Patent Description:
The invention also relates to an agricultural harvester comprising a crop pickup device, a crop receiving station and a cutter device, a method of detaching a replaceable knife from a cutter device of an agricultural harvester, and a knife for a cutter device of an agricultural harvester.

The agricultural harvester may for example be a round baler of the fixed chamber or variable chamber type, examples of which are described in <CIT> and <CIT>. In the case of a round baler the crop receiving station may comprise the baling chamber in which crop material is rotated and pressed to make a round bale. Alternatively, the agricultural harvester may be a square baler, an example of which is described in <CIT> and the crop receiving station may in that case be the pre-chamber in which crop material is collected before being transferred to the baling chamber where it is compressed by a reciprocating plunger to form a square bale. Alternatively, the agricultural harvester may be a loading waggon, an example of which is described in <CIT>, in which the crop receiving station is a loading platform on which the crop material is gathered.

The purpose of the cutter device is to receive crop material from the pickup device and transport the crop material along the feed path to the crop receiving station. The cutter device is configured to cut the crop material when required for improved handling. For example, if the crop material is grass the cutter device may be configured to cut the stalks of the grass into shorter lengths. Cutting of the crop material is optional and the cutter device may be configured for either cutting or non-cutting operation.

Typically, the cutter device of an agricultural harvester comprises a rotating rotor consisting of a tube that carries a plurality of radially-extending tines. The tines of the rotating rotor carry the crop material forward along a feed path that is defined in part by a bottom plate. A plurality of knives extend upwards through slots in the bottom plate into the feed path of the crop material. The knives cooperate with the tines of the rotating rotor to cut the crop material. The knives may also optionally be withdrawn from the feed path and placed in a non-cutting position below the bottom plate so that the crop material is transferred by the rotor along the feed path without being cut. Optionally, some of the knives may be placed in the cutting position while others of the knives are in the non-cutting position or are allowed to return to the non-cutting position, to adjust the cut length of the crop material. A retainer device, for example comprising a comb, may be provided to remove crop material from the tines of the rotating rotor. The knives may be provided with an overload protection mechanism, that allows the knives to be pressed downwards against a resilient element from the cutting position towards the non-cutting position, for example when an obstacle such as a stone passes through the feed path. An example of a cutter device is described in <CIT>. The knives may be provided with a control mechanism as to hold one or more knives in the cutting position. The position control mechanism can be provided with a selection device as to select a limited number of knives that will be brought from the non-cutting position into the cutting position. An example is for instance described in <CIT>.

The disadvantage of such a selection mechanism is that the knives that are unselected will stay in the non-cutting position independent from the position of the cutting or non-cutting position of the selected knives. During the operation of the harvester especially during longer periods of not using one or more knives, the slots in the bottom plate of the non-selected knives can collect dirt and to such an extent that, if the knives are reselected to be brought into the cutting position, the movement of these reselected knives will be obstructed by the crop and dirt in the slots and the reselected knives will not be able to reach the cutting position because of this dirt and crop, and due to that obstruction the overload protection will be activated and the knives will never reach the cutting position again.

Other cutter devices for an agricultural harvester such as a baler are known from <CIT> or <CIT>.

The advantage of the cleaning system of the invention is that not only the slots and the knives that are selected are cleaned when they are moved in and out of cutting position but also the cooperating slots of the knives that are deselected from coming into cutting position will be cleaned during this operation.

Of course with the conventional selection devices to clean all knife slots can be performed by selecting all knives, moving them all IN and then OUT, selecting the knife set again and moving these knives IN again; this time consuming operation.

It is especially advantageous when the harvester is provided with a controller that regularly controls the cutter control device to move from the IN to the OUT of cutting position and reverse.

It is an object of the present invention to provide a cutter device for an agricultural harvester that overcomes or mitigates one or more of the aforesaid technical problems. According to one aspect of the invention there is provided a cutter device according to claim <NUM>. The invention helps to ensure that the cutting knives, and the parts of the cutter device located immediately adjacent the cutting knives especially the slots in the bottom of the cutting unit, are cleaned during movement from knives from the non-cutting position towards the cutting position. This helps the cutter device to continue to operate for longer periods of time, for example openings through which the cutting knives move during a cleaning process.

According to another aspect there is provided a cutter device for an agricultural harvester.

The cutter device can include a rotor with a plurality of tines, wherein the rotor is rotatable to transfer an agricultural crop along a feed path.

The cutter device can include a knife, wherein the position of the knife is adjustable.

The cutter device can include a bottom plate located beneath the rotor. The feed path can be located between the rotor and the bottom plate. The bottom plate can include an opening through which the knife extends in a cutting position.

The cutter device can include a control mechanism. The control mechanism can include a control element that is moveable between at least a primary and a secondary position. The control element can be arranged to control movement of the knife, for example between: a first position in which the knife is in a cutting position in the feed path; a second position in which the knife is retracted from the feed path into a non-cutting position, and a third position, in which the knife is located at an intermediate position between the cutting position and the non-cutting position.

The control mechanism can be arranged such that, in a condition wherein the control element is in the secondary position, the knife is in, or may freely move to, the second position of the knife.

The control mechanism can include a selection mechanism that is arranged to select between the first and second selection configurations.

In the first selection configuration, in response to the control element being actuated to move from the secondary position to the primary position, the control mechanism can be arranged to move the knife from the second position to the first position.

In the second selection configuration, in response to the control element being actuated, the control mechanism can be arranged to move the knife from the second position to the third position during movement of the control element from the secondary position to the primary position. In a condition wherein the control element reaches the primary position, the knife can be freely movable to return to the second position of the knife. At the intermediate position, the knife can be either temporarily held in position in the opening due to e.g. accumulated dirt and/or crop material adjacent the opening and is subsequently forced to the non-cutting position by crop material moving along the flow path, or is freely movable to the non-cutting position due to gravity acting on the knife.

The intermediate position of the knife can correspond to a knife position that is approximately midway between the cutting position and the non-cutting position.

Movement of the knife to the intermediate position in the second selection configuration can comprise <NUM>%-<NUM>% of the total range of movement from the non-cutting position to the cutting position.

Dirt comes into the opening when the machine is operated with all or a part of the knives out. When this dirt is not regularly pressed out of the opening it gets stuck, so the knives are not able to press it out anymore. The state of the art is that unselected knives cannot be put into working position when non-selected. In the state of the art cutting units cleaning of the openings is only possible by first selecting all knives to be put into the cutting position, pressing all knives in and then deselect the knives that should be deselected.

The cutter device can include a positioning device arranged to control movement of the knife. The control mechanism can be arranged to control movement of the positioning device.

In response to the selection mechanism selecting the first selection configuration, the positioning device can be configured to engage the knife and the positioning device can be adjustable, by the control mechanism, between a first position in which the positioning device positions the knife in the cutting position and a second position in which the positioning device positions the knife in the non-cutting position.

The positioning device can be configured to engage the knife and prevent significant movement of the knife independently of the positioning device when the positioning device can be in the first position, and at intermediate positions between the first position and the second position, in response to the selection mechanism selecting the first selection configuration.

The positioning device can be adjustable, by the control mechanism, to a third position in which the positioning device disengages the knife at least in the direction of the cutting position.

The positioning device and the knife can have complementary engaging formations configured to limit relative movement between the positioning device and the knife in a tangential direction relative to the pivot axis of the knife, and to permit relative movement between the positioning device and the knife in a radial direction relative to the pivot axis of the knife. The complementary engaging formations can be configured to permit relative movement between the positioning device and the knife in a radial direction relative to the pivot axis of the knife. Optionally the engaging formations can comprise a rearwards-facing slot that opens through a rear edge of the knife. The engaging formations can comprise an engaging element provided on the positioning device that engages the slot. The engaging element provided on the positioning device may for example comprise a pin.

