Abstract:
A control sensor assembly for an agricultural harvester is provided. The control sensor assembly includes a linkage for connection to a header height control system, a bushing, a mount and a sensor mounted to the mount. The bushing includes a first end connected to the linkage and a second end housing a magnet. The mount includes a body having a through hole extending from a first surface to a second surface opposite the first surface for receiving the bushing and a first rotational stop about the first surface and adjacent the through hole. The sensor is spaced from the second end of the bushing. The control sensor assembly according to the subject application is designed to provide an improved mount for the control sensor assembly that utilizes a single mount to perform multiple functions.

Description:
BACKGROUND 
       [0001]    The subject application relates generally to a control sensor assembly for an agricultural harvester. In particular, the subject application provides an improved mount for the control sensor assembly that utilizes a single mount to perform multiple functions. 
         [0002]    During a harvesting operation, a header at the front of a harvester cuts ripened crops from the field. The header is attached to the front of the harvester and includes mechanisms, for example, for cutting crops, gathering crops and depositing crops into a feederhouse. The objective of the agricultural harvester is to gather as much crop material as possible when traveling across the field. This can become increasingly difficult as the ground contour can vary. As a result, header height control systems are utilized to raise, lower and tilt the header in order to maximize the harvester&#39;s crop yield. 
         [0003]    Generally, a header height control system utilizes a control sensor assembly to accurately detect the contour of the ground for changes in landscape i.e., its position relative to the ground as it travels over uneven terrain. Conventional control sensor assemblies require the use of multiple sensors and parts which consequently requires a larger number of steps and complexity in the installation process. During installation, operators have to ensure that the control sensor assembly is properly oriented for connection to the header height control system. If assembly and installation is done incorrectly, this could lead to increased delays and maintenance costs, improper operation of the harvester, economic loss, as well as damage to components of the agricultural harvester. 
         [0004]    Therefore, there is still a need for an improved mount for a control sensor assembly that reduces potential for human error and performs multiple functions with less assembly parts and requires fewer steps to install the assembly. The subject application addresses the foregoing issues of conventional control sensor assemblies. 
       BRIEF SUMMARY 
       [0005]    In accordance with an aspect, the subject application provides a control sensor assembly for an agricultural harvester. The control sensor assembly comprises a linkage, a bushing, a mount and a sensor. The linkage is for connection to a header height control system. The bushing includes a first end connected to the linkage and a second end housing a magnet. The mount includes a body having a through hole extending from a first surface to a second surface opposite the first surface for receiving the bushing and a first rotational stop about the first surface and adjacent the through hole. The sensor is mounted to the mount and spaced from the second end of the bushing. 
         [0006]    In accordance with another aspect, the subject application provides a header of an agricultural harvester. The header comprises a frame, a linkage and a control sensor assembly mounted to the frame. The control sensor assembly includes a bushing, a mount and a sensor. The bushing includes a first end connected to the linkage and a second end housing a magnet. The mount includes a body having a through hole extending from a first surface to a second surface opposite the first surface for receiving the bushing and a first rotational stop about the first surface and adjacent the through hole. The sensor is mounted to the mount and spaced from the second end of the bushing. 
         [0007]    In accordance with yet another aspect, the subject application provides a mount for mounting a sensor to a header of an agricultural harvester. The mount comprises a body and first and second spaced apart guide surfaces. The body includes a counterbore and a through hole extending through the counterbore from a first surface of the body to a second surface of the body opposite the first surface. The body further includes an anterior surface adjacent the counterbore and extending substantially transverse to the first surface. The first and second spaced apart guide surfaces extend from the first surface. Each guide surface is positioned adjacent a lateral side of the counterbore and the first guide surface includes an engaging surface at an angle relative to an engaging surface of the second guide surface. The first and second guide surfaces each have a mounting surface and an opening through which a fastener is passable for securing the mount to the header. The mounting surface is substantially parallel to and spaced from the first surface for engaging the header. 
