Patent Description:
Cut crop is picked up by a baler and directed into a baling chamber where a bale is formed. Before ejecting the formed bale from the baler it is desirable to bind or wrap the bale prior to ejection from the baling chamber in order to maintain the integrity of the formed bale as it is ejected from the baler.

For this purpose the baler is further provided with a roll of wrapping material and a feed apparatus configured to dispense/convey wrapping material from the roll of wrapping material to the baling chamber. The wrapping material may take any suitable form, though net wrap is a common wrapping material. A cutting apparatus moveable between a retracted position allowing free movement of the wrapping material and an advanced position to cut the wrapping material when the formed bale has been sufficiently wrapped in the wrapping material is also provided. It has also been found necessary to provide a braking apparatus to apply a braking force on the roll of wrapping material as the wrapping material is dispensed from the roll of wrapping material.

In known balers separate actuators to control the operation of the feed apparatus and the braking apparatus have been provided.

There are a variety of different grades of net wrap marketed by various manufacturers of net wrap for use in round balers. While Original Equipment Manufacturers can recommend the use of a certain specification of net wrap (or other wrapping material), whether or not an operator will choose to accept the recommendation is always unknown. Additionally, the rolls of net wrap are sold in differing lengths, resulting in rolls of differing weight. Each of these factors produces variability when using net wrap in the baler. During the wrapping of a bale with net wrap there are a few key characteristics that must take place for a successful start, unspooling, and cut of the net wrap and one of those is tension on the net wrap. The tension on the net wrap can make it more or less difficult to start, cut and unspool, but mainly to start and cut. Ideally, less tension is desired during the start and a lot of tension during the cut, but there are a variety of different ways to perform this task.

<CIT> discloses a round baler having the features of the precharacterising portion of claim <NUM>.

According to a first and second aspects of the present invention, respectively, a round baler according to claim <NUM> and a method of wrapping a round bale using a round baler according to claim <NUM> are provided. Preferred embodiments are provided in the dependent claims.

This has as an advantage that the tensioning element is able to control a down force exerted on the roll of wrapping material by the braking apparatus and so control the tension in the wrapping material.

This has as an advantage that the same actuator, whether it be electrical, hydraulic, or mechanical, may be used to control the braking force on the roll of wrapping material. By variable, it is meant mean that the system will provide a different amount of braking at the start of the wrapping cycle versus the cutoff function of the cycle. Additionally, the invention also provides a different amount of brake force in relation to the size (diameter) of the roll of wrapping material.

Reference to terms such as longitudinal, transverse and vertical are made with respect to a longitudinal vehicle axis which is parallel to a normal forward direction of travel. Reference to height is to the distance of the element to the ground with the apparatus on a level surface.

The invention has particular application to a round baler in which the roll of wrapping material is supported on a pan or by way of a spindle system during dispense. In the illustrated embodiment support by way of a pan type system is shown.

A round baler <NUM> is designed to be towed behind an agricultural vehicle <NUM>. The round baler <NUM> includes a baling chamber <NUM> (an edge of which is shown in <FIG>,<FIG>,<FIG> and <FIG>). The baling chamber <NUM> may be of the fixed or variable variety. A fixed diameter baling chamber is shown in the illustrated embodiment. A wrapping material inlet <NUM> is defined between two of the rollers <NUM>,<NUM> forming the baling chamber <NUM>. It will be understood that the rollers <NUM>,<NUM> are supported for driven rotation in a typical fashion.

Cut crop is introduced into the baling chamber, where the accumulated cut crop is rotated to create a formed bale.

The baler <NUM> is further provided with a roll <NUM> of wrapping material located in a reservoir or storage location <NUM>. A feed apparatus is configured to convey wrapping material from the roll <NUM> of wrapping material to the baling chamber <NUM> to allow for wrapping of the formed bale. A cutting apparatus is also provided, moveable between a retracted position allowing free movement of the wrapping material and an advanced position to cut the wrapping material when the formed bale has been sufficiently wrapped in the wrapping material. A braking apparatus is also provided to apply a braking force on the roll <NUM> of wrapping material as the wrapping material is dispensed from the roll <NUM> of wrapping material in order that tension can be introduced to the wrapping material.

It will be understood that the baler comprises a frame <NUM> to which the various elements are in practice mounted.

In the illustrated embodiment, the roll <NUM> of wrapping material is supported on tray <NUM> provided on a support <NUM> connected to the baler frame <NUM>. The storage location <NUM> further includes a lip <NUM> over which the wrapping material is guided as it is dispensed from the storage location <NUM>. The support <NUM> is provided with a lower wrapping material guide <NUM> extending across the baler <NUM>. In use, a free end of the roll <NUM> of the wrapping material is directed under the lower wrapping material guide <NUM> having passed over the lip <NUM>.

