Patent Description:
Self-propelled agricultural harvesters are well known and include, by way of example, combine harvesters, windrowers, and forage harvesters, all of which typically include a frame or chassis, an operator cab, an engine, and ground-engaging wheels or tracks. A cutting or pick-up header is often carried by the harvester, the header typically being considerably wider than the harvester and mounted to the front side of a feederhouse.

Crop material collected by the header is conveyed into the feederhouse before being conveyed in a generally rearward direction to crop-processing apparatus. In the case of a combine harvester, the processing apparatus serves to thresh the crop material and separate grain therefrom, whereas, in the case of a forage harvester or windrower the crop material is typically passed through conditioning rollers.

The height of the header is typically adjusted by raising and lowering the feederhouse around a lateral feederhouse pivot axis. To permit pitch adjustment of the header with respect to the feederhouse, a header interface frame is often pivotally mounted to the feederhouse over the front opening thereof to permit pitch adjustment around a lateral pitch adjustment axis. A hydraulic cylinder controls adjustment of the lateral tilt.

<CIT>, discloses a combine harvester having a header interface frame that allows for adjustment of the header pitch. <CIT>, discloses a feeder assembly with a front end assembly for allowing pitch adjustment of an attached header by means of hydraulic cylinders coupled to the front end assembly. <CIT>, discloses another feeder house assembly that allows for pitch adjustment of a frame assembly mounted to the front of the feederhouse. A pair of two-way hydraulic cylinders are provided to control the pitch. <CIT>, discloses a feeder house and pitch frame which pivots about a pivot axis. A coil spring is connected in tension above the pivot axis between the pivot frame and the feederhouse. A hydraulic cylinder is connected between the pivot frame and the feederhouse to provide a force opposite to that of the spring. When the hydraulic cylinder provides no force, the spring serves to carry the weight of the header causing it to float above the ground surface. United Kingdom patent <CIT> discloses another example of a header carrier frame pivotally mounted to a feederhouse of a harvester.

As headers get wider and heavier, larger hydraulic cylinders are required to control the lateral pitch. This places strain on the fixings and weldments adding to the cost and complexity of the feederhouse structure.

In some embodiments, a feederhouse assembly for an agricultural harvester includes a feederhouse comprising an inlet end, a pitch frame adjacent the inlet end and arranged to pivot about a pivot axis relative to the feederhouse, a hydraulic cylinder coupling the pitch frame to the feederhouse and configured to apply a hydraulic force to rotate the pitch frame upward, and a spring coupling the pitch frame to the feederhouse and configured to apply a spring force to rotate the pitch frame downward.

A method of connecting a harvesting header to an agricultural harvester includes applying a spring force from a spring to a pitch frame adjacent an inlet end of a feederhouse, applying a hydraulic force from a hydraulic cylinder to the pitch frame, balancing the hydraulic force and the spring force when the pitch frame is in an orientation corresponding to an orientation of the harvesting header, moving the agricultural harvester toward the harvesting header, and securing the harvesting header to the pitch frame. The spring force is oriented to rotate the pitch frame downward, and the hydraulic force is oriented to rotate the pitch frame upward.

An agricultural harvester includes a chassis, a feederhouse mounted to the chassis and comprising an inlet end, a pitch frame adjacent the inlet end and arranged to pivot about a pivot axis relative to the feederhouse, a hydraulic cylinder coupling the pitch frame to the feederhouse and configured to apply a hydraulic force to rotate the pitch frame upward, a spring coupling the pitch frame to the feederhouse and configured to apply a spring force to rotate the pitch frame downward, and a processing system carried by the chassis and structured to receive crop material from the feederhouse.

A non-transitory computer-readable storage medium includes instructions that when executed by a computer, cause the computer to balance a hydraulic force and a spring force on a pitch frame adjacent an inlet end of a feederhouse of an agricultural harvester. When the pitch frame is in an orientation corresponding to an orientation of a harvesting header, the computer moves the agricultural harvester toward the harvesting header and secures the harvesting header to the pitch frame.

The illustrations presented herein are not actual views of any agricultural 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.

<FIG> illustrates an example agricultural harvester embodied as a combine harvester <NUM>. In the context of the present disclosure, the example combine harvester <NUM> is merely illustrative, and other machines and/or implements with like functionality may deploy certain embodiments disclosed herein, such as windrowers, forage harvesters, etc. The example combine harvester <NUM> is shown in <FIG> without a header attached, and includes a feederhouse assembly <NUM> carried by a chassis <NUM> supported by wheels <NUM>. An operator cab <NUM> is mounted to the chassis <NUM>. In some embodiments, other or additional forms of travel may be used, such as tracks. Hydraulic cylinders <NUM> are shown affixed to the underside of the feederhouse assembly <NUM> on one end and to the chassis <NUM> on the other end. The feederhouse assembly <NUM> may move (e.g., up and down, pitch, tilt, etc.) based on actuation of the hydraulic cylinders <NUM>, which causes a detachably coupled header to also be raised, lowered, pitched, and/or tilted. A rotating shaft <NUM> may be configured to provide mechanical power to a header during operation of the combine harvester <NUM>. The rotating shaft <NUM> may be configured to operate at various speeds, as described in, for example, <CIT>.