         [0008]    The subject application provides a unique mount for a non-contact header height control sensor that uses one piece to perform multiple functions. The main block will control shaft end-play, act as a rotational stop, serve as the sensor mount, and mount the entire system to a machine that is using header height control (HHC). A non-contact sensor is a sensor in which the magnet is a separate piece from the sensor body itself unlike a one piece sensor in which everything is contained within the sensor body. The non-contact sensor needs to maintain a specified air gap between the magnet and the sensor body for proper functionality. Thus, a system is needed to control the end play of the magnet that is attached to the rotating shaft and consistently hold the sensor body at the appropriate location. Along with the end play, the rotational motion needs a bearing surface to allow free rotation of the shaft. The system also needs a rotational stop so that during assembly it cannot be assembled incorrectly. The system is also simpler than what is currently used. It has fewer parts and would be used multiple times in comparison to once per header. 
         [0009]    Conventional header height control systems consist of a laser formed piece with two machined hubs welded to it, two bushings pressed into each hub, and two snap rings. The assembly is for one side of the machine and would have a mirror image on the opposite side. The parts in the disclosed system of the subject application would be a machined block and a plastic bearing surface. The subject application&#39;s assembly can be used multiple times e.g., four times, on the header whereas the current system has a left and right and is only used once per head. 
         [0010]    In the subject application, the main block of the system is machined so that from the face of one side to the other side, the distance will be consistent allowing the air gap between the magnet and the sensor body to be precisely controlled. Additionally, the machined rotational stops will automatically be formed into the block. The rotational stops will help with the installation by forcing the installer to properly orient the block with respect to the side of the machine, since this single block will be able to be used in multiple locations on the machine. The plastic bearing surface will also hold multiple functions. On one side of the plastic part, there will be a machined spot for the magnet to be attached to. The opposite end will have another machine feature that will act as a receiver that will accept a driver feature on the header height control linkage. This all can be assembled first and then assembled to the machine. The machine will act as the stop that does not allow the magnet to get farther away from the sensor. 
         [0011]    In addition to controlling the air gap, the resultant advantages of the subject application include having fewer parts that need to be maintained. In conventional header height control systems, the auger and draper head use different parts that perform the same function along with needing a left and right portion which means four separate assembly part numbers, not including sub parts that go into the assembly. The subject application would allow for the same assembly parts to be used on both heads for the left and right sides, reducing four separate assembly part numbers to one. The subject application&#39;s system would require fewer processes to make the assembly than currently is required. Conventional header height control systems require a laser process, forming process, machining process, welding process and painting while the subject application would only need a machining process or a molding process (for a plastic mount) to manufacture the mount. The built in stops will require the assembler to only assemble the subject application in the correct way. The current system is mounted using two bolts which would allow the operator to incorrectly assemble it if they were not paying attention. 
         [0012]    In sum, the subject application provides an improved mount for a non-contact header height control sensor that performs multiple functions including controlling shaft end-play, acting as a rotational stop, serving as a sensor mount, and mounting the entire system to the machine that is using header height control. The resultant advantages of such a mount are that one single part is performing multiple tasks while controlling the air gap needed for the two piece sensor. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0013]    The foregoing summary, as well as the following detailed description of the several aspects of the subject application, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the subject application, there are shown in the drawings several aspects, but it should be understood that the subject application is not limited to the precise arrangements and instrumentalities shown. 
