. Each of the jaws defined by a pair of clamp arms are configured to clamp a plurality of seedlings in one movement or operation. In various preferred embodiments each clamp arm is defined by a long straight beam with one side wall having a resilient cushioning material applied to form a contact surface. This arrangement allows the lifting module to process a section of a row of growing seedlings, with a pair of clamp arms defining a jaw for each line of seedlings used to make up the row.

In a preferred embodiment the invention includes the clamp drive assembly arranged to open and close the plurality of jaws defined by the clamp arms. In various embodiments this clamp drive assembly may be composed of a number of individual components or elements, each of which act or operate on a single set of jaws. In various embodiments the operation of the clamp drive assembly may be coordinated so that each of the jaws defined by the clamp arms are opened and closed at the same time.

In further embodiments each clamp arm may be mounted to one or more actuator arms which extend to engage with a drive component such as a hydraulic ram or electric stepper motor. These drive components can be operated to move the adjacent clamp arms which form a set of jaws towards and away from each other as required during operation of the invention.

In yet other embodiments the clamp drive assembly may be provided by an integrated mechanical drive system with each alternate clamp arm mounted to a common shuttle element. This shuttle element may be driven towards and away from the remaining arm forming a jaw to open and close all the jaws of the module at the same time. In some embodiment the lifting module's plurality of clamp arms and at least part of an associated clamp drive assembly may be mounted to a lift carriage. In various preferred embodiments this lift carriage may define a frame or mounting structure which allows the translation module to raise, lower, pivot or otherwise shift the lifting module. However in some alternative embodiments this lift carriage may be located on or in a guide frame connected to the chassis, where the guide frame constraints and guides the motion of the lift carriage up and down during seedling lifting operations. In a further alternative embodiments the lift carriage may also define or incorporate a roller at various points of contact between the carriage and the guide frame. This roller or rollers ensure that the lift carriage can move smoothly up and down the guide frame while minimising friction between these parts. In such embodiments the lifting module may also include a lift drive configured to raise and lower the clamp arms relative to the chassis. For example, this lift drive may be mounted to or engaged with the guide frame referenced above to apply a force to raise or lower the clamp arms. In some embodiments a lift drive may be formed by a hydraulic ram mounted to the guide frame with the operative end of the hydraulic ram engaged with the lift carriage. Operation of this hydraulic ram will therefore act to move the lift carriage up and down on the guide frame relative to the chassis to facilitate seedling lifting operations.

Those skilled in the art will however appreciate that such a lift drive may not necessarily be provided with other preferred embodiments of the invention. For example, in embodiments where the translation module preferably lifts, lowers and rotates the lifting module, the clamp arms will be lowered into contact with seedlings and lifted away from the ground by the translation module. In such embodiments the lifting module may still incorporate a lift frame, but this lift frame would be engaged with the chassis by connection to the intermediate translation module.

As indicated above the invention includes a packing module to receive and deliver seedlings lifted by the lifting module to a packaging container.

In some alternative embodiments the packing module incorporates a plurality of catch fingers. These catch fingers are arranged into a series of jaws configured to clamp a plurality of seedlings in one motion or operation. The jaw defined by a pair of catch fingers can therefore grasp and hold a plurality of seedlings in place while trimming operations are performed. In further embodiments a packing module may incorporate a finger drive assembly arranged to open and closed the plurality of jaws defined by the catch fingers. In such embodiments a finger drive assembly may be formed from a number of individual components, each of which being associated with a pair of catch fingers which define a jaw.

Those skilled in the art will appreciate that various forms and arrangements of finger drive assemblies may be utilised in conjunction with a range of embodiments of the present invention. For example in some embodiments a hydraulic ram drive may be engage with each pair of catch fingers making up a jaw of the trimming module. In yet other embodiments each alternating member of an array of catch fingers may be mounted to a common shuttle element moved laterally relative to the chassis to open and close jaws defined by the catch fingers.

