Patent Description:
During operation of a forage harvester agricultural crop is fed into the forage harvester and comminuted or rendered into smaller particles on its passage through the forage harvester before being discharged. The comminuted crop causes particular wear on some of the surfaces that it impacts upon when travelling through the harvester. For example, this can be a particular problem in relation to the surfaces in a chopper drum housing or a blower housing.

To address this problem replaceable wear plates have been developed to provide improved longevity to these regions of the forage harvester. In known systems, the wear plate may be held in place by screwing of the wear plate to a suitable support. It will be understood that removing the screws to allow the wear plate to be removed and replaced can be awkward, tedious and time consuming for the operator. In particular this may require some disassembly of the associated housing to permit access to the screws.

Additionally, the screws may become loose due to vibration during operation of the forage harvester and may subsequently be drawn into the processed crop and then into the resulting animal feed, causing a risk of harm to any animals consuming the feed. Alternatively, or additionally, during transit through the forage harvester the screws may interfere with other elements of the forage harvester as they pass through the forage harvester causing damage to such other elements.

Further should all of the screws become loose there is a danger that the wear plate itself may become dislodged and drawn into the flow of crop through the forage harvester. At best the dislodged wear plate may cause a blockage, but potentially the dislodged wear plate could interfere with other elements of the forage harvester as it passes through the forage harvester causing damage to such other elements.

It is an advantage of the present invention that it provides an improved wear plate assembly for use in an agricultural harvester such as a forage harvester.

<CIT> discloses a shredbar for use with a forage harvester. The disclosed shred bar can be considered to be a wear plate assembly according to the precharacterising part of claim <NUM>.

According to a first aspect of the present invention, an agricultural harvester according to claim <NUM> is provided. The agricultural harvester comprises a wear plate. The agricultural harvester further comprises a shear bar assembly to which the support element of the wear plate assembly is mounted. The wear plate assembly for an agricultural harvester comprises a support element having a number of lateral regions, is chracterised in that the or each lateral region is provided with a plurality of first engagement features, and in that one or more replaceable wear plates provided on a first side with a plurality of second engagement features for engagement with the first engagement features, and a plurality of fastenings to secure the or each replaceable wear plate to the support element through the engagement features.

Preferably, each of the first engagement features comprises a female fitting and each of the second engagement features comprises a male fitting for engagement with a respective female fitting.

Preferably, each of the first engagement features comprises a tubular member having an internal section and each of the second engagement features comprises a tubular member having an external section sized for seating within the internal section of the first engagement feature.

Preferably each of the first engagement features is provided with an end portion having a threaded opening, each of the second engagement features is provided with an internal threaded opening and wherein each of the plurality of fastenings is a threaded fastening adapted to engage with each of the threaded opening and the internal threaded opening to secure the or each replaceable wear plate to the support element. Preferably the one or more replaceable wear plates comprises first and second replaceable wear plates.

According to a second third aspect of the present invention a method of assembly of a wear plate assembly according to claim <NUM> is provided.

Preferably where the wear plate assembly includes a second replaceable wear plate the method further comprises locating the second replaceable wear plate such that the first engagement features are seated within the second engagement features, introducing each of the plurality of fastening members through an associated first engagement feature of the support element and into an associated second engagement feature to secure the second replaceable wear plate to the support element through the first and second engagement features.

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.

With reference to <FIG>, in a schematic side view the main components of a forage harvester <NUM> are shown. The forage harvester <NUM> is provided with a front attachment <NUM> which contains cutting equipment for cutting a crop. The cut crop is then fed through a series of compression rollers <NUM> in a compression roller housing <NUM> to a chopper drum assembly <NUM> where the crop is chopped into smaller pieces between a shear bar <NUM> and a plurality of chopper knives <NUM> mounted on a chopper drum <NUM>. The chopped crop next passes through a first duct <NUM> and, in the illustrated embodiment, is fed through a cracker unit <NUM> where the crop is further crushed and threshed. The harvested crop is then blown upwards along a second duct <NUM> by an accelerator <NUM> and exits through a spout <NUM>. In an alternative embodiment, the chopped crop may optionally pass directly from the chopper drum assembly <NUM> to the second duct <NUM>.