           [0014]    In the drawings: 
           [0015]      FIG. 1  is a side view of a frame of a header of an agricultural harvester in accordance with an aspect of the subject application; 
           [0016]      FIG. 2  is a bottom, front perspective view of a control sensor assembly in accordance with an aspect of the subject application; 
           [0017]      FIG. 3  is an exploded bottom perspective view of the control sensor assembly of  FIG. 2 ; 
           [0018]      FIG. 4  is an exploded top perspective view of the control sensor assembly of  FIG. 2 ; 
           [0019]      FIG. 5A  is a lateral cross sectional view of the control sensor assembly of  FIG. 2 ; 
           [0020]      FIG. 5B  is a coronal cross sectional view of the control sensor assembly of  FIG. 2 ; 
           [0021]      FIG. 6  is a bottom, front perspective view of a mount of the control sensor assembly of  FIG. 2 ; 
           [0022]      FIG. 7  is a top perspective view of the mount of  FIG. 6 ; 
           [0023]      FIG. 8  is a coronal cross sectional view of the mount of  FIG. 6 ; 
           [0024]      FIG. 9  is a perspective view of a linkage and bushing of the control sensor assembly of  FIG. 2 ; and 
           [0025]      FIG. 10  is a side perspective view of a header of an agricultural harvester illustrating a header height control system applicable to the subject application with various components omitted for purposes of illustration. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    Reference will now be made in detail to the various aspects of the subject application 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. In reference to the disclosure herein, for purposes of convenience and clarity only, directional terms such as top, bottom, left, right, above, below and diagonal, are used with respect to the accompanying drawings. Such directional terms used in conjunction with the following description of the drawings should not be construed to limit the scope of the subject application in any manner not explicitly set forth. Additionally, the term “a,” as used in the specification, means “at least one.” The terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import. 
         [0027]    “About” as used herein when referring to a measurable value such as an amount, a temporal duration, and the like, is meant to encompass variations of ±20%, ±10%, ±5%, ±1%, or ±0.1% from the specified value, as such variations are appropriate. 
         [0028]    Referring now to the drawings, wherein aspects of the subject application are shown,  FIG. 1  illustrates several features of a frame of a header of an agricultural harvester according to the subject application. For purposes of illustration only and not by way of limitation, the header will be described e.g., as a header with a flexible cutter bar assembly, but can alternatively be any other header having a height control sensor. In addition to the frame, the header includes mechanisms for cutting crops, gathering crops and delivering crops to the agricultural harvester and is positioned relative to a ground surface upon which the agricultural harvester travels. 
         [0029]    In  FIG. 1 , there is shown a control sensor assembly  12  mounted to a side of a frame  10  of a header which can be attached to the front or anterior end of a combine or similar agricultural harvester (not shown). The frame  10  serves generally as a chassis for the header for supporting the various components of the header which are attached thereto. The header can include, among other components, a cutter bar. Such components of the header are known and therefore a detailed description of their structure, function and operation is not necessary for a complete understanding of the subject application. However, headers applicable to the subject application are disclosed in U.S. Pat. Nos. 7,950,212; 7,222,474; and 4,414,793, the entire disclosures of which are incorporated by reference herein for all purposes. 
         [0030]    The cutter bar severs crops as the header of the agricultural harvester travels over the field. The crops are then conveyed towards other downstream components of the agricultural harvester, e.g., auger or feeder (not shown). During operation, the cutter bar is designed to have flexibility in order to accommodate and conform generally to changing ground contours at different locations of the field. As a result, a reliable ground sensor is required to serve as indicators of ground contour changes to adjust the height position of the header and its components. 
         [0031]    A control sensor assembly  12  is configured and operable according to the teachings of the subject application, for following and sensing ground contour changes and outputting signals representative thereof to a header height control system  11  ( FIG. 10 ) of an agricultural harvester. The control sensor assembly  12  allows the header height control system  11  to raise or lower the header as required for maintaining the cutter bar at a desired level above the ground. 
         [0032]    Referring now to  FIGS. 2-5 , there is shown a preferred embodiment of the control sensor assembly  12  in accordance with the subject application. The control sensor assembly  12  includes a linkage  14 , a bushing  16 , a mount  18  and a sensor  20 . The linkage  14  connects the control sensor assembly  12  to the header height control system  11  in a conventional, well-known manner in the art. In accordance with an aspect, the linkage  14  has a proximal end with an aperture configured to receive a shaft  22  connecting the linkage to the bushing  16 . Preferably, the shaft  22  has a circular shaped first end corresponding to the aperture of the linkage  14  and an angular shaped second end e.g., a parallel piped shaft, opposite the first end. The angular shape of the second end corresponds to a slot  24  in the bushing  16  for connecting the linkage  14  and bushing  16 . As such, owing to the corresponding fit between the angular shaped second end and the female end of the bushing, the bushing will rotate correspondingly with rotation of the linkage about an axis defined by the shaft  22 . The linkage  14  also has a distal end with an aperture for adjustably connecting the linkage to the header height control system.  FIG. 9  shows an isolated perspective view of the shaft  22  connecting the linkage  14  to the bushing  16 . 