In some embodiments the packing module may also include a transfer assembly which operates to manoeuvre the clamped trimmed seedlings over a packaging container for later transportation. In such embodiments this transfer assembly may be configured to raise, pivot or otherwise translate the clamping jaws of the packing module to a position above an open transport container used to receive seedlings. Once this positioning is achieved the jaws of the packing module may then be opened to drop the lifted trimmed seedlings into this container, with the transfer assembly then removing the packing module back into position for subsequent alignment with the lifting module.

However those skilled in the art will appreciate that other embodiments of the invention may not necessarily provide a packing module which incorporates or includes plurality of catch fingers and associated finger drive assembly as referenced above.

For example in one alternative embodiment a packing module may include a receiving container which collects, retains or otherwise supports seedlings delivered to it by the lifting module. In preferred forms this container may have a conical form defining a hopper shaped arrangement with an outlet port at the apex of this conical form through which the collected seedlings can be delivered.

In further preferred forms of this embodiment the conical hopper packing module may include one or more aligned serialisation rollers adjacent to the outlet port it defines. These rollers can be used to feed seedlings out from the packing module at a controlled rate and with a fixed orientation. This arrangement may allow - for example - the conical packing module to supply a consistent stream of seedlings to a conveyer belt or similar assembly used to deliver seedlings to a final transportation container.

In yet other embodiments the packing module may include or be formed from an endless loop conveyer belt arranged to receive seedlings delivered to it by the lifting module. This conveyer belt can be configured to transport seedlings to a waiting packaging container.

The invention includes a trimming module used to cut the roots of seedlings lifted by the lifting module. In various embodiments the trimming module can be engaged with either the lifting module or the packing module. For example, in embodiments where the trimming module is engaged with the lifting module seedlings may be lifted and have their roots cut prior to being transferred to the packing module. Alternatively seedlings may only be lifted, and then be transferred to the packing module to have their roots cut by a trimming module engaged with the packing module. In yet other embodiments a trimming module may be formed by an independent component separate to the lifting and packing modules and preferably being able to move relative to the lifting and packing modules.

Preferably a trimming module includes a plurality of root combs, with each root comb located adjacent to a jaw defined by the clamp arms or catch fingers of an associated lifting or packing module. A root comb can be located adjacent to each respective jaw and can be positioned or orientated below one of the catch fingers or clamp arms of the respective jaw.

Preferably a root comb integrated into the invention may be formed by a beam or shaft with substantial the same length as a catch finger or clamp arm and where a plurality of teeth are defined by a sequence of adjacent cavities formed on one side of this shaft. These teeth may have a io rectangular or curved profile, defining a longitudinal array of cavities which can receive the stem of the clamped seedlings and also the bunched together roots of the seedlings.

In some embodiments a trimming module incorporates a comb drive assembly which is arranged to move the root combs up and down relative to each adjacent jaw.

In various embodiments a comb drive assembly may be arranged to induce an initial lateral movement in a root comb to locate the stems of clamped seedlings within the cavities defined by the comb. In such embodiments the comb drive assembly may then operate to move the root combs downwards relative to the jaws to collect and comb the roots of the clamped seedlings together, with the downward movement of the root comb preferably terminating at a fixed distance from the clamping jaw. This motion induced by the comb drive assembly will therefore result in each seedling's roots being bunched together and held in place at a known or controlled distance or length from the original clamping point on the seedling stem. This combing operation can also act to encourage loose soil to separate from the roots of a seedling. In further embodiments the comb drive assembly may also be configurable to allow for changes in the desired distance to which the comb extends down from the jaw. This adjustment can be used to control the length of the roots resulting from trimming operations as discussed further below.

However in preferred embodiments a comb drive assembly may be configured to move the entire trimming module horizontally towards and away from the lifting module. This horizontal movement can bring the root combs into engagement with the seedlings clamped by the adjacent jaws of the lifting module, preferably when the lifting module is raised by the translation module and the trimming module is positioned underneath the lifting module. In such embodiments the translation module can be used to control the relative height of the lifting module above the trimming module, and can also be used to perform an additional raising operation to draw a section of the roots of clamped seedlings through the teeth of the root combs. This raising motion will bunch each seedling's roots together and then perform a combing operation to encourage loose soil to separate from the roots of seedlings.