In general, the combine harvester <NUM> cuts crop materials (e.g., using the header), wherein the cut crop materials are delivered to the front end of the feederhouse assembly <NUM>. Such crop materials are moved upwardly and rearwardly within and beyond the feederhouse assembly <NUM> (e.g., by a conveyer) until reaching a processing system <NUM> comprising a thresher rotor. In one embodiment, the thresher rotor may comprise a single, transverse rotor, such as that found in a Gleaner® Super Series Combine by AGCO. Other designs may be used, such as axial-based, twin rotor, or hybrid designs. The thresher rotor processes the crop materials in known manner and passes a portion of the crop material (e.g., heavier chaff, corn stalks, etc.) toward the rear of the combine harvester <NUM> and another portion (e.g., grain and possibly light chaff) through a cleaning process in known manner. In the processing system <NUM>, the crop materials undergo threshing and separating operations. In other words, the crop materials are threshed and separated by the thresher rotor operating in cooperation with well-known foraminous processing members in the form of threshing concave assemblies and separator grate assemblies, with the grain (and possibly light chaff) escaping through the concave assemblies and the grate assemblies and to a cleaning system located beneath the processor to facilitate the cleaning of the heavier crop material. Bulkier stalk and leaf materials are generally retained by the concave assemblies and the grate assemblies and are discharged out from the processing system <NUM> and ultimately out of the rear of the combine harvester <NUM>. The cleaned grain that drops to the bottom of the cleaning system is delivered by a conveying mechanism that transports the grain to an elevator, which conveys the grain to a grain bin <NUM> located at the top of the combine harvester <NUM>. Any remaining chaff and partially or unthreshed grain is recirculated through the processing system <NUM> via a tailings return conveying mechanism. Because combine processing is known to those having ordinary skill in the art, further discussion thereof is omitted here for brevity. In embodiments in which the agricultural harvester is a windrower or forage harvester, the processing system <NUM> may include conditioning rollers, rather than separation devices.

<FIG> is a simplified side view of the feederhouse assembly <NUM> shown in <FIG>. As shown, a feederhouse <NUM> has an inlet end <NUM> and an outlet end <NUM>. Crop material entering the feederhouse assembly <NUM> from the harvesting header travels from the inlet end <NUM> toward the outlet end <NUM> on the way to the processing system <NUM> (<FIG>). The harvesting header is coupled to the feederhouse <NUM> by a pitch frame <NUM>, which is adjustable to control the orientation of the harvesting header with respect to the combine harvester <NUM>. A tilt frame <NUM> may optionally be coupled to pitch frame <NUM> to enable side inclination of the harvesting header (e.g., wherein the left side of the header is at a different elevation than the right side). Control of the pitch and tilt of the harvesting header is important to enable a farmer to properly harvest crops by keeping the harvesting header parallel to the ground. Adjustment of the pitch frame <NUM> also facilitates connecting and disconnecting the harvesting header because the pitch frame <NUM> can be positioned to match the pitch of the harvesting header.

The pitch frame <NUM> is adjusted by pivoting about a pivot axis <NUM>. A hydraulic cylinder <NUM> and a spring <NUM> couple the pitch frame <NUM> with the feederhouse <NUM>. The hydraulic cylinder <NUM> is configured to apply a force on the pitch frame <NUM> (referred to herein as a hydraulic force, though the force acting on the pitch frame <NUM> is due to movement of a piston of the hydraulic cylinder <NUM>, rather than by direct contact of hydraulic fluid on the pitch frame <NUM>). The hydraulic force is applied to the pitch frame <NUM> in a direction to rotate the pitch frame <NUM> upward. The hydraulic cylinder <NUM> is located below the pivot axis <NUM>, such that when pressurized fluid in the hydraulic cylinder <NUM> pushes the piston outward, the hydraulic cylinder <NUM> pushes the bottom of the pitch frame <NUM> away from the feederhouse <NUM>. Because the pitch frame <NUM> is constrained to the feederhouse <NUM> at the pivot axis <NUM>, the pitch frame <NUM> pitches upward.

