Patent Description:
An agricultural harvester e.g., a plant cutting machine, such as, but not limited to, a combine or a windrower, generally includes a header operable for severing and collecting plant or crop material as the harvester is driven over a crop field. The header has a plant cutting mechanism, e.g., a cutter bar, for severing the plants or crops via, for example, an elongate sickle mechanism including a plurality of knives that are driven to reciprocate sidewardly relative to a non-reciprocating guard structure known as counterknives. After crops are cut, they flow over crop ramps whereupon they are collected inside the header and transported via a conveyor such as a draper conveyor and/or auger conveyor towards a feederhouse located centrally inside the header. While this is a well-known and well-tested cutting method, the reciprocating motion of the knives of the sickle mechanism has a number of disadvantages. The system is subject to vibrations and high peak forces which can cause premature wear of the knives and/or the counterknives or of the drive mechanism itself. These forces may become excessive, especially in the increasingly large harvesters in use today.

An alternative to reciprocating knives is a so-called belt cutter or loop knife cutter, in which the knives are mounted on a continuously moving endless flexible member or carrier, moving along the front edge of the header. The flexible member, which may be, e.g., a belt, a chain, or the like, is guided by a set of pulleys or sprockets, one of which is actively rotated at a desired speed. The knives move in one direction, once again relative to stationary counterknives, along the front side of the flexible member's path, and move in the opposite direction (i.e. in a loop) along the back side of said path. While vibrations and peak forces are much less of an issue with loop knife cutters, the loop knife solution is vulnerable to other problems. A significant problem is the breaking of knives when an obstruction is encountered in the field, such as a large stone or other solid object.

In presently known loop knife systems, such breaking of knives deteriorates the cutting performance, especially as such defects may remain undetected during a harvesting run. Not only do large defects due to breaking of knives go undetected in this way, but this is the case also for smaller defects or for the failure of knives due to excessive wear. Russian patent application <CIT> discloses a header for mowing crops including a continuous loop knife and a sensor for sensing the time of failure of one or more segments of the continuous loop knife.

In accordance with an exemplary embodiment, the subject disclosure provides a header for an agricultural harvester comprising a continuous loop knife assembly comprising a plurality of knives attached to an endless flexible member, and a sensor configured to sense a condition of the plurality of knives in increments comprising non-adjacent groups of one or more knives, whereby substantially an entirety of the plurality of knives is sensed after a plurality of cycles of the continuous knife past the sensor. The header further comprises a motor operatively engaged with the endless flexible belt for moving the plurality of knives past the sensor.

In accordance with another exemplary embodiment, the subject disclosure provides a header for an agricultural harvester comprising a header for an agricultural harvester comprising a continuous loop knife assembly comprising X knives attached to an endless flexible member; and a sensor for sensing a condition of the X knives according to a knife sampling interval Y. The header further comprises a motor operatively engaged with the endless flexible belt for moving the X knives past the sensor, wherein X is an integer, wherein Y is equal to any integer not equal to X or a factor of X, excluding <NUM>, and wherein X/Y has a remainder that does not share a prime number factor with Y.

In accordance with another exemplary embodiment, the subject disclosure provides a method for monitoring a condition of a plurality of movable knives in a continuous loop knife assembly carried by a header of an agricultural harvester comprising sensing, by a sensor, a condition of the plurality of movable knives in increments comprising non-adjacent groups of one or more knives, whereby substantially an entirety of the plurality of movable knives is sensed after a plurality of cycles of the plurality of movable knives past the sensor. The method further comprises displaying, by a monitor in communication with the sensor, the condition of the plurality of movable knives sensed by the sensor.

In accordance with another exemplary embodiment, the subject disclosure provides a method for monitoring conditions of X movable knives in a continuous loop knife assembly carried by a header of an agricultural harvester comprising sensing, by a sensor, a condition of the X movable knives according to a knife sampling interval Y. The method further comprises displaying, by a monitor in communication with the sensor, the condition of the X movable knives sensed by the sensor according to the knife sampling interval Y, wherein X is an integer, wherein Y is an integer equal to any integer not equal to X or a factor of X, excluding <NUM>, and wherein X/Y has a remainder that does not share a prime number factor with Y.

A header according to the subject disclosure effectively senses and monitors the conditions of the knives of a continuous loop knife by sensing conditions of the plurality of knives in increments comprising non-adjacent groups of one or more knives, whereby substantially an entirety of the plurality of knives is sensed after a plurality of cycles of the continuous loop knife past the sensor.