         [0033]    As best shown in  FIGS. 2-4 , the bushing  16  includes a first end connected to the linkage  14  and a second end housing a magnet  26 . In accordance with an aspect, the bushing  16  is preferably configured as a flanged bushing with a flange member  28  and a stem  30  extending from the flange member. The stem  30  is preferably configured as an elongated cylindrical member. The flange member  28  has a diameter larger than that of the stem  30 . As previously discussed, the flange member  28  at the first end of the bushing  16  can include a slot  24  for receiving the angular end of the shaft  22  in order to connect the proximal end of the linkage to the bushing  16 . Alternatively, the slot  24  and the angular end of the shaft  22  can be configured with any other shape suitable for its intended purpose, such as a shaft having a longitudinal cross section of a square, triangle, and the like. In accordance with another aspect, the linkage  14  and the bushing  16  can alternatively be connected with suitable fasteners, e.g. pins, screws, bolts, and the like. 
         [0034]    In accordance with an aspect, the second end of the bushing  16  includes a cavity  25  for housing a magnet  26  of a non-contact magnetic sensor, as further discussed below. As shown in  FIG. 4 , the cavity  25  about a second end of the bushing  16  is preferably shaped to correspondingly receive and fixedly hold the magnet  26 . Specifically, the magnet  26  is fixedly mounted to the bushing  16  allowing it to rotate as the bushing rotates. As further discussed below, the rotational movement of the magnet  26  with respect to the sensor  20  results in an output signal representative of a positional relationship between the header and the ground. 
         [0035]    As best shown in  FIGS. 6-8 , the mount  18  includes a body  32  and spaced apart first and second rotational stops  34 ,  36 . Preferably, the mount  18  is configured as a block for operatively connecting to a flexible cutter bar system. As further discussed below, the block can be appropriately modified such that the control sensor assembly  12  is applicable to different types of headers, e.g., corn header, auger, draper and the like. 
         [0036]    The body  32  includes a counterbore  38  and a through hole  40  extending through the counterbore  38 . The through hole  40  extends from a first surface  42  of the body to a second surface  44  of the body opposite the first surface and has a central longitudinal axis substantially transverse to a plane of the first surface  42 . The body further includes an anterior surface  46  adjacent the counterbore  38  and extending substantially transverse to the first surface  42 . 
         [0037]    As shown in  FIG. 6 , the through hole  40  is configured to receive the second end of the bushing  16 . As shown in  FIGS. 5A and 5B , a seal  48 , e.g., an oil seal, can be coupled around the stem  30  of the bushing  16 . Specifically, the seal  48  is shaped to slidably fit around the cylindrical shape of the stem  30  of the bushing. When assembled to the mount, the seal  48  surrounds the stem  30  and sits adjacent the flange member  28 . Thus, when the through hole  40  receives the bushing  16 , the seal  48  seats within the counterbore  38  and prevents dirt and moisture from entering. 
         [0038]    Additionally, the body is sized so as to have a longitudinal length of the through hole  40  to be greater than a longitudinal length of the stem  30  of the bushing  16  when the bushing is seated on the block. In other words, the bushing  16  is sized to have a longitudinal length such that the second end of the bushing is spaced from the second surface  44  when fully seated on the block. This way, the distal end of the bushing housing the magnet is spaced from the second surface thereby creating an air gap between the magnet and the sensor mounted to the second surface. 