When wherein the control element can be connected to the positioning device. An actuator can be connected to the control element. The actuator can be configured to move the control element between the primary position and the secondary position. Movement of the control element between the primary position and the secondary position adjusts the position of the positioning device, which in turn adjusts the position of the knife. Moving the control element towards the primary position can cause the knife to move towards the cutting position. Moving the control element towards the secondary position can cause the knife to move towards the non-cutting position.

The control mechanism can include a connecting element. The connecting element can be connected to the positioning device.

The connecting element can comprise a resilient connecting element. The resilient connecting element can be configured to enable movement of the positioning device relative to the control element by deformation of the resilient element. The advantage of this arrangement is that if the dirt adjacent the opening is compacted so that the knife is unable to move immediately to the non-cutting position, if the knife can be subsequently loaded, for example by crop material encountering the knife and/or a stone in the crop material, the resilient connecting element will bend thereby preventing damage to the control mechanism.

The resilient connecting element can comprise a spring, such as a kink spring, a coil spring or a flat spring.

In some embodiments, in response to the control element being actuated to move from the secondary position to the primary position, thereby moving the knife from the second position to the third position, the resilient connection element can be arranged to apply a constant force to the positioning member throughout movement of the knife from the second position to the third position.

In some embodiments, in response to the control element being actuated to move from the secondary position to the primary position, thereby moving the knife from the second position to the third position, the resilient connection element is arranged to apply a force to the positioning device, throughout movement of the knife from the second position to the third position, that is greater than or equal to the force applied by the resilient connection element to the positioning device immediately after the control element moves from the second position.

The selection device can include a selection element. The selection element can be arranged to select between the first selection configuration in which the knife is selected and the second selection configuration in which the knife is deselected. The selection mechanism can include a selection control, which can be arranged to actuate the selection element to move between the first selection configuration and the second selection configuration. For example, the selection control can be arranged to move the selection element between the first operational position and the second operational position.

In some embodiments, the selection control can be arranged to selectively block the selection element from selecting the second selection configuration.

The selection control can include a first part for selecting the first selection configuration and a second part for selecting the second selection configuration.

The selection control can include at least one engagement member mounted on an axle, wherein rotation of the axle rotates the engagement member, thereby causing the engagement member to selectively engage the selection element. Optionally, the axle can be arranged parallel to the control element. In some embodiments, in a condition wherein the engagement member does not engage the selection element, the selection element is not blocked from selecting the second configuration.

The engagement member can comprise at least one cam. The cam can include a first part for selecting the first selection configuration and a second part for selecting the second selection configuration.

The at least one engagement member can comprise at least one elongate member, such as a shaft, that protrudes radially outwards from the axle. The at least one engagement member can comprise a plurality of shafts mounted on the axle. Each shaft can protrude radially outwards from the axle, for example in a cruciform arrangement. At least one shaft can be shorter than the other shaft(s), and is arranged not to engage the selection element in at least one operational condition, thereby enabling the selection element to flip over, for example if biassed to do so, as the control element moves from the secondary position to the primary position.

The selection element can be attached to the resilient element and the control element.

The selection element can be arranged to selectively engage the control element. The selection device can be arranged to selectively move the selection element into and out of engagement with the control element.

The positioning device can be attached to a positioning device support by a first pivot having a first pivot axis, and can be arranged to pivot relative to the positioning device support. The control element can be attached to a control element support by a second pivot having a second pivot axis, and can be arranged to pivot relative to the control element support.

The first pivot axis can be arranged transversely to the direction of travel of the cutter device in normal use. The second pivot axis can be arranged transversely to the direction of travel of the cutter device in normal use. The first pivot axis can be located above the second pivot axis. The second pivot axis can be arranged parallel to the first pivot axis.

The first pivot can be located towards an end of the positioning device, for example at an end that can be opposite to an end of the positioning device that engages the knife.

The second pivot axis can be offset from the first pivot axis. Thus the first and second pivot axes are not co-axial. The first pivot axis can be positioned more forwardly than the second pivot axis. The first pivot axis can be positioned vertically higher than the second pivot axis.

The control element can comprise a bar arranged transversely to the direction of travel of the cutter device in normal use. At least one arm can protrude radially outwards from the bar. The second pivot can be located on the at least one arm. The bar can be arranged parallel with the second pivot axis.

A linkage comprising the resilient connecting element and the selection element can connect the positioning device to the control element. The resilient connecting element can be pivotally attached to the positioning device by a third pivot having a third pivot axis. The resilient connecting element can be pivotally attached to the selection element by a fourth pivot having a fourth pivot axis. The selection element can be pivotally attached to the control element by a fifth pivot having a fifth pivot axis. The resilient connecting element can be elongate, for example can comprise an elongate spring. The third pivot can be located towards a first end of the resilient connecting element. The fourth pivot can be located towards a second end of the resilient connecting element. The selection element can be elongate. The fourth pivot can be located towards a first end of the selection element. The fifth pivot can be located in a central portion of the selection element.

An angle A is defined at the fourth pivot between a first notional line connecting a centre of the fourth pivot with a centre of the third pivot and a second notional line connecting the centre of the fourth pivot with a centre of the fifth pivot, the angle A is located on a side of the resilient connecting element and the selection element that is opposite to the side on which the control element is located, wherein the angle A is adjustable as the resilient connecting element and the selection element pivot relative to one another in response to movement of the control element between the primary and secondary positions.

For the first selection configuration, the angle A can be less than <NUM> degrees, throughout the movement of the control element or control bar from the secondary position to the primary position.

For the second selection configuration, the angle A can be less than <NUM> degrees in a condition wherein the control element or control bar is located at the secondary position. The angle A can equal <NUM> degrees in a condition wherein the control element or control bar is located at at least one position that is intermediate between the primary and secondary positions. The angle A can be greater than <NUM> degrees in a condition wherein the control element or control bar is located at the primary position. In the second configuration, the selection element flips its orientation, thereby increasing the angle A to greater than <NUM> degrees.

In some embodiments, the angle A can be less than <NUM> degrees in a condition wherein the control element is located at the secondary position, and the angle A can be greater than <NUM> degrees in a condition wherein the control element is located at the primary position.

In some embodiments, for the first selection configuration, the selection control can be arranged to block the selection element from pivoting about the fifth axis, as the control element moves from the secondary position to the primary position, thereby enabling the knife to move to the cutting position and to be supported in the cutting position.

In some embodiments, for the second selection configuration, the selection control is arranged to allow the selection element to rotate about the fifth axis, as the control element moves from the secondary position to the primary position, thereby enabling the knife to return to its non-cutting position.

The agricultural harvester can comprise a baler, and preferably a round baler. Utilizing the cutter device on a round baler provides significant advantages. For example, a round baler can be arranged to bind the bale during a baling operation, and during the binding process there can be no intake of crop material so there can be an opportunity to clean the knives without loss of time or the risk of material being uncut during the cleaning process.

The baler can include a first hydraulic cylinder for actuating the control element.

The baler can include a second hydraulic cylinder for operating the tailgate.

The first and second hydraulic cylinders can be arranged parallel to one another. This helps to ensure that the control element is operated in parallel and/or at the same time as, the opening of the tailgate.

The round baler can include a binding device. When operated, the binding device is arranged to supply binding material into the baling chamber to bind the bale.