In describing the present invention the term 'inner' is used to describe those elements of the invention which are, in use, closer to an axis of rotation of the chopper drum and 'outer' the opposite. Similarly references to 'upper' and 'lower' are to be understood with reference to the forage harvester in position on level ground.

<FIG> shows a perspective view of a chopper drum assembly <NUM> incorporating the present invention. The chopper drum <NUM> is supported for rotation within a frame. The chopper drum <NUM> is driven about a central longitudinal axis by any suitable means. An upper end of the frame is provided with a housing <NUM> within which a sharpening apparatus may be located. The frame is provided with first and second parallel side walls <NUM>,<NUM>.

The chopper drum <NUM> is mounted in central portion of the frame supported between the side walls <NUM>,<NUM>. The frame is further provided with further mounting means to enable the frame to be located in a suitable position within the forage harvester <NUM>.

A shear bar <NUM> is mounted to an upper part of a shear bar holder <NUM>. The shear bar holder <NUM> is supported from the frame in a known manner so as to be pivoted about an axis <NUM> extending through a lower part of the shear bar holder <NUM>. Pivoting of the shear bar holder about this axis enables a distance between the blades of the chopper knives <NUM> and an edge of the shear bar <NUM> to be adjusted and set.

Elements of a wear plate assembly <NUM> in accordance with the present invention may best be seen in <FIG>. The wear plate assembly <NUM> comprises a support element <NUM> and at least one replaceable wear plate. In the illustrated embodiment, two such replaceable wear plates <NUM>,<NUM> are shown.

The support element <NUM> comprises a generally planar portion <NUM> with a lip <NUM> towards a second end. The generally planar portion <NUM> is provided at a first end with an angled portion <NUM>'. The lip <NUM> is provided at a number of locations with a locating surface <NUM>. In the illustrated embodiment two such locating surfaces <NUM> are shown. The locating surfaces <NUM> are attached to the support element in any suitable manner, for example by welding.

The generally planar portion <NUM> is provided in a first lateral region <NUM>" with a plurality of first openings <NUM>. Each first opening <NUM> is provided with a generally tubular element <NUM> secured to an outer surface of the generally planar portion <NUM>. A first end of each generally tubular element <NUM> may be secured to the generally planar portion <NUM> within a first opening <NUM> in any suitable manner, for example by welding. Alternatively, a first end of each generally tubular element <NUM> may be secured to the generally planar portion <NUM> about a first opening <NUM>, such that the first opening <NUM> and an inner part of each generally tubular element <NUM> are aligned. An outer end of each generally tubular element <NUM> is provided with an aperture <NUM> (<FIG>). The first openings <NUM> and the associated tubular elements <NUM> may be of any suitable shape.

In the illustrated embodiment four such first openings <NUM> (and the associated tubular elements <NUM>) are provided in the first lateral region <NUM>": two in an upper central part and two in a lower part, each located towards an end of the first lateral region <NUM>". Other numbers and distributions of the first openings <NUM> are possible.

The generally planar portion <NUM> is provided in a second lateral region <NUM>‴ with a plurality of second openings <NUM>. Each second opening <NUM> is provided with a generally tubular element <NUM> extending through the generally planar portion <NUM>. Each generally tubular element <NUM> may be secured within a second opening <NUM> to the generally planar portion <NUM> in any suitable manner, for example by welding. An outer end of each generally tubular element <NUM> is provided with an aperture <NUM> (<FIG>). The first openings <NUM> and the associated tubular elements <NUM> may be of any suitable shape.

In the illustrated embodiment four such second openings <NUM> (and the associated tubular elements <NUM>) are provided in the second lateral region <NUM>‴: two in a lower central part having a first lateral spacing and two in an upper part, having a second lateral spacing greater than the first. Other numbers and arrangements of the second openings are possible.