The support <NUM> further incudes a braking element <NUM>. The braking element <NUM> is in the form of a frame comprising first and second side members <NUM> connected by cross members. The braking element includes a handle <NUM>. The braking element <NUM> is mounted for pivoting movement to the support <NUM> by way of a pivot bar <NUM>. The braking element <NUM> further includes rollers <NUM> extending across the braking element <NUM> in the region of the handle <NUM>. The rollers <NUM> are supported within suitable mountings for free rotation with respect to the rest of the handle <NUM>.

A pivoting duck bill applicator <NUM> is mounted on the baler frame <NUM>. The duck bill applicator <NUM> comprises a frame having left and right hand substantially L-shaped side members <NUM> designed in use to allow passage of the wrapping material between them. The duck bill applicator <NUM> is connected to the baler frame <NUM> for movement around a pivot axis <NUM> by way of a bar extending through upper ends of the L-shaped side members <NUM>. The distal end of the duck bill applicator is provided with a duck bill <NUM> comprising opposing plates and a protruding tongue. In the ready position of <FIG>, it can be seen that the wrapping material is held between the opposing plates, with a free end of the wrapping material supported on and extending a short amount from the tongue.

As best seen in <FIG>, a central outer region of the L-shaped side members <NUM> is connected by a cross bar <NUM> supporting an upper wrapping material guide bar <NUM>. A central inner region is provided at one side with an outwardly directed pin <NUM>.

An actuator <NUM> is provided to one side of the baler frame. The actuator <NUM> is mounted for pivoting movement on an actuator support <NUM> provided on the baler frame. A distal end of the actuator <NUM> is provided with a mounting <NUM> connecting the distal end of the actuator <NUM> to one or both L-shaped side members <NUM> (for example by a bar running between the L-shaped members <NUM>). The mounting <NUM> is located to run to (or across) a part of the L-shaped member(s) <NUM> between the pivot axis <NUM> and the central portion of the L-shaped member(s) <NUM>. In the 'ready' position of <FIG>, the actuator <NUM> is in a first extended position (step <NUM>, <FIG>).

A tensioning element <NUM> is provided between the distal end of the actuator <NUM> and the braking element <NUM>. A first end of the tensioning element <NUM> is conveniently connected to the mounting <NUM> and a second end of the tensioning element <NUM> is conveniently connected to a mounting point <NUM> provided on the braking element <NUM>. The mounting point <NUM> is provided on one of the side members <NUM> below the rollers <NUM>. The tensioning element <NUM> comprises a first elastic part and a second inelastic part. Conveniently, the first elastic part comprises a spring element <NUM> connected at one end to the mounting <NUM>. Conveniently, the inelastic part comprises a chain or cable <NUM> connected at a first end to a second end of the first elastic part and at a second end to the mounting point <NUM>. The cable <NUM> may be of any suitable material. A path of the tensioning element between the mounting <NUM> and the braking element <NUM> is constrained by a guide element <NUM> provided on the support <NUM>.

The guide element <NUM> may take any convenient form. It may take the form of a U-shaped guide piece through which the inelastic part of the tensioning element runs or a pulley mounted to the support <NUM> around which the inelastic part of the tensioning element runs. Alternatively, the guide element <NUM> may take the form of an eyelet through which the inelastic part of the tensioning element runs.

A biased cutting element <NUM> is also provided mounted for pivoting movement about a pivot bar <NUM> extending across the baler. The biased cutting element <NUM> comprises a frame having side elements connected at a first end by a cutting knife <NUM>. A biasing element <NUM>, such as spring, is provided between a mounting point <NUM> provided on the baler frame <NUM> and a second end of the biased cutting element <NUM>.

A connecting element <NUM> is provided between the duck bill applicator <NUM> and the biased cutting element <NUM> to one side of these elements. A first end of the connecting element <NUM> is secured to the pivot bar <NUM> supporting the cutting element <NUM>. The ends of the pivot bar <NUM> are constrained for movement within arcuate channels <NUM> defined in the baler frame <NUM>. A second end of the connecting element <NUM> is angled with respect to a main body portion of the connecting element <NUM>. The second end is provided with a linear channel <NUM>. The outwardly directed pin <NUM> is located within the linear channel <NUM>.

The actuator <NUM> is conveniently operated by an electronic control unit <NUM>. The electronic control unit has access to a memory unit <NUM>. The memory unit <NUM> may take any suitable form and is in electronic communication with the electronic control unit <NUM>. The memory unit <NUM> is adapted to store, in any suitable manner such as a database or look up table, reference values as described below.

The electronic control unit <NUM> is also in electronic communication with a bale size sensor <NUM>.