The cutter device can include a controller, such as an electronic controller, that is arranged to operate the agricultural harvester. For example, the controller can be arranged to operate the first hydraulic cylinder to operate the control mechanism and move the knife. For example, the controller can be arranged to actuate the control element to cause the knife to move to the cutting position. The controller can be arranged to actuate the control element to cause the knife to move to the intermediate position. The controller can be arranged to actuate the control element to cause the knife to move to the non-cutting position. The controller can be arranged to operate the second hydraulic cylinder to open and close the tailgate. The controller can be arranged to operate the selection mechanism. The controller can be arranged to operate the binding device.

Moving the knife to undertake a cleaning operation can be initiated by the controller in response to the controller determining that at least one baler operating condition has been met. For example, the controller can be arranged to initiate a knife cleaning operation in response to sensing or determining that no crop material is transported by the cutting rotor (e.g. when the harvester is located on a headland). For embodiments wherein the cutter device is mounted on a round baler, moving the knife to undertake a cleaning operation can be initiated by sensing or determining that the round baler is binding a bale in the baling chamber and / or detecting or determining that the bale has been ejected from the baling chamber, since during those operational conditions there can be no intake of crop material.

The controller can be arranged to actuate the control element and/or selection mechanism in response to the tailgate opening.

The controller can be arranged to actuate the control element and/or selection mechanism in response to the controller determining that the bale size has reached a threshold size. Optionally, the controller can be arranged to actuate the control element and/or selection mechanism in response to signals received from a sensor arranged to monitor bale size.

The controller can be arranged to actuate the control element and/or selection mechanism in response to the controller determining that no crop material is being transported by the cutting rotor towards the baling chamber. Optionally, the controller can be arranged to actuate the control element and/or selection mechanism in response to signals received from a sensor arranged to monitor the flow rate of crop material moving towards the baling chamber.

The controller can be arranged to actuate the control element and/or selection mechanism in response to the controller determining that the tailgate has opened and/or closed. The controller can be arranged to receive signals from a sensor arranged to monitor the operational condition of the tailgate, thereby detecting an open / closed state. For example, the baler can include a sensor, such as a limit switch adjacent the tailgate, and the controller can be arranged to actuate the control element in response to signals received from the sensor adjacent the tailgate.

The controller can be arranged to actuate the control element and/or selection mechanism in response to the controller determining that the binding device is operational.

The controller can be arranged to actuate the control element and/or selection mechanism in response to the controller determining that the bale has been released from the bale chamber.

In each of these instances, no crop material is transported into the bale chamber, which provides an opportunity to undertake a cleaning process to clean the knife and the opening.

For embodiments including a plurality of knives, typically each knife can have a respective positioning device, a respective resilient connecting element, a respective selection element and a respective selection control. Optionally, each selection control can be mounted on the axle. Optionally, the control element can be arranged to adjust the position of each positioning device, and hence each knife, according to the operational condition of the respective selection element.

Typically, the cutter device includes around <NUM> to <NUM> knives, each mounted in a respective opening in the bottom plate, and each individually controllable by the control mechanism in a similar fashion to the knife described above.

For example, the cutter device can include a second knife, wherein the position of the second knife is adjustable.

The bottom plate can include a second opening through which the second knife extends in a cutting position.

The control element can be arranged to control movement of the second knife between: a first position in which the second knife is in a cutting position in the feed path; a second position in which the second knife can be retracted from the feed path into a non-cutting position; and a third position, in which the second knife can be located at an intermediate position between the cutting position and the non-cutting position.

The selection mechanism can be arranged to select between first and second selection configurations for the second knife.

In the first selection configuration, in response to the control element being actuated to move from the secondary position to the primary position, the control mechanism is arranged to move the second knife from the second position to the first position.

In the second selection configuration, in response to the control element being actuated, the control mechanism is arranged to move the second knife from the second position to the third position during movement of the control element from the secondary position to the primary position, and in a condition wherein the control element reaches the primary position, the second knife is freely movable to return to the second position of the second knife.

At the intermediate position, the second knife can be either temporarily held in position in the opening due to accumulated dirt and/or crop material adjacent the opening and can be subsequently forced to the non-cutting position by crop material moving along the flow path, or can be freely movable to the non-cutting position due to gravity acting on the second knife.

The cutter device can include a second positioning device arranged to control movement of the second knife, wherein the control mechanism can be arranged to control operation of the second positioning device.

The cutter device can include a second selection element that can be arranged to select between a first selection configuration in which the second knife is selected and a second selection configuration in which the second knife is non-selected.

The selection mechanism can include a second selection control, which can be arranged to actuate the second selection element to select between the first and second selection configurations.

The second selection control can be mounted on the axle.

The cutter device can include a second resilient connecting element that can be configured to enable movement of the second positioning device relative to the control element by deformation of the second resilient connecting element.

The cutter device can include at least one: further knife, wherein the position of the further knife can be adjustable, for example similarly to the knife and/or the second knife.

The bottom plate can include a further opening through which the further knife extends in a cutting position.

The cutter device can include a further positioning device arranged to control movement of the further knife, wherein the control mechanism can be arranged to control operation of the further positioning device.

The cutter device can include a further selection element that can be arranged to select between a first selection configuration in which the further knife can be selected and a second selection configuration in which the further knife can be non-selected.

The selection mechanism can include a further selection control, which can be arranged to actuate the further selection element to select between the first and second selection configurations.

The further selection control can be mounted on the axle.

The cutter device can include a further resilient connecting element that can be configured to enable movement of the further positioning device relative to the control element by deformation of the further resilient connecting element.

As previously noted, the present invention relates to a cutter device for an agricultural harvester, for example a round baler, a square baler or a loading waggon. In <FIG> of the accompanying drawings the cutter device is part of a variable chamber round baler. It should be noted that the cutter device may alternatively comprise part of another type of baler, for example a fixed chamber round baler or a square baler, or any other type of agricultural harvester, for example a loading wagon.

The variable chamber round baler <NUM> shown in <FIG> comprises a frame <NUM> and a housing <NUM> comprising a fixed part 4a and an openable rear part 4b, wherein the rear part 4b comprises a tailgate <NUM> that can pivot open about a pivot <NUM> in the upper part of the housing <NUM> to release a completed bale from the baler. The frame <NUM> and the fixed front part 4a of the housing <NUM> optionally comprise a unitary structure. The baler <NUM> is mounted on wheels <NUM> and has a drawbar <NUM> allowing it to be drawn by an agricultural vehicle such as a tractor. The baler <NUM> is configured to be driven from the power take off unit of the tractor (not shown).

The baler housing <NUM> encloses a baling chamber <NUM> within which a round (cylindrical) bale B can be formed from bale material, for example agricultural crop material. A bale forming zone is provided within the baling chamber <NUM>, the shape of the bale forming zone being defined the side walls of the housing <NUM> and by one or more endless belts <NUM> that pass around a set of rollers 20a, 20b. At least one of the rollers is a drive roller 20a that is driven via the power take-off unit and drives the belts <NUM> causing them to rotate around the rollers 20a, 20b. The other rollers are undriven idler rollers 20b that rotate with the belts <NUM>.

Two of the idler rollers 20b comprise tensioning rollers 20b', which are mounted on a tensioning arm <NUM>. An intermediate roller <NUM> is located in the belt run between the movable rollers 20b'. The intermediate roller <NUM> guides the belt <NUM> as it runs from the rear part of the baling chamber <NUM> around the movable rollers 20b' and the intermediate roller <NUM>, and back to the front part of the baling chamber <NUM>. A third roller 20b" mounted on the arm <NUM> takes up any slack and effectively tensions the belts <NUM> as the arm <NUM> moves. The tensioning arm <NUM> can be pivoted about a pivot axis <NUM> to accommodate a change in the size of the bale forming zone defined by the belts <NUM> within the baling chamber <NUM>. A belt tensioner (not shown), for example a hydraulic or electric actuator, is connected between the tensioning arm <NUM> and the frame <NUM> and is operable to adjust the pressure on the tensioning arm <NUM> and the tension in the belts <NUM>. This affects the degree of compression of the bale material and the density of the bale B.