The subject disclosure enables a timely determination of wear or damage to the knives in a loop knife cutting system, so that damaged knives may be replaced before significant deterioration of the cutting performance occurs. The subject disclosure also allows long term monitoring of the knife conditions, enabling the detection of wear and the efficient planning of maintenance and review of the cutting system.

Other features and advantages of the subject disclosure will be apparent from the following more detailed description of the exemplary embodiments.

The foregoing summary, as well as the following detailed description of the exemplary embodiments of the subject disclosure, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the subject disclosure, there are shown in the drawings exemplary embodiments. It should be understood, however, that the subject disclosure is not limited to the precise arrangements and instrumentalities shown. In the drawings:.

Reference will now be made in detail to the various exemplary embodiments of the subject disclosure illustrated in the accompanying drawings. Wherever possible, the same or like reference numbers will be used throughout the drawings to refer to the same or like features. It should be noted that the drawings are in simplified form and are not drawn to precise scale.

Referring to <FIG>, a representative agricultural harvester <NUM> which, e.g., may be a combine harvester, is shown. The agricultural harvester comprises a header <NUM> mounted at the front of the combine. A plurality of knives <NUM> and a cutterbar <NUM>, described in greater detail below, are disposed at a front or leading end of the header in the direction of travel of the combine. The knives and the cutterbar are maintained at a given height above ground level while the combine <NUM> moves through a field of crops that are to be harvested. An optional rotating reel <NUM> guides the crops towards the knives. Cut crops are transported from both lateral sides of the header <NUM> towards a central area by an auger <NUM> (or draper conveyors, not shown). The main body <NUM> of the combine is supported by front and rear wheels <NUM> and comprises the threshing rotors and a cleaning section generally known by those of ordinary skill in the art and, as such, are not depicted <FIG>. From the central area of the header <NUM>, crops are transported into the main body <NUM> of the combine by a feeder <NUM>.

More detailed views of a header frame <NUM> provided with a loop knife cutting system are shown in <FIG> and <FIG>. The frame <NUM> comprises sidewalls <NUM>, a header floor <NUM> and a back wall <NUM>. The back wall <NUM> comprises a central opening <NUM> through which crops are transferred to the feeder, when the header is attached thereto. The knives <NUM> and the cutterbar <NUM> extend between laterally placed dividers <NUM> along the full length of the header. <FIG> shows a detailed image of one side of the header frame. In this view, the knives <NUM> and the cutterbar <NUM> are clearly shown. The term 'cutterbar' is used herein to refer to an assembly of elements which are rigidly connected together. The cutterbar <NUM> comprises counterknife fingers <NUM> protruding in the forward direction. In an exemplary embodiment, the header comprises a continuous loop knife assembly comprising a plurality of knives <NUM> attached to an endless flexible member, e.g., an endless flexible belt or chain <NUM>. According to an aspect, the knives <NUM> are triangular steel knives mounted on respective support brackets <NUM> by a bolt connection <NUM>, and these brackets <NUM> are attached to a lateral surface of the belt <NUM>. Any other known way of attaching the knives <NUM> to the belt <NUM> or to an equivalent continuously moving carrier such as a chain, or the like, is contemplated to be within the subject disclosure.

In operation, the knives <NUM> move continuously past the stationary fingers <NUM> of the cutterbar <NUM>, to thereby cut crop stalks in the field. The belt <NUM> is guided by a pair of pulleys <NUM>, one of which is driven actively by a belt drive mechanism such as an actuator or a motor <NUM>. The motor <NUM> may, for example, be a hydraulic motor or an electric motor, coupled to a respective unillustrated hydraulic or electric power source of the combine harvester. The motor <NUM> is operatively engaged with the endless flexible belt <NUM> for moving the plurality of knives past a sensor <NUM>, described below.

As shown in <FIG>, a protective lateral housing <NUM> is formed around the knives <NUM>, at the location where they make the <NUM>° turn along the circumference of the pulley <NUM>. This housing <NUM> serves as a possible location for placing the sensor <NUM> in a cutting system according to the subject disclosure. As described below, other sensor locations are possible and the subject disclosure is not limited to headers including the housing <NUM>. The illustrated header design is therefore used merely as an example of a possible way of implementing a sensor in accordance with the subject disclosure.

<FIG> illustrates the sensor <NUM> mounted on the lateral housing <NUM>. The sensor <NUM> is schematically represented as a cylinder, in order to indicate the general location of the sensor, given that various sensor types may be used. The sensor <NUM> can be attached to the housing <NUM> by any suitable attachment mechanism. An opening is made in the upper surface <NUM> of the housing <NUM> and the sensor <NUM> is mounted in the opening, so that the knives <NUM> pass in front of the sensor <NUM>. An electric wire connection <NUM> is shown to indicate the way in which a measurement signal issues from the sensor <NUM> and is transmitted to a processing unit <NUM>, described below. Other types of connections may be used depending on the sensor type, such as wireless connections.