Conveniently signals between the electronic components are provided by way of a suitable data communication network <NUM> such as one compliant with the ISOBUS standard (a network in conformance to ISO <NUM>).

The electronic control unit <NUM> may conveniently comprise a single processor located on the baler or its functions may be split between a first processor located on the baler and one or more additional processors located on an agricultural vehicle towing the baler, the additional processor(s) being in electronic communication with the first processor.

In the 'ready' position of <FIG> a relatively unused roll <NUM> of wrapping material can be seen. A free end of the roll <NUM> of wrapping material has been guided over the lip <NUM>, under the lower wrapping material guide <NUM> and introduced to the duck bill applicator <NUM>. The free end of the wrapping material has been guided over the upper wrapping material guide bar <NUM> and into the duck bill <NUM> where the wrapping material is loosely held in place by the opposing plates. A small portion of the free end of the wrapping material extends from the duck bill <NUM>.

The tensioning element <NUM> acts on the braking element <NUM>, urging the braking element <NUM> to rotate about the pivot bar <NUM> so that at least one of the rollers <NUM> exerts a downward force on the roll <NUM> of wrapping material. This downward force restrains the speed of rotation of the roll <NUM> of wrapping material and this braking effect tensions the wrapping material as it is drawn from the roll <NUM> of wrapping material.

In operation the electronic control unit <NUM> receives signals from the bale size sensor indicative of the size of the formed bale. When the electronic control unit determines that a desired bale size has been achieved, for example by comparing the signals with values stored in the memory unit <NUM>, the actuator <NUM> is operated by the electronic control unit <NUM> causing the actuator <NUM> to contract from the extended position (<FIG>) to a first retracted position (<FIG>) (step <NUM>, <FIG>).

This has a number of effects. Firstly, the mounting <NUM> is moved downwards causing the pivoting duck bill applicator <NUM> to pivot clockwise (as shown in the <FIG>, <FIG>, <FIG> and <FIG>) around the pivot axis <NUM>, so that the duck bill <NUM> is moved toward into the wrapping material inlet <NUM>. Secondly the connecting element <NUM> is moved downward causing displacement of pivot bar <NUM> and also rotation of the cutting element <NUM> about the pivot bar <NUM>. This movement of the duck bill applicator <NUM> reduces the separation of the upper wrapping material guide bar <NUM> and the lower wrapping material guide <NUM> so reducing the tension in the wrapping material.

In order to move the duck bill <NUM> into the wrapping material inlet <NUM>, the actuator <NUM> is then operated by the electronic control unit <NUM> to contract to a second (fully) retracted position (<FIG>) (step <NUM>). This movement also causes the actuator to pivot about the actuator support <NUM>. This causes further rotation of the duck bill applicator <NUM> about pivot axis <NUM> urging the duck bill <NUM> into the wrapping material inlet <NUM>.

In this way, a free end of the wrapping material is introduced into the baling chamber <NUM>, such that as the formed bale within the baling chamber <NUM> is rotated by the driven rollers, the wrapping material is caught between the rotating bale and the baling chamber, initially between the formed bale and driven roller <NUM>, and drawn into the baling chamber <NUM> to wrap the rotating bale.

The movement of the actuator <NUM> also causes the cutting element <NUM> to be further driven clockwise about the pivot bar <NUM> as the connecting element <NUM> is further displaced.

With the actuator in the second retracted position, the tensioning element <NUM> causes the least braking force on the roll <NUM> of wrapping material.

Once the wrapping material is being drawn from the reservoir <NUM> under the action of the rotating formed bale the duck bill <NUM> can be removed from the wrapping material inlet <NUM>. To achieve this, the actuator <NUM> is operated causing it to return to the first retracted position (<FIG>) (step <NUM>). This causes the cutting element <NUM> to be moved anticlockwise and the cutting knife <NUM> moved away from the wrapping material. The movement of the duck bill applicator <NUM> also causes movement of the wrapping material guide bar <NUM> so as to increase the path length between the reservoir <NUM> and the wrapping material inlet <NUM> thereby increasing the tension in the wrapping material during wrapping. This also causes the actuator <NUM> to be rotated back about the actuator support <NUM> to its previous position.

With the actuator <NUM> in the first retracted position, the tensioning element <NUM> causes the braking element <NUM> to exert a reduced force on the roll <NUM> of wrapping material.

Sensors <NUM> in electrical communication with the electronic control unit <NUM> provide signals for determining progress of the wrapping operation. When sufficient wrapping material has been drawn into the baling chamber for the desired wrapping of the formed bale, the actuator <NUM> is once again operated to adopt the extended position of <FIG> (step <NUM>). This causes the duck bill applicator <NUM> to be rotated towards the ready position of <FIG>. This further increases the path of the wrapping material between the reservoir <NUM> and the wrapping material inlet <NUM> greatly increasing the tension in the wrapping material for the cutting operation.