In further preferred embodiments the comb drive assembly may include at least one hydraulic or pneumatic ram configured to move the trimming module horizontally relative to the chassis towards and away from the lifting module. A hydraulic or pneumatic ram or rams can be operated to precisely control the motion or position of the trimming module on the chassis and to align and engage clamped seedlings with the teeth of the root combs.

A trimming module provided in accordance with the invention also preferably includes a plurality of trimming blades, with each trimming blade being located adjacent to a root comb and preferably underneath or below the root comb. A trimming blade may be formed by a beam or shaft having substantially the same length as a root comb with a sharpened edge being provided on one side of this beam.

In preferred embodiments a trimming module may also include a trimming blade drive assembly which is arranged to move each trimming blade across the width of an adjacent root comb. The lateral or transverse movement of the trimming blades acts to sever seedling roots which project from the bottom of root combs in preferred embodiments. This trimming operation therefore results in a lifted seedling which has a root ball combed to a specific length and severed at this length. As indicated above, the depth to which the comb extends from the jaw may also be adjust in various embodiments to control the length of the roots after trimming operations.

In some embodiments a trimming blade drive assembly may be formed by an independent or stand-alone drive structure provided for each and every trimming blade incorporated into a trimming module. However in other embodiments the lateral cutting motion induced in the trimming blades may be provided by additional components of a comb drive assembly. For example, in some embodiments a combined comb and trimming blade drive assembly may be provided which acts to initially move each root comb and trimming blade laterally into engagement with the roots of clamped seedlings, then downwards to comb these roots to a fixed length and lastly to move each associated trimming blade laterally to sever the roots at this desired length.

The present invention may provide many potential advantages over the current prior art.

The invention provides a machine which introduces significant automation into the processing of bare rooted trees at nursery sites. In various embodiments the machine provided by the invention substantially reduces the manual labour required to lift seedlings and trim their root balls to desired and consistent lengths.

The invention also preferably allows for the efficient collection and packaging of bare rooted trees in a transport container after the lifting and trimming of the related seedlings.

In various embodiments the invention provides a machine which can operate in a substantially continuous manner to traverse growing rows of seedlings, either under its own power or being towed by a tractor or similar vehicle.

Brief description of the drawings

Additional and further aspects of the present invention will be apparent to the reader from the following description of embodiments, given in by way of example only, with reference to the accompanying drawings in which:

• Figure 1 provides an expanded perspective view of a seedling lifting and root trimming machine as provided in accordance with one embodiment of the invention,

• Figure 2 provides a perspective view of the lifting module and associated lifting carriage integrated in to the machine of figure 1,

• Figure 3 provides a perspective view of a single clamp arm jaw with attached actuator arms as provided in the machine of figures 1 and 2,

• Figure 4 provides a perspective view of elements of the packing module integrated in to the machine of figure 1, and • Figure 5 provides a perspective view of a root comb and associated components of a comb drive assembly of a trimming module as provided with the packing module of figure 4,

• Figure 6 provides an enlarged view of the components of the comb drive assembly and end of the root comb shown with respect to figure 5,

• Figure 7 provides a perspective view of a lifting module engaged with a trimming module in accordance with a further embodiment of the invention,

• Figures 8a, 8b provide views of the two forms of clamp arm assemblies integrated into the lifting module of figure 7,

• Figures 9a, 9b show front views of the lifting and trimming modules of figure 7 when the lifting module jaws are open (figure 9a) and closed (figure 9b),

• Figure 10 shows two side views of the lifting module of figures 7 through 9 mounted to elements of a chassis, and

• Figures 11a through llh show a sequence of schematic views illustrating the motion of a lifting module and trimming module relative to a packing module as provided in accordance with a further embodiment.

Further aspects of the invention will become apparent from the following description of the invention which is given by way of example only of particular embodiments.