         [0039]    As shown in  FIG. 7 , the through hole  40  extends to the second surface  44  of the body. The sensor  20  is mounted onto the second surface  44 . Preferably, the second surface  44  of the body comprises a recess  50  for at least partially receiving a complementary seal  52 , e.g., an O-ring, ( FIG. 4 ) for preventing dirt and moisture from entering and causing the control sensor assembly  12  to malfunction. When assembled, the seal  52  is positioned within the recess  50  as shown in  FIGS. 5A and 5B . Additionally, the second surface  44  can include a pair of openings  54  for mounting the sensor  20  onto the mount  18  with suitable fasteners, e.g. pins, screws, bolts and the like. 
         [0040]    As best shown in  FIG. 6 , the first and second spaced apart rotational stops  34 ,  36  extend from the first surface  42 . Each rotational stop  34 ,  36  is positioned adjacent a lateral side of the counterbore  38  and the first rotational stop  34  includes an engaging surface  56  at an angle α of about 80 to 100 degrees relative to an engaging surface  58  of the second rotational stop  36 . Of course, the rotational stops can alternatively be configured with an angle α more or less than 80 to 100 degrees or any angle between 80 and 100 degrees. The first rotational stop  34  and second rotational stop  36  are respectively spaced from each other about the first surface  42  of the mount  18 . 
         [0041]    The engaging surfaces  56 ,  58  of the respective first and second rotational stops  34 ,  36  define a space or range of motion the linkage  14  can pivot relative the mount  18 . While the first and second rotational stops  34 ,  36  are referred to as rotational stops, they do not necessarily have to, but can, function as rotational stops. Instead, the first and second rotational stops  34 ,  36  can be guide surfaces collectively forming a one way guide slot to aid in properly assembling the linkage  14  to the mount  18  in a proper orientation. In other words, the first and second rotational stops  34 ,  36  collectively form a guide slot having a posterior back wall and a tapered opening about its anterior end. The guide slot is preferably configured to have a posterior end complementary in shape to receive the bushing  16  and an open anterior end through which the linkage  14  will reside in with enough play so that the inner side walls of the guide slot do not engage the linkage  14  during general operation. 
         [0042]    The through hole  40  has a diameter slightly larger than the diameter of the stem  30  of the bushing  16  such that the bushing  16  is rotatable therein. As the bushing  16  rotates, the linkage  14  connected to the second end of the bushing  16  rotates. The linkage  14  has a limited range of motion as defined by its connections with the header height control system and is generally restricted to movement between the first and second rotational stops  34 ,  36 . 
         [0043]    As shown in  FIG. 6 , the mount  18  includes a curved section  60  extending between the first and second rotational stops  34 ,  36 . The curved section  60  is sized and configured to receive the flange member  28  of the bushing  16 . Specifically, it is shaped to be complementary to the shape of the flange member  28  of the bushing  16 . 
         [0044]    The rotational stops  34 ,  36  each have a mounting surface  62  substantially parallel to and spaced from the first surface  42  for engaging with the header and an opening  64  through which a fastener is passable for securing the mount  18  to the frame of a header. The mount  18  can be connected to the frame  10  with any suitable fasteners, e.g. pins, screws, bolts and the like. Alternatively, the mount  18  and the type of fasteners used can be adjusted to accommodate different headers, e.g., a corn header, draper, auger and the like. 
         [0045]    When fully assembled and attached to the header, the mounting surface  62  of the rotational stops  34 ,  36  directly engages the frame  10  and the linkage  14  is positioned completely between the first and second rotational stops  34 ,  36 . The proximal end of the linkage  14  is also positioned completely between the mounting surface  62  of the first surface  42 . 
         [0046]    Referring to  FIGS. 6 and 7 , the mount  18  further includes lateral side surfaces  66  extending substantially transverse to the first surface  42 . Further, each of the first and second rotational stops  34 ,  36  include lateral side surfaces substantially parallel to and in line with respective lateral side surfaces  66  of the body. 
         [0047]    Referring back to  FIGS. 2-4 , the sensor  20  is mounted to the mount  18  and spaced from the second end of the bushing  16 . As discussed above, the second surface  44  of the body of the mount  18  contains a pair of openings  54  for mounting the sensor  20  onto the mount  18 . 