The wear plate assembly <NUM> further comprises a first element <NUM> extending laterally across the angled portion <NUM>' of the generally planar portion <NUM> of the support element <NUM>. The first element <NUM> is fixedly secured in position in relation to the support element <NUM> by any suitable method, for example by welding. The first element <NUM> may be of any suitable shape. In the illustrated embodiment, the first element is generally planar. The first element <NUM> is provided with a number of openings or windows <NUM>. In the illustrated embodiment, two such windows <NUM> are provided. The windows <NUM> are used to secure and locate a pair of block elements <NUM>. The block elements <NUM> may be secured in any suitable manner, for example by welding. Each of the block elements <NUM> is provided with a central through bore <NUM>. In use the block elements <NUM> extend into suitably shaped openings in the shear bar holder <NUM>. A pin or shaft <NUM> (<FIG>) extends though the shear bar holder and the bores <NUM> to provide an axis of rotation for the support <NUM> with respect to the shear bar holder <NUM>.

A first removable wear plate <NUM> is releasably mounted on the generally planar portion <NUM> of the support element <NUM> next to the first element <NUM>. It can be seen that, in the illustrated embodiment, the first removable wear plate <NUM> overlies the angled portion <NUM>' adjacent the first element <NUM> and the first lateral region <NUM>" of the generally planar portion <NUM> of the support <NUM>. The first removable wear plate <NUM> is of arcuate form such that an inner surface of the first removable wear plate <NUM> follows the desired dimensions of the chopper drum assembly <NUM>. In use, the inner surface of the first removable wear plate <NUM> sits flush with an inner surface of the adjacent first element <NUM>. An outer surface of the first removable wear plate <NUM> is provided with a number of laterally spaced bosses <NUM>, each boss being provided with a threaded inner bore <NUM>. An outer surface <NUM> of each boss <NUM> may be of any suitable shape. Each boss is permanently secured to the outer surface of the first removable wear plate <NUM> in any suitable manner, for example by welding.

A second removable wear plate <NUM> is releasably mounted on the generally planar portion <NUM> of the support element <NUM> next to the first removable wear plate <NUM>. The second removable wear plate <NUM> is of arcuate form such that the inner surface of the second removable wear plate <NUM> follows the desired dimensions of the chopper drum assembly <NUM>. In use, the inner surface of the second removable wear plate <NUM> sits flush with the inner surface of the adjacent first removable wear plate <NUM>. An outer surface of the second removable wear plate <NUM> is provided with a number of laterally spaced bosses <NUM>, each boss <NUM> being provided with a threaded inner bore <NUM>. An outer surface <NUM> of each boss <NUM> may be of any suitable shape. Each boss <NUM> is permanently secured to the outer surface of the second removable wear plate <NUM> in any suitable manner, for example by welding.

It will be appreciated that the bosses <NUM> on the outer side of the first removable plate <NUM> are adapted to be seated within a corresponding first opening <NUM> or an inner part of the tubular member <NUM> and that the bosses <NUM> on the outer side of the first removable plate <NUM> are adapted to be seated within a corresponding inner part of the tubular member <NUM>. Thus while each may be of any suitable shape, the shapes are required to match.

In use a plurality of first threaded fasteners <NUM> are used to secure the first removable plate <NUM> in position and a plurality of second threaded fasteners <NUM> are used to secure the second moveable plate <NUM> in position (<FIG>).

An example fixing of the first removable wear plate <NUM> is illustrated in <FIG>, <FIG> where the first removable wear plate <NUM> is shown overlying the first planar region of the planar portion <NUM> of the support element <NUM>. The outer surface of the boss <NUM> is located within an upper region of the generally tubular element <NUM>. A threaded fastener <NUM> extends through a washer assembly <NUM> and the aperture <NUM> in the end of the generally tubular element <NUM> and engages with the threaded inner bore <NUM> of the boss <NUM> to draw the boss <NUM> into the generally tubular element <NUM> thereby securing the first removable plate <NUM> in position against the first planar region of the planar portion <NUM> of the support element <NUM>. Any suitable washer assembly <NUM> may be used.