Optionally, the baling chamber <NUM> is defined in part by one or more press rollers <NUM> and/or a starter roller <NUM>, which do not engage the belts <NUM>. The press rollers <NUM> and the starter roller <NUM> are located on opposite sides of a feed opening <NUM> through which bale material is fed into the baling chamber <NUM>. The press rollers <NUM> and/or the starter roller <NUM> may optionally be driven rollers.

The baler includes a pick-up mechanism <NUM> for picking up bale material from the ground and feeding it into the baling chamber <NUM> along a feed path <NUM>. A cutter device <NUM> comprising a rotating rotor <NUM> is provided to drive the bale material along the feed path <NUM> and optionally to cut the bale material before it enters the baling chamber.

The bale material is circulated within the baling chamber <NUM> and compressed by the rotating belts <NUM> and the rollers 20a, 20b, <NUM>, <NUM> to form a round bale B. When the bale B has been formed and has reached the desired diameter it is bound with a suitable binding material, typically twine, net or film, which may be fed into the baling chamber <NUM> from a binding device <NUM> and wrapped around the bale B. The binding material may for example be fed into the baling chamber <NUM> between the lowermost idler roller 20b in the front part 4a of the housing and the upper press roller <NUM>. The bound bale can be ejected from the baling chamber <NUM> onto the ground by opening the tailgate <NUM>.

Except as described below, all the aforesaid features are conventional and they will not therefore be described in further detail.

The pick-up mechanism <NUM> and the cutter device <NUM> are shown in more detail in <FIG>. The pick-up mechanism <NUM> is conventional and comprises a plurality of pick-up tines <NUM> that rotate to pick up the crop material from the ground and feed it to the cutter device <NUM>. The pick-up mechanism <NUM> is supported on the ground by a pair of wheels <NUM> that are adjustable to adjust the height of the pick-up mechanism <NUM> above the ground.

The cutter device <NUM> is positioned above and behind the pick-up mechanism <NUM> and is configured to drive the bale material along the feed path towards the baling chamber <NUM>.

The cutter device <NUM> is also operable to cut the bale material if required before it enters the baling chamber <NUM>.

The cutter device <NUM> includes a rotating rotor <NUM> comprising a tube <NUM> and a plurality of tine plates <NUM> that are mounted on the tube <NUM>. As depicted in <FIG>, in this embodiment each tine plate <NUM> comprises three tines <NUM> that are spaced evenly around the axis of the tube <NUM>, although the number and spacing of the tines may be different. Also in this embodiment the tine plates <NUM> are preferably attached to the tube <NUM> in pairs and the pairs of tine plates are set in a helical arrangement in which each pair of tine plates is offset from the adjacent pair of plates on each side thereof. Again, the arrangement of the tine plates <NUM> on the tube <NUM> may be different. Optionally, an auger <NUM> is provided at each end of the drive tube <NUM> to draw cut crop material inwards from the ends of the pick-up mechanism towards the centre thereof so that it can be fed into the baling chamber <NUM> by the cutter device <NUM>.

The pick-up mechanism <NUM> and the cutter device <NUM> are both driven from a drive chain <NUM> by a main shaft <NUM>, which is driven from the PTO of the tractor. Alternatively, a different drive mechanism may be provided.

As shown in <FIG> and <FIG>, a retainer mechanism <NUM> in the form of a comb is provided above and behind the rotating rotor <NUM> to remove cut crop material from the rotor after it has passed along the feed path <NUM>. A plurality of knives <NUM> are provided below and behind the rotating rotor <NUM> to cut the crop material as it is carried along the feed path <NUM> by the rotating rotor <NUM>. The knives <NUM> extend into the feed path <NUM> through slots <NUM> in a bottom plate <NUM> located beneath the rotating rotor <NUM>. More details of the knife <NUM> and the bottom plate <NUM> are shown in <FIG> and <FIG>. Alternatively, the positions of the rotor, the knives and the bottom plate may be inverted, so that the rotor is placed below the plate and the knives (the plate then being referred to as a top plate).

<FIG> depicts the main components of the cutter unit <NUM>, including the rotor <NUM>, the retainer mechanism <NUM>, the bottom plate <NUM> and one of the knives <NUM>. The rotor <NUM> rotates in a rotation direction R and feeds crop material along a feed path <NUM> between the rotor <NUM> and the bottom plate <NUM> in a flow direction F.

The following description of the structure of the knife <NUM> and the control system for moving the knife <NUM> is applicable to at least some, and typically each, of the knives <NUM>. The knife <NUM> is shown in solid lines in a raised cutting position C in which it extends into the feed path <NUM> through a slot <NUM> in the bottom plate <NUM>. When the knife <NUM> is in the cutting position C it cooperates with the tines <NUM> on the rotating rotor <NUM> to cut the crop material as it is driven along the feed path <NUM>. In this embodiment the knife <NUM> extends through the gap between a pair of tines <NUM> so that the tines pass by on opposite sides of the knife <NUM> to produce a cutting action. The knife <NUM> has a cutting edge <NUM>, which may be serrated.

The knife <NUM> is also shown in broken lines in a non-cutting position N in which it is lowered through the slot <NUM> so that it lies below the bottom plate <NUM> and does not extend substantially into the feed path <NUM>. When the knife <NUM> is in the non-cutting position N it does not significantly come into contact with crop material moving along the feed path <NUM> and the crop material is therefore fed by the rotating rotor <NUM> to the baling chamber <NUM> without being cut.

The knife <NUM> is approximately triangular-shaped and is pivotable between the cutting position C and the non-cutting position N by pivoting about a knife pivot shaft <NUM> located towards the front end of the knife <NUM>. The pivot shaft <NUM> is preferably partially circular in cross section and fits within a circular hole <NUM> provided at the front end of the knife, allowing rotation of the knife <NUM> about the pivot shaft <NUM>.

The pivot shaft <NUM> has a pair of flat faces <NUM> on opposite sides of the shaft, wherein the distance between the faces <NUM> is less than the diameter of the pivot shaft <NUM>. The knife <NUM> includes a shaft slot <NUM> that preferably extends forwards from the hole <NUM> to the front end of the knife <NUM>. The minimum width of the shaft slot <NUM> is greater than the distance between the faces <NUM>, allowing the shaft <NUM> to pass through the shaft slot <NUM> when the slot and the faces <NUM> are aligned. This allows the knife <NUM> to be attached to and detached from the shaft <NUM>. If the shaft slot <NUM> is not aligned with the faces <NUM> of the shaft <NUM> the knife <NUM> cannot be detached from the shaft <NUM>.

The pivot shaft <NUM> and the knife <NUM> therefore have complementary looking formations comprising the shaft slot <NUM> and the faces <NUM> that lock the knife <NUM> to the pivot shaft <NUM> in a first configuration and allow separation of the knife from the pivot shaft in a second configuration. The pivot shaft <NUM> and the knife <NUM> are adjustable between the first configuration and the second configuration by relative rotation of the knife <NUM> and the pivot shaft <NUM>. Relative rotation can be achieved by rotating the knife <NUM> about the pivot shaft <NUM> and/or by rotating the pivot shaft <NUM> about its axis.