         [0048]    The sensor  20  is preferably a non-contact magnetic sensor, such as a Hall effect sensor. In order to properly function, the control sensor assembly  12  needs to properly maintain the air gap between the sensor  20  and the magnet  26 . This air gap formed between the sensor  20  and the magnet  26 , as a result of the bushing  16  having a longitudinal length sized less than a longitudinal length of the through hole  40 , allows for proper functionality of the non-contact magnetic sensor. Unlike currently used sensors, the sensor  20  disclosed in the subject application does not have connected moving parts. Thus, the sensor  20  disclosed in the subject application does not result in wear that can result in damage to the sensor. 
         [0049]    As shown in  FIG. 2 , the control sensor assembly  12  can be fully assembled prior to installation to the frame  10 . As previously discussed, the through hole  40  on the mount  18  extends between the first surface  42  and the second surface  44 . When fully assembled, the stem  30  of the bushing  16  is received within the through hole  40  about the first surface  42 . The proximal end of the linkage  14  is connected to the flange member  28  of the bushing  16 . The sensor  20  is mounted about the second surface  44  of the mount  18  such that the magnet  26  on the bushing  16  is spaced from the sensor  20  defining an air gap therebetween. When fully assembled, the control sensor assembly  12  is secured to the frame  10  of the header. As previously discussed, the rotational stops  34 ,  36  (or guide slot) assist in proper placement of the mount  18  when securing the mount onto the frame  10 . 
         [0050]    Referring now to  FIG. 10 , there is shown a side view of a frame  10  of a header. When fully assembled and installed onto the frame  10 , the control sensor assembly  12  (not shown) is connected to the header height control system  11 . Specifically, the linkage  14  connects the control sensor assembly  12  to the header height control system  11 . During harvesting operations, the header of the agricultural harvester travels along the field. As the header travels across the field, the cutter bar assembly  76  moves up and down causing the sensor arm  68  to move up and down. The sensor arm  68  is configured to rest on the cutter bar assembly  76 . The sensor arm  68  is also welded to a sensor rod  70 . Thus, when the sensor arm moves up or down, the sensor rod  70  rotates as well. The rotation of the sensor rod  70  causes a linking member  72  to rotate accordingly. Further, the linking member  72  is coupled to the linkage  14  of the control sensor assembly  12  by a connector  74 . As a result, the rotational motion of the linking member causes the linkage  14  to rotate. 
         [0051]    When the linkage  14  of the control sensor assembly  12  ( FIG. 2 ) rotates, the bushing  16  and the magnet  26  rotate. Specifically, the magnet  26  is fixedly mounted to the bushing  16  allowing it to rotate as the bushing rotates. The rotation of the magnet results in the sensor  20  outputting a signal representative of a positional relationship between the header and the ground. Specifically, the sensor  20  configured as a Hall effect sensor produces a voltage representative of the positional relationship between the header and the ground. 
         [0052]    In sum, when the cutter bar assembly  76  moves up or down, the header height control system  11  and its components discussed above cause movement of the linkage  14  and magnet  26  of the control sensor assembly  12 . When the magnet  26  rotates, the sensor  20  produces an output voltage representative of the positional relationship between the header and the ground. The output voltage is transmitted to a computer of the agricultural harvester. 
         [0053]    Although the frame  10  as shown in  FIG. 1  is configured to have two sensor assemblies spaced along a side end of the frame, additional sensor assemblies can be placed at additional locations along the width of the header. For example, a draper header can have four control sensor assemblies, two for tilt and two for height. Additionally, an auger head can have four control sensor assemblies, while a corn header can have between two and four or more control sensor assemblies. 
         [0054]    While the subject application has been described with reference to several aspects, it will be appreciated by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the subject application. In addition, modifications may be made to adapt a particular situation or material to the teachings of the subject application without departing from the essential scope thereof. It is to be understood, therefore, that the subject application not be limited to the particular aspects disclosed, but it is intended to cover modifications within the spirit and scope of the subject application as defined by the appended claims.