The hydraulic cylinder <NUM> may be a single-action hydraulic cylinder. The piston of a single-action hydraulic cylinder is driven only in a single direction by the hydraulic fluid. Thus, the hydraulic cylinder <NUM> may be connected to only a single pressure line <NUM>. In contrast with double-action hydraulic cylinders, which can be driven in two opposite directions by fluid in two pressure lines, single-action hydraulic cylinders may be smaller, simpler, and/or less expensive to manufacture and maintain. The weight of the harvesting header or another load on the pitch frame <NUM> forces the pitch frame <NUM> to pitch downward, absent a balancing force of the hydraulic cylinder <NUM> on the pitch frame <NUM>. Typically, the hydraulic cylinder <NUM> is configured such that pressurized fluid pushes the piston outward. In such embodiments, the hydraulic cylinder <NUM> is connected to the pitch frame <NUM> and the feederhouse <NUM> below the pivot axis <NUM>. In other embodiments, the pressurized fluid may push the piston inward, in which case the hydraulic cylinder <NUM> may be located above the pivot axis <NUM>.

The spring <NUM> is configured to apply a spring force on the pitch frame <NUM> via a rod <NUM> coupled to the pitch frame <NUM>. The spring force is applied in a parallel and opposite direction from the hydraulic force. The spring force tends to return the hydraulic cylinder <NUM> to a compressed position. In <FIG>, the hydraulic cylinder <NUM> is shown extended, and the spring <NUM> is shown compressed.

<FIG> is a simplified side view of the feederhouse assembly <NUM> when the pitch frame <NUM> is pitched relatively downward from the orientation shown in <FIG>. The piston of the hydraulic cylinder <NUM> is shown in <FIG> in its compressed (i.e., not extended) position. In this embodiment, the configuration of the spring <NUM> shown in <FIG> is its natural state, and the configuration of the spring <NUM> shown in <FIG> is compressed. Thus, when the spring <NUM> is compressed as shown in <FIG>, the spring <NUM> exerts the spring force on the pitch frame <NUM> via the rod <NUM>; when the spring <NUM> is not compressed, as shown in <FIG>, the spring force is decreased or even zero. Thus, the spring <NUM> is depicted as a compression spring. In other embodiments, the spring <NUM> may be an extension spring, and the connection to the pitch frame <NUM> may be altered such that the spring nonetheless applies the spring force in the appropriate direction. In further embodiments, a compression spring may be located above the pivot axis <NUM> with different mounting hardware, such that the compression spring pushes the top of the pitch frame <NUM> forward.

Though the hydraulic cylinder <NUM> is depicted above the spring <NUM> in <FIG> and <FIG> for clarity, these parts may also be located horizontally adjacent one another on the pitch frame <NUM>. Furthermore, the feederhouse assembly <NUM> may typically include two or more of each of the hydraulic cylinder <NUM> and the spring <NUM> (e.g., one of each at each side of the pitch frame <NUM>).

The feederhouse assembly <NUM> may also include a control valve <NUM> connected to the hydraulic cylinder <NUM> by a fluid line <NUM> to modify the pressure of fluid in the hydraulic cylinder <NUM>. The control valve <NUM> may be connected to a fluid source, such as a reservoir or compressor. A controller <NUM> may operate the control valve <NUM>, and may interact with a control system of the combine harvester <NUM> (<FIG>), such as a terminal in the operator cab <NUM>. For example, the controller <NUM> may send and receive electrical signals to the control valve <NUM>.

The spring <NUM> may be selected such that it exerts a large enough force to overcome the force of the hydraulic cylinder <NUM> when the fluid line <NUM> is not pressurized. That is, the spring <NUM> should be strong enough to push the pitch frame <NUM> downward against the force of the hydraulic cylinder <NUM> when the hydraulic cylinder <NUM> is exerting its minimum hydraulic force. When the hydraulic cylinder <NUM> is fully extended, the spring <NUM> is more compressed, so the spring force is larger than when the spring <NUM> is less compressed. Thus, the speed at which the pitch frame <NUM> moves when the hydraulic cylinder <NUM> is not pressurized may not be constant. Nonetheless, the spring force enables the agricultural harvester to lower the pitch frame <NUM> when the harvesting header is not attached. Because rotating the pitch frame <NUM> downward without the harvesting header attached is not generally time-sensitive, it may be acceptable for the spring force to only slightly overcome the minimum hydraulic force in the range in which downward motion is desired. Thus, the combine harvester <NUM> may take, for example, <NUM> seconds or more to lower the pitch frame <NUM> to a selected "low" position when the harvesting header is not attached (which may be higher than the lowest possible position when a header is attached). When the harvesting header is attached, the weight of the harvesting header provides additional downward force, so the pitch frame <NUM> can be lowered more quickly and potentially farther than it could with only the spring force and the weight of the pitch frame <NUM> itself.

