Patent Description:
Combine harvesters are used by farmers and agricultural contractors to harvest a wide range of crops. During a harvest operation a crop gathering header is supported on a front end of a feederhouse which is mounted to a chassis. The feederhouse houses a conveyor which is typically a chain and slat conveyor that moves cut crop material generally rearwardly from the header to crop processing apparatus.

Harvesting is often a dusty operation which large amounts of dust thrown up around the header and feederhouse inlet. The dust both inhibits the operator's direct visibility of the header and builds up on top of the feederhouse which eventually creates an obstruction to lines of sight. Furthermore, accumulated dust and debris on top of the feederhouse can contact the underside of the cab and obstruct clear lifting of the header in addition to presenting a fire hazard.

Efforts have been made to alleviate the problems caused by dust given off during harvest. For example, <CIT> discloses a suction fan within a tube that is mounted on top of the feederhouse. Holes provided between the tube and the feederhouse allow for the suction fan to suck dust and debris from the feederhouse and discharge it from an outlet of the tube positioned outboard of the feederhouse. <CIT> also discloses a cleaning fan which is arranged to blow air across the top of the feederhouse to prevent or reduce the build up of dust and other debris on top of the feederhouse. Further combine harvester are e.g. known from <CIT> and <CIT>.

In accordance with a first aspect of the invention there is provided a combine harvester comprising a feederhouse mounted to a chassis and being adapted at a front end to support a crop gathering header in a manner that places a front inlet in communication with a discharge opening of the header. The feederhouse defines a crop conveying passage and houses a conveyor. A duct is mounted on the feederhouse and defines a channel that is in communication with the crop conveying passage via a first opening which has a first closure element associated therewith. A fan is arranged to move air through the duct. A second opening is provided in the duct, the second opening having associated therewith a second closure element that is movable between an open position and a closed position. The fan is selectively operable in a first direction to create a 'suction' airflow to extract dust from the crop conveying passage and discharge the dust through the duct, and a second direction to generate a 'blowing' airflow to open the second closure element and vent air through the second opening. The second opening is configured to direct the vented air across a top surface of the feederhouse.

The first opening may be one of a first set of openings provided between the channel and the crop conveying passage, each of the openings of the first set of openings having a respective closure element associated therewith. Similarly, the second opening may be one of a second set of openings provided in the duct, each of the openings of the second set of openings having a respective closure element associated therewith.

The provision of the second opening or 'vent' together with the second closure element which can be 'blown' open allows for the fan to be exploited in a reverse mode to create a cleaning airstream which is vented across the top of the feederhouse. Advantageously, a single fan can be used for both sucking the dust from the feederhouse inlet and for keeping the top of the feederhouse clear of debris. The requirement for an additional fan to provide this latter function is avoided thus saving on cost and complexity.

In a preferred embodiment the or each second closure element comprises a flap that is pivotally attached to the duct. A biasing element such as a spring may optionally be provided with each flap to bias the flap into a closed position. Alternatively, or in addition to this, the flaps may be pulled into the closed position by a vacuum created when the fan is operable in the first (sucking) direction.

The or each first closure element associated with the first opening or first set of openings respectively may comprise a flap that is pivotally attached within the duct so as to open into the duct.

The duct preferably comprises a downwardly-facing outlet which is outboard of the feederhouse to discharge collected dust and debris downwardly away from the operator's field of view of the header.

In some embodiments the fan is driven by a motor that is mounted to the duct on an outside surface thereof. The motor may be an electric motor or a hydraulic motor, by way of example, to simplify quick reversing of the fan direction as required during operation.

In some embodiments a fan drive controller is configured to drive the fan in the first direction during a harvest mode of operation so as to cause dust and other debris to be sucked from the crop conveying passage. The fan drive controller may be further configured to automatically resume driving the fan in the first direction after driving the fan in the second direction for a predetermined period. Advantageously, the fan may be driven in the second direction for a predetermined period of time, for example <NUM> to <NUM> seconds, so as to clear accumulated debris from the top of the feederhouse before resuming in the first 'sucking' direction.

In one embodiment the fan may be driven in the second direction in response to a detected lifting of the feederhouse. In this case, lifting of the feederhouse is indicative of a suspension of the harvest operation wherein cutting of the standing crop is paused or stopped. For example, the header is typically lifted at the end of a cutting turn when reaching the headland or if a blockage or failure occurs. When the header is lifted extraction of the dust from the crop conveying passage is less critical and so this offers an optimal time to reverse the fan and clean accumulated debris from the top of the feederhouse.

In another embodiment, sensing means are provided to detect material accumulation on the feederhouse. For example, a camera may be conveniently mounted to record an image of the feederhouse wherein image processing means are also provided to process the image to determine whether the debris has accumulated on top of the feederhouse. In one embodiment a visual indicator, for example a white painted shape, may be provided on top of the feederhouse such that obscuration of the indicator is interpreted by the image processing as meaning that the debris has accumulated. In another embodiment a simple optical or proximity sensor may be configured to detect build up of material on top of the feederhouse.