The knife <NUM> can be moved between the cutting position C and the non-cutting position N by a positioning device <NUM>. In this employment the positioning device <NUM> comprises an arm that can be pivoted about a pivot axis <NUM> located at or near the rear end of the positioning device <NUM>. A first engaging formation <NUM> is provided at the front end of the positioning device <NUM>, which engages a complementary second engaging formation <NUM> provided towards the rear end of the knife <NUM>. In this embodiment the first engaging formation <NUM> comprises a pin and the second engaging formation <NUM> comprises a slot that opens through the lower rear edge <NUM> of the knife <NUM>. The slot extends forwards towards the pivot axis of the knife <NUM>, which is defined by the axis of the pivot shaft <NUM>.

The positioning device <NUM> can be pivoted between a first position P1 in which it positions the knife in the cutting position C and a second position P2 in which it positions the knife in the non-cutting position N. The positioning device <NUM> can also be moved to a third position P3 below the second position P2, where it can be disengaged from the knife <NUM> to allow the knife to move independently of the positioning device <NUM>, at least towards the cutting position C. The positioning device <NUM> is thus configured to engage the knife <NUM> and prevent significant movement of the knife independently of the positioning device <NUM> when the positioning device is in the first position P1 and at intermediate positions between the first position P1 and the second position P2. The term "significant movement" as used herein means movement that exceeds normal play between the knife <NUM> and the positioning device <NUM>.

The knife <NUM> is therefore positively connected to the positioning device <NUM> at the first position P1 and at intermediate positions between the first position P1 and the second position P2, so that the knife <NUM> cannot move significantly without corresponding movement of the positioning device <NUM>. When the positioning device <NUM> is in the third position P3 it can be disengaged from the knife, which allows free rotation of the knife <NUM> from the non-cutting position N towards the cutting position C. The term "disengaged" as used herein covers both full disengagement in which the knife <NUM> can move entirely independently of the positioning device <NUM>, and partial disengagement wherein the knife <NUM> can move independently of the positioning device <NUM> from the non-cutting position N towards the cutting position C, but where movement in the opposite direction from the cutting position C towards the non-cutting position N is not entirely free. It is noted that in this embodiment the second and third positions P2 and P3 are adjacent positions. Alternatively, the second and third positions P2 and P3 may coincide.

The positioning device <NUM> and the complementary engaging formations <NUM>, <NUM> may take different forms. For example, the positioning device and the knife may have complementary engaging formations that are configured to maintain engagement between the positioning device and the knife in the first position P1 and the second position P2 and all intermediate positions in between the first and the second position, and to permit disengagement of the positioning device from the knife in the third position P3 at least in the direction of movement towards the cutting position. Optionally, the engaging formations <NUM>, <NUM> may be configured to limit relative movement between the positioning device <NUM> and the knife <NUM> in a tangential direction relative to the pivot axis of the knife, and to permit relative movement between the positioning device and the knife in a radial direction relative to the pivot axis of the knife.

The cutter device also includes a control mechanism <NUM> that controls movement of the positioning device <NUM> between the first position P1, the second position P2 and the third position P3. The control mechanism <NUM> includes a control element <NUM> that is connected to the positioning device <NUM>, and an actuator <NUM> (shown in <FIG>) that is connected to the control element <NUM> and is configured to move the control element between a primary position C1 and a secondary position C2.

In this embodiment the control element <NUM> comprises a bar that extends transversely across the cutter device <NUM> substantially parallel to the axis of the rotor <NUM>. The bar is attached by pivot arms <NUM> to a pivot axis <NUM>, which is preferably located adjacent to, for example just below, the pivot axis <NUM> of the positioning device <NUM>. The pivot arms <NUM> pivot about the pivot axis <NUM>, allowing the control element <NUM> to swing between the primary position C1 that is shown in <FIG> in solid lines and the secondary position C2 that is shown in broken lines. In this embodiment the primary position C1 comprises a forward position and the secondary position C2 comprises a rearward position.

The control mechanism <NUM> further comprises a connecting element <NUM> that is connected to the positioning device <NUM>. In this embodiment the connecting element <NUM> comprises a resilient connecting element that is configured to enable movement of the positioning device <NUM> relative to the control element <NUM> by deformation of the connecting element <NUM>. The resilient connecting element <NUM> may for example comprise a kink spring, a coil spring or a flat spring. As described below, resilient connecting element <NUM> provides an overload protection mechanism <NUM> that allows the knife <NUM> to move from the cutting position C to the non-cutting position N when subjected to an overload force, for example when an obstruction such as a rock passes along the feed path between the rotor and the knife.

The control mechanism <NUM> includes a selection mechanism <NUM>. The selection mechanism <NUM> is arranged to enable alternative connection configurations between the positioning device <NUM> and the knife <NUM> to be selected. The connecting element <NUM> may be connected to the control element <NUM> by the selection mechanism <NUM>. These alternative connection configurations include a first selection configuration comprising a selected configuration in which the positioning device <NUM> engages the knife and controls movement of the knife between the cutting position C and the non-cutting position N, and a second selection configuration comprising a de-selected (or non-selected) configuration in which the positioning device <NUM> allows the knife to return to the non-cutting position N, regardless of the position of the control element <NUM>. In at least some arrangements, when the knife <NUM> is de-selected by the selection mechanism <NUM> the positioning device <NUM> does not fully disengage the knife <NUM>, for example to help facilitate selection of the knife <NUM> at a later time. In other arrangements, the positioning device <NUM> fully disengages the knife <NUM>, at least at the third position.

In an embodiment, when a knife <NUM> is deselected, it is brought first to an intermediate position between the cutting position C and the non-cutting position N, and the positioning device then allows the knife to fall from the intermediate position to the non-cutting position. Typically, the intermediate position is approximately midway between the cutting position C and the non-cutting position N. The intermediate position can be <NUM>%-<NUM>% of the total range of movement from the non-cutting position to the cutting position.

The selection mechanism <NUM> allows a user to select which of the plurality of knives <NUM> are moved to the cutting position C when the control element <NUM> moves from the secondary position C2 to the primary position C1. Each de-selected knife <NUM> is moved to a position that is intermediate between the non-cutting position N and the cutting position C. The knives <NUM> may return to the non-cutting position N under the force of gravity and/or as a result of being pressed downwards by bale material passing along the feed path <NUM>.

In the embodiment shown in the drawings the selection mechanism <NUM> comprises a selection element, such as a selection lever <NUM>, and a selection device, such as a selection control <NUM>. The selection lever <NUM> has a first end <NUM> that is attached to the connecting element <NUM> and a free second end <NUM>. The selection lever <NUM> is attached to the pivot arm <NUM> through a pivot connection <NUM> that is located between the first and second ends <NUM>, <NUM>. The selection lever <NUM> can be pivoted between a first position S1 in which the first end <NUM> engages the control element <NUM> and a second position S2 in which the second end <NUM> engages the control element <NUM>.

In this embodiment the selection control <NUM> comprises an engagement member in the form of a radial cam surface <NUM> that can engage the second end <NUM> of the selection lever <NUM>. The selection control <NUM> is mounted on a hexagonal bar 96a. The selection control <NUM> can be rotated to adjust the position of the selection lever <NUM> between the first position S1 in which the first end <NUM> engages the control element <NUM> and an intermediate third position S3 between the first position S1 and the second position S2, in which the first end <NUM> disengages the control element <NUM>. Subsequent movement of the selection lever <NUM> between the third position S3 and the second position S2 will be described below. At least some selection controls <NUM>, and typically each selection control <NUM>, is mounted on the same hexagonal bar 96a, and are therefore actuated simultaneously by rotating the hexagonal bar 96a.