An example fixing of the second removable wear plate <NUM> is illustrated in <FIG>, <FIG> where the second removable wear plate <NUM> is shown overlying the second planar region of the planar portion <NUM> of the support element <NUM>. The outer surface of the boss <NUM> is located within an upper region of the generally tubular element <NUM>. A threaded fastener <NUM> extends through a washer assembly <NUM> and the aperture <NUM> in the end of the generally tubular element <NUM> and engages with the threaded inner bore <NUM> of the boss <NUM> to draw the boss <NUM> into the generally tubular element <NUM> thereby securing the second removable plate <NUM> in position against the second planar region of the planar portion <NUM> of the support element <NUM>. Any suitable washer assembly <NUM> may be used.

As noted, the shear bar holder <NUM> is mounted to the frame and is rotatable with respect to the frame about the axis <NUM> extending through a lower part of the shear bar holder <NUM>. This allows the upper end of the wear plate assembly to be located in a desired position. A wedge adjuster <NUM> can be located between an element <NUM> of the frame and the support surface <NUM> to locate a lower end of the wear plate assembly <NUM> with respect to the frame and the chopper drum <NUM>. It will be appreciated that this adjustment can be conducted without affecting the location of the shear bar <NUM> (or the upper end of the wear plate assembly <NUM>).

It can be seen in each case that the threaded fastener <NUM>,<NUM> enters through the support element <NUM>. In each case the threaded fastener <NUM>,<NUM> is received within a blind bore former by the boss <NUM>,<NUM> and the outer surface of the associated wear plate <NUM>,<NUM>. As such the threaded fastener <NUM>,<NUM> cannot be exposed to the processed crop.

By releasing the wedge adjuster <NUM> and removing the wedge, the wear plate assembly is able to rotate about the shaft <NUM>. In this way the lower end of the wear plate assembly <NUM> is lowered away from the chopper drum <NUM> to the position shown in <FIG>.

In order to remove a wear plate, an operator first loosens the associated threaded fasteners <NUM>,<NUM> such that the free ends of the threaded fasteners <NUM>,<NUM> no longer engage with the relevant threaded inner bore <NUM>,<NUM>. The wedge of the wedge adjuster <NUM> is removed allowing the lower end of the wear plate assembly <NUM> to be lowered. The wear plates <NUM>,<NUM> can then be removed (as shown by the arrows in <FIG>). From <FIG> it will be understood that it is easier to first remove the second removable plate <NUM> before removing the first removable plate <NUM>. It will be understood that accessing the removeable wear plates <NUM>,<NUM> in this way the operator does not need to obtain access to the interior of the chopper drum assembly.

Similarly, when replacing the replaceable wear plates <NUM>,<NUM>, it is easier to locate and place the first replaceable wear plate <NUM> once the second replaceable wear plate <NUM> has been removed.

Once the desired replaceable wear plate or plates have been replaced, the wedge of the wedge adjuster <NUM> is replaced and the wedge adjuster <NUM> adjusted such that the wear plate assembly <NUM> is in the desired position in relation to the chopper drum <NUM>. The operator then tightens the screws <NUM>,<NUM> as required. Any final adjustments to the wedge adjuster <NUM> can then be made.

It will be understood that should the screws <NUM>, <NUM> work loose then they will fall out away from the chopper drum assembly <NUM> without a risk that they will fall into the flow of processed crop passing through the forage harvester <NUM>.

Further, the matching shapes of the bosses <NUM>,<NUM> and their associated tubular elements <NUM>,<NUM> will tend to prevent the replaceable wear plates <NUM>,<NUM> from working loose as a result of the operation of the forage harvester <NUM>.

Claim 1:
An agricultural harvester comprising a wear plate assembly (<NUM>), the wear plate assembly (<NUM>) comprising: a support element (<NUM>) having a number of lateral regions (<NUM>",<NUM>‴), characterised in that the or each lateral region is provided with a plurality of first engagement features, and in that the wear plate assembly further comprises one or more replaceable wear plates (<NUM>) provided on a first side with a plurality of second engagement features for engagement with the first engagement features, and a plurality of fastenings (<NUM>,<NUM>) to secure the or each replaceable wear plate (<NUM>,<NUM>) to the support element (<NUM>) through the engagement features, wherein the harvester further comprises a shear bar assembly (<NUM>,<NUM>) to which the support element (<NUM>) of the wear plate assembly (<NUM>) is mounted.