Further, with the actuator <NUM> in the extended position, the tensioning element <NUM> causes the braking element <NUM> to exert the greatest braking force on the roll <NUM> of wrapping material.

Movement of the duck bill applicator <NUM> also causes movement of the pivot bar on which the cutting element <NUM> is mounted, such that force exerted by the biasing element <NUM> causes the cutting element <NUM> to be driven clockwise and the cutting knife <NUM> to be driven across the path of the wrapping material between the duck bill applicator <NUM> and the wrapping material inlet <NUM>. This severs the wrapping material.

As the wrapping material is consumed, the diameter of the roll <NUM> of binding material reduces. The tensioning element <NUM> of the present invention has as an advantage that due to the constrained movement of the tensioning element <NUM> (cable <NUM>) by the guide element <NUM> in use the pressure exerted by the braking element <NUM> due to the tensioning element <NUM> at the stages of wrapping of the bale is increased as the diameter of the roll <NUM> of binding material reduces thereby allowing maintenance of the desired degree of tensioning of the wrapping material throughout the useful life of the roll of wrapping material (as illustrated by <FIG> in relation to <FIG>, <FIG> in relation to <FIG> and so on).

This arrangement has a further advantage. When it is desired to replace a consumed roll of wrapping material with a fresh roll of wrapping material an operator using the handle <NUM> rotates the braking element <NUM> about the pivot bar <NUM> (anticlockwise in the Figures). The tension in the tensioning element <NUM> is such as to hold the braking element <NUM> away from the tray <NUM> (due to the relative position of the mounting point <NUM> and guide element <NUM>) while the old roll of wrapping material is exchanged for the new). Once the new roll <NUM> of wrapping material is in position, the operator rotates the braking element <NUM> back into position such that the rollers <NUM> once again push down on the roll <NUM> of wrapping material.

<FIG> show a further embodiment in which a further arrangement for constraining the path of the tensioning element <NUM> between the mounting <NUM> and a modified barking element <NUM>. The braking element <NUM> is substantially similar to that of previous embodiments save that at an elongate element <NUM> is provided on the side elements <NUM> of the frame of the braking element to support the rollers <NUM>. The mounting point <NUM> is provided on the elongate element <NUM> in order to connect the second end of the tensioning element <NUM> is to the braking element <NUM>. The guide element <NUM> in the form of a first pulley provided on a part of the support <NUM> is supplemented by a second guide element <NUM> in the form of a second pulley such that the cable <NUM> follows a sinuous path around the first and second pulleys. In use a cover plate <NUM> is provided to prevent ingress of environmental contaminants such as loose cut crop.

The second guide element <NUM> is mounted about an axle <NUM> held in a substantially U-shaped bracket <NUM> and extending through elongate apertures <NUM> provided in each of the support <NUM> and the cover plate <NUM>. The bracket <NUM> is itself adjustable by way of a screw threaded member <NUM>. By adjusting the separation of the first and second pulleys using the screw threaded member <NUM> an operator can obtain a degree of control of the braking tension and adjust for the quality/robustness of the wrapping material being used.

The braking element <NUM> is provided in the region of the pivot bar <NUM> with a cammed surface <NUM> terminating at either end with shoulders <NUM>. The cammed surface <NUM> co-operates with a stop <NUM> provided on the support <NUM>. The stop <NUM> together with the shoulders <NUM> defines the extremes of movement of the braking element <NUM> between at one end allowing release of the braking element <NUM> to allow loading of fresh roll of wrapping material and at the other end retaining the hollow tube of an exhausted roll of wrapping material within the tray <NUM>.

A gas spring <NUM> or similar may also be provided between the support <NUM> and the braking element <NUM>. This is of use in protecting the operator when engaging/disengaging the system when unloading an exhausted tube of wrapping material and loading of a replacement roll of wrapping material, so that the force needed to displace the braking element <NUM> is not extreme or harmful to the operator.

Claim 1:
A round baler (<NUM>) comprises a baling chamber (<NUM>), a wrapping material reservoir (<NUM>), a feed apparatus having an actuator (<NUM>), the feed apparatus configured to convey a wrapping material from the wrapping material reservoir (<NUM>) to the baling chamber (<NUM>), a cutting apparatus moveable between a retracted position allowing free movement of the wrapping material and an advanced position to cut the wrapping material, the actuator (<NUM>) controlling operation of the feed apparatus and the cutting apparatus characterised in that the round baler (<NUM>) further comprises a braking apparatus for applying a braking force on a roll (<NUM>) of wrapping material installed in the wrapping material reservoir (<NUM>), and a tensioning element (<NUM>) connecting the actuator (<NUM>) to the braking apparatus.