According to the subject disclosure, the sensor <NUM> is configured to sense a condition of the plurality of knives <NUM> in increments comprising non-adjacent groups of one of more knives, whereby substantially an entirety of the plurality of knives is sensed after a plurality of cycles of the continuous loop knife assembly past the sensor. As stated, the sensor <NUM> may be any of various sensor types. According to an exemplary embodiment, a suitable sensor is a visual image recording device such as, e.g., a camera, configured to detect images of knives <NUM> passing in front of the sensor.

The processing unit <NUM> is shown symbolically as a rectangle in <FIG>. Any processing unit known as such in the art for monitoring the output of a visual image recording device type sensor may be used. This unit may be incorporated in a control unit of an agricultural implement such as a combine harvester equipped with a cutting system of the subject disclosure. The processing unit <NUM> is configured to receive a signal from the sensor <NUM>, process the signal and derive therefrom one or more parameters indicative of the condition of each knife, visible wear or breakage. Other suitable sensors suitable for sensing a condition of the knives <NUM> and communicating with the processing unit <NUM> can include, without limitation, inductive sensors, optical, e.g., laser sensors, pneumatic proximity sensors, and infra-red photodiode sensors.

The processing unit <NUM> is furthermore configured to compare the derived parameters to reference values (such as the reference value, e.g., image, of a non-damaged knife). In doing so, the processing unit produces a result of the comparison that can be interpreted by an operator of the system and/or determines if the comparison exceeds a predetermined threshold value. If the processing unit determines that the comparison exceeds a predetermined threshold value, it can alert the user via an audible signal indicating damage to the knives that requires stopping and reviewing the cutting system. According to another aspect, the sensor can be configured to be in communication with a visual interface or monitor <NUM> (<FIG>) for displaying the condition of the plurality of knives sensed by the sensor. Producing such a signal may be based on the degree of damage to individual knives as well as on the number of knives to which a given degree of damage has been detected. The result of the comparison can be reported on the monitor <NUM>, so that the knife condition (degree of damage, number of knives damaged/worn/missing) may be continuously checked by the operator. In a combine harvester, the monitor <NUM> can be provided in the driver's cabin. The monitor is thus in communication with the sensor for displaying the condition of the plurality of knives sensed by the sensor. The interface or monitor <NUM> preferably comprises input means allowing the operator to set thresholds in terms of the values of the parameters derived from the detected signals or images, and/or in terms of the number of knives to which a given degree of damage may be allowed before a warning signal is given.

According to an exemplary embodiment, the processing unit is configured to automatically stop the header when it is detected by the sensor that a pre-defined degree of damage is reached or exceeded. According to another exemplary embodiment, the processing unit is configured to report an estimated remaining life time of the knifes, for example by estimating when the average state of wear will be equal to the worn out state, which is the state when average measured length equals the worn out length, based on the evolution of the average state of wear over time. Still further, the processing unit <NUM> may comprise or be connected to a memory wherein a history of the knife condition may be stored, enabling long term monitoring of wear of the knives, so that maintenance and review can be planned in an efficient way. The operator interpreting or checking the results, can also be outside of the driver's cabin. In particular, an operator can interpret or check the results remotely on a remote visual interface or monitor, for example in case of a remotely controlled combine or in case of an autonomous combine. When the operator is outside of the driver's cabin, the results can be communicated directly to the operator, for example via a network to the operator's computer or via a wireless connection to a wireless device, or indirectly, for example via a cloud service.

Referring to <FIG>, there is shown a continuous loop knife assembly 100a with a sensor <NUM> (in this instance, a camera) positioned generally consistent with the location of the sensor <NUM> of <FIG>. The camera of <FIG> is configured to have a field of view <NUM> sufficient to capture an image of a single knife of the plurality of knives in the non-adjacent groups, e.g., 90a, 90b, 90c, etc. of one or more knives. As used herein, "non-adjacent groups of one or more knives" means groups comprising of one or more knives whose conditions are captured by the sensor and which are separated from other groups comprising of one or more knives whose conditions are captured by the sensor by at least one knife whose condition(s) is/are not captured by the sensor.

Referring to <FIG>, there is shown a continuous loop knife assembly 100b with a sensor <NUM> (in this instance, a camera) configured to have a field of view <NUM> sufficient to capture images of adjacent knives of the plurality of knives in non-adjacent groups of one or more knives.

Referring to <FIG>, there is shown a continuous loop knife assembly 100c with a plurality of sensors <NUM> (in this instance, cameras) each having a field of view for sensing different knives of the plurality of knives in the non-adjacent groups of one or more knives.