There is also disclosed a method of removing accumulated material on a feederhouse of a combine harvester, comprising the steps of sucking air from a crop conveying passage of the feederhouse and into a duct via a first plurality of openings that are provided between the crop conveying passage and the duct with a fan, and reversing the fan to blow air through a second plurality of openings that are provided in the duct. Advantageously, the same fan is used for both the extraction of dust from the crop conveying passage and the clearing of accumulated dust and debris from on top of the feederhouse.

Further advantages of the invention will become apparent from the following description of specific embodiments with reference to the appended drawings in which:.

The illustrations presented herein are not actual views of any combine harvester or portion thereof, but are merely idealized representations that are employed to describe example embodiments of the present disclosure. Additionally, elements common between figures may retain the same numerical designation.

Relative terms such as 'front', 'rear', 'left', 'right', 'longitudinal' and 'transverse' will be made with reference to the longitudinal axis of a combine harvester travelling in the normal forward direction of travel indicated by arrow F in <FIG>. The terms 'direction of conveyance', 'upstream', and 'downstream' are made with reference to the general flow of crop material through the combine harvester. The terms 'axial', 'radial' and 'tangential' will be used in relation to the associated rotation axis.

<FIG> illustrates in schematic form some of the main components of the crop processing systems of a combine harvester <NUM> and will be used to explain the flow of material below. Combine harvester <NUM>, hereinafter referred to as 'combine', includes a frame <NUM> supported on front wheels <NUM> and rear steerable wheels (not shown) which engage the ground <NUM>. A driver's cab <NUM> is also supported on the frame <NUM> and houses a driver's station from where a driver controls the combine <NUM>.

A cutting header <NUM> is detachably supported on the front of a feederhouse <NUM> which is pivotable about a transverse axis x to lift and lower the header <NUM> in a conventional manner using, for example, hydraulic lift actuators <NUM> that are connected between the frame <NUM> and a bracket <NUM> secured to the underside of the feederhouse <NUM>.

The combine <NUM> is driven in a forward direction (arrow F) across a field of standing crop <NUM> in a known manner. A cutter bar 20a, typically of a known reciprocating sickle type, advances through the crop and serves to cut the standing crop material which is gathered transversely inwardly by draper belts (not shown) and/or a transversely-extending auger 20b. The gathered crop material is then conveyed through a discharge opening 20c (<FIG>) provided in the rear wall of header <NUM> and into feederhouse <NUM>.

With particular reference to <FIG>, an elevator <NUM>, in the form of a chain and slat elevator, is housed within the feederhouse <NUM> and serves to convey the crop material stream upwardly and rearwardly from the header <NUM> to the crop processor designated generally at <NUM>. At this stage the crop material stream is unprocessed.

The crop processor <NUM> of the illustrated combine <NUM> includes an axial flow threshing and separating rotors <NUM> fed by a tangential flow, crop material impelling, feed beater <NUM> (<FIG>). However, it should be appreciated that alternative crop processors may be employed without deviating from the scope of the invention, such as tangential-flow cylinders. The crop material goes on to be threshed and separated into clean grain and residue material including straw and chaff in a known manner. The details of the crop processing systems downstream of the elevator <NUM> is not essential to the understanding of the invention and so will not be described any further.

Elevator <NUM> comprises a front roller 28a positioned immediately behind the opening 20c and journaled between sidewalls <NUM> of the feederhouse <NUM> by means of a cross shaft 29a. A pulley 29b is keyed to cross shaft 29a and driven by a belt 29c in a known manner. A rear roller 28b is journaled in a rear region of the feederhouse <NUM> and preferably coaxial with axis x. A plurality (four in the illustrated example) of continuous chains 28c, 28d, 28e, 28f are each wrapped between the front and rear rollers 28a, 28b. Transversely-extending slats <NUM> are mounted between adjacent pairs of chains in a known manner, for example as disclosed by <CIT>.

The front end of the feederhouse <NUM> is adapted to support the header <NUM> in a manner that places a front inlet <NUM> in communication with the discharge opening 20c of the header <NUM>. The feederhouse <NUM> comprises a top cover <NUM>, a floor <NUM> and the two sidewalls <NUM>-<NUM>, <NUM>-<NUM> which together bound a crop conveying passage <NUM> inside which the elevator <NUM> is located.