Best modes for carrying out the invention

Figure 1 provides an expanded perspective view of a seedling lifting and root trimming machine as provided in accordance with one embodiment of the invention.

The machine 1 shown by figure 1 includes a chassis 2 which is used to mount a lifting module 3 and a packing module 4.

As can also be seen from figures 2 and 3 the lifting module includes an array of clamp arms 5 arranged into pairs to define a series of jaws 6. These clamp arms are formed by a long straight beam with one side wall having a resilient cushioning material applied to form a contact surface 7. Each of the jaws defined are configured to clamp a section of a line of seedlings when the jaws are closed around their stems. The facing contact surfaces 7 of each of the arms clamp a number of seedlings planted in a line extending a distance equal to the length of each arm.

Figure 2 also shows in further detail the clamp arms of the lifting module engaged with a lifting carriage 8. This lifting carriage suspends the clamp arms from a guide frame 9 connected to the chassis 2, with the carriage 8 integrating a roller 10 at each point of contact with the guide frame. Figure 1 also shows a lift drive 11, which is formed in this embodiment by a hydraulic ram mounted to the upper section of the guide frame 9. The drive end of this ram is connected to the upper region of the lifting carriage, allowing the ram to push and pull the carriage up and down to perform seedling lifting operations.

Figure 3 provides a perspective view of a single clamp arm jaw 6 with attached actuator arms 12 as provided in the machine of figures 1 and 2. The actuator arms 12 connected to each clamp arm 5 are engaged together at their mid-points by pivot axle 13. The remote end 14 of each actuator arm is then linked to its opposite neighbour by an element of a clamp drive assembly such as a hydraulic ram. As can be seen from figure 3 the activation of rams used to link the remote ends 14 of the actuator arms will result in an opening and closing motion in the jaw 6.

The clamp drive assembly and lift drive 11 operate in coordination with the operation of a translation module (not shown) associated with the chassis 2. This translation module is used to move the packing module towards, underneath and into alignment with the lifting module along a guide 15 which extends longitudinally along the length of the chassis. The lift drive 11 lowers the jaws 6 of the lifting module to a position where they can be clamped around the stems of several lines of seedlings once the clamp drive assembly closes the jaws. The lift drive then operates to lift the clamped lines of seedlings upwards, providing clearance underneath the jaws for the packing module to be positioned in alignment with the lifting module. The lifted seedlings can then be clamped by the packing module as discussed below with respect to figure 4, and the lifting module jaws are then released with the translation module activating again to move the packing module out from underneath the lifting module.

Figure 4 provides a perspective view of elements of the packing module integrated into the machine of figure 1.

The packing module 4 is configured to grasp and package seedlings lifted and transferred by the lifting module 3. As can be seen from figures 1 and 4 the packing module incorporates a plurality of catch fingers 16 arranged into a plurality of jaws 17, each jaw being configured to clamp a plurality of seedlings. The packing module includes a finger drive assembly which operates to open and close these jaws to clamp a series of lines of seedlings transferred from the lifting module. In the embodiment shown this finger drive assembly is implemented by each alternate catch finger 16 being mounted to a movable shuttle element 18 moved laterally to open or close each jaw in unison.

The packing module also includes a transfer assembly which operates to manoeuvre the clamped trimmed seedlings over a packaging container for later transportation. This transfer assembly can be used to manoeuvre and rotate the catch fingers to present the open ends of each jaw distal from the shuttle 18 to an open packaging container. The jaws can then be opened to allow gravity to slide the lifted, trimmed seedlings out of the jaws and into the container.

Figure 5 provides a perspective view of portions of a trimming module provided on the underside of the packing module of figure 4. The trimming module includes a root comb 19 and associated components of a comb drive assembly 20 under each alternate catch finger of the packing module 4. Figure 6 also provides an enlarged view of the components of the comb drive assembly 20 and end of the root comb 19 shown with respect to figure 5.