<FIG> shows the positioning device <NUM> in the third position P3 in which the first engaging formation <NUM>, e.g. comprising a pin, is withdrawn from the second engaging formation <NUM> comprising the slot that opens through the rear edge <NUM> of the knife, so that the positioning device <NUM> is disengaged from the knife <NUM>. This allows the knife <NUM> to move independently of the positioning device <NUM>. The knife <NUM> is shown in solid lines in the non-cutting position N and also in broken lines in the detachment or removal position L, in which the knife is rotated beyond the cutting position C. Owing to the disengagement of the positioning device <NUM> the knife <NUM> can be rotated freely, for example by hand, in a circular path O around the pivot shaft <NUM> from the non-cutting position N to the removal position L.

The pivot shaft <NUM> can also if necessary be rotated about its axis from a locked configuration shown in solid lines to an unlocked configuration shown in broken lines in which the faces <NUM> on the sides of the shaft are aligned with the shaft slot <NUM> of the knife <NUM>. This allows the knife <NUM> to be removed by pulling it rearwards in a removal direction V. A knife detachment handle <NUM>, for example as shown in <FIG>, may optionally be provided for rotating the pivot shaft <NUM>.

<FIG> illustrates operation of the overload protection mechanism <NUM> that allows the knife <NUM> to move from the cutting position C towards the non-cutting position N when subjected to an overload force, for example when an obstruction S such as a stone or rock passes along the feed path between the rotor <NUM> and the knife <NUM>.

The control mechanism <NUM> comprises a connecting element <NUM> that is connected between the selection lever <NUM> and the positioning device <NUM>. In this embodiment the connecting element <NUM> comprises a resilient connecting element, for example a kink spring, a coil spring or a flat spring. The resilient connecting element <NUM> is configured to enable movement of the positioning device <NUM> relative to the control element <NUM> by deformation of the connecting element <NUM>.

For example, if an obstruction S such as a stone or rock passes along the feed path between the rotor <NUM> and the knife <NUM>, the obstruction may press the knife <NUM> downwards from the cutting position C as shown in broken lines towards the non-cutting position N shown in solid lines, allowing the obstruction S to pass along the feed path without damaging either the rotor <NUM> or the knife <NUM>. The force applied by the obstruction S to the knife <NUM> causes the resilient connecting element <NUM> to deform elastically, for example by bending. In <FIG> the deformed connecting element <NUM>' is shown in solid lines. After the obstruction S has passed, the resilient connecting element <NUM> resumes its normal undeformed shape as shown in broken lines, thereby returning the knife <NUM> to the cutting position C.

<FIG> illustrates two different configurations of the selection mechanism <NUM> with the control element <NUM> in the secondary position S2. In the first configuration shown in solid lines, the knife <NUM> is held in the cutting position C by the positioning device <NUM>. The selection lever <NUM> lies in the first position S1 in which the first end <NUM> of the selection lever <NUM> is pressed against the control element <NUM> by the connecting element <NUM>.

In the second configuration shown in broken lines, the knife <NUM> is in the non-cutting position and the selection lever <NUM> is in the second position S2 in which the second end <NUM> of the selection lever <NUM> is pressed against the control element <NUM>.

<FIG> is an isometric view of a base structure <NUM> of the cutter device, showing upper parts of a first set of knives <NUM>(C) in the cutting position C and a second set of knives <NUM>(N) in the non-cutting position N. In this embodiment the first and second sets of knives alternate along the length of the base structure <NUM>. However, the knives may be arranged in differently in numerous alternative sets. Only the tips of the second set of knives <NUM>(N) can be seen as the knives have been retracted through the slots <NUM> and are located almost entirely below the bottom plate <NUM>. The first set of knives <NUM>(C) extend through the slots <NUM> in the bottom plate <NUM> into the feed path of the bale material. A number of reinforcing plates <NUM> are attached to the upper surface of the bottom plate <NUM> to strengthen it and increase its rigidity.

An actuator <NUM> is connected to the control element <NUM> and is configured to move the control element between the primary position C1 and the secondary position C2 to move the selected knives <NUM> between the cutting position C and the non-cutting position N. An optional knife detachment handle <NUM> is shown removably attached to one end of the pivot shaft <NUM>. The knife detachment handle <NUM> allows the pivot shaft <NUM> to be rotated about its axis from the locked configuration to the unlocked configuration, allowing the knife <NUM> to be removed by pulling it in the removal direction V.

The knife <NUM> is shown in more detail in <FIG>. The knife <NUM> is approximately triangular in shape and has a cutting edge <NUM>, which may optionally be serrated, a bottom edge <NUM> and a rear edge <NUM>. A circular hole <NUM> is provided at the front end of the knife to receive the pivot shaft <NUM>, allowing the knife <NUM> to pivot between the cutting position C and the non-cutting position N.

A shaft slot <NUM> extends from the hole <NUM> to the edge of the knife <NUM>. In this embodiment the shaft slot <NUM> extends forwards from the hole <NUM> to the front end of the knife <NUM>, but it could alternatively extend downwards. The minimum width W of the shaft slot <NUM> is less than the diameter D of the hole <NUM> and less than the diameter of the pivot shaft <NUM>, but greater than the distance between the faces <NUM> of the pivot shaft <NUM>. This allows the shaft <NUM> to pass through the shaft slot <NUM> when the slot <NUM> and the faces <NUM> are aligned. This enables the knife <NUM> to be detached from the shaft <NUM> and attached to the shaft. If the shaft slot <NUM> is not aligned with the faces <NUM> of the shaft <NUM> the knife <NUM> cannot be detached from the shaft <NUM>.

The knife <NUM> includes the second engaging formation <NUM>, which engages the first engaging formation <NUM> of the positioning device <NUM>. The second engaging formation <NUM> is provided towards the rear end of the knife <NUM>. In this embodiment the second engaging formation <NUM> comprises a slot that opens through the rear edge <NUM> of the knife <NUM> and extends forwards towards the pivot axis of the knife <NUM>, which is defined by the axis of the pivot shaft <NUM> and the centre of the hole <NUM>. Optionally, the rear edge <NUM> extends at an angle of at least <NUM>° relative to the bottom plate <NUM> so that it helps to prevent crop material being drawn into the opening in the bottom plate and helps to remove accumulated dirt from the slot <NUM> as the knife <NUM> moves from the cutting position C to the non-cutting position N.

<FIG> illustrate movement of the knife <NUM> and interaction between the knife and the control mechanism <NUM> as the knife moves between its various positions.

In <FIG> the knife <NUM> is shown in solid lines in the cutting position C. The control element <NUM> is in the primary position C1 and the positioning device <NUM> is located in the first position P1 in which it is fully engaged with the second engaging formation <NUM> so that it holds the knife <NUM> in the cutting position C.

The knife <NUM> is also shown in broken lines in the non-cutting position N with the control element <NUM> in the secondary position C2 and the positioning device <NUM> in the third position P3, in which it is disengaged from the knife <NUM>. Movement of the control element <NUM> from the secondary position C2 to the primary position C1 will cause the positioning device <NUM> to engage the second engaging formation <NUM> and move the knife <NUM> from the non-cutting position N to the cutting position C. In both configurations the selection device <NUM> is in the selection position and the selection lever <NUM> is in the first position S1 in which it is pressed against the control element <NUM>, so that the knife <NUM> moves with the control element <NUM> between the cutting position C and the non-cutting position N.

<FIG> shows the knife <NUM> in the non-cutting position N. The control element <NUM> is shown in solid lines in an intermediate position C3 as it moves between the secondary position C2 and the primary position C1. The selection device <NUM> is in the selection position so that the knife <NUM> moves with the control element <NUM>. The positioning device <NUM> is shown in solid lines in the second position P2 in which it is engages with the second engaging formation <NUM> of the knife <NUM>. The positioning device <NUM> is also shown in broken lines in the third position P3, in which it is disengaged from the knife <NUM>. As noted above, movement of the control element <NUM> from the secondary position C2 towards the primary position C1 causes the positioning device <NUM> to engage the second engaging formation <NUM> and move the knife <NUM> from the non-cutting position N towards the cutting position C.