With reference to <FIG>, a duct <NUM> is mounted on the top cover <NUM> and defines a channel <NUM> that is in communication with the crop conveying passage <NUM> via a set of dust extraction openings <NUM>-<NUM> to <NUM>-<NUM> (<FIG> and <FIG>), each having respective closure elements <NUM>-<NUM> to <NUM>-<NUM>. The duct <NUM> is preferably formed of moulded plastic and extends in a generally transverse direction across a front region of the feederhouse <NUM>, preferably over substantially the full width thereof. At one end (the left-hand end in the illustrated embodiment) the duct <NUM> is closed and, at the other end (the right-hand end as shown) the duct <NUM> comprises a downwardly-facing outlet <NUM> which is outboard of the feederhouse <NUM>. The outlet <NUM> is preferably flared outwardly so as to better spread the collected dust in the downward direction.

Whilst the duct <NUM> is shown as being arranged transversely across the top cover <NUM> it is envisaged that the duct may instead be arranged at a different angle. Moreover, the duct <NUM> may be located further back (towards the cab <NUM>) than shown.

<FIG>, <FIG> show a set of seven dust extraction openings <NUM>-<NUM> to <NUM>-<NUM>. It should be appreciated that in alternative embodiments more or less openings may be provided between the channel <NUM> and the crop conveying passage <NUM>. In one example, only one dust extraction opening <NUM> is provided. However, a more effective flow path for the extraction of dust is delivered by the provision of a plurality of spaced-apart openings.

Each of the dust extraction openings is provided with a respective closure element <NUM>-<NUM> to <NUM>-<NUM>. Each closure element <NUM> may be in the form of a flap that is pivotally attached within the duct <NUM> and movable between a closed position and an open position. Each closure element opens into the duct <NUM>. When in the closed position each flap substantially blocks the passage of air through the associated dust extraction opening <NUM>.

<FIG> illustrates an alternative configuration in which a dust extraction opinion <NUM> is provided between the channel <NUM> and the crop conveying passage <NUM>, wherein the opening <NUM> is provided in the end of an upstanding elbow duct <NUM>. The elbow duct <NUM> extends into the duct <NUM> and directs the suction airflow (to be discussed below) through <NUM>° so that the opening <NUM> provided in the end thereof faces transversely and in alignment with the duct <NUM>. The closure element <NUM> (shown in the closed position in solid line and in the open position in dashed line) associated with the opening <NUM> is hinged along a top edge so that it closes under the force of gravity.

A fan <NUM> is provided to move air through the duct <NUM>. The fan <NUM> is preferably positioned inside the duct <NUM> and preferably comprises an impellor that rotates either in a first direction to create a suction airflow, or a second direction to create a blowing airflow. A motor <NUM> is mounted to the duct <NUM>, preferably on an outside surface of the duct <NUM>. The motor <NUM> is configured to drive the fan <NUM> so that the fan <NUM> is selectively operable in the first or second direction. The motor <NUM> is preferably a hydraulic motor but may instead be an electric motor. Alternatively, the fan may be driven by a mechanical drive that derives torque from a prime mover of the combine <NUM>. The operation of the fan <NUM> will be discussed in more detail below.

A recess <NUM> is preferably provided in an outer surface of the duct <NUM> so as to receive the motor <NUM> and to which the motor is secured by appropriate fixings. The recess is preferably formed in an elbow portion of the duct <NUM> as best seen in <FIG>.

A fan drive controller <NUM> is illustrated schematically in <FIG> and is configured to control the motor <NUM> and thus also the fan <NUM>. The fan drive controller <NUM> may be electronic and may be embedded in a vehicle electronic control unit or, alternatively, be configured as a standalone controller.

A set of vents <NUM>-<NUM> to <NUM>-<NUM> (<FIG>) are formed in the duct <NUM>, preferably along a rear-facing side thereof. The vents <NUM>-<NUM> to <NUM>-<NUM> each comprise an opening <NUM>-<NUM> to <NUM>-<NUM> with a respective closure element which is preferably in the form of a flap <NUM>-<NUM> to <NUM>-<NUM> that is pivotally attached to the duct <NUM>. Whilst shown as having a substantially vertical hinge, the flaps <NUM> may instead be pivotally attached along a horizontal edge. Whilst shown with six vents <NUM>-<NUM> to <NUM>-<NUM>, it should be appreciated that more or less vents could instead be provided. For example, in one embodiment just one vent may be provided.

Each flap <NUM> is movable between a closed position as shown in <FIG>, and an open position as shown in <FIG> and <FIG>. The vents <NUM> are configured so as to direct air vented from the duct <NUM> across the top cover <NUM> as illustrated by arrows V in <FIG> and <FIG>. The vent openings <NUM> and associated flaps <NUM> may be of any suitable configuration provided that the flaps <NUM> serve to substantially seal the opening <NUM> when in the closed position. For example, the vent openings <NUM> may be rectangular, elliptical or square.

Each flap <NUM> is preferably hinged to the duct <NUM> by a hinge <NUM> which preferably presents a biasing force to bias the associated flap <NUM> into the closed position.