This drive assembly 20 includes a pair of mounting axles 21 which are engaged with the ends of the comb by sets of offset cams 22. Rotation of the axles then results in the comb being translated laterally and into engagement with seedlings clamped by the jaw. As can be seen from these figures each comb defines a series of alternating projecting teeth 23 and cavities 24, where each cavity is used to receive and locate the stem of a clamped seedling when the comb is translated laterally.

Further components of this comb drive assembly are engaged with the mounting axles and operate to raise and lower these axles and the associated comb relative to the jaw 17 during seedling trimming operations. As the comb is moved downwards by the drive assembly each of the cavities it defines combs the roots of a seedling into a compact bunch while also encouraging the removal of soil from the root ball. The comb can then hold the bunched root ball at a desired distance from where the seedling's stem is clamped by the jaw 17.

The trimming module also includes a trimming blade positioned underneath each root comb. Each trimming blade is operated by components of a trimming blade drive assembly which acts to move each trimming blade across an adjacent root comb to sever seedling roots projecting from the root comb. This cutting movement is executed once the associated root comb has been lowered to a desired depth relative to the jaw 17, setting the length to which seedling roots are to be trimmed.

Figure 7 provides a perspective view of a lifting module 100 as provided in accordance with a further embodiment of the invention. The lifting module defines an array of jaws formed by two different forms of clamp arm assemblies A, B as shown with respect to figures 8a, 8b. These assemblies also define components of an associated trimming module mounted underneath the jaws of the lifting module.

As can be seen from figure 7 the assemblies of figures 8a and 8b are deployed in a staggered or alternating arrangement to ensure correct operation of trimming blades 101 utilised by the trimming module. Figures 9a and 9b provide front views of the lifting module when the jaws are open (figure 9a) and closed (figure 9b), while the motion arrows illustrated by figures 8a, 8b show the respective path of trimming blades provided by the trimming module.

Each assembly provides a clamp arm 102 faced with a rubber gripping pad and each assembly operates by the pulling of a wire rope which activates internal cams and rollers at their pivot points to create a gripping tension and lifting motion and then a raking and combing motion until the cut length is reached at which point the trimming blades trim the roots.

In the embodiment shown the clamp arms 102 expand outwards to press against seedlings at a height of 80mm above the ground. The clamped seedlings are then lifted to remove them from the ground and to trim the roots and the clamp arms are returned to the open configuration shown in figure 9a. Opened jaws are then reinserted between a new array of seedlings and then closed again to complete a further lifting operation.

Jaws close tight on the seedlings then once the lifting module 100 is lifted upwards the trimming blades 101 extend as shown by the motion arrows illustrated. Once the cut length of the roots are met a tension spring activates to move the trimming blades to trim the roots to the desired length. The seedlings are lifted by the forward and circular motion shown with respect to figure 10 to be positioned for hand over to a packing module (not shown).

Figure 10 shows two side views of the lifting module 100 mounted to elements of a chassis 103 of the apparatus provided in the embodiment of figures 7 through 9. This figure shows relative positions which the lifting module experiences when moved by a translation module 104 which imparts a rotational or cyclic motion to the lifting module. This motion lowers the lifting module down towards a bed 105 where seedlings are grown upwards towards a lifted position as shown by the rotational arrow illustrated.

Figures 11a through llh show a sequence of schematic views illustrating the motion of a lifting module 200 and trimming module 201 relative to a packing module 202 as provided in accordance with a further embodiment. These views illustrate a time sequence of events and motions bought about by the operation of a translation module (not shown) in this additional embodiment. For clarity these figures show the relative positioning of the lifting, trimming and packing modules to a towing tractor 203.

Figure 11a shows the positioning of a lifting module in the process of grasping an array of seedlings. The trimming module is located slightly above and to the rear of the lifting module and the packing module is to the rear of both of these components.

Figure lib shows the next series of motions completed by these components where the lifting module is raised above the ground after having grasped and extracted an array of seedlings. The lifting module is raised to a height which allows the trimming module to move forward, underneath and into alignment with the lifting module.

Figure 11c then illustrates how the lifting model module moves vertically upwards further to assist in the completion of a root trimming process completed by the trimming module. At this stage the trimming module acts to comb soil from roots and to cut these roots to a desired fixed length.