<FIG> is a simplified flow chart illustrating a method <NUM> of connecting a harvesting header to a combine harvester, such as the combine harvester <NUM> shown in <FIG> and having a feederhouse assembly <NUM> as shown in <FIG> and <FIG>. As shown in block <NUM> of <FIG>, the spring <NUM> applies a spring force to the pitch frame <NUM> adjacent the inlet end <NUM> of the feederhouse <NUM>. The spring force is oriented to rotate the pitch frame <NUM> downward.

As shown in block <NUM>, the hydraulic cylinder <NUM> applies a hydraulic force to the pitch frame <NUM>. The hydraulic force is oriented to pitch the pitch frame upward, and is in a direction opposite the spring force.

Block <NUM> and block <NUM> may occur at the same time or may occur in any order. Block <NUM> depicts balancing the hydraulic force and the spring force when the pitch frame is in an orientation corresponding to an orientation of the harvesting header. The weight of the pitch frame <NUM> may also be included in this balancing, such that the pitch frame <NUM> is at the proper orientation to connect with the harvesting header.

As shown in block <NUM>, the combine harvester moves toward the harvesting header. The harvesting header is secured to the pitch frame in block <NUM>.

For example, the controller <NUM> may be configured to cause mechanical coupling between the pitch frame <NUM> and the harvesting header without intervention by any person located proximal to the coupling location. When the pitch frame <NUM> is near a harvesting header, sensors may detect the orientation and position of the harvesting header and of the pitch frame <NUM>. The controller <NUM> may receive information from the sensors, and may adjust the pressure provided to the hydraulic cylinder <NUM> by the control valve <NUM> to match the orientation of the pitch frame <NUM> to the orientation of the harvesting header. The controller <NUM> may then alert an operator to move the combine harvester <NUM> forward until it meets the harvesting header, or may provide a signal to the control system of the combine harvester <NUM> to perform this action automatically. Thus, the harvesting header may be connected without requiring the operator to make any measurements or adjustments at the point of connection. This may increase safety by enabling the operator to remain away from pinch points. Connecting harvesting headers is described in further detail in <CIT>.

Still other embodiments involve a computer-readable storage medium (e.g., a non-transitory computer-readable storage medium) having processor-executable instructions configured to implement one or more of the techniques presented herein. An example computer-readable medium that may be devised is illustrated in <FIG>, wherein an implementation <NUM> includes a computer-readable storage medium <NUM> (e.g., a flash drive, CD-R, DVD-R, application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), a platter of a hard disk drive, etc.), on which is computer-readable data <NUM>. This computer-readable data <NUM> in turn includes a set of processor-executable instructions <NUM> configured to operate according to one or more of the principles set forth herein. In some embodiments, the processor-executable instructions <NUM> may be configured to cause a computer to perform operations <NUM> when executed via a processing unit, such as at least some of the example method <NUM> depicted in <FIG>. Many such computer-readable media may be devised by those of ordinary skill in the art that are configured to operate in accordance with one or more of the techniques presented herein.

Advantages of including a spring in the feederhouse assembly disclosed herein is that single-action hydraulic cylinders can be used to control the pitch of the harvesting header. Single-action hydraulic cylinders are generally lighter and cheaper than dual-action hydraulic cylinders. If a dual-action hydraulic cylinder is replaced directly with a single-action hydraulic cylinder, the agricultural harvester can rely on the weight of the harvesting header to rotate the pitch frame downward. However, when the harvesting header is not attached, the agricultural harvester does not have a safe method for rotating the pitch frame downward. This makes it difficult to attach a harvesting header, because the pitch frame must be aligned with the harvesting header. One method that has been used by some operators is to press the pitch frame on the ground and drive the agricultural harvester forward. This, however, can damage the pitch frame, and can be more dangerous than a pitch control system.

Claim 1:
A feederhouse assembly (<NUM>) for an agricultural harvester (<NUM>), the feederhouse assembly (<NUM>) comprising:
a feederhouse (<NUM>) comprising an inlet end (<NUM>);
a pitch frame (<NUM>) adjacent the inlet end (<NUM>) and arranged to pivot about a pivot axis (<NUM>) relative to the feederhouse (<NUM>);
a hydraulic cylinder (<NUM>) coupling the pitch frame (<NUM>) to the feederhouse (<NUM>) and configured to apply a hydraulic force to rotate the pitch frame (<NUM>) upward; and
characterized in that the feederhouse assembly (<NUM>) further comprises a spring (<NUM>) coupling the pitch frame (<NUM>) to the feederhouse (<NUM>) and configured to apply a spring force to rotate the pitch frame (<NUM>) downward.