<FIG> illustrate a process for deselecting a knife by at least partially disengaging the positioning device <NUM> so that the knife <NUM> can move to the non-cutting position N.

As shown in <FIG>, when the control element <NUM> is in the C2 position shown in broken lines, the selection device <NUM> is rotated to the de-selection position in which the cam surface <NUM> pushes the selection lever <NUM> to the third position S3. The control element <NUM> then rotates forwards from the secondary position C2 to the primary position C1 through an intermediate position C4 shown in solid lines. In this intermediate position C4 the knife <NUM> is pushed to an intermediate position between the non-cutting position N and the cutting position C, for example around midway between the cutting position C and the non-cutting position N, which helps to remove any accumulated dirt from the slot <NUM> in the bottom plate <NUM>.

When the control element <NUM> reaches the intermediate position C4 shown in solid lines in <FIG> the three pivot axes X, Y, Z of the positioning device <NUM> and the selection lever <NUM> are aligned. In other words, the angle A is equal to <NUM>°, where A is the angle formed between a line that connects the pivot axes X, Y of the connecting element <NUM> and a line that connects the pivot axes Y, Z of the selection lever <NUM>. It is noted that the angle A changes as the control element <NUM> moves from the secondary position C2 to the primary position C1 owing to the fact that the pivot axis <NUM> of the control element <NUM> is offset from the pivot axis <NUM> of the positioning device <NUM>.

As soon as the control element <NUM> rotates from the secondary position C2 past the intermediate position C4 towards the primary position C1 that is shown in chain lines in <FIG>, the angle A increases from less than <NUM>° at C2, to more than <NUM>° between C4 and C1 because the pivot axis <NUM> of the control element <NUM> is offset from the pivot axis <NUM> of the positioning device <NUM>. The compressed connecting element <NUM> then causes the selection lever <NUM> to flip over to the second position S2 shown in <FIG>. As a result, the positioning device <NUM> is not fully supported anymore allowing the knife <NUM> to fall or be pressed by bale material towards the non-cutting position N shown in broken lines in <FIG>.

<FIG> shows the selection lever <NUM>' in an intermediate position as it flips over from the third position S3 to the second position S2. The positioning device <NUM> is in position P2 and is no longer supporting the knife <NUM>, allowing the knife <NUM> to move towards the non-cutting position N.

<FIG> shows the selection lever <NUM> in the second position S2 and the control element <NUM> in the first position C1. The knife <NUM> is in the non-cutting position N.

The number of knives <NUM> that are in the cutting position C at any one time is typically selected according to the harvesting strategy employed by the user. For example, the type of animal that the crop will feed and how much power it is desirable to expend to cut the crop. The greater the number of knives <NUM>, the shorter the length of individual crop pieces. With fewer knives <NUM> deployed to the cutting positions C there is less intensive cutting and the lengths of the crop stalks will be longer.

<FIG> show a part of a cutter device according to a second embodiment of the invention. The cutter device according to the second embodiment is similar to the first embodiment, except for the differences outlined below. Accordingly, reference numbers used in <FIG> to identify features that have a direct equivalent feature in the first embodiment, are the same as those used in the first embodiment.

It is apparent from a comparison of <FIG> and <FIG> that each selection control 96b in the second embodiment has a different arrangement from the selection controls <NUM> in the first embodiment. Rather than having a radial cam surface <NUM> mounted on an axle 96a for a respective knife, in the second embodiment, each selection control 96b comprises a plurality of engagement members in the form of shafts <NUM> that protrude radially outwards from the axle 96a. In the arrangement shown in <FIG>, the shafts <NUM> have a generally cruciform arrangement comprising first, second, third and fourth shafts <NUM>. Each of the first, second and third shafts <NUM> is each arranged to selectively engage the selection element <NUM> according to the rotational orientation of the axle 96a. When one of the first, second and third shafts <NUM> engages the selection element adjacent pivot axis Y, the selection element <NUM> is prevented from flipping over by pivoting about axis <NUM> as the control element <NUM> moves from the secondary position C2 to the primary position C1 (see <FIG> and17) despite being urged to do so by the resilient connecting element <NUM>. That is, the selection element <NUM> is held in the first operating condition, wherein the knife <NUM> is selected, while one of the first, second and third engagement shafts <NUM> engages the selection element <NUM> adjacent pivot axis Y. The fourth shaft 97a of the cruciform arrangement has a shorter radial length than the first, second and third shafts <NUM> of the cruciform arrangement. As shown in <FIG>, the shortest shaft 97a is arranged such that when the shortest shaft 97a is generally oriented towards the selection element <NUM> the shortest shaft 97a does not engage the selection element <NUM>, and therefore does not block the selection element <NUM> from flipping over as the control element <NUM> moves from the secondary position C2 to the primary position C1. That is, the selection element <NUM> is not prevented from rotating about pivot axis Z and deselecting its knife <NUM> (see <FIG>) when biased to do so by the resilient connecting element <NUM>. In some embodiments, the fourth shaft 97a can be omitted entirely.

In the second embodiment, the pivot axis <NUM> is spaced further apart from the pivot axis <NUM> when compared with the distance separating the pivot axes <NUM>,<NUM> in the first embodiment. The geometry of the second embodiment, together with the arrangement of the selection control <NUM>, enables the movements of the selection element <NUM> and knife <NUM>.

The second embodiment provides a similar bottom plate slot <NUM> cleaning operation to the first embodiment. When starting at the secondary position C2 all knives <NUM> and positioning devices <NUM> proceed upwards towards the cutting position C when control element <NUM> moves from the secondary position C2 towards the primary position C1 because angle A is less than <NUM>° (see <FIG>). When moving towards the primary position C1, the control element <NUM> passes through an intermediate position C4, wherein each knife <NUM> (that is both selected and non-selected knives <NUM>) moves to a respective intermediate position between the cutting position C and the non-cutting position N, for example midway between the cutting position C and the non-cutting position N. At the intermediate position C4, the angle A is approximately equal to <NUM>° since the axes of the three pivot points X, Y, Z of the positioning device <NUM> and the selection element <NUM> are aligned. As the control element <NUM> moves further towards the primary position C1, for any non-selected knives <NUM> (those knives for which the selection control <NUM> is oriented such that the shorter fourth shaft 97a faces towards the selection element <NUM>,) the selection element <NUM> rotates about axis Z and flips to the position shown in <FIG> since the resilient connecting element <NUM> biases it to do so. In this condition, any force applied to the deselected knives <NUM> in the direction of the flow of crop material, will cause the deselected knives <NUM> to fall to the non-cutting position N under the action of gravity. It is apparent that in <FIG>, the angle A is significantly larger than <NUM>°. For each selected knife <NUM> (each knife <NUM> wherein its respective selection control <NUM> has one of the first, second and third shafts <NUM> engaged with the respective selection element <NUM>), as the control element <NUM> moves to the primary position C1 and angle A increases above <NUM>°, the selected knives <NUM> are moved to the cutting position C and are held in the cutting position C as shown in <FIG> since the selection element <NUM> is blocked from flipping over by rotating about pivot axis Z despite the resilient connecting member <NUM> biassing it to do so.