Figure lid shows the return of the trimming module to its original position behind the lifting module while the lifting module is raised vertically upwards.

Figure lie then shows how the lifting module is next rotated to pivot upwards further vertically while also being translated backwards towards the packing module. As illustrated by figure Ilf the lifting module is then translated further backwards to sit above the entry face of a packing module hopper. In this position the lifting module operates to release the combed trimmed seedlings into the packing module hopper below it.

Figures 11g and llh shows the return movements undertaken by the lifting module to initially translate backwards towards the tractor and then to rotate to the position shown with respect to figure llh to undertake a new seedling lifting cycle.

In the embodiment shown the translation module 204 is also engaged with a slide positioning rail defined on the chassis 203. Additional components of the translation module may be used to impart a linear motion to the lifting module relative to the chassis to move the lifting module into alignment with a packing module (not shown). Figures 12a, 12b show in further detail the lifting module 200 of figures 11a- h which includes an array of clamping arms 205 used to define sets of clamping jaws 206. Figure 12a shows these jaws in an open configuration, and figure 12b shows these jaws when closed. As can also be seen from these figures the facing contact surfaces 207 of each of the arms has a resilient foam rubber coating applied to cushion seedlings clamped in each jaw. Each set of jaws also extends below a lift carriage 208 used to assist in engaging the lifting module with the translation module (not shown).

Figures 13a, 13b show elements of the trimming module 201 of figures 11a- llh both before and after alignment and receipt of seedlings lifted by the lifting module 200 of figures 12a and 12b. Figures 14a, 14b show in further detail the action of the trimming blade and trimming blade drive assembly integrated into the trimming module of figures 13a, 13b.

As can be seen from figure 13a the trimming module 201 is placed in a receiving configuration with an array of root combs 219 and trimming blades 220 displaced from an adjacent locating wall 221. This configuration allows the root systems of clamped seedlings to be manoeuvred between these elements. Figure 13b shows the locating configuration of the trimming module 201 when the root combs and trimming blades are pivoted into contact with each adjacent locating wall to secure seedling root balls inside the teeth of each root comb.

As can be seen from figures 14a, 14b a notched trimming blade 220 is mounted above and on top of each root comb 219, with the blade notches aligned with the teeth cavities of the comb to receive a seedling root ball. Figure 14a shows the trimming assembly prior to a root trimming operation, while figure 14b shows the position of the trimming blade after this operation once the trimming blade drive has pulled the blade along the surface of the comb towards the right side of the image. As can be seen from figure 14b the passage of the blade over the comb will act to sever the root ball of the clamped seedling where it intersects with the comb.

In the preceding description and the following claims the word "comprise" or equivalent variations thereof is used in an inclusive sense to specify the presence of the stated feature or features. This term does not preclude the presence or addition of further features in various embodiments.

It is to be understood that the present invention is not limited to the embodiments described herein and further and additional embodiments within the spirit and scope of the invention will be apparent to the skilled reader from the examples illustrated with reference to the drawings. In particular, the invention may reside in any combination of features described herein, or may reside in alternative embodiments or combinations of these features with known equivalents to given features. Modifications and variations of the example embodiments of the invention discussed above will be apparent to those skilled in the art and may be made without departure of the scope of the invention as defined in the appended claims.

Claims

What we claim is:

1. A seedling lifting and root trimming machine which includes a lifting module configured to clamp and lift a plurality of seedlings from a growing medium, and a trimming module configured to cut the roots of seedlings lifted by the lifting module, and a packing module configured to deliver seedlings to a packaging container after the trimming module has cut the roots of the seedlings, a chassis engaged with the lifting module and the packing module, and a translation module configured to move the lifting module towards and away from the packing module, or to move the packing module towards and away from the lifting module.

2. A seedling lifting and root trimming machine as claimed in claim 1 which is used to lift and trim forestry seedlings grown in rows composed of parallel planting lines.