The subject disclosure further provides a method for monitoring a condition of a plurality of movable knives <NUM> in a continuous loop knife assembly 100a, 100b or 100c carried by a header of an agricultural harvester comprising sensing, by a sensor, a condition of the plurality of movable knives in increments comprising non-adjacent groups of one or more knives, whereby substantially an entirety of the plurality of movable knives is sensed after a plurality of cycles of the plurality of movable knives past the sensor. The method further comprises displaying, by a monitor in communication with the sensor, the condition of the plurality of movable knives sensed by the sensor.

The above-described method can further comprise capturing images with the sensor of adjacent knives of the plurality of movable knives in the non-adjacent groups of one or more knives. In addition, the sensor can include a plurality of spaced apart sensors <NUM>, and the method can further comprise sensing different knives of the plurality of movable knives in the non-adjacent groups of one or more knives by the plurality of spaced apart sensors.

In accordance with a further exemplary embodiment, there is provided a header for an agricultural harvester comprising a continuous loop knife assembly 100a, 100b or 100c comprising X knives attached to an endless flexible belt; and a sensor for sensing a condition of the X knives according to a knife sampling interval Y. The header further comprises a motor operatively engaged with the endless flexible belt for moving the X knives past the sensor, wherein X is an integer, wherein Y is equal to any integer not equal to X or a factor of X, excluding <NUM>, and wherein X/Y has a remainder that does not share a prime number factor with Y. According to the subject disclosure, the sensor can be a visual image recording device or camera (or other suitable sensor).

Further, the number, type and placement of the sensor(s) can be as generally set forth in <FIG>. For example, similar to <FIG>, the sensor can be a visual image recording device having a field of view sufficient to capture images of adjacent knives of the X knives. Similar to <FIG>, the sensor includes a plurality of spaced apart sensors for sensing the condition of spaced apart knives of the X knives. In particular, the plurality of sensors can comprise visual image recording devices having separate fields of view for capturing images of the spaced apart knives of the X knives. In addition, the header can comprise a monitor in communication with the sensor for enabling a user to display the condition of the X knives sensed by the sensor according to the knife sampling interval Y.

The subject disclosure further provides a method for monitoring conditions of X movable knives in a continuous loop knife assembly carried by a header of an agricultural harvester comprising sensing, by a sensor, a condition of the X movable knives according to a knife sampling interval Y. The method further comprises displaying, by a monitor in communication with the sensor, the condition of the X movable knives sensed by the sensor according to the knife sampling interval Y, wherein X is an integer, wherein Y is an integer equal to any integer not equal to X or a factor of X, excluding <NUM>, and wherein X/Y has a remainder that does not share a prime number factor with Y.

The above-described method can further comprise capturing images with the sensor of adjacent knives of the X movable knives. In addition, the sensor can include a plurality of spaced apart sensors, and the method can further comprise sensing a condition of the X movable knives by the plurality of spaced apart sensors. Additionally, the plurality of spaced apart sensors can comprise visual image recording devices having separate fields of view for capturing images of the X movable knives.

By capturing an image of knives at a predetermined interval not equal to an integer fraction of the total number of knives on the loop, the knives that are analyzed will change with each cycle of the plurality of movable knives that passes the sensor. In so doing, all of the knives on the loop will be analyzed before any are repeated. For example, if there are ten knives on the loop and every third knife is analyzed, then during the first cycle, knife numbers <NUM>, <NUM> and <NUM> would be analyzed. In the second cycle, knife numbers <NUM>, <NUM> and <NUM> would be analyzed, and in the third cycle, knife numbers <NUM>, <NUM>, <NUM> and <NUM> would be analyzed.

Claim 1:
A header (<NUM>) for an agricultural harvester (<NUM>), the header (<NUM>) comprising:
a continuous loop knife assembly (100a, 100b, 100c) including a plurality of knives (<NUM>) attached to an endless flexible member (<NUM>);
a sensor (<NUM>) configured to sense a condition of the plurality of knives (<NUM>); and
a motor (<NUM>) operatively engaged with the endless flexible member (<NUM>) for moving the plurality of knives (<NUM>) past the sensor (<NUM>); and characterized in that
the sensor (<NUM>) is configured to sense the condition of the plurality of knives (<NUM>) in increments comprising non-adjacent groups (90a, 90b, 90c) of one or more knives (<NUM>), whereby substantially an entirety of the plurality of knives (<NUM>) is sensed after a plurality of cycles of the continuous loop knife assembly (100a, 100b, 100c) past the sensor (<NUM>).