Moving the knives <NUM> into and out of the slots <NUM> in the manner described above cleans those slots <NUM> by dislodging accumulated dirt and crop material in and adjacent to the opening. It will be apparent from the description above that for the second embodiment when the control element <NUM> moves from the secondary position C2 to the primary position C1, whether the knives <NUM> are selected or not, all of the knives <NUM> come to at least the intermediate knife position within their respective slots <NUM>, and therefore all the knives <NUM> clean their respective slots <NUM>. All selection elements <NUM> move from an angle A that is less than <NUM>° when the control element is in the secondary position C2 to angle A that is greater than <NUM>° in position C1. Each selection element <NUM> will flip over in a condition where angle A is greater than <NUM>° unless the selection control <NUM> prevents it from flipping over. This contrasts with the first embodiment, wherein the angle A is always less than <NUM>° if the selection lever <NUM> is not selected by the selection control <NUM> to enable it to flip over.

<FIG> shows a control system <NUM> that can be used with each of the first and second embodiments of the invention. The control system <NUM> includes an input device <NUM> and a display <NUM>, which are typically located in a tractor. The input device <NUM> enables the driver of the tractor to control operation of the baler <NUM> from the tractor, for example by selecting certain modes of operation and setting operating parameters.

The control system <NUM> includes a baler controller <NUM>, which can include, for example at least one programmable logic controller (PLC). The baler controller <NUM> is arranged to control operation of the baler. For example, the controller <NUM> can be arranged to operate the first hydraulic cylinder <NUM> to actuate the control element. The controller <NUM> can be arranged to operate the selection mechanism <NUM>. The controller <NUM> can be arranged to operate the binding device <NUM>.

The control system <NUM> includes a line <NUM> that connects the baler controller <NUM> to the actuator <NUM>. The baler controller <NUM> is arranged to control operation of the actuator <NUM> by sending control signals to the actuator <NUM> via the line <NUM>. For example, when the baler controller <NUM> determines from the input signals received from the input device <NUM>, or due to any other determination such as those described below, that the position of the control element <NUM> is to be adjusted, the actuator <NUM> is configured to move the control element <NUM> between a primary position C1 and a secondary position C2.

The control system includes a bale size sensor <NUM> that is arranged to detect the size of the bale B located within the baling chamber <NUM>. The bale size sensor <NUM> is connected to the baler controller <NUM>, and provides an input signal to the baler controller <NUM>, and the baler controller <NUM> is able to determine the size of the bale B in the baling chamber <NUM> according to the signals received from the bale size sensor <NUM>. In some embodiments, the controller <NUM> is arranged to actuate the control element <NUM> and/or selection mechanism <NUM> to undertake a knife cleaning operation in response to signals received from the bale size sensor <NUM>.

The control system includes a tailgate sensor <NUM> that is arranged to detect the position of the tailgate <NUM>, for example the tailgate sensor <NUM> can comprise a switch, such as a limit switch. The tailgate sensor <NUM> is connected to the baler controller <NUM>, and provides an input signal to the baler controller <NUM>, and the baler controller <NUM> is able to determine the rotational orientation of the tailgate <NUM> with respect to the fixed part 4a according to the signals received from the tailgate sensor <NUM>. In some embodiments, the controller <NUM> is arranged to actuate the control element <NUM> and/or selection mechanism <NUM> to undertake a knife cleaning operation in response to signals received from the tailgate sensor <NUM>.

The control system includes a crop material sensor <NUM> that is arranged to detect the flow F of crop material entering the baling chamber <NUM>. The crop material sensor <NUM> is connected to the baler controller <NUM>, and provides an input signal to the baler controller <NUM>, and the baler controller <NUM> is able to determine the flow rate of crop material entering the baling chamber <NUM> according to the signals received from the crop material sensor <NUM>. In some embodiments, the controller <NUM> is arranged to actuate the control element <NUM> and/or selection mechanism <NUM> to undertake a knife cleaning operation in response to signals received from the crop material sensor <NUM>.

The control system <NUM> includes a line <NUM> that connects the baler controller <NUM> to a tailgate cylinder <NUM>. A first end of the tailgate cylinder <NUM> is connected to the tailgate <NUM> at a first pivot connection 216a and a second end of the tailgate cylinder <NUM> is connected to the frame <NUM> at a second pivot connection 216b. The baler controller <NUM> is arranged to control operation of the tailgate cylinder <NUM> to open and close the baler <NUM> by sending control signals to the tailgate cylinder <NUM> via the line <NUM>. For example, when the baler controller <NUM> determines from the input signals received from the bale size sensor <NUM> that the bale B has reached a threshold size, the baler controller <NUM> can be arranged to issue a control signal to the tailgate cylinder <NUM> to automatically open the tailgate <NUM>, to enable the bale B to be ejected from the baling chamber <NUM>. When the baler controller <NUM> determines that the bale B has been ejected from the baling chamber <NUM>, the baler controller <NUM> issues a control signal to the tailgate cylinder <NUM>, via line <NUM>, to close the tailgate <NUM>. In some embodiments, the controller <NUM> is arranged to actuate the control element <NUM> and/or selection mechanism <NUM> to undertake a knife cleaning operation in response to determining that the bale has been released from the baling chamber <NUM>.

The control system <NUM> includes a line <NUM> that connects the baler controller <NUM> to the binding device <NUM>. The baler controller <NUM> is arranged to control operation of the binding device <NUM> to bind the bale B in the baling chamber <NUM> by sending control signals to the binding device <NUM> via the line <NUM>. For example, when the bale controller <NUM> determines from the input signals received from the bale size sensor <NUM> that the bale B has reached a threshold size, the baler controller <NUM> can be arranged to operate the binding device <NUM> to insert binding material into the baling chamber <NUM> to bind the bale B. In some embodiments, the controller <NUM> is arranged to actuate the control element <NUM> and/or selection mechanism <NUM> in response to the binding device operating.

Claim 1:
A cutter device for an agricultural harvester, comprising:
a rotor (<NUM>) with a plurality of tines (<NUM>), wherein the rotor (<NUM>) is rotatable to transfer an agricultural crop along a feed path (<NUM>);
a knife (<NUM>), wherein the position of the knife (<NUM>) is adjustable;
a bottom plate (<NUM>) located beneath the rotor (<NUM>), wherein the feed path (<NUM>) is located between the rotor (<NUM>) and the bottom plate (<NUM>), and the bottom plate (<NUM>) includes an opening (<NUM>) through which the knife (<NUM>) extends at least when in a cutting position (C);
a control mechanism (<NUM>) including a control element (<NUM>) which is movable between at least a primary position (C1) and a secondary position (C2), wherein the control element (<NUM>) is arranged to control movement of the knife (<NUM>) between
• a first position in which the knife (<NUM>) is in a cutting position (C) in the feed path (<NUM>),
• a second position in which the knife (<NUM>) is substantially out of the feed path (<NUM>) in a non-cutting position (N), and
• a third position in which the knife (<NUM>) is located at an intermediate position between the cutting position (C) and the non-cutting position (N),
wherein the control mechanism (<NUM>) is arranged such that, in a condition wherein the control element (<NUM>) is in the secondary position (C2), the knife (<NUM>) is in, or may freely move to, the second position of the knife (N),
and wherein the control mechanism (<NUM>) includes a selection mechanism (<NUM>) that is arranged to select between first and second selection configurations, wherein
• in the first selection configuration, in response to the control element (<NUM>) being actuated to move from the secondary position (C2) to the primary position (C1), the control mechanism (<NUM>) is arranged to move the knife (<NUM>) from the second position (N) to the first position (C), and
• in the second selection configuration, in response to the control element (<NUM>) being actuated, the control mechanism (<NUM>) is arranged to move the knife (<NUM>) from the second position (N) to the third position during movement of the control element (<NUM>) from the secondary position (C2) to the primary position (C1), and in a condition wherein the control element (<NUM>) reaches the primary position (C1), the knife (<NUM>) is freely movable to return to the second position (N) of the knife.