3. A seedling lifting and root trimming machine as claimed in claim 1 or claim 2 wherein the lifting module incorporates a plurality of clamp arms arranged into a plurality of jaws, each jaw being configured to clamp a plurality of seedlings, and a clamp drive assembly arranged to open and close the plurality of jaws defined by the clamp arms.

4. A seedling lifting and root trimming machine as claimed in claim 3 wherein each clamp arm is defined by a long straight beam with one side wall having a resilient cushioning material applied to form a contact surface.

5. A seedling lifting and root trimming machine as claimed in claim 3 wherein the clamp drive assembly is arranged to open and close the plurality of jaws defined by the clamp arms at the same time.

6. A seedling lifting and root trimming machine as claimed in claim 3 wherein the trimming module incorporates a plurality of root combs, each arranged to be located adjacent to a jaw defined by a pair of clamp arms, a comb drive assembly arranged to move each of the plurality of root combs into engagement with seedlings clamped by the adjacent jaw, a plurality of trimming blades, each located adjacent to a root comb, and a trimming blade drive assembly arranged to move each trimming blade across an adjacent root comb to sever seedling roots projecting from the root comb. A seedling lifting and root trimming machine as claimed in claim 6 wherein each root comb is positioned below a clamp arm forming a jaw. A seedling lifting and root trimming machine as claimed in claim 6 wherein at least one root comb is formed by a shaft with substantial the same length as the clamp arms and defines a plurality of teeth with a sequence of adjacent cavities formed on one side of the shaft. A seedling lifting and root trimming machine as claimed in claim 6 wherein the comb drive assembly of the trimming module is arranged to move the trimming module towards the lifting module to engage clamped seedlings within the teeth defined by the root comb. A seedling lifting and root trimming machine as claimed in claim 1 wherein the translation module is adapted to rotate the lifting assembly into alignment with the packing module to allow seedlings clamped by the lifting assembly to be supplied to the packing module. A seedling lifting and root trimming machine as claimed in claim 1 wherein the translation module is arranged to raise the lifting module to pull clamped seedlings from a growing medium. A seedling lifting and root trimming machine as claimed in claim 11 wherein the translation module is arranged to raise the lifting module to allow the trimming module to be moved into alignment with the lifting module.

13. A seedling lifting and root trimming machine as claimed in claim 1 wherein a packing module includes a receiving container which collects seedlings delivered by the lifting module.

14. A seedling lifting and root trimming machine as claimed in claim 13 wherein the receiving container has a conical form defining with an outlet port at the apex of the conical form.

15. A seedling lifting and root trimming machine as claimed in claim 14 wherein the receiving container includes one or more aligned serialisation rollers adjacent to the outlet port.

16. A seedling lifting and root trimming machine as claimed in claim 1 wherein a packing module includes a conveyer belt arranged to receive seedlings delivered to it by the lifting module and transport received seedlings to a packaging container.

17. A seedling lifting and root trimming machine as claimed in claim wherein the chassis mounts at least one axle deploying a pair of wheels.

18. A seedling lifting and root trimming machine as claimed in claim 17 wherein the chassis defines a towing linkage.

19. A method of seedling lifting and root trimming which includes the steps of: i. moving a lifting module into contact with a plurality of seedlings and clamping the seedlings using a plurality of clamp arms arranged into a plurality of jaws, ii. using a translation module to raise the lifting module upwards to pull the clamped seedlings from a growing medium, iii. moving a trimming module underneath and into alignment with the lifting module to engage the roots of the clamped seedlings with the teeth of a plurality of root combs, iv. raising the lifting module upwards to draw a section of the roots of the clamped seedlings through the teeth of the root combs, v. moving at least one trimming blade laterally across the root combs to trim the roots of the clamped seedlings, vi. using the translation module to move the lifting module into alignment with a packaging module to deliver seedlings to a packaging container. A method of seedling lifting and root trimming as claimed in claim 19 wherein the trimming module is moved out of alignment with the lifting module after the trimming blades trim the roots of clamped seedlings and the lifting module is moved out of alignment with the packaging module after clamped seedlings have been supplied to the packaging module.