The fan <NUM> is selectively operable in a first direction to create a suction airflow indicated by arrows 'S' in <FIG> and <FIG>, and a second alternative direction that is opposite to the first direction. When the fan <NUM> is operating in the first direction, the suction airflow serves to force open the closure elements <NUM> and extract dust and other airborne debris from the crop conveying passage <NUM> and discharge the dust through the duct <NUM>. As shown in <FIG>, the suction airflow S is drawn through the front inlet <NUM> and into the duct <NUM> through the suction openings <NUM>-<NUM> to <NUM>-<NUM>. The dust-laden airflow is then drawn through the fan <NUM> before being discharged through the outlet <NUM>, directed downwardly onto the ground clear of the drivers field of view.

The suction airflow also serves to hold the flaps <NUM> in the closed position thus sealing the vent openings <NUM> when the fan <NUM> is operating in the first direction.

When the direction of fan <NUM> is reversed so as to operate in the second direction a blowing airflow is created, the blowing airflow being forced through the duct <NUM> in the opposite direction to the suction airflow. The blowing airflow, indicated by arrows B in <FIG> and <FIG>, serves to force open the flaps <NUM>-<NUM> to <NUM>-<NUM> and vent air through the vent openings <NUM>-<NUM> to <NUM>-<NUM>. The vented air (arrows V) is directed over the top cover <NUM> to clear any accumulated debris formed thereon.

The blowing airflow also serves to hold the closure elements <NUM> in the closed position thus sealing the dust extraction openings <NUM> when the fan <NUM> is operating in the second direction.

The fan drive controller <NUM> is preferably configured to drive the fan <NUM> in the first 'suction' direction during a harvest mode of operation. In one embodiment the fan drive controller receives a signal that is indicative of the combine being operable to harvest the crop <NUM>.

Reversal of the fan <NUM> into the second direction may be triggered by one or more alternative trigger events. In one example, the fan drive controller <NUM> drives the fan <NUM> in the second 'blowing' direction in response to a detected lifting of the feederhouse <NUM>. Such an event is indicative of a temporary cessation of the harvest operation and presents a suitable opportunity to blow any accumulated debris from the top cover <NUM> without interrupting the dust extraction benefits of the suction mode during harvest.

In another example, a sensor (not shown) may be provided to detect accumulated material on the top cover <NUM>. For example, a simple proximity sensor, a scanning optical/acoustic sensor or a camera may be configured to generate a signal that represents a level of accumulated material. The fan drive controller <NUM> may be configured to drive the fan <NUM> in the second 'blowing' direction in response to a detected material accumulation on the top cover <NUM>, optionally a material accumulation above a threshold value.

In yet another example, the fan drive controller <NUM> may reverse the direction of the fan <NUM> in response to a manual command from the operator, received via a user interface located in the cab <NUM>.

With reference to <FIG>, a method according to another embodiment is illustrated in which, in a first step <NUM>, air is sucked from the feederhouse <NUM> into the duct <NUM> which is mounted on the feederhouse. The air is sucked via a first set of openings (such as the suction openings <NUM>-<NUM> to <NUM>-<NUM>) with a fan that operates in a first direction to reduce dust levels. In a second step <NUM> the fan direction is reversed so as to blow air through a second set of openings (such as vent openings <NUM>-<NUM> to <NUM>-<NUM>) and clear accumulated dust from the top of the feederhouse.

Claim 1:
A combine harvester (<NUM>) comprising
- a feederhouse (<NUM>) mounted to a chassis (<NUM>) and being adapted at a front end to support a crop gathering header (<NUM>) in a manner that places a front inlet (<NUM>) in communication with a discharge opening (20c) of the header, the feederhouse (<NUM>) defining a crop conveying passage (<NUM>) and housing a conveyor (<NUM>);
- a duct (<NUM>) mounted on the feederhouse (<NUM>) and defining a channel (<NUM>) that is in communication with the crop conveying passage (<NUM>) via a first opening (<NUM>);
- a fan (<NUM>) arranged to move air through the duct (<NUM>), the fan being operable in a first direction to create a suction airflow (S) to extract dust from the crop conveying passage (<NUM>) and discharge the dust through the duct (<NUM>);
- a second opening (<NUM>) is provided in the duct (<NUM>);
characterised in that the first opening (<NUM>) has associated therewith a first closure element (<NUM>) that is movable between an open position and a closed position, and in that the second opening (<NUM>) having associated therewith a second closure element (<NUM>) that is movable between an open position and a closed position, wherein the fan (<NUM>) is selectively operable in a second direction to create a blowing airflow to open the second closure element (<NUM>) and vent air through the second opening (<NUM>), wherein the second opening (<NUM>) is configured to direct the vented air across a top surface of the feederhouse (<NUM>).